# -*- 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 openerp
from openerp.osv import fields, osv
import openerp.service.model
from openerp.tools.translate import _
import time
from openerp import tools
from openerp import SUPERUSER_ID

class audittrail_rule(osv.osv):
    """
    For Auddittrail Rule
    """
    _name = 'audittrail.rule'
    _description = "Audittrail Rule"
    _columns = {
        "name": fields.char("Rule Name", size=32, required=True),
        "object_id": fields.many2one('ir.model', 'Object', required=True, help="Select object for which you want to generate log."),
        "user_id": fields.many2many('res.users', 'audittail_rules_users',
                                            'user_id', 'rule_id', 'Users', help="if  User is not added then it will applicable for all users"),
        "log_read": fields.boolean("Log Reads", help="Select this if you want to keep track of read/open on any record of the object of this rule"),
        "log_write": fields.boolean("Log Writes", help="Select this if you want to keep track of modification on any record of the object of this rule"),
        "log_unlink": fields.boolean("Log Deletes", help="Select this if you want to keep track of deletion on any record of the object of this rule"),
        "log_create": fields.boolean("Log Creates",help="Select this if you want to keep track of creation on any record of the object of this rule"),
        "log_action": fields.boolean("Log Action",help="Select this if you want to keep track of actions on the object of this rule"),
        "log_workflow": fields.boolean("Log Workflow",help="Select this if you want to keep track of workflow on any record of the object of this rule"),
        "state": fields.selection((("draft", "Draft"), ("subscribed", "Subscribed")), "Status", required=True),
        "action_id": fields.many2one('ir.actions.act_window', "Action ID"),
    }
    _defaults = {
        'state': 'draft',
        'log_create': 1,
        'log_unlink': 1,
        'log_write': 1,
    }
    _sql_constraints = [
        ('model_uniq', 'unique (object_id)', """There is already a rule defined on this object\n You cannot define another: please edit the existing one.""")
    ]
    __functions = {}

    def subscribe(self, cr, uid, ids, *args):
        """
        Subscribe Rule for auditing changes on object and apply shortcut for logs on that object.
        @param cr: the current row, from the database cursor,
        @param uid: the current user’s ID for security checks,
        @param ids: List of Auddittrail Rule’s IDs.
        @return: True
        """
        obj_action = self.pool.get('ir.actions.act_window')
        obj_model = self.pool.get('ir.model.data')
        #start Loop
        for thisrule in self.browse(cr, uid, ids):
            if thisrule.object_id.model not in self.pool:
                raise osv.except_osv(
                        _('WARNING: audittrail is not part of the pool'),
                        _('Change audittrail depends -- Setting rule as DRAFT'))
                self.write(cr, uid, [thisrule.id], {"state": "draft"})
            val = {
                 "name": 'View Log',
                 "res_model": 'audittrail.log',
                 "src_model": thisrule.object_id.model,
                 "domain": "[('object_id','=', " + str(thisrule.object_id.id) + "), ('res_id', '=', active_id)]"

            }
            action_id = obj_action.create(cr, SUPERUSER_ID, val)
            self.write(cr, uid, [thisrule.id], {"state": "subscribed", "action_id": action_id})
            keyword = 'client_action_relate'
            value = 'ir.actions.act_window,' + str(action_id)
            res = obj_model.ir_set(cr, SUPERUSER_ID, 'action', keyword, 'View_log_' + thisrule.object_id.model, [thisrule.object_id.model], value, replace=True, isobject=True, xml_id=False)
            #End Loop
        return True

    def unsubscribe(self, cr, uid, ids, *args):
        """
        Unsubscribe Auditing Rule on object
        @param cr: the current row, from the database cursor,
        @param uid: the current user’s ID for security checks,
        @param ids: List of Auddittrail Rule’s IDs.
        @return: True
        """
        obj_action = self.pool.get('ir.actions.act_window')
        ir_values_obj = self.pool.get('ir.values')
        value=''
        #start Loop
        for thisrule in self.browse(cr, uid, ids):
            if thisrule.id in self.__functions:
                for function in self.__functions[thisrule.id]:
                    setattr(function[0], function[1], function[2])
            w_id = obj_action.search(cr, uid, [('name', '=', 'View Log'), ('res_model', '=', 'audittrail.log'), ('src_model', '=', thisrule.object_id.model)])
            if w_id:
                obj_action.unlink(cr, SUPERUSER_ID, w_id)
                value = "ir.actions.act_window" + ',' + str(w_id[0])
            val_id = ir_values_obj.search(cr, uid, [('model', '=', thisrule.object_id.model), ('value', '=', value)])
            if val_id:
                res = ir_values_obj.unlink(cr, uid, [val_id[0]])
            self.write(cr, uid, [thisrule.id], {"state": "draft"})
        #End Loop
        return True

