# -*- coding: utf-8 -*-
##############################################################################
#
#    OpenERP, Open Source Management Solution
#    Copyright (C) 2004-2010 Tiny SPRL (<http://tiny.be>).
#
#    This program is free software: you can redistribute it and/or modify
#    it under the terms of the GNU Affero General Public License as
#    published by the Free Software Foundation, either version 3 of the
#    License, or (at your option) any later version.
#
#    This program is distributed in the hope that it will be useful,
#    but WITHOUT ANY WARRANTY; without even the implied warranty of
#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#    GNU Affero General Public License for more details.
#
#    You should have received a copy of the GNU Affero General Public License
#    along with this program.  If not, see <http://www.gnu.org/licenses/>.
#
##############################################################################

import time
import pytz
from openerp import SUPERUSER_ID, workflow
from datetime import datetime
from dateutil.relativedelta import relativedelta
from operator import attrgetter

from openerp.osv import fields, osv
from openerp.tools.translate import _
import openerp.addons.decimal_precision as dp
from openerp.osv.orm import browse_record, browse_null
from openerp.tools import DEFAULT_SERVER_DATE_FORMAT, DEFAULT_SERVER_DATETIME_FORMAT, DATETIME_FORMATS_MAP

class purchase_order(osv.osv):

    def _amount_all(self, cr, uid, ids, field_name, arg, context=None):
        res = {}
        cur_obj=self.pool.get('res.currency')
        for order in self.browse(cr, uid, ids, context=context):
            res[order.id] = {
                'amount_untaxed': 0.0,
                'amount_tax': 0.0,
                'amount_total': 0.0,
            }
            val = val1 = 0.0
            cur = order.pricelist_id.currency_id
            for line in order.order_line:
               val1 += line.price_subtotal
               for c in self.pool.get('account.tax').compute_all(cr, uid, line.taxes_id, line.price_unit, line.product_qty, line.product_id, order.partner_id)['taxes']:
                    val += c.get('amount', 0.0)
            res[order.id]['amount_tax']=cur_obj.round(cr, uid, cur, val)
            res[order.id]['amount_untaxed']=cur_obj.round(cr, uid, cur, val1)
            res[order.id]['amount_total']=res[order.id]['amount_untaxed'] + res[order.id]['amount_tax']
        return res

    def _set_minimum_planned_date(self, cr, uid, ids, name, value, arg, context=None):
        if not value: return False
        if type(ids)!=type([]):
            ids=[ids]
        for po in self.browse(cr, uid, ids, context=context):
            if po.order_line:
                cr.execute("""update purchase_order_line set
                        date_planned=%s
                    where
                        order_id=%s and
                        (date_planned=%s or date_planned<%s)""", (value,po.id,po.minimum_planned_date,value))
            cr.execute("""update purchase_order set
                    minimum_planned_date=%s where id=%s""", (value, po.id))
        return True

    def _minimum_planned_date(self, cr, uid, ids, field_name, arg, context=None):
        res={}
        purchase_obj=self.browse(cr, uid, ids, context=context)
        for purchase in purchase_obj:
            res[purchase.id] = False
            if purchase.order_line:
                min_date=purchase.order_line[0].date_planned
                for line in purchase.order_line:
                    if line.date_planned < min_date:
                        min_date=line.date_planned
                res[purchase.id]=min_date
        return res


    def _invoiced_rate(self, cursor, user, ids, name, arg, context=None):
        res = {}
        for purchase in self.browse(cursor, user, ids, context=context):
            tot = 0.0
            for invoice in purchase.invoice_ids:
                if invoice.state not in ('draft','cancel'):
                    tot += invoice.amount_untaxed
            if purchase.amount_untaxed:
                res[purchase.id] = tot * 100.0 / purchase.amount_untaxed
            else:
                res[purchase.id] = 0.0
        return res

    def _shipped_rate(self, cr, uid, ids, name, arg, context=None):
        if not ids: return {}
        res = {}
        for id in ids:
            res[id] = [0.0,0.0]
        cr.execute('''SELECT
                p.purchase_id,sum(m.product_qty), m.state
            FROM
                stock_move m
            LEFT JOIN
                stock_picking p on (p.id=m.picking_id)
            WHERE
                p.purchase_id IN %s GROUP BY m.state, p.purchase_id''',(tuple(ids),))
        for oid,nbr,state in cr.fetchall():
            if state=='cancel':
                continue
            if state=='done':
                res[oid][0] += nbr or 0.0
                res[oid][1] += nbr or 0.0
            else:
                res[oid][1] += nbr or 0.0
        for r in res:
            if not res[r][1]:
                res[r] = 0.0
            else:
                res[r] = 100.0 * res[r][0] / res[r][1]
        return res

    def _get_order(self, cr, uid, ids, context=None):
        result = {}
        for line in self.pool.get('purchase.order.line').browse(cr, uid, ids, context=context):
            result[line.order_id.id] = True
        return result.keys()

    def _invoiced(self, cursor, user, ids, name, arg, context=None):
        res = {}
        for purchase in self.browse(cursor, user, ids, context=context):
            invoiced = False
            if purchase.invoiced_rate == 100.00:
                invoiced = True
            res[purchase.id] = invoiced
        return res
    
    def _get_journal(self, cr, uid, context=None):
        if context is None:
            context = {}
        user = self.pool.get('res.users').browse(cr, uid, uid, context=context)
        company_id = context.get('company_id', user.company_id.id)
        journal_obj = self.pool.get('account.journal')
        res = journal_obj.search(cr, uid, [('type', '=', 'purchase'),
                                            ('company_id', '=', company_id)],
                                                limit=1)
        return res and res[0] or False  

