from odoo import models, fields, api, _
from odoo.exceptions import ValidationError
from datetime import timedelta
import pytz

class RestaurantReservation(models.Model):
    _name = 'restaurant.reservation'
    _description = 'Restaurant Table Reservation'
    _order = 'start_time desc'

    name = fields.Char(string='Reservation Reference', required=True, copy=False, readonly=True, default=lambda self: _('New'))
    customer_name = fields.Char(string='Customer Name', required=True)
    phone = fields.Char(string='Phone Number', required=True)
    email = fields.Char(string='Email')
    num_people = fields.Integer(string='Number of People', default=1)
    
    floor_id = fields.Many2one('restaurant.floor', string='Floor', required=True)
    table_id = fields.Many2one('restaurant.table', string='Table', required=True)
    
    start_time = fields.Datetime(string='Start Time', required=True)
    end_time = fields.Datetime(string='End Time', required=True)

    whatsapp_url = fields.Char(compute='_compute_whatsapp_url')

    def _compute_whatsapp_url(self):
        for rec in self:
            if rec.phone and rec.customer_name and rec.start_time:
                msg = f"Hello {rec.customer_name}, your reservation {rec.name or ''} for {rec.start_time.strftime('%I:%M %p')} is confirmed!"
                rec.whatsapp_url = f"https://wa.me/{rec.phone}?text={msg.replace(' ', '%20')}"
            else:
                rec.whatsapp_url = False
    
    state = fields.Selection([
        ('draft', 'Draft'),
        ('confirmed', 'Confirmed'),
        ('completed', 'Completed'),
        ('cancelled', 'Cancelled')
    ], string='Status', default='draft', tracking=True)

    @api.model
    def create(self, vals):
        if vals.get('name', _('New')) == _('New'):
            vals['name'] = self.env['ir.sequence'].next_by_code('restaurant.reservation') or _('New')
        return super(RestaurantReservation, self).create(vals)

    @api.constrains('table_id', 'start_time', 'end_time', 'state')
    def _check_overlap(self):
        for rec in self:
            if rec.state in ['confirmed', 'completed']:
                overlap = self.search([
                    ('id', '!=', rec.id),
                    ('table_id', '=', rec.table_id.id),
                    ('state', '=', 'confirmed'),
                    ('start_time', '<', rec.end_time),
                    ('end_time', '>', rec.start_time),
                ])
                if overlap:
                    raise ValidationError(_('This table is already reserved for the selected time slot.'))

    @api.constrains('start_time', 'end_time')
    def _check_opening_hours(self):
        restaurant_tz = pytz.timezone('America/Toronto')
        for rec in self:
            local_start = pytz.utc.localize(rec.start_time).astimezone(restaurant_tz)
            local_end = pytz.utc.localize(rec.end_time).astimezone(restaurant_tz)
            
            day = local_start.weekday() # 0=Mon, 6=Sun
            time_start = local_start.hour + local_start.minute / 60.0
            time_end = local_end.hour + local_end.minute / 60.0
            
            if day in [6, 0, 1, 2, 3]: # Sun-Thu
                if time_start < 12.0 or time_end > 21.0:
                    raise ValidationError(_('Reservations for Sunday - Thursday must be between 12:00 PM and 9:00 PM (Local Time).'))
            else: # Fri-Sat
                if time_start < 12.0 or time_end > 23.0:
                    raise ValidationError(_('Reservations for Friday & Saturday must be between 12:00 PM and 11:00 PM (Local Time).'))

    @api.onchange('start_time')
    def _onchange_start_time(self):
        if self.start_time:
            self.end_time = self.start_time + timedelta(hours=1)

    def action_confirm(self):
        self.write({'state': 'confirmed'})
        self._send_confirmation_notification()

    def action_complete(self):
        self.write({'state': 'completed'})

    def action_cancel(self):
        self.write({'state': 'cancelled'})

    def _send_confirmation_notification(self):
        """ Placeholder for WhatsApp/SMS logic """
        for rec in self:
            # Logic for WhatsApp/SMS can be added here
            # e.g., self.env['sms.api']._send_sms(rec.phone, "Your table is confirmed!")
            pass

    @api.model
    def _auto_complete_reservations(self):
        """ Scheduled action to mark past reservations as completed """
        now = fields.Datetime.now()
        past_reservations = self.search([
            ('state', '=', 'confirmed'),
            ('end_time', '<', now)
        ])
        past_reservations.write({'state': 'completed'})