# -*- coding: utf-8 -*-
# Part of Odoo. See LICENSE file for full copyright and licensing details.

from odoo import api, fields, models, _
from odoo.exceptions import ValidationError, UserError
from odoo.tools.misc import formatLang


class EventTemplateTicket(models.Model):
    _name = 'event.type.ticket'
    _description = 'Event Template Ticket'
    _order = 'sequence, name, id'

    sequence = fields.Integer('Sequence', default=10)
    # description
    name = fields.Char(
        string='Name', default=lambda self: _('Registration'),
        required=True, translate=True)
    description = fields.Text(
        'Description', translate=True,
        help="A description of the ticket that you want to communicate to your customers.")
    event_type_id = fields.Many2one(
        'event.type', string='Event Category', ondelete='cascade', required=True)
    # seats
    seats_limited = fields.Boolean(string='Limit Attendees', readonly=True, store=True,
                                   compute='_compute_seats_limited')
    seats_max = fields.Integer(
        string='Maximum Attendees',
        help="Define the number of available tickets. If you have too many registrations you will "
             "not be able to sell tickets anymore. Set 0 to ignore this rule set as unlimited.")

    @api.depends('seats_max')
    def _compute_seats_limited(self):
        for ticket in self:
            ticket.seats_limited = ticket.seats_max

    @api.model
    def _get_event_ticket_fields_whitelist(self):
        """ Whitelist of fields that are copied from event_type_ticket_ids to event_ticket_ids when
        changing the event_type_id field of event.event """
        return ['sequence', 'name', 'description', 'seats_max']


class EventTicket(models.Model):
    """ Ticket model allowing to have different kind of registrations for a given
    event. Ticket are based on ticket type as they share some common fields
    and behavior. Those models come from <= v13 Odoo event.event.ticket that
    modeled both concept: tickets for event templates, and tickets for events. """
    _name = 'event.event.ticket'
    _inherit = 'event.type.ticket'
    _description = 'Event Ticket'
    _order = "event_id, sequence, name, id"

    @api.model
    def default_get(self, fields):
        res = super(EventTicket, self).default_get(fields)
        if 'name' in fields and (not res.get('name') or res['name'] == _('Registration')) and self.env.context.get('default_event_name'):
            res['name'] = _('Registration for %s', self.env.context['default_event_name'])
        return res

    # description
    event_type_id = fields.Many2one(ondelete='set null', required=False)
    event_id = fields.Many2one(
        'event.event', string="Event",
        ondelete='cascade', required=True)
    company_id = fields.Many2one('res.company', related='event_id.company_id')
    # sale
    start_sale_datetime = fields.Datetime(string="Registration Start")
    end_sale_datetime = fields.Datetime(string="Registration End")
    is_launched = fields.Boolean(string='Are sales launched', compute='_compute_is_launched')
    is_expired = fields.Boolean(string='Is Expired', compute='_compute_is_expired')
    sale_available = fields.Boolean(
        string='Is Available', compute='_compute_sale_available', compute_sudo=True,
        help='Whether it is possible to sell these tickets')
    registration_ids = fields.One2many('event.registration', 'event_ticket_id', string='Registrations')
    # seats
    seats_reserved = fields.Integer(string='Reserved Seats', compute='_compute_seats', store=False)
    seats_available = fields.Integer(string='Available Seats', compute='_compute_seats', store=False)
    seats_used = fields.Integer(string='Used Seats', compute='_compute_seats', store=False)
    seats_taken = fields.Integer(string="Taken Seats", compute="_compute_seats", store=False)
    is_sold_out = fields.Boolean(
        'Sold Out', compute='_compute_is_sold_out', help='Whether seats are not available for this ticket.')
    # reports
    color = fields.Char('Color', default="#875A7B")

    @api.depends('end_sale_datetime', 'event_id.date_tz')
    def _compute_is_expired(self):
        for ticket in self:
            ticket = ticket._set_tz_context()
            current_datetime = fields.Datetime.context_timestamp(ticket, fields.Datetime.now())
            if ticket.end_sale_datetime:
                end_sale_datetime = fields.Datetime.context_timestamp(ticket, ticket.end_sale_datetime)
                ticket.is_expired = end_sale_datetime < current_datetime
            else:
                ticket.is_expired = False

    @api.depends('start_sale_datetime', 'event_id.date_tz')
    def _compute_is_launched(self):
        now = fields.Datetime.now()
        for ticket in self:
            if not ticket.start_sale_datetime:
                ticket.is_launched = True
            else:
                ticket = ticket._set_tz_context()
                current_datetime = fields.Datetime.context_timestamp(ticket, now)
                start_sale_datetime = fields.Datetime.context_timestamp(ticket, ticket.start_sale_datetime)
                ticket.is_launched = start_sale_datetime <= current_datetime