    STATE_SELECTION = [
        ('draft', 'Draft PO'),
        ('sent', 'RFQ Sent'),
        ('confirmed', 'Waiting Approval'),
        ('approved', 'Purchase Order'),
        ('except_picking', 'Shipping Exception'),
        ('except_invoice', 'Invoice Exception'),
        ('done', 'Done'),
        ('cancel', 'Cancelled')
    ]
    _track = {
        'state': {
            'purchase.mt_rfq_confirmed': lambda self, cr, uid, obj, ctx=None: obj.state == 'confirmed',
            'purchase.mt_rfq_approved': lambda self, cr, uid, obj, ctx=None: obj.state == 'approved',
            'purchase.mt_rfq_done': lambda self, cr, uid, obj, ctx=None: obj.state == 'done',
        },
    }
    _columns = {
        'name': fields.char('Order Reference', size=64, required=True, select=True, help="Unique number of the purchase order, computed automatically when the purchase order is created."),
        'origin': fields.char('Source Document', size=64,
            help="Reference of the document that generated this purchase order request; a sales order or an internal procurement request."
        ),
        'partner_ref': fields.char('Supplier Reference', states={'confirmed':[('readonly',True)], 'approved':[('readonly',True)],'done':[('readonly',True)]}, size=64,
            help="Reference of the sales order or quotation sent by your supplier. It's mainly used to do the matching when you receive the products as this reference is usually written on the delivery order sent by your supplier."),
        'date_order':fields.date('Order Date', required=True, states={'confirmed':[('readonly',True)], 'approved':[('readonly',True)]}, select=True, help="Date on which this document has been created."),
        'date_approve':fields.date('Date Approved', readonly=1, select=True, help="Date on which purchase order has been approved"),
        'partner_id':fields.many2one('res.partner', 'Supplier', required=True, states={'confirmed':[('readonly',True)], 'approved':[('readonly',True)],'done':[('readonly',True)]},
            change_default=True, track_visibility='always'),
        'dest_address_id':fields.many2one('res.partner', 'Customer Address (Direct Delivery)',
            states={'confirmed':[('readonly',True)], 'approved':[('readonly',True)],'done':[('readonly',True)]},
            help="Put an address if you want to deliver directly from the supplier to the customer. " \
                "Otherwise, keep empty to deliver to your own company."
        ),
        'warehouse_id': fields.many2one('stock.warehouse', 'Destination Warehouse'),
        'location_id': fields.many2one('stock.location', 'Destination', required=True, domain=[('usage','<>','view')], states={'confirmed':[('readonly',True)], 'approved':[('readonly',True)],'done':[('readonly',True)]} ),
        'pricelist_id':fields.many2one('product.pricelist', 'Pricelist', required=True, states={'confirmed':[('readonly',True)], 'approved':[('readonly',True)],'done':[('readonly',True)]}, help="The pricelist sets the currency used for this purchase order. It also computes the supplier price for the selected products/quantities."),
        'currency_id': fields.many2one('res.currency','Currency', readonly=True, required=True,states={'draft': [('readonly', False)],'sent': [('readonly', False)]}),
        'state': fields.selection(STATE_SELECTION, 'Status', readonly=True, help="The status of the purchase order or the quotation request. A quotation is a purchase order in a 'Draft' status. Then the order has to be confirmed by the user, the status switch to 'Confirmed'. Then the supplier must confirm the order to change the status to 'Approved'. When the purchase order is paid and received, the status becomes 'Done'. If a cancel action occurs in the invoice or in the reception of goods, the status becomes in exception.", select=True),
        'order_line': fields.one2many('purchase.order.line', 'order_id', 'Order Lines', states={'approved':[('readonly',True)],'done':[('readonly',True)]}),
        'validator' : fields.many2one('res.users', 'Validated by', readonly=True),
        'notes': fields.text('Terms and Conditions'),
        'invoice_ids': fields.many2many('account.invoice', 'purchase_invoice_rel', 'purchase_id', 'invoice_id', 'Invoices', help="Invoices generated for a purchase order"),
        'picking_ids': fields.one2many('stock.picking.in', 'purchase_id', 'Picking List', readonly=True, help="This is the list of incoming shipments that have been generated for this purchase order."),
        'shipped':fields.boolean('Received', readonly=True, select=True, help="It indicates that a picking has been done"),
        'shipped_rate': fields.function(_shipped_rate, string='Received Ratio', type='float'),
        'invoiced': fields.function(_invoiced, string='Invoice Received', type='boolean', help="It indicates that an invoice has been paid"),
        'invoiced_rate': fields.function(_invoiced_rate, string='Invoiced', type='float'),
        'invoice_method': fields.selection([('manual','Based on Purchase Order lines'),('order','Based on generated draft invoice'),('picking','Based on incoming shipments')], 'Invoicing Control', required=True,
            readonly=True, states={'draft':[('readonly',False)], 'sent':[('readonly',False)]},
            help="Based on Purchase Order lines: place individual lines in 'Invoice Control / On Purchase Order lines' from where you can selectively create an invoice.\n" \
                "Based on generated invoice: create a draft invoice you can validate later.\n" \
                "Based on incoming shipments: let you create an invoice when receptions are validated."
        ),
        'minimum_planned_date':fields.function(_minimum_planned_date, fnct_inv=_set_minimum_planned_date, string='Expected Date', type='date', select=True, help="This is computed as the minimum scheduled date of all purchase order lines' products.",
            store = {
                'purchase.order.line': (_get_order, ['date_planned'], 10),
            }
        ),
        'amount_untaxed': fields.function(_amount_all, digits_compute= dp.get_precision('Account'), string='Untaxed Amount',
            store={
                'purchase.order.line': (_get_order, None, 10),
            }, multi="sums", help="The amount without tax", track_visibility='always'),
        'amount_tax': fields.function(_amount_all, digits_compute= dp.get_precision('Account'), string='Taxes',
            store={
                'purchase.order.line': (_get_order, None, 10),
            }, multi="sums", help="The tax amount"),
        'amount_total': fields.function(_amount_all, digits_compute= dp.get_precision('Account'), string='Total',
            store={
                'purchase.order.line': (_get_order, None, 10),
            }, multi="sums",help="The total amount"),
        'fiscal_position': fields.many2one('account.fiscal.position', 'Fiscal Position'),
        'payment_term_id': fields.many2one('account.payment.term', 'Payment Term'),
        'product_id': fields.related('order_line','product_id', type='many2one', relation='product.product', string='Product'),
        'create_uid':  fields.many2one('res.users', 'Responsible'),
        'company_id': fields.many2one('res.company','Company',required=True,select=1, states={'confirmed':[('readonly',True)], 'approved':[('readonly',True)]}),
        'journal_id': fields.many2one('account.journal', 'Journal'),
    }
    _defaults = {
        'date_order': fields.date.context_today,
        'state': 'draft',
        'name': lambda obj, cr, uid, context: '/',
        'shipped': 0,
        'invoice_method': 'order',
        'invoiced': 0,
        'pricelist_id': lambda self, cr, uid, context: context.get('partner_id', False) and self.pool.get('res.partner').browse(cr, uid, context['partner_id']).property_product_pricelist_purchase.id,
        'company_id': lambda self,cr,uid,c: self.pool.get('res.company')._company_default_get(cr, uid, 'purchase.order', context=c),
        'journal_id': _get_journal,
        'currency_id': lambda self, cr, uid, context: self.pool.get('res.users').browse(cr, uid, uid, context=context).company_id.currency_id.id
    }
    _sql_constraints = [
        ('name_uniq', 'unique(name, company_id)', 'Order Reference must be unique per Company!'),
    ]
    _name = "purchase.order"
    _inherit = ['mail.thread', 'ir.needaction_mixin']
    _description = "Purchase Order"
    _order = 'date_order desc, id desc'

    def create(self, cr, uid, vals, context=None):
        if vals.get('name','/')=='/':
            vals['name'] = self.pool.get('ir.sequence').get(cr, uid, 'purchase.order') or '/'
        if context is None:
            context = {}
        context.update({'mail_create_nolog': True})
        order =  super(purchase_order, self).create(cr, uid, vals, context=context)
        self.message_post(cr, uid, [order], body=_("RFQ created"), context=context)
        return order

    def unlink(self, cr, uid, ids, context=None):
        purchase_orders = self.read(cr, uid, ids, ['state'], context=context)
        unlink_ids = []
        for s in purchase_orders:
            if s['state'] in ['draft','cancel']:
                unlink_ids.append(s['id'])
            else:
                raise osv.except_osv(_('Invalid Action!'), _('In order to delete a purchase order, you must cancel it first.'))

