import logging
from odoo import models, fields, api
from odoo.addons.pos_enterprise.utils.date_utils import compute_seconds_since

_logger = logging.getLogger(__name__)


class PosPreparationState(models.Model):
    _inherit = 'pos.prep.state'

    def _update_kds_report(self, pdis_state, old_last_stage_change=None):
        """
        Synchronous KDS report update.
        Optimized to minimize database calls and avoid redundant aggregations.
        """
        if not pdis_state.prep_line_id:
            return

        order_line = pdis_state.prep_line_id.pos_order_line_id
        if not order_line:
            return

        order = order_line.order_id
        stage = pdis_state.stage_id
        if not stage:
            return

        display = stage.prep_display_id
        if not display:
            return

        stage_ids = display.stage_ids.ids
        if not stage_ids:
            return

        first_stage_id = stage_ids[0]
        last_stage_id = stage_ids[-1]
        second_last_stage_id = stage_ids[-2] if len(stage_ids) > 1 else False

        # Determine if this is a completion or a reset
        is_completed = False
        if len(stage_ids) > 1:
            if stage.id == last_stage_id:
                is_completed = True
            elif second_last_stage_id and stage.id == second_last_stage_id and not pdis_state.todo:
                is_completed = True
        else:
            if not pdis_state.todo:
                is_completed = True

        is_reset = (stage.id == first_stage_id and pdis_state.todo)

        if not (is_completed or is_reset):
            return

        display_id = display.id
        order_id = order.id
        order_name = order.name or order.pos_reference or "Order"

        KdsLineReport = self.env['pos.kds.report.line'].sudo()
        KdsOrderReport = self.env['pos.kds.report.order'].sudo()

        try:
            if is_reset:
                _logger.info("KDS Reset: Order %s on display %s", order_name, display.name)
                line_report = KdsLineReport.search([
                    ('pos_order_line_id', '=', order_line.id),
                    ('prep_display_id', '=', display_id)
                ], limit=1)
                if line_report:
                    line_report.unlink()

                order_report = KdsOrderReport.search([
                    ('pos_order_id', '=', order_id),
                    ('prep_display_id', '=', display_id)
                ], limit=1)

                if order_report:
                    res = KdsLineReport._read_group(
                        [('pos_order_id', '=', order_id), ('prep_display_id', '=', display_id)],
                        aggregates=['completion_time:max']
                    )
                    max_comp_time = res[0][0] if res else 0
                    if max_comp_time == 0:
                        order_report.unlink()
                    else:
                        order_report.write({'completion_time': max_comp_time})
                return

            # --- Completed ---
            # Use a slightly larger epsilon for -1 check to be safe with float/int conversions if any
            prep_time = order_line.preparation_time
            svc_time = order_line.service_time

            # Fallback timing logic
            if prep_time == -1:
                if old_last_stage_change:
                    # If we have the old timestamp, it means we spent time in the previous stage
                    prep_time = int(compute_seconds_since(old_last_stage_change))
                else:
                    # Otherwise use the current stage entry time
                    prep_time = int(compute_seconds_since(pdis_state.last_stage_change))
            
            if svc_time == -1:
                if is_completed and stage.id == last_stage_id and old_last_stage_change:
                    # If moving to last stage, service time is time spent in previous stage
                    svc_time = int(compute_seconds_since(old_last_stage_change))
                else:
                    svc_time = 0

            prep_time = max(0, prep_time)
            svc_time = max(0, svc_time)
            comp_time = prep_time + svc_time

            _logger.info("KDS Completed: Order %s, Line %s: Prep=%ss, Svc=%ss, Total=%ss", 
                         order_name, order_line.product_id.name, prep_time, svc_time, comp_time)

            vals = {
                'pos_order_id': order_id,
                'pos_order_line_id': order_line.id,
                'product_id': order_line.product_id.id,
                'prep_display_id': display_id,
                'preparation_time': prep_time,
                'service_time': svc_time,
                'completion_time': comp_time,
                'completion_datetime': fields.Datetime.now(),
            }

            line_report = KdsLineReport.search([
                ('pos_order_line_id', '=', order_line.id),
                ('prep_display_id', '=', display_id)
            ], limit=1)

            if line_report:
                line_report.write(vals)
            else:
                KdsLineReport.create(vals)

            # Update Order Report - Optimized to avoid _read_group inside loops
            order_report = KdsOrderReport.search([
                ('pos_order_id', '=', order_id),
                ('prep_display_id', '=', display_id)
            ], limit=1)

            if order_report:
                # Only update if the new completion time is greater, or if it's been some time
                if comp_time > order_report.completion_time:
                    order_report.write({
                        'completion_time': comp_time,
                        'completion_datetime': vals['completion_datetime'],
                    })
            else:
                KdsOrderReport.create({
                    'pos_order_id': order_id,
                    'prep_display_id': display_id,
                    'completion_time': comp_time,
                    'completion_datetime': vals['completion_datetime'],
                })

        except Exception as e:
            _logger.error("KDS reporting failed for order %s: %s", order_name, e, exc_info=True)

    def _record_status_change_prep_time(self, pdis_state):
        super()._record_status_change_prep_time(pdis_state)
        self._update_kds_report(pdis_state)

    def _record_stage_change_prep_time(self, pdis_state, old_last_stage_change, prep_order_completion_time):
        super()._record_stage_change_prep_time(pdis_state, old_last_stage_change, prep_order_completion_time)
        self._update_kds_report(pdis_state, old_last_stage_change=old_last_stage_change)