# -*- encoding: utf-8 -*-
##############################################################################
#
#    OpenERP, Open Source Management Solution
#    Copyright (C) 2004-TODAY OpenERP S.A. <http://www.openerp.com>
#
#    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/>.
#
##############################################################################

from openerp.osv import fields, osv
from openerp.tools.translate import _
from openerp.tools import DEFAULT_SERVER_DATETIME_FORMAT as DF
from openerp.addons.website.models.website import slug
from urlparse import urljoin
from itertools import product
from collections import Counter

import datetime
import logging
import re
import uuid

_logger = logging.getLogger(__name__)

class survey_stage(osv.Model):
    """Stages for Kanban view of surveys"""

    _name = 'survey.stage'
    _description = 'Survey Stage'
    _order = 'sequence asc'

    _columns = {
        'name': fields.char(string="Name", required=True, translate=True),
        'sequence': fields.integer(string="Sequence"),
        'closed': fields.boolean(string="Closed", help="If closed, people won't be able to answer to surveys in this column."),
        'fold': fields.boolean(string="Folded in kanban view")
    }
    _defaults = {
        'sequence': 1,
        'closed': False
    }
    _sql_constraints = [
        ('positive_sequence', 'CHECK(sequence >= 0)', 'Sequence number MUST be a natural')
    ]


class survey_survey(osv.Model):
    '''Settings for a multi-page/multi-question survey.
    Each survey can have one or more attached pages, and each page can display
    one or more questions.
    '''

    _name = 'survey.survey'
    _description = 'Survey'
    _rec_name = 'title'
    _inherit = ['mail.thread', 'ir.needaction_mixin']

    # Protected methods #

    def _has_questions(self, cr, uid, ids, context=None):
        """ Ensure that this survey has at least one page with at least one
        question. """
        for survey in self.browse(cr, uid, ids, context=context):
            if not survey.page_ids or not [page.question_ids
                            for page in survey.page_ids if page.question_ids]:
                return False
        return True

    ## Function fields ##

    def _is_designed(self, cr, uid, ids, name, arg, context=None):
        res = dict()
        for survey in self.browse(cr, uid, ids, context=context):
            if not survey.page_ids or not [page.question_ids
                            for page in survey.page_ids if page.question_ids]:
                res[survey.id] = False
            else:
                res[survey.id] = True
        return res

    def _get_tot_sent_survey(self, cr, uid, ids, name, arg, context=None):
        """ Returns the number of invitations sent for this survey, be they
        (partially) completed or not """
        res = dict((id, 0) for id in ids)
        sur_res_obj = self.pool.get('survey.user_input')
        for id in ids:
            res[id] = sur_res_obj.search(cr, uid,  # SUPERUSER_ID,
                [('survey_id', '=', id), ('type', '=', 'link')],
                context=context, count=True)
        return res

    def _get_tot_start_survey(self, cr, uid, ids, name, arg, context=None):
        """ Returns the number of started instances of this survey, be they
        completed or not """
        res = dict((id, 0) for id in ids)
        sur_res_obj = self.pool.get('survey.user_input')
        for id in ids:
            res[id] = sur_res_obj.search(cr, uid,  # SUPERUSER_ID,
                ['&', ('survey_id', '=', id), '|', ('state', '=', 'skip'), ('state', '=', 'done')],
                context=context, count=True)
        return res

    def _get_tot_comp_survey(self, cr, uid, ids, name, arg, context=None):
        """ Returns the number of completed instances of this survey """
        res = dict((id, 0) for id in ids)
        sur_res_obj = self.pool.get('survey.user_input')
        for id in ids:
            res[id] = sur_res_obj.search(cr, uid,  # SUPERUSER_ID,
                [('survey_id', '=', id), ('state', '=', 'done')],
                context=context, count=True)
        return res

    def _get_public_url(self, cr, uid, ids, name, arg, context=None):
        """ Computes a public URL for the survey """
        base_url = self.pool.get('ir.config_parameter').get_param(cr, uid,
            'web.base.url')
        res = {}
        for survey in self.browse(cr, uid, ids, context=context):
            res[survey.id] = urljoin(base_url, "survey/start/%s" % slug(survey))
        return res

    def _get_public_url_html(self, cr, uid, ids, name, arg, context=None):
        """ Computes a public URL for the survey (html-embeddable version)"""
        urls = self._get_public_url(cr, uid, ids, name, arg, context=context)
        for id, url in urls.iteritems():
            urls[id] = '<a href="%s">%s</a>' % (url, _("Click here to start survey"))
        return urls

    def _get_print_url(self, cr, uid, ids, name, arg, context=None):
        """ Computes a printing URL for the survey """
        base_url = self.pool.get('ir.config_parameter').get_param(cr, uid,
            'web.base.url')
        res = {}
        for survey in self.browse(cr, uid, ids, context=context):
            res[survey.id] = urljoin(base_url, "survey/print/%s" % slug(survey))
        return res

    def _get_result_url(self, cr, uid, ids, name, arg, context=None):
        """ Computes an URL for the survey results """
        base_url = self.pool.get('ir.config_parameter').get_param(cr, uid,
            'web.base.url')
        res = {}
        for survey in self.browse(cr, uid, ids, context=context):
            res[survey.id] = urljoin(base_url, "survey/results/%s" % slug(survey))
        return res