        # automatically sending subflow.delete upon deletion
        self.signal_purchase_cancel(cr, uid, unlink_ids)

        return super(purchase_order, self).unlink(cr, uid, unlink_ids, context=context)

    def button_dummy(self, cr, uid, ids, context=None):
        return True

    def onchange_pricelist(self, cr, uid, ids, pricelist_id, context=None):
        if not pricelist_id:
            return {}
        return {'value': {'currency_id': self.pool.get('product.pricelist').browse(cr, uid, pricelist_id, context=context).currency_id.id}}

    def onchange_dest_address_id(self, cr, uid, ids, address_id):
        if not address_id:
            return {}
        address = self.pool.get('res.partner')
        values = {'warehouse_id': False}
        supplier = address.browse(cr, uid, address_id)
        if supplier:
            location_id = supplier.property_stock_customer.id
            values.update({'location_id': location_id})
        return {'value':values}

    def onchange_warehouse_id(self, cr, uid, ids, warehouse_id):
        if not warehouse_id:
            return {}
        warehouse = self.pool.get('stock.warehouse').browse(cr, uid, warehouse_id)
        return {'value':{'location_id': warehouse.lot_input_id.id, 'dest_address_id': False}}

    def onchange_partner_id(self, cr, uid, ids, partner_id):
        partner = self.pool.get('res.partner')
        if not partner_id:
            return {'value': {
                'fiscal_position': False,
                'payment_term_id': False,
                }}
        supplier_address = partner.address_get(cr, uid, [partner_id], ['default'])
        supplier = partner.browse(cr, uid, partner_id)
        return {'value': {
            'pricelist_id': supplier.property_product_pricelist_purchase.id,
            'fiscal_position': supplier.property_account_position and supplier.property_account_position.id or False,
            'payment_term_id': supplier.property_supplier_payment_term.id or False,
            }}

    def invoice_open(self, cr, uid, ids, context=None):
        mod_obj = self.pool.get('ir.model.data')
        act_obj = self.pool.get('ir.actions.act_window')

        result = mod_obj.get_object_reference(cr, uid, 'account', 'action_invoice_tree2')
        id = result and result[1] or False
        result = act_obj.read(cr, uid, [id], context=context)[0]
        inv_ids = []
        for po in self.browse(cr, uid, ids, context=context):
            inv_ids+= [invoice.id for invoice in po.invoice_ids]
        if not inv_ids:
            raise osv.except_osv(_('Error!'), _('Please create Invoices.'))
         #choose the view_mode accordingly
        if len(inv_ids)>1:
            result['domain'] = "[('id','in',["+','.join(map(str, inv_ids))+"])]"
        else:
            res = mod_obj.get_object_reference(cr, uid, 'account', 'invoice_supplier_form')
            result['views'] = [(res and res[1] or False, 'form')]
            result['res_id'] = inv_ids and inv_ids[0] or False
        return result

    def view_invoice(self, cr, uid, ids, context=None):
        '''
        This function returns an action that display existing invoices of given sales order ids. It can either be a in a list or in a form view, if there is only one invoice to show.
        '''
        mod_obj = self.pool.get('ir.model.data')
        wizard_obj = self.pool.get('purchase.order.line_invoice')
        #compute the number of invoices to display
        inv_ids = []
        for po in self.browse(cr, uid, ids, context=context):
            if po.invoice_method == 'manual':
                if not po.invoice_ids:
                    context.update({'active_ids' :  [line.id for line in po.order_line]})
                    wizard_obj.makeInvoices(cr, uid, [], context=context)

        for po in self.browse(cr, uid, ids, context=context):
            inv_ids+= [invoice.id for invoice in po.invoice_ids]
        res = mod_obj.get_object_reference(cr, uid, 'account', 'invoice_supplier_form')
        res_id = res and res[1] or False

        return {
            'name': _('Supplier Invoices'),
            'view_type': 'form',
            'view_mode': 'form',
            'view_id': [res_id],
            'res_model': 'account.invoice',
            'context': "{'type':'in_invoice', 'journal_type': 'purchase'}",
            'type': 'ir.actions.act_window',
            'nodestroy': True,
            'target': 'current',
            'res_id': inv_ids and inv_ids[0] or False,
        }

    def view_picking(self, cr, uid, ids, context=None):
        '''
        This function returns an action that display existing pîcking orders of given purchase order ids.
        '''
        mod_obj = self.pool.get('ir.model.data')
        pick_ids = []
        for po in self.browse(cr, uid, ids, context=context):
            pick_ids += [picking.id for picking in po.picking_ids]

        action_model, action_id = tuple(mod_obj.get_object_reference(cr, uid, 'stock', 'action_picking_tree4'))
        action = self.pool[action_model].read(cr, uid, action_id, context=context)
        ctx = eval(action['context'])
        ctx.update({
            'search_default_purchase_id': ids[0]
        })
        if pick_ids and len(pick_ids) == 1:
            form_view_ids = [view_id for view_id, view in action['views'] if view == 'form']
            view_id = form_view_ids and form_view_ids[0] or False
            action.update({
                'views': [],
                'view_mode': 'form',
                'view_id': view_id,
                'res_id': pick_ids[0]
            })

        action.update({
            'context': ctx,
        })
        return action

    def wkf_approve_order(self, cr, uid, ids, context=None):
        self.write(cr, uid, ids, {'state': 'approved', 'date_approve': fields.date.context_today(self,cr,uid,context=context)})
        return True

    def print_confirm(self,cr,uid,ids,context=None):
        print "Confirmed"

    def print_double(self,cr,uid,ids,context=None):
        print "double Approval"

    def print_router(self,cr,uid,ids,context=None):
        print "Routed"

    def wkf_send_rfq(self, cr, uid, ids, context=None):
        '''
        This function opens a window to compose an email, with the edi purchase template message loaded by default
        '''
        ir_model_data = self.pool.get('ir.model.data')
        try:
            template_id = ir_model_data.get_object_reference(cr, uid, 'purchase', 'email_template_edi_purchase')[1]
        except ValueError:
            template_id = False
        try:
            compose_form_id = ir_model_data.get_object_reference(cr, uid, 'mail', 'email_compose_message_wizard_form')[1]
        except ValueError:
            compose_form_id = False 
        ctx = dict(context)
        ctx.update({
            'default_model': 'purchase.order',
            'default_res_id': ids[0],
            'default_use_template': bool(template_id),
            'default_template_id': template_id,
            'default_composition_mode': 'comment',
        })
        return {
            'name': _('Compose Email'),
            'type': 'ir.actions.act_window',
            'view_type': 'form',
            'view_mode': 'form',
            'res_model': 'mail.compose.message',
            'views': [(compose_form_id, 'form')],
            'view_id': compose_form_id,
            'target': 'new',
            'context': ctx,
        }

    def print_quotation(self, cr, uid, ids, context=None):
        '''
        This function prints the request for quotation and mark it as sent, so that we can see more easily the next step of the workflow
        '''
        assert len(ids) == 1, 'This option should only be used for a single id at a time'
        self.signal_send_rfq(cr, uid, ids)
        return self.pool['report'].get_action(cr, uid, ids, 'purchase.report_purchasequotation', context=context)

    #TODO: implement messages system
    def wkf_confirm_order(self, cr, uid, ids, context=None):
        todo = []
        for po in self.browse(cr, uid, ids, context=context):
            if not po.order_line:
                raise osv.except_osv(_('Error!'),_('You cannot confirm a purchase order without any purchase order line.'))
            for line in po.order_line:
                if line.state=='draft':
                    todo.append(line.id)

        self.pool.get('purchase.order.line').action_confirm(cr, uid, todo, context)
        for id in ids:
            self.write(cr, uid, [id], {'state' : 'confirmed', 'validator' : uid})
        return True

    def _choose_account_from_po_line(self, cr, uid, po_line, context=None):
        fiscal_obj = self.pool.get('account.fiscal.position')
        property_obj = self.pool.get('ir.property')
        if po_line.product_id:
            acc_id = po_line.product_id.property_account_expense.id
            if not acc_id:
                acc_id = po_line.product_id.categ_id.property_account_expense_categ.id
            if not acc_id:
                raise osv.except_osv(_('Error!'), _('Define expense account for this company: "%s" (id:%d).') % (po_line.product_id.name, po_line.product_id.id,))
        else:
            acc_id = property_obj.get(cr, uid, 'property_account_expense_categ', 'product.category', context=context).id
        fpos = po_line.order_id.fiscal_position or False
        return fiscal_obj.map_account(cr, uid, fpos, acc_id)