class audittrail_log(osv.osv):
    """
    For Audittrail Log
    """
    _name = 'audittrail.log'
    _description = "Audittrail Log"

    def _name_get_resname(self, cr, uid, ids, *args):
        data = {}
        for resname in self.browse(cr, uid, ids,[]):
            model_object = resname.object_id
            res_id = resname.res_id
            if model_object and res_id:
                model_pool = self.pool[model_object.model]
                res = model_pool.read(cr, uid, res_id, ['name'])
                data[resname.id] = res['name']
            else:
                 data[resname.id] = False
        return data

    _columns = {
        "name": fields.char("Resource Name",size=64),
        "object_id": fields.many2one('ir.model', 'Object'),
        "user_id": fields.many2one('res.users', 'User'),
        "method": fields.char("Method", size=64),
        "timestamp": fields.datetime("Date"),
        "res_id": fields.integer('Resource Id'),
        "line_ids": fields.one2many('audittrail.log.line', 'log_id', 'Log lines'),
    }

    _defaults = {
        "timestamp": lambda *a: time.strftime("%Y-%m-%d %H:%M:%S")
    }
    _order = "timestamp desc"

class audittrail_log_line(osv.osv):
    """
    Audittrail Log Line.
    """
    _name = 'audittrail.log.line'
    _description = "Log Line"
    _columns = {
          'field_id': fields.many2one('ir.model.fields', 'Fields', required=True),
          'log_id': fields.many2one('audittrail.log', 'Log'),
          'log': fields.integer("Log ID"),
          'old_value': fields.text("Old Value"),
          'new_value': fields.text("New Value"),
          'old_value_text': fields.text('Old value Text'),
          'new_value_text': fields.text('New value Text'),
          'field_description': fields.char('Field Description', size=64),
        }

# Monkeypatch the model RPC endpoint for auditing changes.

def get_value_text(cr, uid, pool, resource_pool, method, field, value):
    """
    Gets textual values for the fields.
        If the field is a many2one, it returns the name.
        If it's a one2many or a many2many, it returns a list of name.
        In other cases, it just returns the value.
    :param cr: the current row, from the database cursor,
    :param uid: the current user’s ID for security checks,
    :param pool: current db's pooler object.
    :param resource_pool: pooler object of the model which values are being changed.
    :param field: for which the text value is to be returned.
    :param value: value of the field.
    :param recursive: True or False, True will repeat the process recursively
    :return: string value or a list of values(for O2M/M2M)
    """

    field_obj = (resource_pool._all_columns.get(field)).column
    if field_obj._type in ('one2many','many2many'):
        data = pool[field_obj._obj].name_get(cr, uid, value)
        #return the modifications on x2many fields as a list of names
        res = map(lambda x:x[1], data)
    elif field_obj._type == 'many2one':
        #return the modifications on a many2one field as its value returned by name_get()
        res = value and value[1] or value
    else:
        res = value
    return res

def create_log_line(cr, uid, log_id, model, lines=None):
    """
    Creates lines for changed fields with its old and new values

    @param cr: the current row, from the database cursor,
    @param uid: the current user’s ID for security checks,
    @param model: Object which values are being changed
    @param lines: List of values for line is to be created
    """
    if lines is None:
        lines = []
    pool = openerp.registry(cr.dbname)
    obj_pool = pool[model.model]
    model_pool = pool.get('ir.model')
    field_pool = pool.get('ir.model.fields')
    log_line_pool = pool.get('audittrail.log.line')
    for line in lines:
        field_obj = obj_pool._all_columns.get(line['name'])
        assert field_obj, _("'%s' field does not exist in '%s' model" %(line['name'], model.model))
        field_obj = field_obj.column
        old_value = line.get('old_value', '')
        new_value = line.get('new_value', '')
        search_models = [model.id]
        if obj_pool._inherits:
            search_models += model_pool.search(cr, uid, [('model', 'in', obj_pool._inherits.keys())])
        field_id = field_pool.search(cr, uid, [('name', '=', line['name']), ('model_id', 'in', search_models)])
        if field_obj._type == 'many2one':
            old_value = old_value and old_value[0] or old_value
            new_value = new_value and new_value[0] or new_value
        vals = {
                "log_id": log_id,
                "field_id": field_id and field_id[0] or False,
                "old_value": old_value,
                "new_value": new_value,
                "old_value_text": line.get('old_value_text', ''),
                "new_value_text": line.get('new_value_text', ''),
                "field_description": field_obj.string
                }
        line_id = log_line_pool.create(cr, uid, vals)
    return True

def log_fct(cr, uid_orig, model, method, fct_src, *args, **kw):
    """
    Logging function: This function is performing the logging operation
    @param model: Object whose values are being changed
    @param method: method to log: create, read, write, unlink, action or workflow action
    @param fct_src: execute method of Object proxy

