pos_order_line_discount/models/pos_order.py

# -*- coding: utf-8 -*-
from odoo import models, api, fields
from odoo.tools import float_compare, float_round
import logging

_logger = logging.getLogger(__name__)


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

    def _distribute_discount_to_lines(self, order, discount_amount, is_percentage=False):
        """
        Distribute an order-level discount amount to individual order lines
        :param order: pos.order record
        :param discount_amount: The discount amount to distribute
        :param is_percentage: If True, discount_amount is a percentage; otherwise it's a fixed amount
        :return: Dictionary with line_id as key and discount value as value
        """
        if not order.lines:
            return {}

        # Filter out reward lines and lines with zero price
        regular_lines = order.lines.filtered(lambda l: not l.is_reward_line and l.price_subtotal > 0)
        if not regular_lines:
            return {}

        # Calculate total tax-exclusive amount for proportional distribution
        total_amount = sum(line.price_subtotal for line in regular_lines)
        if total_amount <= 0:
            return {}

        line_discounts = {}
        
        if is_percentage:
            # Apply the same percentage discount to all regular lines
            for line in regular_lines:
                # For percentage discounts, we simply add the percentages (simplified approach)
                # In a real scenario, you might want to compound them properly
                new_discount = min(100, line.discount + discount_amount)
                line_discounts[line.id] = new_discount
        else:
            # Distribute fixed amount proportionally based on line tax-exclusive subtotal
            remaining_discount = discount_amount
            lines_count = len(regular_lines)
            
            for i, line in enumerate(regular_lines):
                if i == lines_count - 1:
                    # Last line gets the remaining discount to avoid rounding issues
                    # Calculate the additional discount percentage for this line based on tax-exclusive price
                    if line.price_subtotal > 0:
                        additional_discount_percentage = (remaining_discount / line.price_subtotal) * 100
                        new_discount = min(100, line.discount + additional_discount_percentage)
                    else:
                        new_discount = line.discount
                    line_discounts[line.id] = new_discount
                else:
                    # Calculate proportional discount for this line based on tax-exclusive price
                    line_ratio = line.price_subtotal / total_amount if total_amount > 0 else 0
                    line_discount_amount = discount_amount * line_ratio
                    # Calculate the additional discount percentage for this line based on tax-exclusive price
                    if line.price_subtotal > 0:
                        additional_discount_percentage = (line_discount_amount / line.price_subtotal) * 100
                        new_discount = min(100, line.discount + additional_discount_percentage)
                    else:
                        new_discount = line.discount
                    line_discounts[line.id] = new_discount
                    remaining_discount -= line_discount_amount
                    
        return line_discounts

    def _apply_line_discounts(self, order, line_discounts):
        """
        Apply calculated discounts to order lines
        :param order: pos.order record
        :param line_discounts: Dictionary with line_id as key and discount value as value
        """
        for line in order.lines:
            if line.id in line_discounts:
                # Apply the calculated discount
                line.discount = line_discounts[line.id]
                # Trigger the onchange to recalculate the line amounts
                line._onchange_amount_line_all()
                
    @api.model
    def _process_order_rewards_as_line_discounts(self, order):
        """
        Process loyalty rewards as line discounts instead of order-level discounts
        :param order: pos.order record
        """
        if not order.config_id.apply_line_discount_on_rewards:
            return
            
        # Find reward lines
        reward_lines = order.lines.filtered(lambda l: l.is_reward_line)
        
        for reward_line in reward_lines:
            reward = reward_line.reward_id
            if reward and reward.reward_type == 'discount':
                # Calculate the discount amount that should be applied to regular lines
                reward_amount = abs(reward_line.price_subtotal)
                
                # Remove the reward line
                reward_line.unlink()
                
                # Distribute the discount to regular lines
                is_percentage = (reward.discount_mode == 'percent')
                discount_value = reward_amount if not is_percentage else reward.discount
                
                line_discounts = self._distribute_discount_to_lines(
                    order, 
                    discount_value, 
                    is_percentage=is_percentage
                )
                
                # Apply the discounts to lines
                self._apply_line_discounts(order, line_discounts)

    @api.model
    def _process_order(self, order, draft, existing_order):
        """
        Override to process rewards as line discounts
        """
        pos_order_id = super(PosOrder, self)._process_order(order, draft, existing_order)
        
        # Convert order-level rewards to line discounts
        if isinstance(pos_order_id, int):
            pos_order = self.browse(pos_order_id)
            self._process_order_rewards_as_line_discounts(pos_order)
            
        return pos_order_id


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

    def _compute_amount_line_all(self):
        """
        Override to handle line-level discounts properly
        """
        res = super(PosOrderLine, self)._compute_amount_line_all()
        # Additional logic for line discounts can be added here if needed
        return res

    @api.onchange('discount')
    def _onchange_discount(self):
        """
        Override to handle line discount changes
        """
        super(PosOrderLine, self)._onchange_discount()
        # Additional logic for handling line discount changes can be added here