    def _prepare_inv_line(self, cr, uid, account_id, order_line, context=None):
        """Collects require data from purchase order line that is used to create invoice line
        for that purchase order line
        :param account_id: Expense account of the product of PO line if any.
        :param browse_record order_line: Purchase order line browse record
        :return: Value for fields of invoice lines.
        :rtype: dict
        """
        return {
            'name': order_line.name,
            'account_id': account_id,
            'price_unit': order_line.price_unit or 0.0,
            'quantity': order_line.product_qty,
            'product_id': order_line.product_id.id or False,
            'uos_id': order_line.product_uom.id or False,
            'invoice_line_tax_id': [(6, 0, [x.id for x in order_line.taxes_id])],
            'account_analytic_id': order_line.account_analytic_id.id or False,
            'purchase_line_id': order_line.id,
        }

    def action_cancel_draft(self, cr, uid, ids, context=None):
        if not len(ids):
            return False
        self.write(cr, uid, ids, {'state':'draft','shipped':0})
        for p_id in ids:
            # Deleting the existing instance of workflow for PO
            self.delete_workflow(cr, uid, [p_id]) # TODO is it necessary to interleave the calls?
            self.create_workflow(cr, uid, [p_id])
        return True

    def action_invoice_create(self, cr, uid, ids, context=None):
        """Generates invoice for given ids of purchase orders and links that invoice ID to purchase order.
        :param ids: list of ids of purchase orders.
        :return: ID of created invoice.
        :rtype: int
        """
        if context is None:
            context = {}
        journal_obj = self.pool.get('account.journal')
        inv_obj = self.pool.get('account.invoice')
        inv_line_obj = self.pool.get('account.invoice.line')

        res = False
        uid_company_id = self.pool.get('res.users').browse(cr, uid, uid, context=context).company_id.id
        for order in self.browse(cr, uid, ids, context=context):
            context.pop('force_company', None)
            if order.company_id.id != uid_company_id:
                #if the company of the document is different than the current user company, force the company in the context
                #then re-do a browse to read the property fields for the good company.
                context['force_company'] = order.company_id.id
                order = self.browse(cr, uid, order.id, context=context)
            pay_acc_id = order.partner_id.property_account_payable.id
            journal_ids = journal_obj.search(cr, uid, [('type', '=', 'purchase'), ('company_id', '=', order.company_id.id)], limit=1)
            if not journal_ids:
                raise osv.except_osv(_('Error!'),
                    _('Define purchase journal for this company: "%s" (id:%d).') % (order.company_id.name, order.company_id.id))

            # generate invoice line correspond to PO line and link that to created invoice (inv_id) and PO line
            inv_lines = []
            for po_line in order.order_line:
                acc_id = self._choose_account_from_po_line(cr, uid, po_line, context=context)
                inv_line_data = self._prepare_inv_line(cr, uid, acc_id, po_line, context=context)
                inv_line_id = inv_line_obj.create(cr, uid, inv_line_data, context=context)
                inv_lines.append(inv_line_id)

                po_line.write({'invoiced': True, 'invoice_lines': [(4, inv_line_id)]}, context=context)

            # get invoice data and create invoice
            inv_data = {
                'name': order.partner_ref or order.name,
                'reference': order.partner_ref or order.name,
                'account_id': pay_acc_id,
                'type': 'in_invoice',
                'partner_id': order.partner_id.id,
                'currency_id': order.currency_id.id,
                'journal_id': len(journal_ids) and journal_ids[0] or False,
                'invoice_line': [(6, 0, inv_lines)],
                'origin': order.name,
                'fiscal_position': order.fiscal_position.id or False,
                'payment_term': order.payment_term_id.id or False,
                'company_id': order.company_id.id,
            }
            inv_id = inv_obj.create(cr, uid, inv_data, context=context)

            # compute the invoice
            inv_obj.button_compute(cr, uid, [inv_id], context=context, set_total=True)

            # Link this new invoice to related purchase order
            order.write({'invoice_ids': [(4, inv_id)]}, context=context)
            res = inv_id
        return res

    def invoice_done(self, cr, uid, ids, context=None):
        self.write(cr, uid, ids, {'state':'approved'}, context=context)
        return True

    def has_stockable_product(self, cr, uid, ids, *args):
        for order in self.browse(cr, uid, ids):
            for order_line in order.order_line:
                if order_line.product_id and order_line.product_id.type in ('product', 'consu'):
                    return True
        return False

    def action_cancel(self, cr, uid, ids, context=None):
        for purchase in self.browse(cr, uid, ids, context=context):
            for pick in purchase.picking_ids:
                if pick.state not in ('draft','cancel'):
                    raise osv.except_osv(
                        _('Unable to cancel this purchase order.'),
                        _('First cancel all receptions related to this purchase order.'))
            self.pool.get('stock.picking') \
                .signal_button_cancel(cr, uid, map(attrgetter('id'), purchase.picking_ids))
            for inv in purchase.invoice_ids:
                if inv and inv.state not in ('cancel','draft'):
                    raise osv.except_osv(
                        _('Unable to cancel this purchase order.'),
                        _('You must first cancel all receptions related to this purchase order.'))
            self.pool.get('account.invoice') \
                .signal_invoice_cancel(cr, uid, map(attrgetter('id'), purchase.invoice_ids))
        self.write(cr,uid,ids,{'state':'cancel'})

        self.signal_purchase_cancel(cr, uid, ids)
        return True

    def date_to_datetime(self, cr, uid, userdate, context=None):
        """ Convert date values expressed in user's timezone to
        server-side UTC timestamp, assuming a default arbitrary
        time of 12:00 AM - because a time is needed.
    
        :param str userdate: date string in in user time zone
        :return: UTC datetime string for server-side use
        """
        # TODO: move to fields.datetime in server after 7.0
        user_date = datetime.strptime(userdate, DEFAULT_SERVER_DATE_FORMAT)
        if context and context.get('tz'):
            tz_name = context['tz']
        else:
            tz_name = self.pool.get('res.users').read(cr, SUPERUSER_ID, uid, ['tz'])['tz']
        if tz_name:
            utc = pytz.timezone('UTC')
            context_tz = pytz.timezone(tz_name)
            user_datetime = user_date + relativedelta(hours=12.0)
            local_timestamp = context_tz.localize(user_datetime, is_dst=False)
            user_datetime = local_timestamp.astimezone(utc)
            return user_datetime.strftime(DEFAULT_SERVER_DATETIME_FORMAT)
        return user_date.strftime(DEFAULT_SERVER_DATETIME_FORMAT)

    def _prepare_order_picking(self, cr, uid, order, context=None):
        return {
            'name': self.pool.get('ir.sequence').get(cr, uid, 'stock.picking.in'),
            'origin': order.name + ((order.origin and (':' + order.origin)) or ''),
            'date': self.date_to_datetime(cr, uid, order.date_order, context),
            'partner_id': order.partner_id.id,
            'invoice_state': '2binvoiced' if order.invoice_method == 'picking' else 'none',
            'type': 'in',
            'purchase_id': order.id,
            'company_id': order.company_id.id,
            'move_lines' : [],
        }

    def _prepare_order_line_move(self, cr, uid, order, order_line, picking_id, context=None):
        ''' prepare the stock move data from the PO line '''
        return {
            'name': order_line.name or '',
            'product_id': order_line.product_id.id,
            'product_qty': order_line.product_qty,
            'product_uos_qty': order_line.product_qty,
            'product_uom': order_line.product_uom.id,
            'product_uos': order_line.product_uom.id,
            'date': self.date_to_datetime(cr, uid, order.date_order, context),
            'date_expected': self.date_to_datetime(cr, uid, order_line.date_planned, context),
            'location_id': order.partner_id.property_stock_supplier.id,
            'location_dest_id': order.location_id.id,
            'picking_id': picking_id,
            'partner_id': order.dest_address_id.id or order.partner_id.id,
            'move_dest_id': order_line.move_dest_id.id,
            'state': 'draft',
            'type':'in',
            'purchase_line_id': order_line.id,
            'company_id': order.company_id.id,
            'price_unit': order_line.price_unit
        }

    def _create_pickings(self, cr, uid, order, order_lines, picking_id=False, context=None):
        """Creates pickings and appropriate stock moves for given order lines, then
        confirms the moves, makes them available, and confirms the picking.

