import json
import logging
from markupsafe import Markup
from odoo import api, fields, models

_logger = logging.getLogger(__name__)

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

    x_logged_cancellations = fields.Text(string='Logged Cancellations', default='[]')

    @api.model
    def _process_order(self, order, existing_order):
        # Extract frontend cancelled lines log
        cancelled_lines = order.get('x_cancelled_lines', [])
        
        res = super()._process_order(order, existing_order)
        
        pos_order = self.browse(res) if isinstance(res, int) else res
        
        if pos_order and cancelled_lines:
            pos_order._log_cancelled_lines_to_chatter(cancelled_lines)
            
        return res

    def _log_cancelled_lines_to_chatter(self, cancelled_lines):
        self.ensure_one()
        try:
            logged_ids = json.loads(self.x_logged_cancellations or '[]')
        except Exception:
            logged_ids = []
            
        new_cancellations = []
        for cancel in cancelled_lines:
            cancel_id = cancel.get('id')
            if cancel_id and cancel_id not in logged_ids:
                new_cancellations.append(cancel)
                logged_ids.append(cancel_id)
                
        if new_cancellations:
            body = "<strong>Product Cancellation/Reduction Log:</strong><ul>"
            for cancel in new_cancellations:
                if cancel.get('action') == 'delete':
                    action_str = f"Deleted completely (quantity was {cancel.get('qty', 0)})"
                else:
                    action_str = f"Reduced quantity by {cancel.get('cancelled_qty', 0)} (from {cancel.get('qty', 0)} to {float(cancel.get('qty', 0)) - float(cancel.get('cancelled_qty', 0))})"
                body += f"<li><strong>{cancel.get('product_name')}</strong>: {action_str} by <strong>{cancel.get('employee_name', 'Unknown')}</strong></li>"
            body += "</ul>"
            self.message_post(body=Markup(body))
            self.write({'x_logged_cancellations': json.dumps(logged_ids)})

    def action_pos_order_cancel(self):
        # Capture the cashier / employee who cancelled the order
        employee_id = self.env.context.get('cancelled_by_employee_id')
        employee_name = "Unknown Employee"
        if employee_id:
            employee = self.env['hr.employee'].browse(employee_id)
            if employee.exists():
                employee_name = employee.name
        else:
            employee_name = self.env.user.name

        # Flush any pending x_cancelled_lines that were accumulated on the
        # frontend but never sent via _process_order (i.e. the order was
        # cancelled without payment). The JS passes these as a dict keyed by
        # order ID: { "<order_id>": [...cancelled_lines...] }
        cancelled_lines_map = self.env.context.get('cancelled_lines_map', {})

        res = super().action_pos_order_cancel()

        for order in self:
            order.message_post(body=Markup("<strong>Order Cancelled</strong> by <strong>{}</strong>").format(employee_name))

            # Log any frontend-tracked line deletions/reductions that happened
            # before this cancellation. Use str(order.id) as the JS context key
            # since JSON object keys are always strings.
            pending_lines = cancelled_lines_map.get(str(order.id)) or cancelled_lines_map.get(order.id)
            if pending_lines:
                order._log_cancelled_lines_to_chatter(pending_lines)

        # Prevent Odoo backend warning regarding custom action properties
        if isinstance(res, dict) and 'type' not in res:
            res['type'] = ''

        return res

    def _prepare_pos_log(self, body):
        if self.employee_id and hasattr(self.employee_id, 'pos_role') and self.employee_id.pos_role:
            role_selection = dict(self.env['hr.employee']._fields['pos_role'].selection)
            role_name = role_selection.get(self.employee_id.pos_role, "Cashier")
            return body + Markup("<br/>") + f"{role_name} {self.employee_id.name}"
        return super()._prepare_pos_log(body)