# -*- coding: utf-8 -*-
# Part of Odoo. See LICENSE file for full copyright and licensing details.
import base64
import random
import re
from operator import itemgetter

from odoo import api, Command, fields, models, modules, _
from odoo.addons.bus.websocket import WebsocketConnectionHandler


class ImLivechatChannel(models.Model):
    """ Livechat Channel
        Define a communication channel, which can be accessed with 'script_external' (script tag to put on
        external website), 'script_internal' (code to be integrated with odoo website) or via 'web_page' link.
        It provides rating tools, and access rules for anonymous people.
    """

    _name = 'im_livechat.channel'
    _inherit = ['rating.parent.mixin']
    _description = 'Livechat Channel'
    _rating_satisfaction_days = 14  # include only last 14 days to compute satisfaction

    def _default_user_ids(self):
        return [(6, 0, [self._uid])]

    def _default_button_text(self):
        return _('Have a Question? Chat with us.')

    def _default_default_message(self):
        return _('How may I help you?')

    # attribute fields
    name = fields.Char('Channel Name', required=True)
    button_text = fields.Char('Text of the Button', default=_default_button_text,
        help="Default text displayed on the Livechat Support Button", translate=True)
    default_message = fields.Char('Welcome Message', default=_default_default_message,
        help="This is an automated 'welcome' message that your visitor will see when they initiate a new conversation.", translate=True)
    input_placeholder = fields.Char('Chat Input Placeholder', help='Text that prompts the user to initiate the chat.', translate=True)
    header_background_color = fields.Char(default="#875A7B", help="Default background color of the channel header once open")
    title_color = fields.Char(default="#FFFFFF", help="Default title color of the channel once open")
    button_background_color = fields.Char(default="#875A7B", help="Default background color of the Livechat button")
    button_text_color = fields.Char(default="#FFFFFF", help="Default text color of the Livechat button")

    # computed fields
    web_page = fields.Char('Web Page', compute='_compute_web_page_link', store=False, readonly=True,
        help="URL to a static page where you client can discuss with the operator of the channel.")
    are_you_inside = fields.Boolean(string='Are you inside the matrix?',
        compute='_are_you_inside', store=False, readonly=True)
    available_operator_ids = fields.Many2many('res.users', compute='_compute_available_operator_ids')
    script_external = fields.Html('Script (external)', compute='_compute_script_external', store=False, readonly=True, sanitize=False)
    nbr_channel = fields.Integer('Number of conversation', compute='_compute_nbr_channel', store=False, readonly=True)

    image_128 = fields.Image("Image", max_width=128, max_height=128)

    # relationnal fields
    user_ids = fields.Many2many('res.users', 'im_livechat_channel_im_user', 'channel_id', 'user_id', string='Operators', default=_default_user_ids)
    channel_ids = fields.One2many('discuss.channel', 'livechat_channel_id', 'Sessions')
    chatbot_script_count = fields.Integer(string='Number of Chatbot', compute='_compute_chatbot_script_count')
    rule_ids = fields.One2many('im_livechat.channel.rule', 'channel_id', 'Rules')

    def _are_you_inside(self):
        for channel in self:
            channel.are_you_inside = bool(self.env.uid in [u.id for u in channel.user_ids])

    @api.depends('user_ids.im_status')
    def _compute_available_operator_ids(self):
        for record in self:
            record.available_operator_ids = record.user_ids.filtered(lambda user: user.im_status == 'online')

    @api.depends('rule_ids.chatbot_script_id')
    def _compute_chatbot_script_count(self):
        data = self.env['im_livechat.channel.rule']._read_group(
            [('channel_id', 'in', self.ids)], ['channel_id'], ['chatbot_script_id:count_distinct'])
        mapped_data = {channel.id: count_distinct for channel, count_distinct in data}
        for channel in self:
            channel.chatbot_script_count = mapped_data.get(channel.id, 0)

    def _compute_script_external(self):
        values = {
            "dbname": self._cr.dbname,
        }
        for record in self:
            values["channel_id"] = record.id
            values["url"] = record.get_base_url()
            record.script_external = self.env['ir.qweb']._render('im_livechat.external_loader', values) if record.id else False

    def _compute_web_page_link(self):
        for record in self:
            record.web_page = "%s/im_livechat/support/%i" % (record.get_base_url(), record.id) if record.id else False

