<?php

namespace App\Http\Controllers\Api\Tenant;

use App\Http\Controllers\Controller;
use App\Http\Requests\Tenant\EventStoreRequest;
use Illuminate\Support\Str;
use App\Http\Resources\Tenant\EventResource;
use App\Models\Event;
use App\Models\Tenant;
use Illuminate\Http\Request;
use Illuminate\Http\Resources\Json\AnonymousResourceCollection;
use Illuminate\Http\JsonResponse;
use Illuminate\Support\Facades\Gate;
use Illuminate\Validation\ValidationException;

class EventController extends Controller
{
    /**
     * Display a listing of the tenant's events.
     */
    public function index(Request $request): AnonymousResourceCollection
    {
        $tenantId = $request->attributes->get('tenant_id');
        
        if (!$tenantId) {
            throw ValidationException::withMessages([
                'tenant_id' => 'Tenant ID not found in request context.',
            ]);
        }

        $query = Event::where('tenant_id', $tenantId)
            ->with(['eventType', 'photos'])
            ->orderBy('created_at', 'desc');

        // Apply filters
        if ($request->has('status')) {
            $query->where('status', $request->status);
        }

        if ($request->has('type_id')) {
            $query->where('event_type_id', $request->type_id);
        }

        // Pagination
        $perPage = $request->get('per_page', 15);
        $events = $query->paginate($perPage);

        return EventResource::collection($events);
    }

    /**
     * Store a newly created event in storage.
     */
    public function store(EventStoreRequest $request): JsonResponse
    {
        $tenantId = $request->attributes->get('tenant_id');
        
        // Check credits balance
        $tenant = Tenant::findOrFail($tenantId);
        if ($tenant->event_credits_balance <= 0) {
            return response()->json([
                'error' => 'Insufficient event credits. Please purchase more credits.',
            ], 402);
        }

        $validated = $request->validated();

        $event = Event::create(array_merge($validated, [
            'tenant_id' => $tenantId,
            'status' => 'draft', // Default status
            'slug' => $this->generateUniqueSlug($validated['name'], $tenantId),
        ]));

        // Decrement credits
        $tenant->decrement('event_credits_balance', 1);

        $event->load(['eventType', 'tenant']);

        return response()->json([
            'message' => 'Event created successfully',
            'data' => new EventResource($event),
        ], 201);
    }

    /**
     * Display the specified event.
     */
    public function show(Request $request, Event $event): JsonResponse
    {
        $tenantId = $request->attributes->get('tenant_id');

        // Ensure event belongs to tenant
        if ($event->tenant_id !== $tenantId) {
            return response()->json(['error' => 'Event not found'], 404);
        }

        $event->load([
            'eventType',
            'photos' => fn ($query) => $query->with('likes')->latest(),
            'tasks',
            'tenant' => fn ($query) => $query->select('id', 'name', 'event_credits_balance')
        ]);

        return response()->json([
            'data' => new EventResource($event),
        ]);
    }

    /**
     * Update the specified event in storage.
     */
    public function update(EventStoreRequest $request, Event $event): JsonResponse
    {
        $tenantId = $request->attributes->get('tenant_id');

        // Ensure event belongs to tenant
        if ($event->tenant_id !== $tenantId) {
            return response()->json(['error' => 'Event not found'], 404);
        }

        $validated = $request->validated();

        // Update slug if name changed
        if ($validated['name'] !== $event->name) {
            $validated['slug'] = $this->generateUniqueSlug($validated['name'], $tenantId, $event->id);
        }

        $event->update($validated);

        $event->load(['eventType', 'tenant']);

        return response()->json([
            'message' => 'Event updated successfully',
            'data' => new EventResource($event),
        ]);
    }

    /**
     * Remove the specified event from storage.
     */
    public function destroy(Request $request, Event $event): JsonResponse
    {
        $tenantId = $request->attributes->get('tenant_id');

        // Ensure event belongs to tenant
        if ($event->tenant_id !== $tenantId) {
            return response()->json(['error' => 'Event not found'], 404);
        }

        // Soft delete
        $event->delete();

        return response()->json([
            'message' => 'Event deleted successfully',
        ]);
    }

    /**
     * Bulk update event status (publish/unpublish)
     */
    public function bulkUpdateStatus(Request $request): JsonResponse
    {
        $tenantId = $request->attributes->get('tenant_id');
        $validated = $request->validate([
            'event_ids' => 'required|array',
            'event_ids.*' => 'exists:events,id',
            'status' => 'required|in:draft,published,archived',
        ]);

        $updatedCount = Event::whereIn('id', $validated['event_ids'])
            ->where('tenant_id', $tenantId)
            ->update(['status' => $validated['status']]);

        return response()->json([
            'message' => "{$updatedCount} events updated successfully",
            'updated_count' => $updatedCount,
        ]);
    }

    /**
     * Generate unique slug for event name
     */
    private function generateUniqueSlug(string $name, int $tenantId, ?int $excludeId = null): string
    {
        $slug = Str::slug($name);
        $originalSlug = $slug;

        $counter = 1;
        while (Event::where('slug', $slug)
            ->where('tenant_id', $tenantId)
            ->where('id', '!=', $excludeId)
            ->exists()) {
            $slug = $originalSlug . '-' . $counter;
            $counter++;
        }

        return $slug;
    }

    /**
     * Search events by name or description
     */
    public function search(Request $request): AnonymousResourceCollection
    {
        $tenantId = $request->attributes->get('tenant_id');
        $query = $request->get('q', '');

        if (strlen($query) < 2) {
            return EventResource::collection(collect([]));
        }

        $events = Event::where('tenant_id', $tenantId)
            ->where(function ($q) use ($query) {
                $q->where('name', 'like', "%{$query}%")
                  ->orWhere('description', 'like', "%{$query}%");
            })
            ->with('eventType')
            ->limit(10)
            ->get();

        return EventResource::collection($events);
    }
}