# -*- encoding: 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
from datetime import datetime
from dateutil.relativedelta import relativedelta

from openerp.osv import fields, osv
import openerp.addons.decimal_precision as dp
from openerp.tools.translate import _

class account_asset_category(osv.osv):
    _name = 'account.asset.category'
    _description = 'Asset category'

    _columns = {
        'name': fields.char('Name', size=64, required=True, select=1),
        'note': fields.text('Note'),
        'account_analytic_id': fields.many2one('account.analytic.account', 'Analytic account'),
        'account_asset_id': fields.many2one('account.account', 'Asset Account', required=True, domain=[('type','=','other')]),
        'account_depreciation_id': fields.many2one('account.account', 'Depreciation Account', required=True, domain=[('type','=','other')]),
        'account_expense_depreciation_id': fields.many2one('account.account', 'Depr. Expense Account', required=True, domain=[('type','=','other')]),
        'journal_id': fields.many2one('account.journal', 'Journal', required=True),
        'company_id': fields.many2one('res.company', 'Company', required=True),
        'method': fields.selection([('linear','Linear'),('degressive','Degressive')], 'Computation Method', required=True, help="Choose the method to use to compute the amount of depreciation lines.\n"\
            "  * Linear: Calculated on basis of: Gross Value / Number of Depreciations\n" \
            "  * Degressive: Calculated on basis of: Residual Value * Degressive Factor"),
        'method_number': fields.integer('Number of Depreciations', help="The number of depreciations needed to depreciate your asset"),
        'method_period': fields.integer('Period Length', help="State here the time between 2 depreciations, in months", required=True),
        'method_progress_factor': fields.float('Degressive Factor'),
        'method_time': fields.selection([('number','Number of Depreciations'),('end','Ending Date')], 'Time Method', required=True,
                                  help="Choose the method to use to compute the dates and number of depreciation lines.\n"\
                                       "  * Number of Depreciations: Fix the number of depreciation lines and the time between 2 depreciations.\n" \
                                       "  * Ending Date: Choose the time between 2 depreciations and the date the depreciations won't go beyond."),
        'method_end': fields.date('Ending date'),
        'prorata':fields.boolean('Prorata Temporis', help='Indicates that the first depreciation entry for this asset have to be done from the purchase date instead of the first January'),
        'open_asset': fields.boolean('Skip Draft State', help="Check this if you want to automatically confirm the assets of this category when created by invoices."),
    }

    _defaults = {
        'company_id': lambda self, cr, uid, context: self.pool.get('res.company')._company_default_get(cr, uid, 'account.asset.category', context=context),
        'method': 'linear',
        'method_number': 5,
        'method_time': 'number',
        'method_period': 12,
        'method_progress_factor': 0.3,
    }

    def onchange_account_asset(self, cr, uid, ids, account_asset_id, context=None):
        res = {'value':{}}
        if account_asset_id:
           res['value'] = {'account_depreciation_id': account_asset_id}
        return res


class account_asset_asset(osv.osv):
    _name = 'account.asset.asset'
    _description = 'Asset'

    def unlink(self, cr, uid, ids, context=None):
        for asset in self.browse(cr, uid, ids, context=context):
            if asset.account_move_line_ids: 
                raise osv.except_osv(_('Error!'), _('You cannot delete an asset that contains posted depreciation lines.'))
        return super(account_asset_asset, self).unlink(cr, uid, ids, context=context)

    def _get_period(self, cr, uid, context=None):
        periods = self.pool.get('account.period').find(cr, uid, context=context)
        if periods:
            return periods[0]
        else:
            return False

    def _get_last_depreciation_date(self, cr, uid, ids, context=None):
        """
        @param id: ids of a account.asset.asset objects
        @return: Returns a dictionary of the effective dates of the last depreciation entry made for given asset ids. If there isn't any, return the purchase date of this asset
        """
        cr.execute("""
            SELECT a.id as id, COALESCE(MAX(l.date),a.purchase_date) AS date
            FROM account_asset_asset a
            LEFT JOIN account_move_line l ON (l.asset_id = a.id)
            WHERE a.id IN %s
            GROUP BY a.id, a.purchase_date """, (tuple(ids),))
        return dict(cr.fetchall())