    @api.depends('channel_ids')
    def _compute_nbr_channel(self):
        data = self.env['discuss.channel']._read_group([
            ('livechat_channel_id', 'in', self.ids),
        ], ['livechat_channel_id'], ['__count'])
        channel_count = {livechat_channel.id: count for livechat_channel, count in data}
        for record in self:
            record.nbr_channel = channel_count.get(record.id, 0)

    # --------------------------
    # Action Methods
    # --------------------------
    def action_join(self):
        self.ensure_one()
        return self.write({'user_ids': [(4, self._uid)]})

    def action_quit(self):
        self.ensure_one()
        return self.write({'user_ids': [(3, self._uid)]})

    def action_view_rating(self):
        """ Action to display the rating relative to the channel, so all rating of the
            sessions of the current channel
            :returns : the ir.action 'action_view_rating' with the correct context
        """
        self.ensure_one()
        action = self.env['ir.actions.act_window']._for_xml_id('im_livechat.rating_rating_action_livechat')
        action['context'] = {'search_default_parent_res_name': self.name}
        return action

    def action_view_chatbot_scripts(self):
        action = self.env['ir.actions.act_window']._for_xml_id('im_livechat.chatbot_script_action')
        chatbot_script_ids = self.env['im_livechat.channel.rule'].search(
            [('channel_id', 'in', self.ids)]).mapped('chatbot_script_id')
        if len(chatbot_script_ids) == 1:
            action['res_id'] = chatbot_script_ids.id
            action['view_mode'] = 'form'
            action['views'] = [(False, 'form')]
        else:
            action['domain'] = [('id', 'in', chatbot_script_ids.ids)]
        return action

    # --------------------------
    # Channel Methods
    # --------------------------
    def _get_livechat_discuss_channel_vals(
        self, anonymous_name, previous_operator_id=None, chatbot_script=None, user_id=None, country_id=None, lang=None
    ):
        user_operator = False
        if chatbot_script:
            if chatbot_script.id not in self.browse(self.ids).mapped('rule_ids.chatbot_script_id.id'):
                return False
        else:
            user_operator = self._get_operator(previous_operator_id=previous_operator_id, lang=lang, country_id=country_id)
            if not user_operator:
                # no one available
                return False
        # partner to add to the discuss.channel
        operator_partner_id = user_operator.partner_id.id if user_operator else chatbot_script.operator_partner_id.id
        members_to_add = [Command.create({'partner_id': operator_partner_id, 'is_pinned': False})]
        visitor_user = False
        if user_id:
            visitor_user = self.env['res.users'].browse(user_id)
            if visitor_user and visitor_user.active and user_operator and visitor_user != user_operator:  # valid session user (not public)
                members_to_add.append(Command.create({'partner_id': visitor_user.partner_id.id}))

        if chatbot_script:
            name = chatbot_script.title
        else:
            name = ' '.join([
                visitor_user.display_name if visitor_user else anonymous_name,
                user_operator.livechat_username or user_operator.name
            ])

        return {
            'channel_member_ids': members_to_add,
            'livechat_active': True,
            'livechat_operator_id': operator_partner_id,
            'livechat_channel_id': self.id,
            'chatbot_current_step_id': chatbot_script._get_welcome_steps()[-1].id if chatbot_script else False,
            'anonymous_name': False if user_id else anonymous_name,
            'country_id': country_id,
            'channel_type': 'livechat',
            'name': name,
        }

    def _get_less_active_operator(self, operator_statuses, operators):
        """ Retrieve the most available operator based on the following criteria:
        - Lowest number of active chats.
        - Not in  a call.
        - If an operator is in a call and has two or more active chats, don't
          give priority over an operator with more conversations who is not in a
          call.