    # Model fields #

    _columns = {
        'title': fields.char('Title', required=1, translate=True),
        'res_model': fields.char('Category'),
        'page_ids': fields.one2many('survey.page', 'survey_id', 'Pages'),
        'stage_id': fields.many2one('survey.stage', string="Stage", ondelete="set null"),
        'auth_required': fields.boolean('Login required',
            help="Users with a public link will be requested to login before taking part to the survey",
            oldname="authenticate"),
        'users_can_go_back': fields.boolean('Users can go back',
            help="If checked, users can go back to previous pages."),
        'tot_sent_survey': fields.function(_get_tot_sent_survey,
            string="Number of sent surveys", type="integer"),
        'tot_start_survey': fields.function(_get_tot_start_survey,
            string="Number of started surveys", type="integer"),
        'tot_comp_survey': fields.function(_get_tot_comp_survey,
            string="Number of completed surveys", type="integer"),
        'description': fields.html('Description', translate=True,
            oldname="description", help="A long description of the purpose of the survey"),
        'color': fields.integer('Color Index'),
        'user_input_ids': fields.one2many('survey.user_input', 'survey_id',
            'User responses', readonly=1),
        'designed': fields.function(_is_designed, string="Is designed?",
            type="boolean"),
        'public_url': fields.function(_get_public_url,
            string="Public link", type="char"),
        'public_url_html': fields.function(_get_public_url_html,
            string="Public link (html version)", type="char"),
        'print_url': fields.function(_get_print_url,
            string="Print link", type="char"),
        'result_url': fields.function(_get_result_url,
            string="Results link", type="char"),
        'email_template_id': fields.many2one('email.template',
            'Email Template', ondelete='set null'),
        'thank_you_message': fields.html('Thank you message', translate=True,
            help="This message will be displayed when survey is completed"),
        'quizz_mode': fields.boolean(string='Quizz mode')
    }

    def _default_stage(self, cr, uid, context=None):
        ids = self.pool['survey.stage'].search(cr, uid, [], limit=1, context=context)
        if ids:
            return ids[0]
        return False

    _defaults = {
        'color': 0,
        'stage_id': lambda self, *a, **kw: self._default_stage(*a, **kw)
    }

    def _read_group_stage_ids(self, cr, uid, ids, domain, read_group_order=None, access_rights_uid=None, context=None):
        """ Read group customization in order to display all the stages in the
        kanban view, even if they are empty """
        stage_obj = self.pool.get('survey.stage')
        order = stage_obj._order
        access_rights_uid = access_rights_uid or uid

        if read_group_order == 'stage_id desc':
            order = '%s desc' % order

        stage_ids = stage_obj._search(cr, uid, [], order=order, access_rights_uid=access_rights_uid, context=context)
        result = stage_obj.name_get(cr, access_rights_uid, stage_ids, context=context)

        # restore order of the search
        result.sort(lambda x, y: cmp(stage_ids.index(x[0]), stage_ids.index(y[0])))

        fold = {}
        for stage in stage_obj.browse(cr, access_rights_uid, stage_ids, context=context):
            fold[stage.id] = stage.fold or False
        return result, fold

    _group_by_full = {
        'stage_id': _read_group_stage_ids
    }

    # Public methods #

    def copy_data(self, cr, uid, id, default=None, context=None):
        vals = dict()
        current_rec = self.read(cr, uid, id, fields=['title'], context=context)
        title = _("%s (copy)") % (current_rec.get('title'))
        vals['title'] = title
        vals['user_input_ids'] = []
        return super(survey_survey, self).copy_data(cr, uid, id, default=vals,
            context=context)

    def next_page(self, cr, uid, user_input, page_id, go_back=False, context=None):
        '''The next page to display to the user, knowing that page_id is the id
        of the last displayed page.

        If page_id == 0, it will always return the first page of the survey.

        If all the pages have been displayed and go_back == False, it will
        return None

        If go_back == True, it will return the *previous* page instead of the
        next page.

        .. note::
            It is assumed here that a careful user will not try to set go_back
            to True if she knows that the page to display is the first one!
            (doing this will probably cause a giant worm to eat her house)'''
        survey = user_input.survey_id
        pages = list(enumerate(survey.page_ids))

        # First page
        if page_id == 0:
            return (pages[0][1], 0, len(pages) == 1)

        current_page_index = pages.index((filter(lambda p: p[1].id == page_id, pages))[0])

        # All the pages have been displayed
        if current_page_index == len(pages) - 1 and not go_back:
            return (None, -1, False)
        # Let's get back, baby!
        elif go_back and survey.users_can_go_back:
            return (pages[current_page_index - 1][1], current_page_index - 1, False)
        else:
            # This will show the last page
            if current_page_index == len(pages) - 2:
                return (pages[current_page_index + 1][1], current_page_index + 1, True)
            # This will show a regular page
            else:
                return (pages[current_page_index + 1][1], current_page_index + 1, False)

    def filter_input_ids(self, cr, uid, filters, finished=False, context=None):
        '''If user applies any filters, then this function returns list of
           filtered user_input_id and label's strings for display data in web.
           :param filters: list of dictionary (having: row_id, ansewr_id)
           :param finished: True for completely filled survey,Falser otherwise.
           :returns list of filtered user_input_ids.
        '''
        if context is None:
            context = {}
        if filters:
            input_line_obj = self.pool.get('survey.user_input_line')
            domain_filter, choice, filter_display_data = [], [], []
            for filter in filters:
                row_id, answer_id = filter['row_id'], filter['answer_id']
                if row_id == 0:
                    choice.append(answer_id)
                else:
                    domain_filter.extend(['|', ('value_suggested_row.id', '=', row_id), ('value_suggested.id', '=', answer_id)])
            if choice:
                domain_filter.insert(0, ('value_suggested.id', 'in', choice))
            else:
                domain_filter = domain_filter[1:]
            line_ids = input_line_obj.search(cr, uid, domain_filter, context=context)
            filtered_input_ids = [input.user_input_id.id for input in input_line_obj.browse(cr, uid, line_ids, context=context)]
        else:
            filtered_input_ids, filter_display_data = [], []
        if finished:
            user_input = self.pool.get('survey.user_input')
            if not filtered_input_ids:
                current_filters = user_input.search(cr, uid, [], context=context)
                user_input_objs = user_input.browse(cr, uid, current_filters, context=context)
            else:
                user_input_objs = user_input.browse(cr, uid, filtered_input_ids, context=context)
            return [input.id for input in user_input_objs if input.state == 'done']
        return filtered_input_ids