    def _compute_board_amount(self, cr, uid, asset, i, residual_amount, amount_to_depr, undone_dotation_number, posted_depreciation_line_ids, total_days, depreciation_date, context=None):
        #by default amount = 0
        amount = 0
        if i == undone_dotation_number:
            amount = residual_amount
        else:
            if asset.method == 'linear':
                amount = amount_to_depr / (undone_dotation_number - len(posted_depreciation_line_ids))
                if asset.prorata:
                    amount = amount_to_depr / asset.method_number
                    days = total_days - float(depreciation_date.strftime('%j'))
                    if i == 1:
                        amount = (amount_to_depr / asset.method_number) / total_days * days
                    elif i == undone_dotation_number:
                        amount = (amount_to_depr / asset.method_number) / total_days * (total_days - days)
            elif asset.method == 'degressive':
                amount = residual_amount * asset.method_progress_factor
                if asset.prorata:
                    days = total_days - float(depreciation_date.strftime('%j'))
                    if i == 1:
                        amount = (residual_amount * asset.method_progress_factor) / total_days * days
                    elif i == undone_dotation_number:
                        amount = (residual_amount * asset.method_progress_factor) / total_days * (total_days - days)
        return amount

    def _compute_board_undone_dotation_nb(self, cr, uid, asset, depreciation_date, total_days, context=None):
        undone_dotation_number = asset.method_number
        if asset.method_time == 'end':
            end_date = datetime.strptime(asset.method_end, '%Y-%m-%d')
            undone_dotation_number = 0
            while depreciation_date <= end_date:
                depreciation_date = (datetime(depreciation_date.year, depreciation_date.month, depreciation_date.day) + relativedelta(months=+asset.method_period))
                undone_dotation_number += 1
        if asset.prorata:
            undone_dotation_number += 1
        return undone_dotation_number

    def compute_depreciation_board(self, cr, uid, ids, context=None):
        depreciation_lin_obj = self.pool.get('account.asset.depreciation.line')
        currency_obj = self.pool.get('res.currency')
        for asset in self.browse(cr, uid, ids, context=context):
            if asset.value_residual == 0.0:
                continue
            posted_depreciation_line_ids = depreciation_lin_obj.search(cr, uid, [('asset_id', '=', asset.id), ('move_check', '=', True)],order='depreciation_date desc')
            old_depreciation_line_ids = depreciation_lin_obj.search(cr, uid, [('asset_id', '=', asset.id), ('move_id', '=', False)])
            if old_depreciation_line_ids:
                depreciation_lin_obj.unlink(cr, uid, old_depreciation_line_ids, context=context)

            amount_to_depr = residual_amount = asset.value_residual
            if asset.prorata:
                depreciation_date = datetime.strptime(self._get_last_depreciation_date(cr, uid, [asset.id], context)[asset.id], '%Y-%m-%d')
            else:
                # depreciation_date = 1st January of purchase year
                purchase_date = datetime.strptime(asset.purchase_date, '%Y-%m-%d')
                #if we already have some previous validated entries, starting date isn't 1st January but last entry + method period
                if (len(posted_depreciation_line_ids)>0):
                    last_depreciation_date = datetime.strptime(depreciation_lin_obj.browse(cr,uid,posted_depreciation_line_ids[0],context=context).depreciation_date, '%Y-%m-%d')
                    depreciation_date = (last_depreciation_date+relativedelta(months=+asset.method_period))
                else:
                    depreciation_date = datetime(purchase_date.year, 1, 1)
            day = depreciation_date.day
            month = depreciation_date.month
            year = depreciation_date.year
            total_days = (year % 4) and 365 or 366