        If ``picking_id`` is provided, the stock moves will be added to it, otherwise
        a standard outgoing picking will be created to wrap the stock moves, as returned
        by :meth:`~._prepare_order_picking`.

        Modules that wish to customize the procurements or partition the stock moves over
        multiple stock pickings may override this method and call ``super()`` with
        different subsets of ``order_lines`` and/or preset ``picking_id`` values.

        :param browse_record order: purchase order to which the order lines belong
        :param list(browse_record) order_lines: purchase order line records for which picking
                                                and moves should be created.
        :param int picking_id: optional ID of a stock picking to which the created stock moves
                               will be added. A new picking will be created if omitted.
        :return: list of IDs of pickings used/created for the given order lines (usually just one)
        """
        stock_picking = self.pool.get('stock.picking')
        if not picking_id:
            picking_id = stock_picking.create(cr, uid, self._prepare_order_picking(cr, uid, order, context=context))
        todo_moves = []
        stock_move = self.pool.get('stock.move')
        for order_line in order_lines:
            if not order_line.product_id:
                continue
            if order_line.product_id.type in ('product', 'consu'):
                move = stock_move.create(cr, uid, self._prepare_order_line_move(cr, uid, order, order_line, picking_id, context=context))
                if order_line.move_dest_id and order_line.move_dest_id.state != 'done':
                    order_line.move_dest_id.write({'location_id': order.location_id.id})
                todo_moves.append(move)
        stock_move.action_confirm(cr, uid, todo_moves)
        stock_move.force_assign(cr, uid, todo_moves)
        stock_picking.signal_button_confirm(cr, uid, [picking_id])
        return [picking_id]

    def action_picking_create(self, cr, uid, ids, context=None):
        picking_ids = []
        for order in self.browse(cr, uid, ids):
            picking_ids.extend(self._create_pickings(cr, uid, order, order.order_line, None, context=context))

        # Must return one unique picking ID: the one to connect in the subflow of the purchase order.
        # In case of multiple (split) pickings, we should return the ID of the critical one, i.e. the
        # one that should trigger the advancement of the purchase workflow.
        # By default we will consider the first one as most important, but this behavior can be overridden.
        return picking_ids[0] if picking_ids else False

    def picking_done(self, cr, uid, ids, context=None):
        self.write(cr, uid, ids, {'shipped':1,'state':'approved'}, context=context)
        self.message_post(cr, uid, ids, body=_("Products received"), context=context)
        return True

    def copy(self, cr, uid, id, default=None, context=None):
        if not default:
            default = {}
        default.update({
            'state':'draft',
            'shipped':False,
            'invoiced':False,
            'invoice_ids': [],
            'picking_ids': [],
            'partner_ref': '',
            'name': self.pool.get('ir.sequence').get(cr, uid, 'purchase.order'),
        })
        return super(purchase_order, self).copy(cr, uid, id, default, context)

    def do_merge(self, cr, uid, ids, context=None):
        """
        To merge similar type of purchase orders.
        Orders will only be merged if:
        * Purchase Orders are in draft
        * Purchase Orders belong to the same partner
        * Purchase Orders are have same stock location, same pricelist
        Lines will only be merged if:
        * Order lines are exactly the same except for the quantity and unit

         @param self: The object pointer.
         @param cr: A database cursor
         @param uid: ID of the user currently logged in
         @param ids: the ID or list of IDs
         @param context: A standard dictionary

         @return: new purchase order id

        """
        #TOFIX: merged order line should be unlink
        def make_key(br, fields):
            list_key = []
            for field in fields:
                field_val = getattr(br, field)
                if field in ('product_id', 'move_dest_id', 'account_analytic_id'):
                    if not field_val:
                        field_val = False
                if isinstance(field_val, browse_record):
                    field_val = field_val.id
                elif isinstance(field_val, browse_null):
                    field_val = False
                elif isinstance(field_val, list):
                    field_val = ((6, 0, tuple([v.id for v in field_val])),)
                list_key.append((field, field_val))
            list_key.sort()
            return tuple(list_key)

        if context is None:
            context = {}

        # Compute what the new orders should contain

        new_orders = {}

        for porder in [order for order in self.browse(cr, uid, ids, context=context) if order.state == 'draft']:
            order_key = make_key(porder, ('partner_id', 'location_id', 'pricelist_id'))
            new_order = new_orders.setdefault(order_key, ({}, []))
            new_order[1].append(porder.id)
            order_infos = new_order[0]
            if not order_infos:
                order_infos.update({
                    'origin': porder.origin,
                    'date_order': porder.date_order,
                    'partner_id': porder.partner_id.id,
                    'dest_address_id': porder.dest_address_id.id,
                    'warehouse_id': porder.warehouse_id.id,
                    'location_id': porder.location_id.id,
                    'pricelist_id': porder.pricelist_id.id,
                    'state': 'draft',
                    'order_line': {},
                    'notes': '%s' % (porder.notes or '',),
                    'fiscal_position': porder.fiscal_position and porder.fiscal_position.id or False,
                })
            else:
                if porder.date_order < order_infos['date_order']:
                    order_infos['date_order'] = porder.date_order
                if porder.notes:
                    order_infos['notes'] = (order_infos['notes'] or '') + ('\n%s' % (porder.notes,))
                if porder.origin:
                    order_infos['origin'] = (order_infos['origin'] or '') + ' ' + porder.origin

            for order_line in porder.order_line:
                line_key = make_key(order_line, ('name', 'date_planned', 'taxes_id', 'price_unit', 'product_id', 'move_dest_id', 'account_analytic_id'))
                o_line = order_infos['order_line'].setdefault(line_key, {})
                if o_line:
                    # merge the line with an existing line
                    o_line['product_qty'] += order_line.product_qty * order_line.product_uom.factor / o_line['uom_factor']
                else:
                    # append a new "standalone" line
                    for field in ('product_qty', 'product_uom'):
                        field_val = getattr(order_line, field)
                        if isinstance(field_val, browse_record):
                            field_val = field_val.id
                        o_line[field] = field_val
                    o_line['uom_factor'] = order_line.product_uom and order_line.product_uom.factor or 1.0



        allorders = []
        orders_info = {}
        for order_key, (order_data, old_ids) in new_orders.iteritems():
            # skip merges with only one order
            if len(old_ids) < 2:
                allorders += (old_ids or [])
                continue

            # cleanup order line data
            for key, value in order_data['order_line'].iteritems():
                del value['uom_factor']
                value.update(dict(key))
            order_data['order_line'] = [(0, 0, value) for value in order_data['order_line'].itervalues()]

            # create the new order
            context.update({'mail_create_nolog': True})
            neworder_id = self.create(cr, uid, order_data)
            self.message_post(cr, uid, [neworder_id], body=_("RFQ created"), context=context)
            orders_info.update({neworder_id: old_ids})
            allorders.append(neworder_id)