    def get_filter_display_data(self, cr, uid, filters, context):
        '''Returns data to display current filters
        :param filters: list of dictionary (having: row_id, answer_id)
        :param finished: True for completely filled survey, False otherwise.
        :returns list of dict having data to display filters.
        '''
        filter_display_data = []
        if filters:
            question_obj = self.pool.get('survey.question')
            label_obj = self.pool.get('survey.label')
            for filter in filters:
                row_id, answer_id = filter['row_id'], filter['answer_id']
                question_id = label_obj.browse(cr, uid, answer_id, context=context).question_id.id
                question = question_obj.browse(cr, uid, question_id, context=context)
                if row_id == 0:
                    labels = label_obj.browse(cr, uid, [answer_id], context=context)
                else:
                    labels = label_obj.browse(cr, uid, [row_id, answer_id], context=context)
                filter_display_data.append({'question_text': question.question, 'labels': [label.value for label in labels]})
        return filter_display_data

    def prepare_result(self, cr, uid, question, current_filters=[], context=None):
        ''' Compute statistical data for questions by counting number of vote per choice on basis of filter '''
        if context is None:
            context = {}
        #Calculate and return statistics for choice
        if question.type in ['simple_choice', 'multiple_choice']:
            result_summary = {}
            [result_summary.update({label.id: {'text': label.value, 'count': 0, 'answer_id': label.id}}) for label in question.labels_ids]
            for input_line in question.user_input_line_ids:
                if input_line.answer_type == 'suggestion' and result_summary.get(input_line.value_suggested.id) and (not(current_filters) or input_line.user_input_id.id in current_filters):
                    result_summary[input_line.value_suggested.id]['count'] += 1
            result_summary = result_summary.values()

        #Calculate and return statistics for matrix
        if question.type == 'matrix':
            rows, answers, res = {}, {}, {}
            [rows.update({label.id: label.value}) for label in question.labels_ids_2]
            [answers.update({label.id: label.value}) for label in question.labels_ids]
            for cell in product(rows.keys(), answers.keys()):
                res[cell] = 0
            for input_line in question.user_input_line_ids:
                if input_line.answer_type == 'suggestion' and not(current_filters) or input_line.user_input_id.id in current_filters:
                    res[(input_line.value_suggested_row.id, input_line.value_suggested.id)] += 1
            result_summary = {'answers': answers, 'rows': rows, 'result': res}

        #Calculate and return statistics for free_text, textbox, datetime
        if question.type in ['free_text', 'textbox', 'datetime']:
            result_summary = []
            for input_line in question.user_input_line_ids:
                if not(current_filters) or input_line.user_input_id.id in current_filters:
                    result_summary.append(input_line)

        #Calculate and return statistics for numerical_box
        if question.type == 'numerical_box':
            result_summary = {'input_lines': []}
            all_inputs = []
            for input_line in question.user_input_line_ids:
                if not(current_filters) or input_line.user_input_id.id in current_filters:
                    all_inputs.append(input_line.value_number)
                    result_summary['input_lines'].append(input_line)
            if all_inputs:
                result_summary.update({'average': round(sum(all_inputs) / len(all_inputs), 2),
                                       'max': round(max(all_inputs), 2),
                                       'min': round(min(all_inputs), 2),
                                       'most_comman': Counter(all_inputs).most_common(5)})
        return result_summary

    def get_input_summary(self, cr, uid, question, current_filters=[], context=None):
        ''' Returns overall summary of question e.g. answered, skipped, total_inputs on basis of filter '''
        if context is None:
            context = {}
        result = {}
        if question.survey_id.user_input_ids:
            total_input_ids = current_filters or [input_id.id for input_id in question.survey_id.user_input_ids if input_id.state != 'new']
            result['total_inputs'] = len(total_input_ids)
            question_input_ids = []
            for user_input in question.user_input_line_ids:
                if not user_input.skipped:
                    question_input_ids.append(user_input.user_input_id.id)
            result['answered'] = len(set(question_input_ids) & set(total_input_ids))
            result['skipped'] = result['total_inputs'] - result['answered']
        return result

    # Actions

    def action_start_survey(self, cr, uid, ids, context=None):
        ''' Open the website page with the survey form '''
        trail = ""
        if context and 'survey_token' in context:
            trail = "/" + context['survey_token']
        return {
            'type': 'ir.actions.act_url',
            'name': "Start Survey",
            'target': 'self',
            'url': self.read(cr, uid, ids, ['public_url'], context=context)[0]['public_url'] + trail
        }

    def action_send_survey(self, cr, uid, ids, context=None):
        ''' Open a window to compose an email, pre-filled with the survey
        message '''
        if not self._has_questions(cr, uid, ids, context=None):
            raise osv.except_osv(_('Error!'), _('You cannot send an invitation for a survey that has no questions.'))

        survey_browse = self.pool.get('survey.survey').browse(cr, uid, ids,
            context=context)[0]
        if survey_browse.stage_id.closed:
            raise osv.except_osv(_('Warning!'),
                _("You cannot send invitations for closed surveys."))

        assert len(ids) == 1, 'This option should only be used for a single \
                                survey at a time.'
        ir_model_data = self.pool.get('ir.model.data')
        templates = ir_model_data.get_object_reference(cr, uid,
                                'survey', 'email_template_survey')
        template_id = templates[1] if len(templates) > 0 else False
        ctx = dict(context)

        ctx.update({'default_model': 'survey.survey',
                    'default_res_id': ids[0],
                    'default_survey_id': ids[0],
                    'default_use_template': bool(template_id),
                    'default_template_id': template_id,
                    'default_composition_mode': 'comment'}
                   )
        return {
            'type': 'ir.actions.act_window',
            'view_type': 'form',
            'view_mode': 'form',
            'res_model': 'survey.mail.compose.message',
            'target': 'new',
            'context': ctx,
        }

    def action_print_survey(self, cr, uid, ids, context=None):
        ''' Open the website page with the survey printable view '''
        trail = ""
        if context and 'survey_token' in context:
            trail = "/" + context['survey_token']
        return {
            'type': 'ir.actions.act_url',
            'name': "Print Survey",
            'target': 'self',
            'url': self.read(cr, uid, ids, ['print_url'], context=context)[0]['print_url'] + trail
        }

    def action_result_survey(self, cr, uid, ids, context=None):
        ''' Open the website page with the survey results view '''
        return {
            'type': 'ir.actions.act_url',
            'name': "Results of the Survey",
            'target': 'self',
            'url': self.read(cr, uid, ids, ['result_url'], context=context)[0]['result_url']
        }

    def action_test_survey(self, cr, uid, ids, context=None):
        ''' Open the website page with the survey form into test mode'''
        return {
            'type': 'ir.actions.act_url',
            'name': "Results of the Survey",
            'target': 'self',
            'url': self.read(cr, uid, ids, ['public_url'], context=context)[0]['public_url'] + "/phantom"
        }




class survey_page(osv.Model):
    '''A page for a survey.