            undone_dotation_number = self._compute_board_undone_dotation_nb(cr, uid, asset, depreciation_date, total_days, context=context)
            for x in range(len(posted_depreciation_line_ids), undone_dotation_number):
                i = x + 1
                amount = self._compute_board_amount(cr, uid, asset, i, residual_amount, amount_to_depr, undone_dotation_number, posted_depreciation_line_ids, total_days, depreciation_date, context=context)
                company_currency = asset.company_id.currency_id.id
                current_currency = asset.currency_id.id
                # compute amount into company currency
                amount = currency_obj.compute(cr, uid, current_currency, company_currency, amount, context=context)
                residual_amount -= amount
                vals = {
                     'amount': amount,
                     'asset_id': asset.id,
                     'sequence': i,
                     'name': str(asset.id) +'/' + str(i),
                     'remaining_value': residual_amount,
                     'depreciated_value': (asset.purchase_value - asset.salvage_value) - (residual_amount + amount),
                     'depreciation_date': depreciation_date.strftime('%Y-%m-%d'),
                }
                depreciation_lin_obj.create(cr, uid, vals, context=context)
                # Considering Depr. Period as months
                depreciation_date = (datetime(year, month, day) + relativedelta(months=+asset.method_period))
                day = depreciation_date.day
                month = depreciation_date.month
                year = depreciation_date.year
        return True

    def validate(self, cr, uid, ids, context=None):
        if context is None:
            context = {}
        return self.write(cr, uid, ids, {
            'state':'open'
        }, context)

    def set_to_close(self, cr, uid, ids, context=None):
        return self.write(cr, uid, ids, {'state': 'close'}, context=context)

    def set_to_draft(self, cr, uid, ids, context=None):
        return self.write(cr, uid, ids, {'state': 'draft'}, context=context)

    def _amount_residual(self, cr, uid, ids, name, args, context=None):
        cr.execute("""SELECT
                l.asset_id as id, SUM(abs(l.debit-l.credit)) AS amount
            FROM
                account_move_line l
            WHERE
                l.asset_id IN %s GROUP BY l.asset_id """, (tuple(ids),))
        res=dict(cr.fetchall())
        for asset in self.browse(cr, uid, ids, context):
            res[asset.id] = asset.purchase_value - res.get(asset.id, 0.0) - asset.salvage_value
        for id in ids:
            res.setdefault(id, 0.0)
        return res

    def onchange_company_id(self, cr, uid, ids, company_id=False, context=None):
        val = {}
        if company_id:
            company = self.pool.get('res.company').browse(cr, uid, company_id, context=context)
            if company.currency_id.company_id and company.currency_id.company_id.id != company_id:
                val['currency_id'] = False
            else:
                val['currency_id'] = company.currency_id.id
        return {'value': val}
    
    def onchange_purchase_salvage_value(self, cr, uid, ids, purchase_value, salvage_value, context=None):
        val = {}
        for asset in self.browse(cr, uid, ids, context=context):
            if purchase_value:
                val['value_residual'] = purchase_value - salvage_value
            if salvage_value:
                val['value_residual'] = purchase_value - salvage_value
        return {'value': val}    