            # make triggers pointing to the old orders point to the new order
            for old_id in old_ids:
                self.redirect_workflow(cr, uid, [(old_id, neworder_id)])
                self.signal_purchase_cancel(cr, uid, [old_id]) # TODO Is it necessary to interleave the calls?
        return orders_info


class purchase_order_line(osv.osv):
    def _amount_line(self, cr, uid, ids, prop, arg, context=None):
        res = {}
        cur_obj=self.pool.get('res.currency')
        tax_obj = self.pool.get('account.tax')
        for line in self.browse(cr, uid, ids, context=context):
            taxes = tax_obj.compute_all(cr, uid, line.taxes_id, line.price_unit, line.product_qty, line.product_id, line.order_id.partner_id)
            cur = line.order_id.pricelist_id.currency_id
            res[line.id] = cur_obj.round(cr, uid, cur, taxes['total'])
        return res

    def _get_uom_id(self, cr, uid, context=None):
        try:
            proxy = self.pool.get('ir.model.data')
            result = proxy.get_object_reference(cr, uid, 'product', 'product_uom_unit')
            return result[1]
        except Exception, ex:
            return False

    _columns = {
        'name': fields.text('Description', required=True),
        'product_qty': fields.float('Quantity', digits_compute=dp.get_precision('Product Unit of Measure'), required=True),
        'date_planned': fields.date('Scheduled Date', required=True, select=True),
        'taxes_id': fields.many2many('account.tax', 'purchase_order_taxe', 'ord_id', 'tax_id', 'Taxes'),
        'product_uom': fields.many2one('product.uom', 'Product Unit of Measure', required=True),
        'product_id': fields.many2one('product.product', 'Product', domain=[('purchase_ok','=',True)], change_default=True),
        'move_ids': fields.one2many('stock.move', 'purchase_line_id', 'Reservation', readonly=True, ondelete='set null'),
        'move_dest_id': fields.many2one('stock.move', 'Reservation Destination', ondelete='set null'),
        'price_unit': fields.float('Unit Price', required=True, digits_compute= dp.get_precision('Product Price')),
        'price_subtotal': fields.function(_amount_line, string='Subtotal', digits_compute= dp.get_precision('Account')),
        'order_id': fields.many2one('purchase.order', 'Order Reference', select=True, required=True, ondelete='cascade'),
        'account_analytic_id':fields.many2one('account.analytic.account', 'Analytic Account',),
        'company_id': fields.related('order_id','company_id',type='many2one',relation='res.company',string='Company', store=True, readonly=True),
        'state': fields.selection([('draft', 'Draft'), ('confirmed', 'Confirmed'), ('done', 'Done'), ('cancel', 'Cancelled')], 'Status', required=True, readonly=True,
                                  help=' * The \'Draft\' status is set automatically when purchase order in draft status. \
                                       \n* The \'Confirmed\' status is set automatically as confirm when purchase order in confirm status. \
                                       \n* The \'Done\' status is set automatically when purchase order is set as done. \
                                       \n* The \'Cancelled\' status is set automatically when user cancel purchase order.'),
        'invoice_lines': fields.many2many('account.invoice.line', 'purchase_order_line_invoice_rel', 'order_line_id', 'invoice_id', 'Invoice Lines', readonly=True),
        'invoiced': fields.boolean('Invoiced', readonly=True),
        'partner_id': fields.related('order_id','partner_id',string='Partner',readonly=True,type="many2one", relation="res.partner", store=True),
        'date_order': fields.related('order_id','date_order',string='Order Date',readonly=True,type="date"),

    }
    _defaults = {
        'product_uom' : _get_uom_id,
        'product_qty': lambda *a: 1.0,
        'state': lambda *args: 'draft',
        'invoiced': lambda *a: 0,
    }
    _table = 'purchase_order_line'
    _name = 'purchase.order.line'
    _description = 'Purchase Order Line'

    def copy_data(self, cr, uid, id, default=None, context=None):
        if not default:
            default = {}
        default.update({'state':'draft', 'move_ids':[],'invoiced':0,'invoice_lines':[]})
        return super(purchase_order_line, self).copy_data(cr, uid, id, default, context)

    def unlink(self, cr, uid, ids, context=None):
        procurement_ids_to_cancel = []
        for line in self.browse(cr, uid, ids, context=context):
            if line.move_dest_id:
                procurement_ids_to_cancel.extend(procurement.id for procurement in line.move_dest_id.procurements)
        if procurement_ids_to_cancel:
            self.pool['procurement.order'].action_cancel(cr, uid, procurement_ids_to_cancel)
        return super(purchase_order_line, self).unlink(cr, uid, ids, context=context)

    def onchange_product_uom(self, cr, uid, ids, pricelist_id, product_id, qty, uom_id,
            partner_id, date_order=False, fiscal_position_id=False, date_planned=False,
            name=False, price_unit=False, context=None):
        """
        onchange handler of product_uom.
        """
        if context is None:
            context = {}
        if not uom_id:
            return {'value': {'price_unit': price_unit or 0.0, 'name': name or '', 'product_uom' : uom_id or False}}
        context = dict(context, purchase_uom_check=True)
        return self.onchange_product_id(cr, uid, ids, pricelist_id, product_id, qty, uom_id,
            partner_id, date_order=date_order, fiscal_position_id=fiscal_position_id, date_planned=date_planned,
            name=name, price_unit=price_unit, context=context)

    def _get_date_planned(self, cr, uid, supplier_info, date_order_str, context=None):
        """Return the datetime value to use as Schedule Date (``date_planned``) for
           PO Lines that correspond to the given product.supplierinfo,
           when ordered at `date_order_str`.

           :param browse_record | False supplier_info: product.supplierinfo, used to
               determine delivery delay (if False, default delay = 0)
           :param str date_order_str: date of order, as a string in
               DEFAULT_SERVER_DATE_FORMAT
           :rtype: datetime
           :return: desired Schedule Date for the PO line
        """
        supplier_delay = int(supplier_info.delay) if supplier_info else 0
        return datetime.strptime(date_order_str, DEFAULT_SERVER_DATE_FORMAT) + relativedelta(days=supplier_delay)

    def _check_product_uom_group(self, cr, uid, context=None):
        group_uom = self.pool.get('ir.model.data').get_object(cr, uid, 'product', 'group_uom')
        res = [user for user in group_uom.users if user.id == uid]
        return len(res) and True or False


    def onchange_product_id(self, cr, uid, ids, pricelist_id, product_id, qty, uom_id,
            partner_id, date_order=False, fiscal_position_id=False, date_planned=False,
            name=False, price_unit=False, context=None):
        """
        onchange handler of product_id.
        """
        if context is None:
            context = {}

        res = {'value': {'price_unit': price_unit or 0.0, 'name': name or '', 'product_uom' : uom_id or False}}
        if not product_id:
            return res

        product_product = self.pool.get('product.product')
        product_uom = self.pool.get('product.uom')
        res_partner = self.pool.get('res.partner')
        product_pricelist = self.pool.get('product.pricelist')
        account_fiscal_position = self.pool.get('account.fiscal.position')
        account_tax = self.pool.get('account.tax')

        # - check for the presence of partner_id and pricelist_id
        #if not partner_id:
        #    raise osv.except_osv(_('No Partner!'), _('Select a partner in purchase order to choose a product.'))
        #if not pricelist_id:
        #    raise osv.except_osv(_('No Pricelist !'), _('Select a price list in the purchase order form before choosing a product.'))

