<?php

namespace App\Http\Controllers\Api;

use App\Http\Controllers\Controller;
use App\Models\Reservation;
use Carbon\CarbonInterface;
use Illuminate\Http\JsonResponse;
use Illuminate\Http\Request;

class ReservationVerifyController extends Controller
{
    /**
     * 移动端「今日」核销：仅允许活动日（activity_days.activity_date）为当天的预约核销。
     */
    private function activityDayNotTodayMessage(Reservation $reservation): ?string
    {
        $reservation->loadMissing('activityDay');
        $today = now()->toDateString();

        if (!$reservation->activity_day_id || !$reservation->activityDay) {
            return '该预约未关联活动场次，仅支持核销「活动日为今日」的预约';
        }

        $ad = $reservation->activityDay->activity_date;
        $dateStr = $ad instanceof CarbonInterface ? $ad->format('Y-m-d') : (string) $ad;

        if ($dateStr !== $today) {
            return '仅可核销活动日为今日的预约。该预约活动日为：'.$dateStr;
        }

        return null;
    }

    /**
     * 扫码后先查询预约信息，不修改状态（用于移动端「确认后再核销」）。
     */
    public function preview(Request $request): JsonResponse
    {
        $data = $request->validate([
            'qr_token' => ['required', 'string'],
        ]);

        $reservation = Reservation::with([
            'venue:id,name,reservation_notice',
            'activity:id,title',
            'activityDay:id,activity_id,activity_date',
        ])->where('qr_token', $data['qr_token'])->first();

        if (!$reservation) {
            return response()->json(['message' => '无效的二维码或预约不存在'], 404);
        }

        $this->ensureVenuePermission($request, $reservation->venue_id);

        $blockReason = null;
        if ($reservation->status === 'verified') {
            $blockReason = '该预约已核销';
        } elseif ($reservation->status === 'cancelled') {
            $blockReason = '该预约已取消，不能核销';
        }

        $canVerify = $reservation->status === 'pending';
        if ($canVerify) {
            $dayMsg = $this->activityDayNotTodayMessage($reservation);
            if ($dayMsg !== null) {
                $canVerify = false;
                $blockReason = $dayMsg;
            }
        }

        return response()->json([
            'reservation' => $reservation,
            'can_verify' => $canVerify,
            'verify_block_reason' => $blockReason,
        ]);
    }

    public function index(Request $request): JsonResponse
    {
        $user = $request->user();
        $query = Reservation::with([
            'venue:id,name,reservation_notice',
            'activity:id,title',
            'activityDay:id,activity_id,activity_date',
        ])
            // 核销端列表：待核销在前，同状态内按 id 倒序
            ->orderByRaw("CASE WHEN status = 'pending' THEN 0 ELSE 1 END")
            ->orderByDesc('id');

        if (!$user->isSuperAdmin()) {
            $venueIds = $user->venues()->pluck('venues.id');
            $query->whereIn('venue_id', $venueIds);
        }

        if ($request->filled('status') && $request->string('status')->toString() !== 'all') {
            $query->where('status', (string) $request->string('status'));
        }
        if ($request->filled('keyword')) {
            $keyword = trim((string) $request->input('keyword'));
            $query->where(function ($q) use ($keyword) {
                $q->where('visitor_name', 'like', "%{$keyword}%")
                    ->orWhere('visitor_phone', 'like', "%{$keyword}%")
                    ->orWhere('id_card', 'like', "%{$keyword}%")
                    ->orWhere('qr_token', 'like', "%{$keyword}%");
            });
        }
        $dateField = (string) $request->input('date_field', 'created_at');
        if ($request->filled('start_date') || $request->filled('end_date')) {
            if ($dateField === 'activity_day') {
                $start = $request->filled('start_date') ? (string) $request->input('start_date') : null;
                $end = $request->filled('end_date') ? (string) $request->input('end_date') : $start;
                $query->whereHas('activityDay', function ($q) use ($start, $end) {
                    if ($start !== null && $start !== '') {
                        $q->whereDate('activity_date', '>=', $start);
                    }
                    if ($end !== null && $end !== '') {
                        $q->whereDate('activity_date', '<=', $end);
                    }
                });
            } else {
                if ($request->filled('start_date')) {
                    $query->whereDate('created_at', '>=', (string) $request->input('start_date'));
                }
                if ($request->filled('end_date')) {
                    $query->whereDate('created_at', '<=', (string) $request->input('end_date'));
                }
            }
        }

        return response()->json($query->limit(500)->get());
    }

    /**
     * 今日（活动日为当天）预约单数、已核销单数，与移动端「今日报名」同权限与场馆范围。
     * 一大一小按 1 单计算（按预约订单数统计）。
     */
    public function todaySummary(Request $request): JsonResponse
    {
        $user = $request->user();
        $today = now()->toDateString();

        $base = Reservation::query()
            ->whereHas('activityDay', function ($q) use ($today) {
                $q->whereDate('activity_date', $today);
            });

        if (!$user->isSuperAdmin()) {
            $venueIds = $user->venues()->pluck('venues.id');
            $base->whereIn('venue_id', $venueIds);
        }

        $totalOrders = (clone $base)->whereNotIn('status', ['cancelled'])->count();
        $verifiedOrders = (clone $base)->where('status', 'verified')->count();

        return response()->json([
            'total_orders' => (int) $totalOrders,
            'verified_orders' => (int) $verifiedOrders,
        ]);
    }

    public function verifyByToken(Request $request): JsonResponse
    {
        $data = $request->validate([
            'qr_token' => ['required', 'string'],
        ]);

        $reservation = Reservation::with('venue')->where('qr_token', $data['qr_token'])->firstOrFail();
        $this->ensureVenuePermission($request, $reservation->venue_id);

        if ($reservation->status === 'verified') {
            return response()->json(['message' => '该预约已核销'], 422);
        }
        if ($reservation->status === 'cancelled') {
            return response()->json(['message' => '该预约已取消，不能核销'], 422);
        }

        $dayBlock = $this->activityDayNotTodayMessage($reservation);
        if ($dayBlock !== null) {
            return response()->json(['message' => $dayBlock], 422);
        }

        $reservation->update([
            'status' => 'verified',
            'verified_by' => $request->user()->id,
            'verified_at' => now(),
        ]);

        return response()->json([
            'message' => '核销成功',
            'reservation' => $reservation->fresh()->load([
                'venue:id,name,reservation_notice',
                'activity:id,title',
                'activityDay:id,activity_id,activity_date',
                'verifier:id,name,username',
            ]),
        ]);
    }

    private function ensureVenuePermission(Request $request, int $venueId): void
    {
        $user = $request->user();
        if ($user->isSuperAdmin()) {
            return;
        }

        $allowed = $user->venues()->where('venues.id', $venueId)->exists();
        abort_unless($allowed, 403, '仅可核销已绑定场馆预约');
    }
}