    @return: Returns result as per method of Object proxy
    """
    pool = openerp.registry(cr.dbname)
    resource_pool = pool[model]
    model_pool = pool.get('ir.model')
    model_ids = model_pool.search(cr, SUPERUSER_ID, [('model', '=', model)])
    model_id = model_ids and model_ids[0] or False
    assert model_id, _("'%s' Model does not exist..." %(model))
    model = model_pool.browse(cr, SUPERUSER_ID, model_id)

    # fields to log. currently only used by log on read()
    field_list = []
    old_values = new_values = {}

    if method == 'create':
        res = fct_src(cr, uid_orig, model.model, method, *args, **kw)
        if res:
            res_ids = [res]
            new_values = get_data(cr, uid_orig, pool, res_ids, model, method)
    elif method == 'read':
        res = fct_src(cr, uid_orig, model.model, method, *args, **kw)
        if isinstance(res, dict):
            records = [res]
        else:
            records = res
        # build the res_ids and the old_values dict. Here we don't use get_data() to
        # avoid performing an additional read()
        res_ids = []
        for record in records:
            res_ids.append(record['id'])
            old_values[(model.id, record['id'])] = {'value': record, 'text': record}
        # log only the fields read
        field_list = args[1]
    elif method == 'unlink':
        res_ids = args[0]
        old_values = get_data(cr, uid_orig, pool, res_ids, model, method)
        # process_data first as fct_src will unlink the record
        self.process_data(cr, uid_orig, pool, res_ids, model, method, old_values, new_values, field_list)
        return fct_src(cr, uid_orig, model.model, method, *args, **kw)
    else: # method is write, action or workflow action
        res_ids = []
        if args:
            res_ids = args[0]
            if isinstance(res_ids, (long, int)):
                res_ids = [res_ids]
        if res_ids:
            # store the old values into a dictionary
            old_values = get_data(cr, uid_orig, pool, res_ids, model, method)
        # process the original function, workflow trigger...
        res = fct_src(cr, uid_orig, model.model, method, *args, **kw)
        if method == 'copy':
            res_ids = [res]
        if res_ids:
            # check the new values and store them into a dictionary
            new_values = get_data(cr, uid_orig, pool, res_ids, model, method)
    # compare the old and new values and create audittrail log if needed
    process_data(cr, uid_orig, pool, res_ids, model, method, old_values, new_values, field_list)
    return res

def get_data(cr, uid, pool, res_ids, model, method):
    """
    This function simply read all the fields of the given res_ids, and also recurisvely on
    all records of a x2m fields read that need to be logged. Then it returns the result in
    convenient structure that will be used as comparison basis.

        :param cr: the current row, from the database cursor,
        :param uid: the current user’s ID. This parameter is currently not used as every
            operation to get data is made as super admin. Though, it could be usefull later.
        :param pool: current db's pooler object.
        :param res_ids: Id's of resource to be logged/compared.
        :param model: Object whose values are being changed
        :param method: method to log: create, read, unlink, write, actions, workflow actions
        :return: dict mapping a tuple (model_id, resource_id) with its value and textual value
            { (model_id, resource_id): { 'value': ...
                                         'textual_value': ...
                                       },
            }
    """
    data = {}
    resource_pool = pool[model.model]
    # read all the fields of the given resources in super admin mode
    for resource in resource_pool.read(cr, SUPERUSER_ID, res_ids, resource_pool._all_columns):
        values = {}
        values_text = {}
        resource_id = resource['id']
        # loop on each field on the res_ids we just have read
        for field in resource:
            if field in ('__last_update', 'id'):
                continue
            values[field] = resource[field]
            # get the textual value of that field for this record
            values_text[field] = get_value_text(cr, SUPERUSER_ID, pool, resource_pool, method, field, resource[field])

