<?php

namespace App\Http\Controllers;

use App\Models\Attachment;
use App\Models\AttachmentExtension;
use Illuminate\Http\JsonResponse;
use Illuminate\Http\Request;

class AttachmentExtensionController extends Controller
{
    private function ensureAdmin(Request $request): ?JsonResponse
    {
        $user = $request->user();
        if (!$user || !$user->roles()->where('name', 'ROLE_ADMIN')->exists()) {
            return response()->json(['message' => 'Forbidden'], 403);
        }

        return null;
    }

    public function index(Request $request): JsonResponse
    {
        if ($error = $this->ensureAdmin($request)) {
            return $error;
        }

        $extensions = AttachmentExtension::query()
            ->with('group')
            ->orderBy('extension')
            ->get()
            ->map(fn (AttachmentExtension $extension) => $this->serializeExtension($extension));

        return response()->json($extensions);
    }

    public function publicIndex(): JsonResponse
    {
        $extensions = AttachmentExtension::query()
            ->whereNotNull('attachment_group_id')
            ->whereHas('group', fn ($query) => $query->where('is_active', true))
            ->orderBy('extension')
            ->pluck('extension')
            ->filter()
            ->values();

        return response()->json($extensions);
    }

    public function store(Request $request): JsonResponse
    {
        if ($error = $this->ensureAdmin($request)) {
            return $error;
        }

        $data = $this->validatePayload($request, true);
        $extension = $this->normalizeExtension($data['extension']);
        if ($extension === '') {
            return response()->json(['message' => 'Invalid extension.'], 422);
        }

        if (AttachmentExtension::query()->where('extension', $extension)->exists()) {
            return response()->json(['message' => 'Extension already exists.'], 422);
        }

        $created = AttachmentExtension::create([
            'extension' => $extension,
            'attachment_group_id' => $data['attachment_group_id'] ?? null,
            'allowed_mimes' => $data['allowed_mimes'] ?? null,
        ]);

        $created->load('group');

        return response()->json($this->serializeExtension($created), 201);
    }

    public function update(Request $request, AttachmentExtension $attachmentExtension): JsonResponse
    {
        if ($error = $this->ensureAdmin($request)) {
            return $error;
        }

        $data = $this->validatePayload($request, false);

        if (array_key_exists('attachment_group_id', $data)) {
            $attachmentExtension->attachment_group_id = $data['attachment_group_id'];
        }
        if (array_key_exists('allowed_mimes', $data)) {
            $attachmentExtension->allowed_mimes = $data['allowed_mimes'];
        }

        $attachmentExtension->save();
        $attachmentExtension->load('group');

        return response()->json($this->serializeExtension($attachmentExtension));
    }

    public function destroy(Request $request, AttachmentExtension $attachmentExtension): JsonResponse
    {
        if ($error = $this->ensureAdmin($request)) {
            return $error;
        }

        if (Attachment::query()->where('attachment_extension_id', $attachmentExtension->id)->exists()) {
            return response()->json(['message' => 'Extension is in use.'], 422);
        }

        $attachmentExtension->delete();

        return response()->json(null, 204);
    }

    private function validatePayload(Request $request, bool $requireExtension): array
    {
        $rules = [
            'attachment_group_id' => ['nullable', 'integer', 'exists:attachment_groups,id'],
            'allowed_mimes' => ['nullable', 'array'],
            'allowed_mimes.*' => ['string', 'max:150'],
        ];

        if ($requireExtension) {
            $rules['extension'] = ['required', 'string', 'max:30'];
        }

        return $request->validate($rules);
    }

    private function normalizeExtension(string $value): string
    {
        return ltrim(strtolower(trim($value)), '.');
    }

    private function serializeExtension(AttachmentExtension $extension): array
    {
        return [
            'id' => $extension->id,
            'extension' => $extension->extension,
            'attachment_group_id' => $extension->attachment_group_id,
            'allowed_mimes' => $extension->allowed_mimes,
            'group' => $extension->group ? [
                'id' => $extension->group->id,
                'name' => $extension->group->name,
                'is_active' => $extension->group->is_active,
            ] : null,
        ];
    }
}