    @api.depends('is_expired', 'start_sale_datetime', 'event_id.date_tz', 'seats_available', 'seats_max')
    def _compute_sale_available(self):
        for ticket in self:
            ticket.sale_available = ticket.is_launched and not ticket.is_expired and not ticket.is_sold_out

    @api.depends('seats_max', 'registration_ids.state', 'registration_ids.active')
    def _compute_seats(self):
        """ Determine available, reserved, used and taken seats. """
        # initialize fields to 0 + compute seats availability
        for ticket in self:
            ticket.seats_reserved = ticket.seats_used = ticket.seats_available = 0
        # aggregate registrations by ticket and by state
        results = {}
        if self.ids:
            state_field = {
                'open': 'seats_reserved',
                'done': 'seats_used',
            }
            query = """ SELECT event_ticket_id, state, count(event_id)
                        FROM event_registration
                        WHERE event_ticket_id IN %s AND state IN ('open', 'done') AND active = true
                        GROUP BY event_ticket_id, state
                    """
            self.env['event.registration'].flush_model(['event_id', 'event_ticket_id', 'state', 'active'])
            self.env.cr.execute(query, (tuple(self.ids),))
            for event_ticket_id, state, num in self.env.cr.fetchall():
                results.setdefault(event_ticket_id, {})[state_field[state]] = num

        # compute seats_available
        for ticket in self:
            ticket.update(results.get(ticket._origin.id or ticket.id, {}))
            if ticket.seats_max > 0:
                ticket.seats_available = ticket.seats_max - (ticket.seats_reserved + ticket.seats_used)
            ticket.seats_taken = ticket.seats_reserved + ticket.seats_used

    @api.depends('seats_limited', 'seats_available')
    def _compute_is_sold_out(self):
        for ticket in self:
            ticket.is_sold_out = ticket.seats_limited and not ticket.seats_available

    @api.constrains('start_sale_datetime', 'end_sale_datetime')
    def _constrains_dates_coherency(self):
        for ticket in self:
            if ticket.start_sale_datetime and ticket.end_sale_datetime and ticket.start_sale_datetime > ticket.end_sale_datetime:
                raise UserError(_('The stop date cannot be earlier than the start date. '
                                  'Please check ticket %(ticket_name)s', ticket_name=ticket.name))

    @api.constrains('registration_ids', 'seats_max')
    def _check_seats_availability(self, minimal_availability=0):
        sold_out_tickets = []
        for ticket in self:
            if ticket.seats_max and ticket.seats_available < minimal_availability:
                sold_out_tickets.append((_(
                    '- the ticket "%(ticket_name)s" (%(event_name)s): Missing %(nb_too_many)i seats.',
                    ticket_name=ticket.name, event_name=ticket.event_id.name, nb_too_many=-ticket.seats_available)))
        if sold_out_tickets:
            raise ValidationError(_('There are not enough seats available for:')
                                  + '\n%s\n' % '\n'.join(sold_out_tickets))

    @api.depends('seats_max', 'seats_available')
    @api.depends_context('name_with_seats_availability')
    def _compute_display_name(self):
        """Adds ticket seats availability if requested by context."""
        if not self.env.context.get('name_with_seats_availability'):
            return super()._compute_display_name()
        for ticket in self:
            if not ticket.seats_max:
                name = ticket.name
            elif not ticket.seats_available:
                name = _('%(ticket_name)s (Sold out)', ticket_name=ticket.name)
            else:
                name = _(
                    '%(ticket_name)s (%(count)s seats remaining)',
                    ticket_name=ticket.name,
                    count=formatLang(self.env, ticket.seats_available, digits=0),
                )
            ticket.display_name = name

    def _get_ticket_multiline_description(self):
        """ Compute a multiline description of this ticket. It is used when ticket
        description are necessary without having to encode it manually, like sales
        information. """
        return '%s\n%s' % (self.display_name, self.event_id.display_name)

    def _set_tz_context(self):
        self.ensure_one()
        return self.with_context(tz=self.event_id.date_tz or 'UTC')

    @api.ondelete(at_uninstall=False)
    def _unlink_except_if_registrations(self):
        if self.registration_ids:
            raise UserError(_(
                "The following tickets cannot be deleted while they have one or more registrations linked to them:\n- %s",
                '\n- '.join(self.mapped('name'))))