    Pages are essentially containers, allowing to group questions by ordered
    screens.

    .. note::
        A page should be deleted if the survey it belongs to is deleted. '''

    _name = 'survey.page'
    _description = 'Survey Page'
    _rec_name = 'title'
    _order = 'sequence'

    # Model Fields #

    _columns = {
        'title': fields.char('Page Title', required=1,
            translate=True),
        'survey_id': fields.many2one('survey.survey', 'Survey',
            ondelete='cascade', required=True),
        'question_ids': fields.one2many('survey.question', 'page_id',
            'Questions'),
        'sequence': fields.integer('Page number'),
        'description': fields.html('Description',
            help="An introductory text to your page", translate=True,
            oldname="note"),
    }
    _defaults = {
        'sequence': 10
    }

    # Public methods #

    def copy_data(self, cr, uid, ids, default=None, context=None):
        vals = {}
        current_rec = self.read(cr, uid, ids, fields=['title'], context=context)
        title = _("%s (copy)") % (current_rec.get('title'))
        vals.update({'title': title})
        return super(survey_page, self).copy_data(cr, uid, ids, default=vals,
            context=context)


class survey_question(osv.Model):
    ''' Questions that will be asked in a survey.

    Each question can have one of more suggested answers (eg. in case of
    dropdown choices, multi-answer checkboxes, radio buttons...).'''
    _name = 'survey.question'
    _description = 'Survey Question'
    _rec_name = 'question'
    _order = 'sequence'

    # Model fields #

    _columns = {
        # Question metadata
        'page_id': fields.many2one('survey.page', 'Survey page',
            ondelete='cascade', required=1),
        'survey_id': fields.related('page_id', 'survey_id', type='many2one',
            relation='survey.survey', string='Survey'),
        'sequence': fields.integer(string='Sequence'),

        # Question
        'question': fields.char('Question Name', required=1, translate=True),
        'description': fields.html('Description', help="Use this field to add \
            additional explanations about your question", translate=True,
            oldname='descriptive_text'),

        # Answer
        'type': fields.selection([('free_text', 'Long Text Zone'),
                ('textbox', 'Text Input'),
                ('numerical_box', 'Numerical Value'),
                ('datetime', 'Date and Time'),
                ('simple_choice', 'Multiple choice: only one answer'),
                ('multiple_choice', 'Multiple choice: multiple answers allowed'),
                ('matrix', 'Matrix')], 'Type of Question', required=1),
        'matrix_subtype': fields.selection([('simple', 'One choice per row'),
            ('multiple', 'Multiple choices per row')], 'Matrix Type'),
        'labels_ids': fields.one2many('survey.label',
            'question_id', 'Types of answers', oldname='answer_choice_ids'),
        'labels_ids_2': fields.one2many('survey.label',
            'question_id_2', 'Rows of the Matrix'),
        # labels are used for proposed choices
        # if question.type == simple choice | multiple choice
        #                    -> only labels_ids is used
        # if question.type == matrix
        #                    -> labels_ids are the columns of the matrix
        #                    -> labels_ids_2 are the rows of the matrix

        # Display options
        'column_nb': fields.selection([('12', '1'),
                                       ('6', '2'),
                                       ('4', '3'),
                                       ('3', '4'),
                                       ('2', '6')],
            'Number of columns'),
            # These options refer to col-xx-[12|6|4|3|2] classes in Bootstrap
        'display_mode': fields.selection([('columns', 'Radio Buttons/Checkboxes'),
                                          ('dropdown', 'Selection Box')],
                                         'Display mode'),

        # Comments
        'comments_allowed': fields.boolean('Show Comments Field',
            oldname="allow_comment"),
        'comments_message': fields.char('Comment Message', translate=True),
        'comment_count_as_answer': fields.boolean('Comment Field is an Answer Choice',
            oldname='make_comment_field'),

        # Validation
        'validation_required': fields.boolean('Validate entry',
            oldname='is_validation_require'),
        'validation_email': fields.boolean('Input must be an email'),
        'validation_length_min': fields.integer('Minimum Text Length'),
        'validation_length_max': fields.integer('Maximum Text Length'),
        'validation_min_float_value': fields.float('Minimum value'),
        'validation_max_float_value': fields.float('Maximum value'),
        'validation_min_date': fields.datetime('Minimum Date'),
        'validation_max_date': fields.datetime('Maximum Date'),
        'validation_error_msg': fields.char('Error message',
                                            oldname='validation_valid_err_msg',
                                            translate=True),

        # Constraints on number of answers (matrices)
        'constr_mandatory': fields.boolean('Mandatory Answer',
            oldname="is_require_answer"),
        'constr_error_msg': fields.char("Error message",
            oldname='req_error_msg', translate=True),
        'user_input_line_ids': fields.one2many('survey.user_input_line',
                                               'question_id', 'Answers',
                                               domain=[('skipped', '=', False)]),
    }

    _defaults = {
        'page_id': lambda self, cr, uid, context: context.get('page_id'),
        'sequence': 10,
        'type': 'free_text',
        'matrix_subtype': 'simple',
        'column_nb': '12',
        'display_mode': 'columns',
        'constr_error_msg': lambda s, cr, uid, c: _('This question requires an answer.'),
        'validation_error_msg': lambda s, cr, uid, c: _('The answer you entered has an invalid format.'),
        'validation_required': False,
        'comments_message': lambda s, cr, uid, c: _('If other, precise:'),
    }