        # - determine name and notes based on product in partner lang.
        context_partner = context.copy()
        if partner_id:
            lang = res_partner.browse(cr, uid, partner_id).lang
            context_partner.update( {'lang': lang, 'partner_id': partner_id} )
        product = product_product.browse(cr, uid, product_id, context=context_partner)
        #call name_get() with partner in the context to eventually match name and description in the seller_ids field
        dummy, name = product_product.name_get(cr, uid, product_id, context=context_partner)[0]
        if product.description_purchase:
            name += '\n' + product.description_purchase
        res['value'].update({'name': name})

        # - set a domain on product_uom
        res['domain'] = {'product_uom': [('category_id','=',product.uom_id.category_id.id)]}

        # - check that uom and product uom belong to the same category
        product_uom_po_id = product.uom_po_id.id
        if not uom_id:
            uom_id = product_uom_po_id

        if product.uom_id.category_id.id != product_uom.browse(cr, uid, uom_id, context=context).category_id.id:
            if context.get('purchase_uom_check') and self._check_product_uom_group(cr, uid, context=context):
                res['warning'] = {'title': _('Warning!'), 'message': _('Selected Unit of Measure does not belong to the same category as the product Unit of Measure.')}
            uom_id = product_uom_po_id

        res['value'].update({'product_uom': uom_id})

        # - determine product_qty and date_planned based on seller info
        if not date_order:
            date_order = fields.date.context_today(self,cr,uid,context=context)


        supplierinfo = False
        for supplier in product.seller_ids:
            if partner_id and (supplier.name.id == partner_id):
                supplierinfo = supplier
                if supplierinfo.product_uom.id != uom_id:
                    res['warning'] = {'title': _('Warning!'), 'message': _('The selected supplier only sells this product by %s') % supplierinfo.product_uom.name }
                min_qty = product_uom._compute_qty(cr, uid, supplierinfo.product_uom.id, supplierinfo.min_qty, to_uom_id=uom_id)
                if (qty or 0.0) < min_qty: # If the supplier quantity is greater than entered from user, set minimal.
                    if qty:
                        res['warning'] = {'title': _('Warning!'), 'message': _('The selected supplier has a minimal quantity set to %s %s, you should not purchase less.') % (supplierinfo.min_qty, supplierinfo.product_uom.name)}
                    qty = min_qty
        dt = self._get_date_planned(cr, uid, supplierinfo, date_order, context=context).strftime(DEFAULT_SERVER_DATETIME_FORMAT)
        qty = qty or 1.0
        res['value'].update({'date_planned': date_planned or dt})
        if qty:
            res['value'].update({'product_qty': qty})

        # - determine price_unit and taxes_id
        if pricelist_id:
            price = product_pricelist.price_get(cr, uid, [pricelist_id],
                    product.id, qty or 1.0, partner_id or False, {'uom': uom_id, 'date': date_order})[pricelist_id]
        else:
            price = product.standard_price

        taxes = account_tax.browse(cr, uid, map(lambda x: x.id, product.supplier_taxes_id))
        fpos = fiscal_position_id and account_fiscal_position.browse(cr, uid, fiscal_position_id, context=context) or False
        taxes_ids = account_fiscal_position.map_tax(cr, uid, fpos, taxes)
        res['value'].update({'price_unit': price, 'taxes_id': taxes_ids})

        return res

    product_id_change = onchange_product_id
    product_uom_change = onchange_product_uom

    def action_confirm(self, cr, uid, ids, context=None):
        self.write(cr, uid, ids, {'state': 'confirmed'}, context=context)
        return True


class procurement_order(osv.osv):
    _inherit = 'procurement.order'
    _columns = {
        'purchase_id': fields.many2one('purchase.order', 'Purchase Order'),
    }

    def check_buy(self, cr, uid, ids, context=None):
        ''' return True if the supply method of the mto product is 'buy'
        '''
        user = self.pool.get('res.users').browse(cr, uid, uid, context=context)
        for procurement in self.browse(cr, uid, ids, context=context):
            if procurement.product_id.supply_method <> 'buy':
                return False
        return True

    def check_supplier_info(self, cr, uid, ids, context=None):
        partner_obj = self.pool.get('res.partner')
        user = self.pool.get('res.users').browse(cr, uid, uid, context=context)
        for procurement in self.browse(cr, uid, ids, context=context):
            message = ''
            partner = procurement.product_id.seller_id #Taken Main Supplier of Product of Procurement.

            if not procurement.product_id.seller_ids:
                message = _('No supplier defined for this product !')
            elif not partner:
                message = _('No default supplier defined for this product')
            elif not partner_obj.address_get(cr, uid, [partner.id], ['delivery'])['delivery']:
                message = _('No address defined for the supplier')

            if message:
                if procurement.message != message:
                    cr.execute('update procurement_order set message=%s where id=%s', (message, procurement.id))
                return False

            if user.company_id and user.company_id.partner_id:
                if partner.id == user.company_id.partner_id.id:
                    raise osv.except_osv(_('Configuration Error!'), _('The product "%s" has been defined with your company as reseller which seems to be a configuration error!' % procurement.product_id.name))

        return True


    def action_po_assign(self, cr, uid, ids, context=None):
        """ This is action which call from workflow to assign purchase order to procurements
        @return: True
        """
        res = self.make_po(cr, uid, ids, context=context)
        res = res.values()
        return len(res) and res[0] or 0 #TO CHECK: why workflow is generated error if return not integer value

    def create_procurement_purchase_order(self, cr, uid, procurement, po_vals, line_vals, context=None):
        """Create the purchase order from the procurement, using
           the provided field values, after adding the given purchase
           order line in the purchase order.

           :params procurement: the procurement object generating the purchase order
           :params dict po_vals: field values for the new purchase order (the
                                 ``order_line`` field will be overwritten with one
                                 single line, as passed in ``line_vals``).
           :params dict line_vals: field values of the single purchase order line that
                                   the purchase order will contain.
           :return: id of the newly created purchase order
           :rtype: int
        """
        po_vals.update({'order_line': [(0,0,line_vals)]})
        return self.pool.get('purchase.order').create(cr, uid, po_vals, context=context)

    def _get_purchase_schedule_date(self, cr, uid, procurement, company, context=None):
        """Return the datetime value to use as Schedule Date (``date_planned``) for the
           Purchase Order Lines created to satisfy the given procurement.

           :param browse_record procurement: the procurement for which a PO will be created.
           :param browse_report company: the company to which the new PO will belong to.
           :rtype: datetime
           :return: the desired Schedule Date for the PO lines
        """
        procurement_date_planned = datetime.strptime(procurement.date_planned, DEFAULT_SERVER_DATETIME_FORMAT)
        schedule_date = (procurement_date_planned - relativedelta(days=company.po_lead))
        return schedule_date

    def _get_purchase_order_date(self, cr, uid, procurement, company, schedule_date, context=None):
        """Return the datetime value to use as Order Date (``date_order``) for the
           Purchase Order created to satisfy the given procurement.