        :param operator_statuses: list of dictionaries containing the operator's
            id, the number of active chats and a boolean indicating if the
            operator is in a call. The list is ordered by the number of active
            chats (ascending) and whether the operator is in a call
            (descending).
        :param operators: recordset of :class:`ResUsers` operators to choose from.
        :return: the :class:`ResUsers` record for the chosen operator
        """
        if not operators:
            return False

        # 1) only consider operators in the list to choose from
        operator_statuses = [
            s for s in operator_statuses if s['livechat_operator_id'] in set(operators.partner_id.ids)
        ]

        # 2) try to select an inactive op, i.e. one w/ no active status (no recent chat)
        active_op_partner_ids = {s['livechat_operator_id'] for s in operator_statuses}
        candidates = operators.filtered(lambda o: o.partner_id.id not in active_op_partner_ids)
        if candidates:
            return random.choice(candidates)

        # 3) otherwise select least active ops, based on status ordering (count + in_call)
        best_status = operator_statuses[0]
        best_status_op_partner_ids = {
            s['livechat_operator_id']
            for s in operator_statuses
            if (s['count'], s['in_call']) == (best_status['count'], best_status['in_call'])
        }
        candidates = operators.filtered(lambda o: o.partner_id.id in best_status_op_partner_ids)
        return random.choice(candidates)

    def _get_operator(self, previous_operator_id=None, lang=None, country_id=None):
        """ Return an operator for a livechat. Try to return the previous
        operator if available. If not, one of the most available operators be
        returned.

        A livechat is considered 'active' if it has at least one message within
        the 30 minutes. This method will try to match the given lang and
        country_id.

        (Some annoying conversions have to be made on the fly because this model
        holds 'res.users' as available operators and the discuss_channel model
        stores the partner_id of the randomly selected operator)

        :param previous_operator_id: id of the previous operator with whom the
            visitor was chatting.
        :param lang: code of the preferred lang of the visitor.
        :param country_id: id of the country of the visitor.
        :return : user
        :rtype : res.users
        """
        if not self.available_operator_ids:
            return False
        self.env.cr.execute("""
            WITH operator_rtc_session AS (
                SELECT COUNT(DISTINCT s.id) as nbr, member.partner_id as partner_id
                  FROM discuss_channel_rtc_session s
                  JOIN discuss_channel_member member ON (member.id = s.channel_member_id)
                  GROUP BY member.partner_id
            )
            SELECT COUNT(DISTINCT c.id), COALESCE(rtc.nbr, 0) > 0 as in_call, c.livechat_operator_id
            FROM discuss_channel c
            LEFT OUTER JOIN mail_message m ON c.id = m.res_id AND m.model = 'discuss.channel'
            LEFT OUTER JOIN operator_rtc_session rtc ON rtc.partner_id = c.livechat_operator_id
            WHERE c.channel_type = 'livechat' AND c.create_date > ((now() at time zone 'UTC') - interval '24 hours')
            AND (
                c.livechat_active IS TRUE
                OR m.create_date > ((now() at time zone 'UTC') - interval '30 minutes')
            )
            AND c.livechat_operator_id in %s
            GROUP BY c.livechat_operator_id, rtc.nbr
            ORDER BY COUNT(DISTINCT c.id) < 2 OR rtc.nbr IS NULL DESC, COUNT(DISTINCT c.id) ASC, rtc.nbr IS NULL DESC""",
            (tuple(self.available_operator_ids.partner_id.ids),)
        )
        operator_statuses = self.env.cr.dictfetchall()
        operator = None
        # Try to match the previous operator
        if previous_operator_id in self.available_operator_ids.partner_id.ids:
            previous_operator_status = next(
                (status for status in operator_statuses if status['livechat_operator_id'] == previous_operator_id),
                None
            )
            if not previous_operator_status or previous_operator_status['count'] < 2 or not previous_operator_status['in_call']:
                previous_operator_user = next(
                    available_user
                    for available_user in self.available_operator_ids
                    if available_user.partner_id.id == previous_operator_id
                )
                return previous_operator_user
        # Try to match an operator with the same main lang as the visitor
        # If no operator with the same lang, try to match an operator with the addition lang
        if lang:
            same_lang_operator_ids = self.available_operator_ids.filtered(lambda operator: operator.partner_id.lang == lang)
            if same_lang_operator_ids:
                operator = self._get_less_active_operator(operator_statuses, same_lang_operator_ids)
            else:
                addition_lang_operator_ids = self.available_operator_ids.filtered(lambda operator: lang in operator.res_users_settings_id.livechat_lang_ids.mapped('code'))
                if addition_lang_operator_ids:
                    operator = self._get_less_active_operator(operator_statuses, addition_lang_operator_ids)
        # Try to match an operator with the same country as the visitor
        if country_id and not operator:
            same_country_operator_ids = self.available_operator_ids.filtered(lambda operator: operator.partner_id.country_id.id == country_id)
            if same_country_operator_ids:
                operator = self._get_less_active_operator(operator_statuses, same_country_operator_ids)
        # Try to get a random operator, regardless of the lang or the country
        if not operator:
            operator = self._get_less_active_operator(operator_statuses, self.available_operator_ids)
        return operator