    _sql_constraints = [
        ('positive_len_min', 'CHECK (validation_length_min >= 0)', 'A length must be positive!'),
        ('positive_len_max', 'CHECK (validation_length_max >= 0)', 'A length must be positive!'),
        ('validation_length', 'CHECK (validation_length_min <= validation_length_max)', 'Max length cannot be smaller than min length!'),
        ('validation_float', 'CHECK (validation_min_float_value <= validation_max_float_value)', 'Max value cannot be smaller than min value!'),
        ('validation_date', 'CHECK (validation_min_date <= validation_max_date)', 'Max date cannot be smaller than min date!')
    ]

    def copy_data(self, cr, uid, ids, default=None, context=None):
        # This will prevent duplication of user input lines in case of question duplication
        # (in cascade, this will also allow to duplicate surveys without duplicating bad user input
        # lines)
        vals = {'user_input_line_ids': []}

        # Updating question title
        current_rec = self.read(cr, uid, ids, context=context)
        question = _("%s (copy)") % (current_rec.get('question'))
        vals['question'] = question

        return super(survey_question, self).copy_data(cr, uid, ids, default=vals,
            context=context)

    # Validation methods

    def validate_question(self, cr, uid, question, post, answer_tag, context=None):
        ''' Validate question, depending on question type and parameters '''
        try:
            checker = getattr(self, 'validate_' + question.type)
        except AttributeError:
            _logger.warning(question.type + ": This type of question has no validation method")
            return {}
        else:
            return checker(cr, uid, question, post, answer_tag, context=context)

    def validate_free_text(self, cr, uid, question, post, answer_tag, context=None):
        errors = {}
        answer = post[answer_tag].strip()
        # Empty answer to mandatory question
        if question.constr_mandatory and not answer:
            errors.update({answer_tag: question.constr_error_msg})
        return errors

    def validate_textbox(self, cr, uid, question, post, answer_tag, context=None):
        errors = {}
        answer = post[answer_tag].strip()
        # Empty answer to mandatory question
        if question.constr_mandatory and not answer:
            errors.update({answer_tag: question.constr_error_msg})
        # Email format validation
        # Note: this validation is very basic:
        #     all the strings of the form
        #     <something>@<anything>.<extension>
        #     will be accepted
        if answer and question.validation_email:
            if not re.match(r"[^@]+@[^@]+\.[^@]+", answer):
                errors.update({answer_tag: _('This answer must be an email address')})
        # Answer validation (if properly defined)
        # Length of the answer must be in a range
        if answer and question.validation_required:
            if not (question.validation_length_min <= len(answer) <= question.validation_length_max):
                errors.update({answer_tag: question.validation_error_msg})
        return errors

    def validate_numerical_box(self, cr, uid, question, post, answer_tag, context=None):
        errors = {}
        answer = post[answer_tag].strip()
        # Empty answer to mandatory question
        if question.constr_mandatory and not answer:
            errors.update({answer_tag: question.constr_error_msg})
        # Checks if user input is a number
        if answer:
            try:
                floatanswer = float(answer)
            except ValueError:
                errors.update({answer_tag: _('This is not a number')})
        # Answer validation (if properly defined)
        if answer and question.validation_required:
            # Answer is not in the right range
            try:
                floatanswer = float(answer)  # check that it is a float has been done hereunder
                if not (question.validation_min_float_value <= floatanswer <= question.validation_max_float_value):
                    errors.update({answer_tag: question.validation_error_msg})
            except ValueError:
                pass
        return errors

    def validate_datetime(self, cr, uid, question, post, answer_tag, context=None):
        errors = {}
        answer = post[answer_tag].strip()
        # Empty answer to mandatory question
        if question.constr_mandatory and not answer:
            errors.update({answer_tag: question.constr_error_msg})
        # Checks if user input is a datetime
        if answer:
            try:
                dateanswer = datetime.datetime.strptime(answer, DF)
            except ValueError:
                errors.update({answer_tag: _('This is not a date/time')})
                return errors
        # Answer validation (if properly defined)
        if answer and question.validation_required:
            # Answer is not in the right range
            try:
                dateanswer = datetime.datetime.strptime(answer, DF)
                if not (datetime.datetime.strptime(question.validation_min_date, DF) <= dateanswer <= datetime.datetime.strptime(question.validation_max_date, DF)):
                    errors.update({answer_tag: question.validation_error_msg})
            except ValueError:  # check that it is a datetime has been done hereunder
                pass
        return errors

    def validate_simple_choice(self, cr, uid, question, post, answer_tag, context=None):
        errors = {}
        if question.comments_allowed:
            comment_tag = "%s_%s" % (answer_tag, 'comment')
        # Empty answer to mandatory question
        if question.constr_mandatory and not answer_tag in post:
            errors.update({answer_tag: question.constr_error_msg})
        if question.constr_mandatory and answer_tag in post and post[answer_tag].strip() == '':
            errors.update({answer_tag: question.constr_error_msg})
        # Answer is a comment and is empty
        if question.constr_mandatory and answer_tag in post and post[answer_tag] == "-1" and question.comment_count_as_answer and comment_tag in post and not post[comment_tag].strip():
            errors.update({answer_tag: question.constr_error_msg})
        return errors

    def validate_multiple_choice(self, cr, uid, question, post, answer_tag, context=None):
        errors = {}
        if question.constr_mandatory:
            answer_candidates = dict_keys_startswith(post, answer_tag)
            comment_flag = answer_candidates.pop(("%s_%s" % (answer_tag, -1)), None)
            if question.comments_allowed:
                comment_answer = answer_candidates.pop(("%s_%s" % (answer_tag, 'comment')), '').strip()
            # There is no answer neither comments (if comments count as answer)
            if not answer_candidates and question.comment_count_as_answer and (not comment_flag or not comment_answer):
                errors.update({answer_tag: question.constr_error_msg})
            # There is no answer at all
            if not answer_candidates and not question.comment_count_as_answer:
                errors.update({answer_tag: question.constr_error_msg})
        return errors