            field_obj = resource_pool._all_columns.get(field).column
            if field_obj._type in ('one2many','many2many'):
                # check if an audittrail rule apply in super admin mode
                if check_rules(cr, SUPERUSER_ID, field_obj._obj, method):
                    # check if the model associated to a *2m field exists, in super admin mode
                    x2m_model_ids = pool.get('ir.model').search(cr, SUPERUSER_ID, [('model', '=', field_obj._obj)])
                    x2m_model_id = x2m_model_ids and x2m_model_ids[0] or False
                    assert x2m_model_id, _("'%s' Model does not exist..." %(field_obj._obj))
                    x2m_model = pool.get('ir.model').browse(cr, SUPERUSER_ID, x2m_model_id)
                    field_resource_ids = list(set(resource[field]))
                    if model.model == x2m_model.model:
                        # we need to remove current resource_id from the many2many to prevent an infinit loop
                        if resource_id in field_resource_ids:
                            field_resource_ids.remove(resource_id)
                    data.update(get_data(cr, SUPERUSER_ID, pool, field_resource_ids, x2m_model, method))

        data[(model.id, resource_id)] = {'text':values_text, 'value': values}
    return data

def prepare_audittrail_log_line(cr, uid, pool, model, resource_id, method, old_values, new_values, field_list=None):
    """
    This function compares the old data (i.e before the method was executed) and the new data
    (after the method was executed) and returns a structure with all the needed information to
    log those differences.

    :param cr: the current row, from the database cursor,
    :param uid: the current user’s ID. This parameter is currently not used as every
        operation to get data is made as super admin. Though, it could be usefull later.
    :param pool: current db's pooler object.
    :param model: model object which values are being changed
    :param resource_id: ID of record to which values are being changed
    :param method: method to log: create, read, unlink, write, actions, workflow actions
    :param old_values: dict of values read before execution of the method
    :param new_values: dict of values read after execution of the method
    :param field_list: optional argument containing the list of fields to log. Currently only
        used when performing a read, it could be usefull later on if we want to log the write
        on specific fields only.

    :return: dictionary with
        * keys: tuples build as ID of model object to log and ID of resource to log
        * values: list of all the changes in field values for this couple (model, resource)
          return {
            (model.id, resource_id): []
          }

    The reason why the structure returned is build as above is because when modifying an existing
    record, we may have to log a change done in a x2many field of that object
    """
    if field_list is None:
        field_list = []
    key = (model.id, resource_id)
    lines = {
        key: []
    }
    # loop on all the fields
    for field_name, field_definition in pool[model.model]._all_columns.items():
        if field_name in ('__last_update', 'id'):
            continue
        #if the field_list param is given, skip all the fields not in that list
        if field_list and field_name not in field_list:
            continue
        field_obj = field_definition.column
        if field_obj._type in ('one2many','many2many'):
            # checking if an audittrail rule apply in super admin mode
            if check_rules(cr, SUPERUSER_ID, field_obj._obj, method):
                # checking if the model associated to a *2m field exists, in super admin mode
                x2m_model_ids = pool.get('ir.model').search(cr, SUPERUSER_ID, [('model', '=', field_obj._obj)])
                x2m_model_id = x2m_model_ids and x2m_model_ids[0] or False
                assert x2m_model_id, _("'%s' Model does not exist..." %(field_obj._obj))
                x2m_model = pool.get('ir.model').browse(cr, SUPERUSER_ID, x2m_model_id)
                # the resource_ids that need to be checked are the sum of both old and previous values (because we
                # need to log also creation or deletion in those lists).
                x2m_old_values_ids = old_values.get(key, {'value': {}})['value'].get(field_name, [])
                x2m_new_values_ids = new_values.get(key, {'value': {}})['value'].get(field_name, [])
                # We use list(set(...)) to remove duplicates.
                res_ids = list(set(x2m_old_values_ids + x2m_new_values_ids))
                if model.model == x2m_model.model:
                    # we need to remove current resource_id from the many2many to prevent an infinit loop
                    if resource_id in res_ids:
                        res_ids.remove(resource_id)
                for res_id in res_ids:
                    lines.update(prepare_audittrail_log_line(cr, SUPERUSER_ID, pool, x2m_model, res_id, method, old_values, new_values, field_list))
        # if the value value is different than the old value: record the change
        if key not in old_values or key not in new_values or old_values[key]['value'][field_name] != new_values[key]['value'][field_name]:
            data = {
                  'name': field_name,
                  'new_value': key in new_values and new_values[key]['value'].get(field_name),
                  'old_value': key in old_values and old_values[key]['value'].get(field_name),
                  'new_value_text': key in new_values and new_values[key]['text'].get(field_name),
                  'old_value_text': key in old_values and old_values[key]['text'].get(field_name)
            }
            lines[key].append(data)
    return lines

def process_data(cr, uid, pool, res_ids, model, method, old_values=None, new_values=None, field_list=None):
    """
    This function processes and iterates recursively to log the difference between the old
    data (i.e before the method was executed) and the new data and creates audittrail log
    accordingly.

