# Part of Odoo. See LICENSE file for full copyright and licensing details.

import logging
from odoo import api, models

_logger = logging.getLogger(__name__)


class PosOrder(models.Model):
    _inherit = 'pos.order'

    def action_pos_order_paid(self):
        """Override to update the customer's membership level after payment."""
        res = super().action_pos_order_paid()
        for order in self:
            if order.partner_id:
                order._update_customer_membership_level()
        return res

    def confirm_coupon_programs(self, coupon_data):
        """Also update membership after the frontend confirms coupon programs to catch current order's points."""
        res = super().confirm_coupon_programs(coupon_data)
        for order in self:
            if order.partner_id:
                order._update_customer_membership_level()
        return res

    def _update_customer_membership_level(self):
        """Determine and update the customer's loyalty membership level.

        1. Sum all paid pos.order amount_total for this partner.
        2. Fetch all loyalty.program where multi_level_membership = True,
           ordered by minimum_spend ascending.
        3. Find the highest level the customer qualifies for
           (highest minimum_spend <= total purchases).
        4. Update res.partner.membership_level_id if it differs.
        5. Consolidate points from other tier cards.
        """
        self.ensure_one()
        partner = self.partner_id
        if not partner:
            return

        # 1. Calculate total purchases for this customer (only paid/done orders)
        total_purchases = self._get_customer_total_purchases(partner)

        # 2. Get all multi-level loyalty programs sorted by minimum spend ASC
        loyalty_programs = self.env['loyalty.program'].sudo().search(
            [('multi_level_membership', '=', True)],
            order='minimum_spend asc',
        )

        if not loyalty_programs:
            _logger.info(
                'No multi-level loyalty programs found. '
                'Skipping membership level update for partner %s (ID: %s).',
                partner.name, partner.id,
            )
            return

        # 3. Determine the appropriate level
        matched_program = None
        for program in loyalty_programs:
            min_spend = program.minimum_spend or 0.0
            if total_purchases >= min_spend:
                matched_program = program
            else:
                break

        if not matched_program:
            _logger.info(
                'Customer %s (ID: %s) total purchases %.2f do not meet '
                'the minimum spend of any multi-level loyalty program. '
                'Clearing membership level.',
                partner.name, partner.id, total_purchases,
            )
            if partner.membership_level_id:
                partner.sudo().write({'membership_level_id': False})
            return

        # 4. Compare with current level and update if different
        current_level_id = partner.membership_level_id.id if partner.membership_level_id else False
        if current_level_id != matched_program.id:
            _logger.info(
                'Updating membership level for customer %s (ID: %s): '
                '%s -> %s (total purchases: %.2f)',
                partner.name,
                partner.id,
                partner.membership_level_id.name if partner.membership_level_id else 'None',
                matched_program.name,
                total_purchases,
            )
            partner.sudo().write({'membership_level_id': matched_program.id})
        else:
            _logger.debug(
                'Membership level unchanged for customer %s (ID: %s): '
                '%s (total purchases: %.2f)',
                partner.name,
                partner.id,
                matched_program.name,
                total_purchases,
            )

        # 5. Transfer points from old loyalty card(s) to new loyalty card
        all_multi_level_program_ids = loyalty_programs.mapped('id')
        other_programs = [pid for pid in all_multi_level_program_ids if pid != matched_program.id]
        
        if other_programs:
            old_cards = self.env['loyalty.card'].sudo().search([
                ('partner_id', '=', partner.id),
                ('program_id', 'in', other_programs),
                ('points', '!=', 0),
            ])

            if old_cards:
                new_card = self.env['loyalty.card'].sudo().search([
                    ('partner_id', '=', partner.id),
                    ('program_id', '=', matched_program.id),
                ], limit=1)

                if not new_card:
                    new_card = self.env['loyalty.card'].sudo().create({
                        'partner_id': partner.id,
                        'program_id': matched_program.id,
                        'points': 0,
                    })

                for old_card in old_cards:
                    pts_to_transfer = old_card.points
                    if abs(pts_to_transfer) > 0.0001:  # Simple check to avoid floating point noise transfers
                        new_card.points += pts_to_transfer
                        old_card.points = 0
                        _logger.info(
                            'Transferred %s points from loyalty program "%s" to "%s" for customer %s (ID: %s)',
                            pts_to_transfer,
                            old_card.program_id.name,
                            new_card.program_id.name,
                            partner.name,
                            partner.id,
                        )

    @api.model
    def _get_customer_total_purchases(self, partner):
        """Calculate the total amount of paid/done POS orders for a given partner.

        :param partner: res.partner record
        :returns: float total of amount_total across all qualifying orders
        """
        orders = self.sudo().search([
            ('partner_id', '=', partner.id),
            ('state', 'in', ('paid', 'done')),
        ])
        return sum(orders.mapped('amount_total'))