    def validate_matrix(self, cr, uid, question, post, answer_tag, context=None):
        errors = {}
        if question.constr_mandatory:
            lines_number = len(question.labels_ids_2)
            answer_candidates = dict_keys_startswith(post, answer_tag)
            comment_answer = answer_candidates.pop(("%s_%s" % (answer_tag, 'comment')), '').strip()
            # Number of lines that have been answered
            if question.matrix_subtype == 'simple':
                answer_number = len(answer_candidates)
            elif question.matrix_subtype == 'multiple':
                answer_number = len(set([sk.rsplit('_', 1)[0] for sk in answer_candidates.keys()]))
            else:
                raise RuntimeError("Invalid matrix subtype")
            # Validate that each line has been answered
            if answer_number != lines_number:
                errors.update({answer_tag: question.constr_error_msg})
        return errors


class survey_label(osv.Model):
    ''' A suggested answer for a question '''
    _name = 'survey.label'
    _rec_name = 'value'
    _order = 'sequence'
    _description = 'Survey Label'

    def _check_question_not_empty(self, cr, uid, ids, context=None):
        '''Ensure that field question_id XOR field question_id_2 is not null'''
        for label in self.browse(cr, uid, ids, context=context):
            # 'bool()' is required in order to make '!=' act as XOR with objects
            return bool(label.question_id) != bool(label.question_id_2)

    _columns = {
        'question_id': fields.many2one('survey.question', 'Question',
            ondelete='cascade'),
        'question_id_2': fields.many2one('survey.question', 'Question',
            ondelete='cascade'),
        'sequence': fields.integer('Label Sequence order'),
        'value': fields.char("Suggested value", translate=True,
            required=True),
        'quizz_mark': fields.float('Score for this answer', help="A positive score indicates a correct answer; a negative or null score indicates a wrong answer"),
    }
    defaults = {
        'sequence': 100,
    }
    _constraints = [
        (_check_question_not_empty, "A label must be attached to one and only one question", ['question_id', 'question_id_2'])
    ]


class survey_user_input(osv.Model):
    ''' Metadata for a set of one user's answers to a particular survey '''
    _name = "survey.user_input"
    _rec_name = 'date_create'
    _description = 'Survey User Input'

    def _quizz_get_score(self, cr, uid, ids, name, args, context=None):
        ret = dict()
        for user_input in self.browse(cr, uid, ids, context=context):
            ret[user_input.id] = sum([uil.quizz_mark for uil in user_input.user_input_line_ids] or [0.0])
        return ret

    _columns = {
        'survey_id': fields.many2one('survey.survey', 'Survey', required=True,
                                     readonly=1, ondelete='restrict'),
        'date_create': fields.datetime('Creation Date', required=True,
                                       readonly=1),
        'deadline': fields.datetime("Deadline",
                                help="Date by which the person can open the survey and submit answers",
                                oldname="date_deadline"),
        'type': fields.selection([('manually', 'Manually'), ('link', 'Link')],
                                 'Answer Type', required=1, readonly=1,
                                 oldname="response_type"),
        'state': fields.selection([('new', 'Not started yet'),
                                   ('skip', 'Partially completed'),
                                   ('done', 'Completed')],
                                  'Status',
                                  readonly=True),
        'test_entry': fields.boolean('Test entry', readonly=1),
        'token': fields.char("Identification token", readonly=1, required=1),

        # Optional Identification data
        'partner_id': fields.many2one('res.partner', 'Partner', readonly=1),
        'email': fields.char("E-mail", readonly=1),

        # Displaying data
        'last_displayed_page_id': fields.many2one('survey.page',
                                              'Last displayed page'),
        # The answers !
        'user_input_line_ids': fields.one2many('survey.user_input_line',
                                               'user_input_id', 'Answers'),

        # URLs used to display the answers
        'result_url': fields.related('survey_id', 'result_url', string="Public link to the survey results"),
        'print_url': fields.related('survey_id', 'print_url', string="Public link to the empty survey"),

        'quizz_score': fields.function(_quizz_get_score, type="float", string="Score for the quiz")
    }
    _defaults = {
        'date_create': fields.datetime.now,
        'type': 'manually',
        'state': 'new',
        'token': lambda s, cr, uid, c: uuid.uuid4().__str__(),
        'quizz_score': 0.0,
    }

    _sql_constraints = [
        ('unique_token', 'UNIQUE (token)', 'A token must be unique!'),
        ('deadline_in_the_past', 'CHECK (deadline >= date_create)', 'The deadline cannot be in the past')
    ]

    def copy_data(self, cr, uid, id, default=None, context=None):
        raise osv.except_osv(_('Warning!'), _('You cannot duplicate this \
            element!'))

    def do_clean_emptys(self, cr, uid, automatic=False, context=None):
        ''' Remove empty user inputs that have been created manually
            (used as a cronjob declared in data/survey_cron.xml) '''
        empty_user_input_ids = self.search(cr, uid, [('type', '=', 'manually'),
                                                     ('state', '=', 'new'),
                                                     ('date_create', '<', (datetime.datetime.now() - datetime.timedelta(hours=1)).strftime(DF))],
                                           context=context)
        if empty_user_input_ids:
            self.unlink(cr, uid, empty_user_input_ids, context=context)

    def action_survey_resent(self, cr, uid, ids, context=None):
        ''' Sent again the invitation '''
        record = self.browse(cr, uid, ids[0], context=context)
        context = context or {}
        context.update({
            'survey_resent_token': True,
            'default_partner_ids': record.partner_id and [record.partner_id.id] or [],
            'default_multi_email': record.email or "",
            'default_public': 'email_private',
        })
        return self.pool.get('survey.survey').action_send_survey(cr, uid,
            [record.survey_id.id], context=context)

    def action_view_answers(self, cr, uid, ids, context=None):
        ''' Open the website page with the survey form '''
        user_input = self.read(cr, uid, ids, ['print_url', 'token'], context=context)[0]
        return {
            'type': 'ir.actions.act_url',
            'name': "View Answers",
            'target': 'self',
            'url': '%s/%s' % (user_input['print_url'], user_input['token'])
        }

    def action_survey_results(self, cr, uid, ids, context=None):
        ''' Open the website page with the survey results '''
        return {
            'type': 'ir.actions.act_url',
            'name': "Survey Results",
            'target': 'self',
            'url': self.read(cr, uid, ids, ['result_url'], context=context)[0]['result_url']
        }


