<?php

/**
 * File Revision Controller — client API
 *
 * @author  Ball Studios <https://git.balls.studio>
 * @license MIT
 */

namespace Pterodactyl\Addons\AdvancedAdmin\Http\Controllers\Client;

use Illuminate\Http\JsonResponse;
use Illuminate\Http\Request;
use Illuminate\Routing\Controller;
use Symfony\Component\HttpFoundation\StreamedResponse;
use Pterodactyl\Addons\AdvancedAdmin\Models\FileRevision;
use Pterodactyl\Addons\AdvancedAdmin\Services\Revisions\DiffService;
use Pterodactyl\Addons\AdvancedAdmin\Services\Revisions\RevisionService;
use Pterodactyl\Addons\AdvancedAdmin\Services\Revisions\RevisionStorageService;
use Pterodactyl\Models\Server;

class FileRevisionController extends Controller
{
    public function __construct(
        private readonly RevisionService        $revisionService,
        private readonly DiffService            $diffService,
        private readonly RevisionStorageService $storage,
    ) {}

    /** GET /api/client/servers/{server}/addons/files/revisions?path= */
    public function index(Request $request, Server $server): JsonResponse
    {
        $this->requirePermission($request, $server, 'file.read');

        $path = $request->string('path', '')->toString();
        abort_if(empty($path), 422, 'path parameter is required.');

        $path     = $this->storage->guardFilePath($path);
        $pathHash = $this->storage->pathHash($server->id, $path);

        $revisions = FileRevision::query()
            ->where('server_id', $server->id)
            ->where('path_hash', $pathHash)
            ->with('author:id,username,email')
            ->orderByDesc('revision_number')
            ->paginate(25);

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

    /** GET /api/client/servers/{server}/addons/files/revisions/{revision} */
    public function show(Request $request, Server $server, FileRevision $revision): JsonResponse
    {
        $this->requirePermission($request, $server, 'file.read');
        $this->assertBelongsToServer($revision, $server);

        return response()->json(['data' => $revision->load('author:id,username,email')]);
    }

    /** GET /api/client/servers/{server}/addons/files/revisions/{revision}/diff */
    public function diff(Request $request, Server $server, FileRevision $revision): JsonResponse
    {
        $this->requirePermission($request, $server, 'file.read');
        $this->assertBelongsToServer($revision, $server);

        $content = $this->storage->retrieve($revision->storage_key);

        // If binary, return a placeholder diff
        if ($this->storage->isBinary($content)) {
            return response()->json(['binary' => true, 'lines' => []]);
        }

        // Fetch previous revision for comparison
        $previous = FileRevision::query()
            ->where('server_id', $server->id)
            ->where('path_hash', $revision->path_hash)
            ->where('revision_number', $revision->revision_number - 1)
            ->first();

        $oldContent = $previous ? $this->storage->retrieve($previous->storage_key) : '';

        $lines = $this->diffService->diff($oldContent, $content, basename($revision->file_path));
        return response()->json(['binary' => false, 'lines' => $lines]);
    }

    /** GET /api/client/servers/{server}/addons/files/revisions/{revision}/download */
    public function download(Request $request, Server $server, FileRevision $revision): StreamedResponse
    {
        $this->requirePermission($request, $server, 'file.read');
        $this->assertBelongsToServer($revision, $server);

        $content  = $this->storage->retrieve($revision->storage_key);
        $filename = basename($revision->file_path) . ".rev{$revision->revision_number}";

        return response()->streamDownload(function () use ($content) {
            echo $content;
        }, $filename, ['Content-Type' => 'application/octet-stream']);
    }

    /** POST /api/client/servers/{server}/addons/files/revisions/{revision}/restore */
    public function restore(Request $request, Server $server, FileRevision $revision): JsonResponse
    {
        $this->requirePermission($request, $server, 'file.update');
        $this->assertBelongsToServer($revision, $server);

        $content = $this->revisionService->restore($revision, $request->user()->id);

        return response()->json([
            'restored' => true,
            'content'  => $content,
            'revision' => $revision->revision_number,
        ]);
    }

    /** DELETE /api/client/servers/{server}/addons/files/revisions/{revision} */
    public function destroy(Request $request, Server $server, FileRevision $revision): JsonResponse
    {
        // Only admins can manually delete revisions
        abort_unless($request->user()?->root_admin, 403, 'Admin access required.');
        $this->assertBelongsToServer($revision, $server);

        $this->revisionService->delete($revision);
        return response()->json(['deleted' => true]);
    }

    // ─── Helpers ──────────────────────────────────────────────────────────────

    private function requirePermission(Request $request, Server $server, string $permission): void
    {
        $user = $request->user();
        abort_unless($user, 401);

        $isOwner = $server->owner_id === $user->id;
        $isAdmin = $user->root_admin;

        if (!$isOwner && !$isAdmin) {
            $subuser = $server->subusers()->where('user_id', $user->id)->first();
            abort_unless(
                $subuser && in_array($permission, $subuser->permissions ?? [], true),
                403,
                "Permission '{$permission}' required."
            );
        }
    }

    private function assertBelongsToServer(FileRevision $revision, Server $server): void
    {
        abort_unless($revision->server_id === $server->id, 404);
    }
}