<?php

namespace App\Domain\PlannedItem\Actions;

use App\Domain\Trip\Services\CalendarSlotService;
use App\Models\PlannableItem;
use App\Models\CalendarSlot;
use App\Models\PlannedItem;
use Carbon\Carbon;

class CreatePlannedItemAction
{
    public function __construct(
        private CalendarSlotService $calendarSlotService
    ) {}

    /**
     * Create a new planned item from datetime parameters
     *
     * @param array $data ['plannable_item_id', 'trip_id', 'start_datetime', 'end_datetime', 'sort_order'?]
     * @return CalendarSlot The calendar slot with loaded planned items
     * @throws \Exception
     */
    public function execute(array $data): CalendarSlot
    {
        $startDatetime = Carbon::parse($data['start_datetime']);
        $endDatetime = Carbon::parse($data['end_datetime']);
        $slotDate = $startDatetime->toDateString();

        // Verify the plannable item belongs to the trip
        $plannableItem = PlannableItem::findOrFail($data['plannable_item_id']);
        if ($plannableItem->trip_id !== $data['trip_id']) {
            throw new \Exception('Plannable item does not belong to this trip');
        }

        // Use database transaction to prevent race conditions
        $calendarSlot = \DB::transaction(function () use ($data, $plannableItem, $startDatetime, $endDatetime, $slotDate) {
            // Use firstOrCreate to prevent duplicate slots with same times
            $calendarSlot = CalendarSlot::firstOrCreate(
                [
                    'trip_id' => $data['trip_id'],
                    'datetime_start' => $startDatetime,
                    'datetime_end' => $endDatetime,
                    'slot_date' => $slotDate,
                ],
                [
                    'name' => $plannableItem->name,
                    'slot_order' => 0, // Will be recalculated
                ]
            );

            // Recalculate slot orders to ensure consistency
            $this->calendarSlotService->recalculateSlotOrdersForDate(
                $data['trip_id'],
                $slotDate
            );

            // Create PlannedItem link (use firstOrCreate to prevent race condition duplicates)
            PlannedItem::firstOrCreate(
                [
                    'plannable_item_id' => $data['plannable_item_id'],
                    'calendar_slot_id' => $calendarSlot->id,
                ],
                [
                    'sort_order' => $data['sort_order'] ?? 0,
                ]
            );

            return $calendarSlot;
        });

        return $calendarSlot->load(['plannedItems.plannableItem']);
    }

    /**
     * Create planned item from existing calendar slot (legacy flow)
     *
     * @param array $data ['plannable_item_id', 'calendar_slot_id', 'sort_order'?]
     * @return PlannedItem
     * @throws \Exception
     */
    public function executeFromSlot(array $data): PlannedItem
    {
        // Validate that calendar slot and plannable item belong to the same trip
        $plannableItem = PlannableItem::findOrFail($data['plannable_item_id']);
        $calendarSlot = CalendarSlot::findOrFail($data['calendar_slot_id']);

        if ($plannableItem->trip_id !== $calendarSlot->trip_id) {
            throw new \Exception('Calendar slot and plannable item must belong to the same trip');
        }

        $plannedItem = PlannedItem::updateOrCreate(
            [
                'plannable_item_id' => $data['plannable_item_id'],
                'calendar_slot_id' => $data['calendar_slot_id'],
            ],
            [
                'sort_order' => $data['sort_order'] ?? 0,
            ]
        );

        return $plannedItem->load(['plannableItem', 'calendarSlot']);
    }
}