class survey_user_input_line(osv.Model):
    _name = 'survey.user_input_line'
    _description = 'Survey User Input Line'
    _rec_name = 'date_create'

    def _answered_or_skipped(self, cr, uid, ids, context=None):
        for uil in self.browse(cr, uid, ids, context=context):
            # 'bool()' is required in order to make '!=' act as XOR with objects
            return uil.skipped != bool(uil.answer_type)

    def _check_answer_type(self, cr, uid, ids, context=None):
        for uil in self.browse(cr, uid, ids, context=None):
            if uil.answer_type:
                if uil.answer_type == 'text':
                    # 'bool()' is required in order to make '!=' act as XOR with objects
                    return bool(uil.value_text)
                elif uil.answer_type == 'number':
                    return (uil.value_number == 0) or (uil.value_number != False)
                elif uil.answer_type == 'date':
                    return bool(uil.value_date)
                elif uil.answer_type == 'free_text':
                    return bool(uil.value_free_text)
                elif uil.answer_type == 'suggestion':
                    return bool(uil.value_suggested)
            return True

    _columns = {
        'user_input_id': fields.many2one('survey.user_input', 'User Input',
                                         ondelete='cascade', required=1),
        'question_id': fields.many2one('survey.question', 'Question',
                                       ondelete='restrict', required=1),
        'page_id': fields.related('question_id', 'page_id', type='many2one',
                                  relation='survey.page', string="Page"),
        'survey_id': fields.related('user_input_id', 'survey_id',
                                    type="many2one", relation="survey.survey",
                                    string='Survey', store=True),
        'date_create': fields.datetime('Create Date', required=1),
        'skipped': fields.boolean('Skipped'),
        'answer_type': fields.selection([('text', 'Text'),
                                         ('number', 'Number'),
                                         ('date', 'Date'),
                                         ('free_text', 'Free Text'),
                                         ('suggestion', 'Suggestion')],
                                        'Answer Type'),
        'value_text': fields.char("Text answer"),
        'value_number': fields.float("Numerical answer"),
        'value_date': fields.datetime("Date answer"),
        'value_free_text': fields.text("Free Text answer"),
        'value_suggested': fields.many2one('survey.label', "Suggested answer"),
        'value_suggested_row': fields.many2one('survey.label', "Row answer"),
        'quizz_mark': fields.float("Score given for this answer")
    }

    _defaults = {
        'skipped': False,
        'date_create': fields.datetime.now()
    }
    _constraints = [
        (_answered_or_skipped, "A question cannot be unanswered and skipped", ['skipped', 'answer_type']),
        (_check_answer_type, "The answer must be in the right type", ['answer_type', 'text', 'number', 'date', 'free_text', 'suggestion'])
    ]

    def __get_mark(self, cr, uid, value_suggested, context=None):
        try:
            mark = self.pool.get('survey.label').browse(cr, uid, int(value_suggested), context=context).quizz_mark
        except KeyError:
            mark = 0.0
        except ValueError:
            mark = 0.0
        return mark

    def create(self, cr, uid, vals, context=None):
        value_suggested = vals.get('value_suggested')
        if value_suggested:
            vals.update({'quizz_mark': self.__get_mark(cr, uid, value_suggested)})
        return super(survey_user_input_line, self).create(cr, uid, vals, context=context)

    def write(self, cr, uid, ids, vals, context=None):
        value_suggested = vals.get('value_suggested')
        if value_suggested:
            vals.update({'quizz_mark': self.__get_mark(cr, uid, value_suggested)})
        return super(survey_user_input_line, self).write(cr, uid, ids, vals, context=context)

    def copy_data(self, cr, uid, id, default=None, context=None):
        raise osv.except_osv(_('Warning!'), _('You cannot duplicate this \
            element!'))

    def save_lines(self, cr, uid, user_input_id, question, post, answer_tag,
                   context=None):
        ''' Save answers to questions, depending on question type

        If an answer already exists for question and user_input_id, it will be
        overwritten (in order to maintain data consistency). '''
        try:
            saver = getattr(self, 'save_line_' + question.type)
        except AttributeError:
            _logger.error(question.type + ": This type of question has no saving function")
            return False
        else:
            saver(cr, uid, user_input_id, question, post, answer_tag, context=context)

    def save_line_free_text(self, cr, uid, user_input_id, question, post, answer_tag, context=None):
        vals = {
            'user_input_id': user_input_id,
            'question_id': question.id,
            'page_id': question.page_id.id,
            'survey_id': question.survey_id.id,
            'skipped': False,
        }
        if answer_tag in post and post[answer_tag].strip() != '':
            vals.update({'answer_type': 'free_text', 'value_free_text': post[answer_tag]})
        else:
            vals.update({'answer_type': None, 'skipped': True})
        old_uil = self.search(cr, uid, [('user_input_id', '=', user_input_id),
                                        ('survey_id', '=', question.survey_id.id),
                                        ('question_id', '=', question.id)],
                              context=context)
        if old_uil:
            self.write(cr, uid, old_uil[0], vals, context=context)
        else:
            self.create(cr, uid, vals, context=context)
        return True

    def save_line_textbox(self, cr, uid, user_input_id, question, post, answer_tag, context=None):
        vals = {
            'user_input_id': user_input_id,
            'question_id': question.id,
            'page_id': question.page_id.id,
            'survey_id': question.survey_id.id,
            'skipped': False
        }
        if answer_tag in post and post[answer_tag].strip() != '':
            vals.update({'answer_type': 'text', 'value_text': post[answer_tag]})
        else:
            vals.update({'answer_type': None, 'skipped': True})
        old_uil = self.search(cr, uid, [('user_input_id', '=', user_input_id),
                                        ('survey_id', '=', question.survey_id.id),
                                        ('question_id', '=', question.id)],
                              context=context)
        if old_uil:
            self.write(cr, uid, old_uil[0], vals, context=context)
        else:
            self.create(cr, uid, vals, context=context)
        return True