    _columns = {
        'account_move_line_ids': fields.one2many('account.move.line', 'asset_id', 'Entries', readonly=True, states={'draft':[('readonly',False)]}),
        'name': fields.char('Asset Name', size=64, required=True, readonly=True, states={'draft':[('readonly',False)]}),
        'code': fields.char('Reference', size=32, readonly=True, states={'draft':[('readonly',False)]}),
        'purchase_value': fields.float('Gross Value', required=True, readonly=True, states={'draft':[('readonly',False)]}),
        'currency_id': fields.many2one('res.currency','Currency',required=True, readonly=True, states={'draft':[('readonly',False)]}),
        'company_id': fields.many2one('res.company', 'Company', required=True, readonly=True, states={'draft':[('readonly',False)]}),
        'note': fields.text('Note'),
        'category_id': fields.many2one('account.asset.category', 'Asset Category', required=True, change_default=True, readonly=True, states={'draft':[('readonly',False)]}),
        'parent_id': fields.many2one('account.asset.asset', 'Parent Asset', readonly=True, states={'draft':[('readonly',False)]}),
        'child_ids': fields.one2many('account.asset.asset', 'parent_id', 'Children Assets'),
        'purchase_date': fields.date('Purchase Date', required=True, readonly=True, states={'draft':[('readonly',False)]}),
        'state': fields.selection([('draft','Draft'),('open','Running'),('close','Close')], 'Status', required=True,
                                  help="When an asset is created, the status is 'Draft'.\n" \
                                       "If the asset is confirmed, the status goes in 'Running' and the depreciation lines can be posted in the accounting.\n" \
                                       "You can manually close an asset when the depreciation is over. If the last line of depreciation is posted, the asset automatically goes in that status."),
        'active': fields.boolean('Active'),
        'partner_id': fields.many2one('res.partner', 'Partner', readonly=True, states={'draft':[('readonly',False)]}),
        'method': fields.selection([('linear','Linear'),('degressive','Degressive')], 'Computation Method', required=True, readonly=True, states={'draft':[('readonly',False)]}, help="Choose the method to use to compute the amount of depreciation lines.\n"\
            "  * Linear: Calculated on basis of: Gross Value / Number of Depreciations\n" \
            "  * Degressive: Calculated on basis of: Residual Value * Degressive Factor"),
        'method_number': fields.integer('Number of Depreciations', readonly=True, states={'draft':[('readonly',False)]}, help="The number of depreciations needed to depreciate your asset"),
        'method_period': fields.integer('Number of Months in a Period', required=True, readonly=True, states={'draft':[('readonly',False)]}, help="The amount of time between two depreciations, in months"),
        'method_end': fields.date('Ending Date', readonly=True, states={'draft':[('readonly',False)]}),
        'method_progress_factor': fields.float('Degressive Factor', readonly=True, states={'draft':[('readonly',False)]}),
        'value_residual': fields.function(_amount_residual, method=True, digits_compute=dp.get_precision('Account'), string='Residual Value'),
        'method_time': fields.selection([('number','Number of Depreciations'),('end','Ending Date')], 'Time Method', required=True, readonly=True, states={'draft':[('readonly',False)]},
                                  help="Choose the method to use to compute the dates and number of depreciation lines.\n"\
                                       "  * Number of Depreciations: Fix the number of depreciation lines and the time between 2 depreciations.\n" \
                                       "  * Ending Date: Choose the time between 2 depreciations and the date the depreciations won't go beyond."),
        'prorata':fields.boolean('Prorata Temporis', readonly=True, states={'draft':[('readonly',False)]}, help='Indicates that the first depreciation entry for this asset have to be done from the purchase date instead of the first January'),
        'history_ids': fields.one2many('account.asset.history', 'asset_id', 'History', readonly=True),
        'depreciation_line_ids': fields.one2many('account.asset.depreciation.line', 'asset_id', 'Depreciation Lines', readonly=True, states={'draft':[('readonly',False)],'open':[('readonly',False)]}),
        'salvage_value': fields.float('Salvage Value', digits_compute=dp.get_precision('Account'), help="It is the amount you plan to have that you cannot depreciate.", readonly=True, states={'draft':[('readonly',False)]}),
    }
    _defaults = {
        'code': lambda obj, cr, uid, context: obj.pool.get('ir.sequence').get(cr, uid, 'account.asset.code'),
        'purchase_date': lambda obj, cr, uid, context: time.strftime('%Y-%m-%d'),
        'active': True,
        'state': 'draft',
        'method': 'linear',
        'method_number': 5,
        'method_time': 'number',
        'method_period': 12,
        'method_progress_factor': 0.3,
        'currency_id': lambda self,cr,uid,c: self.pool.get('res.users').browse(cr, uid, uid, c).company_id.currency_id.id,
        'company_id': lambda self, cr, uid, context: self.pool.get('res.company')._company_default_get(cr, uid, 'account.asset.asset',context=context),
    }

    def _check_recursion(self, cr, uid, ids, context=None, parent=None):
        return super(account_asset_asset, self)._check_recursion(cr, uid, ids, context=context, parent=parent)

    def _check_prorata(self, cr, uid, ids, context=None):
        for asset in self.browse(cr, uid, ids, context=context):
            if asset.prorata and asset.method_time != 'number':
                return False
        return True