           :param browse_record procurement: the procurement for which a PO will be created.
           :param browse_report company: the company to which the new PO will belong to.
           :param datetime schedule_date: desired Scheduled Date for the Purchase Order lines.
           :rtype: datetime
           :return: the desired Order Date for the PO
        """
        seller_delay = int(procurement.product_id.seller_delay)
        return schedule_date - relativedelta(days=seller_delay)

    def _get_warehouse(self, procurement, user_company):
        """
            Return the warehouse containing the procurment stock location (or one of it ancestors)
            If none match, returns then first warehouse of the company
        """
        # TODO refactor the domain once we implement the "parent_of" domain operator
        # NOTE This method has been copied in the `purchase_requisition` module to ensure
        #      retro-compatibility. This code duplication will be deleted in next stable version.
        #      Do not forget to update both version in case of modification.
        company_id = (procurement.company_id or user_company).id
        domains = [
            [
                '&', ('company_id', '=', company_id),
                '|', '&', ('lot_stock_id.parent_left', '<', procurement.location_id.parent_left),
                          ('lot_stock_id.parent_right', '>', procurement.location_id.parent_right),
                     ('lot_stock_id', '=', procurement.location_id.id)
            ],
            [('company_id', '=', company_id)]
        ]

        cr, uid = procurement._cr, procurement._uid
        context = procurement._context
        Warehouse = self.pool['stock.warehouse']
        for domain in domains:
            ids = Warehouse.search(cr, uid, domain, context=context)
            if ids:
                return ids[0]
        return False

    def make_po(self, cr, uid, ids, context=None):
        """ Make purchase order from procurement
        @return: New created Purchase Orders procurement wise
        """
        res = {}
        if context is None:
            context = {}
        company = self.pool.get('res.users').browse(cr, uid, uid, context=context).company_id
        partner_obj = self.pool.get('res.partner')
        uom_obj = self.pool.get('product.uom')
        pricelist_obj = self.pool.get('product.pricelist')
        prod_obj = self.pool.get('product.product')
        acc_pos_obj = self.pool.get('account.fiscal.position')
        seq_obj = self.pool.get('ir.sequence')
        for procurement in self.browse(cr, uid, ids, context=context):
            res_id = procurement.move_id.id
            partner = procurement.product_id.seller_id # Taken Main Supplier of Product of Procurement.
            seller_qty = procurement.product_id.seller_qty
            partner_id = partner.id
            address_id = partner_obj.address_get(cr, uid, [partner_id], ['delivery'])['delivery']
            pricelist_id = partner.property_product_pricelist_purchase.id
            uom_id = procurement.product_id.uom_po_id.id

            qty = uom_obj._compute_qty(cr, uid, procurement.product_uom.id, procurement.product_qty, uom_id)
            if seller_qty:
                qty = max(qty,seller_qty)

            price = pricelist_obj.price_get(cr, uid, [pricelist_id], procurement.product_id.id, qty, partner_id, {'uom': uom_id})[pricelist_id]

            schedule_date = self._get_purchase_schedule_date(cr, uid, procurement, company, context=context)
            purchase_date = self._get_purchase_order_date(cr, uid, procurement, company, schedule_date, context=context)

            #Passing partner_id to context for purchase order line integrity of Line name
            new_context = context.copy()
            new_context.update({'lang': partner.lang, 'partner_id': partner_id})

            product = prod_obj.browse(cr, uid, procurement.product_id.id, context=new_context)
            taxes_ids = procurement.product_id.supplier_taxes_id
            taxes = acc_pos_obj.map_tax(cr, uid, partner.property_account_position, taxes_ids)

            name = product.partner_ref
            if product.description_purchase:
                name += '\n'+ product.description_purchase
            line_vals = {
                'name': name,
                'product_qty': qty,
                'product_id': procurement.product_id.id,
                'product_uom': uom_id,
                'price_unit': price or 0.0,
                'date_planned': schedule_date.strftime(DEFAULT_SERVER_DATETIME_FORMAT),
                'move_dest_id': res_id,
                'taxes_id': [(6,0,taxes)],
            }
            name = seq_obj.get(cr, uid, 'purchase.order') or _('PO: %s') % procurement.name
            po_vals = {
                'name': name,
                'origin': procurement.origin,
                'partner_id': partner_id,
                'location_id': procurement.location_id.id,
                'warehouse_id': self._get_warehouse(procurement, company),
                'pricelist_id': pricelist_id,
                'date_order': purchase_date.strftime(DEFAULT_SERVER_DATETIME_FORMAT),
                'company_id': procurement.company_id.id,
                'fiscal_position': partner.property_account_position and partner.property_account_position.id or False,
                'payment_term_id': partner.property_supplier_payment_term.id or False,
            }
            res[procurement.id] = self.create_procurement_purchase_order(cr, uid, procurement, po_vals, line_vals, context=new_context)
            self.write(cr, uid, [procurement.id], {'state': 'running', 'purchase_id': res[procurement.id]})
        self.message_post(cr, uid, ids, body=_("Draft Purchase Order created"), context=context)
        return res

    def _product_virtual_get(self, cr, uid, order_point):
        procurement = order_point.procurement_id
        if procurement and procurement.state != 'exception' and procurement.purchase_id and procurement.purchase_id.state in ('draft', 'confirmed'):
            return None
        return super(procurement_order, self)._product_virtual_get(cr, uid, order_point)


class mail_mail(osv.Model):
    _name = 'mail.mail'
    _inherit = 'mail.mail'

    def _postprocess_sent_message(self, cr, uid, mail, context=None):
        if mail.model == 'purchase.order':
            self.pool.get('purchase.order').signal_send_rfq(cr, uid, [mail.res_id])
        return super(mail_mail, self)._postprocess_sent_message(cr, uid, mail=mail, context=context)


class product_template(osv.Model):
    _name = 'product.template'
    _inherit = 'product.template'
    _columns = {
        'purchase_ok': fields.boolean('Can be Purchased', help="Specify if the product can be selected in a purchase order line."),
    }
    _defaults = {
        'purchase_ok': 1,
    }


class mail_compose_message(osv.Model):
    _inherit = 'mail.compose.message'

    def send_mail(self, cr, uid, ids, context=None):
        context = context or {}
        if context.get('default_model') == 'purchase.order' and context.get('default_res_id'):
            context = dict(context, mail_post_autofollow=True)
            self.pool.get('purchase.order').signal_send_rfq(cr, uid, [context['default_res_id']])
        return super(mail_compose_message, self).send_mail(cr, uid, ids, context=context)


class account_invoice(osv.Model):
    """ Override account_invoice to add Chatter messages on the related purchase
        orders, logging the invoice reception or payment. """
    _inherit = 'account.invoice'

    def invoice_validate(self, cr, uid, ids, context=None):
        res = super(account_invoice, self).invoice_validate(cr, uid, ids, context=context)
        purchase_order_obj = self.pool.get('purchase.order')
        # read access on purchase.order object is not required
        if not purchase_order_obj.check_access_rights(cr, uid, 'read', raise_exception=False):
            user_id = SUPERUSER_ID
        else:
            user_id = uid
        po_ids = purchase_order_obj.search(cr, user_id, [('invoice_ids', 'in', ids)], context=context)
        for po_id in po_ids:
            purchase_order_obj.message_post(cr, user_id, po_id, body=_("Invoice received"), context=context)
            workflow.trg_write(uid, 'purchase.order', po_id, cr)
        return res

    def confirm_paid(self, cr, uid, ids, context=None):
        res = super(account_invoice, self).confirm_paid(cr, uid, ids, context=context)
        purchase_order_obj = self.pool.get('purchase.order')
        # read access on purchase.order object is not required
        if not purchase_order_obj.check_access_rights(cr, uid, 'read', raise_exception=False):
            user_id = SUPERUSER_ID
        else:
            user_id = uid
        po_ids = purchase_order_obj.search(cr, user_id, [('invoice_ids', 'in', ids)], context=context)
        for po_id in po_ids:
            purchase_order_obj.message_post(cr, user_id, po_id, body=_("Invoice paid"), context=context)
        return res

class account_invoice_line(osv.Model):
    """ Override account_invoice_line to add the link to the purchase order line it is related to"""
    _inherit = 'account.invoice.line'
    _columns = {
        'purchase_line_id': fields.many2one('purchase.order.line',
            'Purchase Order Line', ondelete='set null', select=True,
            readonly=True),
    }

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