    def save_line_numerical_box(self, cr, uid, user_input_id, question, post, answer_tag, context=None):
        vals = {
            'user_input_id': user_input_id,
            'question_id': question.id,
            'page_id': question.page_id.id,
            'survey_id': question.survey_id.id,
            'skipped': False
        }
        if answer_tag in post and post[answer_tag].strip() != '':
            vals.update({'answer_type': 'number', 'value_number': float(post[answer_tag])})
        else:
            vals.update({'answer_type': None, 'skipped': True})
        old_uil = self.search(cr, uid, [('user_input_id', '=', user_input_id),
                                        ('survey_id', '=', question.survey_id.id),
                                        ('question_id', '=', question.id)],
                              context=context)
        if old_uil:
            self.write(cr, uid, old_uil[0], vals, context=context)
        else:
            self.create(cr, uid, vals, context=context)
        return True

    def save_line_datetime(self, cr, uid, user_input_id, question, post, answer_tag, context=None):
        vals = {
            'user_input_id': user_input_id,
            'question_id': question.id,
            'page_id': question.page_id.id,
            'survey_id': question.survey_id.id,
            'skipped': False
        }
        if answer_tag in post and post[answer_tag].strip() != '':
            vals.update({'answer_type': 'date', 'value_date': post[answer_tag]})
        else:
            vals.update({'answer_type': None, 'skipped': True})
        old_uil = self.search(cr, uid, [('user_input_id', '=', user_input_id),
                                        ('survey_id', '=', question.survey_id.id),
                                        ('question_id', '=', question.id)],
                              context=context)
        if old_uil:
            self.write(cr, uid, old_uil[0], vals, context=context)
        else:
            self.create(cr, uid, vals, context=context)
        return True

    def save_line_simple_choice(self, cr, uid, user_input_id, question, post, answer_tag, context=None):
        vals = {
            'user_input_id': user_input_id,
            'question_id': question.id,
            'page_id': question.page_id.id,
            'survey_id': question.survey_id.id,
            'skipped': False
        }
        old_uil = self.search(cr, uid, [('user_input_id', '=', user_input_id),
                                        ('survey_id', '=', question.survey_id.id),
                                        ('question_id', '=', question.id)],
                              context=context)
        if old_uil:
            self.unlink(cr, uid, old_uil, context=context)

        if answer_tag in post and post[answer_tag].strip() != '':
            vals.update({'answer_type': 'suggestion', 'value_suggested': post[answer_tag]})
        else:
            vals.update({'answer_type': None, 'skipped': True})
        self.create(cr, uid, vals, context=context)

        comment_answer = post.pop(("%s_%s" % (answer_tag, 'comment')), '').strip()
        if comment_answer:
            vals.update({'answer_type': 'text', 'value_text': comment_answer})
            self.create(cr, uid, vals, context=context)

        return True

    def save_line_multiple_choice(self, cr, uid, user_input_id, question, post, answer_tag, context=None):
        vals = {
            'user_input_id': user_input_id,
            'question_id': question.id,
            'page_id': question.page_id.id,
            'survey_id': question.survey_id.id,
            'skipped': False
        }
        old_uil = self.search(cr, uid, [('user_input_id', '=', user_input_id),
                                        ('survey_id', '=', question.survey_id.id),
                                        ('question_id', '=', question.id)],
                              context=context)
        if old_uil:
            self.unlink(cr, uid, old_uil, context=context)

        ca = dict_keys_startswith(post, answer_tag)
        comment_answer = ca.pop(("%s_%s" % (answer_tag, 'comment')), '').strip()
        if len(ca) > 0:
            for a in ca:
                vals.update({'answer_type': 'suggestion', 'value_suggested': ca[a]})
                self.create(cr, uid, vals, context=context)
        if comment_answer:
            vals.update({'answer_type': 'text', 'value_text': comment_answer})
            self.create(cr, uid, vals, context=context)
        if not ca and not comment_answer:
            vals.update({'answer_type': None, 'skipped': True})
            self.create(cr, uid, vals, context=context)
        return True

    def save_line_matrix(self, cr, uid, user_input_id, question, post, answer_tag, context=None):
        vals = {
            'user_input_id': user_input_id,
            'question_id': question.id,
            'page_id': question.page_id.id,
            'survey_id': question.survey_id.id,
            'skipped': False
        }
        old_uil = self.search(cr, uid, [('user_input_id', '=', user_input_id),
                                        ('survey_id', '=', question.survey_id.id),
                                        ('question_id', '=', question.id)],
                              context=context)
        if old_uil:
            self.unlink(cr, uid, old_uil, context=context)

        no_answers = True
        ca = dict_keys_startswith(post, answer_tag)

        comment_answer = ca.pop(("%s_%s" % (answer_tag, 'comment')), '').strip()
        if comment_answer:
            vals.update({'answer_type': 'text', 'value_text': comment_answer})
            self.create(cr, uid, vals, context=context)
            no_answers = False

        if question.matrix_subtype == 'simple':
            for row in question.labels_ids_2:
                a_tag = "%s_%s" % (answer_tag, row.id)
                if a_tag in ca:
                    no_answers = False
                    vals.update({'answer_type': 'suggestion', 'value_suggested': ca[a_tag], 'value_suggested_row': row.id})
                    self.create(cr, uid, vals, context=context)

        elif question.matrix_subtype == 'multiple':
            for col in question.labels_ids:
                for row in question.labels_ids_2:
                    a_tag = "%s_%s_%s" % (answer_tag, row.id, col.id)
                    if a_tag in ca:
                        no_answers = False
                        vals.update({'answer_type': 'suggestion', 'value_suggested': col.id, 'value_suggested_row': row.id})
                        self.create(cr, uid, vals, context=context)
        if no_answers:
            vals.update({'answer_type': None, 'skipped': True})
            self.create(cr, uid, vals, context=context)
        return True


def dict_keys_startswith(dictionary, string):
    '''Returns a dictionary containing the elements of <dict> whose keys start
    with <string>.

    .. note::
        This function uses dictionary comprehensions (Python >= 2.7)'''
    return {k: dictionary[k] for k in filter(lambda key: key.startswith(string), dictionary.keys())}