    _constraints = [
        (_check_recursion, 'Error ! You cannot create recursive assets.', ['parent_id']),
        (_check_prorata, 'Prorata temporis can be applied only for time method "number of depreciations".', ['prorata']),
    ]

    def onchange_category_id(self, cr, uid, ids, category_id, context=None):
        res = {'value':{}}
        asset_categ_obj = self.pool.get('account.asset.category')
        if category_id:
            category_obj = asset_categ_obj.browse(cr, uid, category_id, context=context)
            res['value'] = {
                            'method': category_obj.method,
                            'method_number': category_obj.method_number,
                            'method_time': category_obj.method_time,
                            'method_period': category_obj.method_period,
                            'method_progress_factor': category_obj.method_progress_factor,
                            'method_end': category_obj.method_end,
                            'prorata': category_obj.prorata,
            }
        return res

    def onchange_method_time(self, cr, uid, ids, method_time='number', context=None):
        res = {'value': {}}
        if method_time != 'number':
            res['value'] = {'prorata': False}
        return res

    def copy(self, cr, uid, id, default=None, context=None):
        if default is None:
            default = {}
        if context is None:
            context = {}
        default.update({'depreciation_line_ids': [], 'state': 'draft'})
        return super(account_asset_asset, self).copy(cr, uid, id, default, context=context)

    def _compute_entries(self, cr, uid, ids, period_id, context=None):
        result = []
        period_obj = self.pool.get('account.period')
        depreciation_obj = self.pool.get('account.asset.depreciation.line')
        period = period_obj.browse(cr, uid, period_id, context=context)
        depreciation_ids = depreciation_obj.search(cr, uid, [('asset_id', 'in', ids), ('depreciation_date', '<=', period.date_stop), ('depreciation_date', '>=', period.date_start), ('move_check', '=', False)], context=context)
        if context is None:
            context = {}
        context.update({'depreciation_date':period.date_stop})
        return depreciation_obj.create_move(cr, uid, depreciation_ids, context=context)

    def create(self, cr, uid, vals, context=None):
        asset_id = super(account_asset_asset, self).create(cr, uid, vals, context=context)
        self.compute_depreciation_board(cr, uid, [asset_id], context=context)
        return asset_id
    
    def open_entries(self, cr, uid, ids, context=None):
        if context is None:
            context = {}
        context.update({'search_default_asset_id': ids, 'default_asset_id': ids})
        return {
            'name': _('Journal Items'),
            'view_type': 'form',
            'view_mode': 'tree,form',
            'res_model': 'account.move.line',
            'view_id': False,
            'type': 'ir.actions.act_window',
            'context': context,
        }


class account_asset_depreciation_line(osv.osv):
    _name = 'account.asset.depreciation.line'
    _description = 'Asset depreciation line'

    def _get_move_check(self, cr, uid, ids, name, args, context=None):
        res = {}
        for line in self.browse(cr, uid, ids, context=context):
            res[line.id] = bool(line.move_id)
        return res

    _columns = {
        'name': fields.char('Depreciation Name', size=64, required=True, select=1),
        'sequence': fields.integer('Sequence', required=True),
        'asset_id': fields.many2one('account.asset.asset', 'Asset', required=True, ondelete='cascade'),
        'parent_state': fields.related('asset_id', 'state', type='char', string='State of Asset'),
        'amount': fields.float('Current Depreciation', digits_compute=dp.get_precision('Account'), required=True),
        'remaining_value': fields.float('Next Period Depreciation', digits_compute=dp.get_precision('Account'),required=True),
        'depreciated_value': fields.float('Amount Already Depreciated', required=True),
        'depreciation_date': fields.date('Depreciation Date', select=1),
        'move_id': fields.many2one('account.move', 'Depreciation Entry'),
        'move_check': fields.function(_get_move_check, method=True, type='boolean', string='Posted', store=True)
    }