    def _get_channel_infos(self):
        self.ensure_one()

        return {
            'header_background_color': self.header_background_color,
            'button_background_color': self.button_background_color,
            'title_color': self.title_color,
            'button_text_color': self.button_text_color,
            'button_text': self.button_text,
            'input_placeholder': self.input_placeholder,
            'default_message': self.default_message,
            "channel_name": self.name,
            "channel_id": self.id,
        }

    def get_livechat_info(self, username=None):
        self.ensure_one()

        if username is None:
            username = _('Visitor')
        info = {}
        info['available'] = self.chatbot_script_count or len(self.available_operator_ids) > 0
        info['server_url'] = self.get_base_url()
        if info['available']:
            info['options'] = self._get_channel_infos()
            info["options"]["websocket_worker_version"] = WebsocketConnectionHandler._VERSION
            info['options']['current_partner_id'] = (
                self.env.user.partner_id.id if not self.env.user._is_public() else None
            )
            info['options']["default_username"] = username
        return info


class ImLivechatChannelRule(models.Model):
    """ Channel Rules
        Rules defining access to the channel (countries, and url matching). It also provide the 'auto pop'
        option to open automatically the conversation.
    """

    _name = 'im_livechat.channel.rule'
    _description = 'Livechat Channel Rules'
    _order = 'sequence asc'

    regex_url = fields.Char('URL Regex',
        help="Regular expression specifying the web pages this rule will be applied on.")
    action = fields.Selection([
        ('display_button', 'Show'),
        ('display_button_and_text', 'Show with notification'),
        ('auto_popup', 'Open automatically'),
        ('hide_button', 'Hide')], string='Live Chat Button', required=True, default='display_button',
        help="* 'Show' displays the chat button on the pages.\n"\
             "* 'Show with notification' is 'Show' in addition to a floating text just next to the button.\n"\
             "* 'Open automatically' displays the button and automatically opens the conversation pane.\n"\
             "* 'Hide' hides the chat button on the pages.\n")
    auto_popup_timer = fields.Integer('Open automatically timer', default=0,
        help="Delay (in seconds) to automatically open the conversation window. Note: the selected action must be 'Open automatically' otherwise this parameter will not be taken into account.")
    chatbot_script_id = fields.Many2one('chatbot.script', string='Chatbot')
    chatbot_only_if_no_operator = fields.Boolean(
        string='Enabled only if no operator', help='Enable the bot only if there is no operator available')
    channel_id = fields.Many2one('im_livechat.channel', 'Channel',
        help="The channel of the rule")
    country_ids = fields.Many2many('res.country', 'im_livechat_channel_country_rel', 'channel_id', 'country_id', 'Country',
        help="The rule will only be applied for these countries. Example: if you select 'Belgium' and 'United States' and that you set the action to 'Hide', the chat button will be hidden on the specified URL from the visitors located in these 2 countries. This feature requires GeoIP installed on your server.")
    sequence = fields.Integer('Matching order', default=10,
        help="Given the order to find a matching rule. If 2 rules are matching for the given url/country, the one with the lowest sequence will be chosen.")

    def match_rule(self, channel_id, url, country_id=False):
        """ determine if a rule of the given channel matches with the given url
            :param channel_id : the identifier of the channel_id
            :param url : the url to match with a rule
            :param country_id : the identifier of the country
            :returns the rule that matches the given condition. False otherwise.
            :rtype : im_livechat.channel.rule
        """
        def _match(rules):
            for rule in rules:
                # url might not be set because it comes from referer, in that
                # case match the first rule with no regex_url
                if re.search(rule.regex_url or '', url or ''):
                    return rule
            return False
        # first, search the country specific rules (the first match is returned)
        if country_id: # don't include the country in the research if geoIP is not installed
            domain = [('country_ids', 'in', [country_id]), ('channel_id', '=', channel_id)]
            rule = _match(self.search(domain))
            if rule:
                return rule
        # second, fallback on the rules without country
        domain = [('country_ids', '=', False), ('channel_id', '=', channel_id)]
        return _match(self.search(domain))