    :param cr: the current row, from the database cursor,
    :param uid: the current user’s ID,
    :param pool: current db's pooler object.
    :param res_ids: Id's of resource to be logged/compared.
    :param model: model object which values are being changed
    :param method: method to log: create, read, unlink, write, actions, workflow actions
    :param old_values: dict of values read before execution of the method
    :param new_values: dict of values read after execution of the method
    :param field_list: optional argument containing the list of fields to log. Currently only
        used when performing a read, it could be usefull later on if we want to log the write
        on specific fields only.
    :return: True
    """
    if field_list is None:
        field_list = []
    # loop on all the given ids
    for res_id in res_ids:
        # compare old and new values and get audittrail log lines accordingly
        lines = prepare_audittrail_log_line(cr, uid, pool, model, res_id, method, old_values, new_values, field_list)

        # if at least one modification has been found
        for model_id, resource_id in lines:
            line_model = pool.get('ir.model').browse(cr, SUPERUSER_ID, model_id).model

            vals = {
                'method': method,
                'object_id': model_id,
                'user_id': uid,
                'res_id': resource_id,
            }
            if (model_id, resource_id) not in old_values and method not in ('copy', 'read'):
                # the resource was not existing so we are forcing the method to 'create'
                # (because it could also come with the value 'write' if we are creating
                #  new record through a one2many field)
                vals.update({'method': 'create'})
            if (model_id, resource_id) not in new_values and method not in ('copy', 'read'):
                # the resource is not existing anymore so we are forcing the method to 'unlink'
                # (because it could also come with the value 'write' if we are deleting the
                #  record through a one2many field)
                name = old_values[(model_id, resource_id)]['value'].get('name',False)
                vals.update({'method': 'unlink'})
            else :
                name = pool[line_model].name_get(cr, uid, [resource_id])[0][1]
            vals.update({'name': name})
            # create the audittrail log in super admin mode, only if a change has been detected
            if lines[(model_id, resource_id)]:
                log_id = pool.get('audittrail.log').create(cr, SUPERUSER_ID, vals)
                model = pool.get('ir.model').browse(cr, uid, model_id)
                create_log_line(cr, SUPERUSER_ID, log_id, model, lines[(model_id, resource_id)])
    return True

def check_rules(cr, uid, model, method):
    """
    Checks if auditrails is installed for that db and then if one rule match
    @param cr: the current row, from the database cursor,
    @param uid: the current user’s ID,
    @param model: value of _name of the object which values are being changed
    @param method: method to log: create, read, unlink,write,actions,workflow actions
    @return: True or False
    """
    pool = openerp.registry(cr.dbname)
    if 'audittrail.rule' in pool.models:
        model_ids = pool.get('ir.model').search(cr, SUPERUSER_ID, [('model', '=', model)])
        model_id = model_ids and model_ids[0] or False
        if model_id:
            rule_ids = pool.get('audittrail.rule').search(cr, SUPERUSER_ID, [('object_id', '=', model_id), ('state', '=', 'subscribed')])
            for rule in pool.get('audittrail.rule').read(cr, SUPERUSER_ID, rule_ids, ['user_id','log_read','log_write','log_create','log_unlink','log_action','log_workflow']):
                if len(rule['user_id']) == 0 or uid in rule['user_id']:
                    if rule.get('log_'+method,0):
                        return True
                    elif method not in ('default_get','read','fields_view_get','fields_get','search','search_count','name_search','name_get','get','request_get', 'get_sc', 'unlink', 'write', 'create', 'read_group', 'import_data'):
                        if rule['log_action']:
                            return True

# Replace the openerp.service.model functions.

original_execute_cr = openerp.service.model.execute_cr
original_exec_workflow_cr = openerp.service.model.exec_workflow_cr

def execute_cr(cr, uid, model, method, *args, **kw):
    fct_src = original_execute_cr
    if check_rules(cr,uid,model,method):
        return log_fct(cr, uid, model, method, fct_src, *args, **kw)
    return fct_src(cr, uid, model, method, *args, **kw)

def exec_workflow_cr(cr, uid, model, method, *args, **kw):
    fct_src = original_exec_workflow_cr
    if check_rules(cr,uid,model,'workflow'):
        return log_fct(cr, uid, model, method, fct_src, *args, **kw)
    return fct_src(cr, uid, model, method, *args, **kw)

openerp.service.model.execute_cr = execute_cr
openerp.service.model.exec_workflow_cr = exec_workflow_cr

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