    def create_move(self, cr, uid, ids, context=None):
        can_close = False
        if context is None:
            context = {}
        asset_obj = self.pool.get('account.asset.asset')
        period_obj = self.pool.get('account.period')
        move_obj = self.pool.get('account.move')
        move_line_obj = self.pool.get('account.move.line')
        currency_obj = self.pool.get('res.currency')
        created_move_ids = []
        asset_ids = []
        for line in self.browse(cr, uid, ids, context=context):
            depreciation_date = context.get('depreciation_date') or time.strftime('%Y-%m-%d')
            period_ids = period_obj.find(cr, uid, depreciation_date, context=context)
            company_currency = line.asset_id.company_id.currency_id.id
            current_currency = line.asset_id.currency_id.id
            context.update({'date': depreciation_date})
            amount = currency_obj.compute(cr, uid, current_currency, company_currency, line.amount, context=context)
            sign = (line.asset_id.category_id.journal_id.type == 'purchase' and 1) or -1
            asset_name = line.asset_id.name
            reference = line.name
            move_vals = {
                'name': asset_name,
                'date': depreciation_date,
                'ref': reference,
                'period_id': period_ids and period_ids[0] or False,
                'journal_id': line.asset_id.category_id.journal_id.id,
                }
            move_id = move_obj.create(cr, uid, move_vals, context=context)
            journal_id = line.asset_id.category_id.journal_id.id
            partner_id = line.asset_id.partner_id.id
            move_line_obj.create(cr, uid, {
                'name': asset_name,
                'ref': reference,
                'move_id': move_id,
                'account_id': line.asset_id.category_id.account_depreciation_id.id,
                'debit': 0.0,
                'credit': amount,
                'period_id': period_ids and period_ids[0] or False,
                'journal_id': journal_id,
                'partner_id': partner_id,
                'currency_id': company_currency != current_currency and  current_currency or False,
                'amount_currency': company_currency != current_currency and - sign * line.amount or 0.0,
                'date': depreciation_date,
            })
            move_line_obj.create(cr, uid, {
                'name': asset_name,
                'ref': reference,
                'move_id': move_id,
                'account_id': line.asset_id.category_id.account_expense_depreciation_id.id,
                'credit': 0.0,
                'debit': amount,
                'period_id': period_ids and period_ids[0] or False,
                'journal_id': journal_id,
                'partner_id': partner_id,
                'currency_id': company_currency != current_currency and  current_currency or False,
                'amount_currency': company_currency != current_currency and sign * line.amount or 0.0,
                'analytic_account_id': line.asset_id.category_id.account_analytic_id.id,
                'date': depreciation_date,
                'asset_id': line.asset_id.id
            })
            self.write(cr, uid, line.id, {'move_id': move_id}, context=context)
            created_move_ids.append(move_id)
            asset_ids.append(line.asset_id.id)
        # we re-evaluate the assets to determine whether we can close them
        for asset in asset_obj.browse(cr, uid, list(set(asset_ids)), context=context):
            if currency_obj.is_zero(cr, uid, asset.currency_id, asset.value_residual):
                asset.write({'state': 'close'})
        return created_move_ids


class account_move_line(osv.osv):
    _inherit = 'account.move.line'
    _columns = {
        'asset_id': fields.many2one('account.asset.asset', 'Asset', ondelete="restrict"),
        'entry_ids': fields.one2many('account.move.line', 'asset_id', 'Entries', readonly=True, states={'draft':[('readonly',False)]}),

    }

class account_asset_history(osv.osv):
    _name = 'account.asset.history'
    _description = 'Asset history'
    _columns = {
        'name': fields.char('History name', size=64, select=1),
        'user_id': fields.many2one('res.users', 'User', required=True),
        'date': fields.date('Date', required=True),
        'asset_id': fields.many2one('account.asset.asset', 'Asset', required=True),
        'method_time': fields.selection([('number','Number of Depreciations'),('end','Ending Date')], 'Time Method', required=True,
                                  help="The method to use to compute the dates and number of depreciation lines.\n"\
                                       "Number of Depreciations: Fix the number of depreciation lines and the time between 2 depreciations.\n" \
                                       "Ending Date: Choose the time between 2 depreciations and the date the depreciations won't go beyond."),
        'method_number': fields.integer('Number of Depreciations', help="The number of depreciations needed to depreciate your asset"),
        'method_period': fields.integer('Period Length', help="Time in month between two depreciations"),
        'method_end': fields.date('Ending date'),
        'note': fields.text('Note'),
    }
    _order = 'date desc'
    _defaults = {
        'date': lambda *args: time.strftime('%Y-%m-%d'),
        'user_id': lambda self, cr, uid, ctx: uid
    }


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