# -*- coding: utf-8 -*-
from odoo import models, api, fields

class PosPrepDisplay(models.Model):
    _inherit = 'pos.prep.display'

    @api.depends('stage_ids', 'pos_config_ids', 'category_ids')
    def _compute_order_count(self):
        for preparation_display in self:
            open_pdis_lines = preparation_display._get_open_orderlines_in_display()
            progress_orders = open_pdis_lines.filtered(
                lambda state: state.stage_id.id != preparation_display.stage_ids[-1].id
            ).prep_line_id.prep_order_id
            preparation_display.order_count = len(progress_orders)

            completed_order_times = []
            open_prep_order_ids = open_pdis_lines.prep_line_id.prep_order_id.ids
            
            # Fetch at most the last 100 completed preparation orders to avoid huge loops and timeouts
            done_orders = self.env['pos.prep.order'].search(
                [('id', 'not in', open_prep_order_ids)],
                order='id desc',
                limit=100
            )
            
            if done_orders:
                # Batch query all pos.prep.state for these done orders in a single query
                states = self.env['pos.prep.state'].search([
                    ('prep_line_id.prep_order_id', 'in', done_orders.ids),
                    ('stage_id', 'in', preparation_display.stage_ids.ids)
                ])
                
                # Group states by preparation order id in Python
                states_by_order = {}
                for state in states:
                    order_id = state.prep_line_id.prep_order_id.id
                    if order_id not in states_by_order:
                        states_by_order[order_id] = []
                    states_by_order[order_id].append(state)
                
                for order in done_orders:
                    order_lines = states_by_order.get(order.id, [])
                    if order_lines and order.pos_order_id and order.pos_order_id.create_date:
                        max_write_date = max(state.write_date for state in order_lines)
                        completed_order_times.append((max_write_date - order.pos_order_id.create_date).total_seconds())

            preparation_display.average_time = round(sum(completed_order_times) / len(completed_order_times) / 60) if completed_order_times else 0