<?php

/**
 * =============================================================================
 * MODPACK VERSION CHECKER - API CONTROLLER
 * =============================================================================
 * 
 * Part of the ModpackChecker Blueprint extension for Pterodactyl Panel.
 * 
 * PURPOSE:
 * Provides API endpoints for checking modpack versions across multiple platforms
 * (CurseForge, Modrinth, FTB, Technic). Supports both on-demand manual checks
 * from the server console and cached status retrieval for the dashboard badge.
 * 
 * ARCHITECTURE OVERVIEW:
 * This controller serves two distinct use cases:
 * 
 * 1. MANUAL CHECK (manualCheck method)
 *    - Called from: Server console "Check for Updates" button
 *    - Behavior: Makes LIVE API calls via ModpackApiService
 *    - Rate limited: 2 requests per minute per server
 * 
 * 2. DASHBOARD STATUS (getStatus method)
 *    - Called from: Dashboard badge component (UpdateBadge.tsx)
 *    - Behavior: Reads from LOCAL DATABASE CACHE only - NO external API calls
 *    - Why cached? Prevents rate limit hell on panels with many servers
 * 
 * ROUTES (defined in routes/client.php):
 * - POST /api/client/extensions/modpackchecker/servers/{server}/check -> manualCheck()
 * - GET  /api/client/extensions/modpackchecker/status -> getStatus()
 * 
 * @package     Pterodactyl\BlueprintFramework\Extensions\modpackchecker
 * @author      Firefrost Gaming / Frostystyle <dev@firefrostgaming.com>
 * @version     1.0.0
 * @see         ModpackApiService.php (centralized API logic)
 * @see         CheckModpackUpdates.php (cron command that populates the cache)
 * =============================================================================
 */

namespace Pterodactyl\Http\Controllers;

use Pterodactyl\Http\Controllers\Controller;
use Pterodactyl\Models\Server;
use Pterodactyl\Repositories\Wings\DaemonFileRepository;
use Pterodactyl\Services\ModpackApiService;
use Illuminate\Http\Request;
use Illuminate\Http\JsonResponse;
use Illuminate\Support\Facades\DB;
use Illuminate\Support\Facades\RateLimiter;

class ModpackAPIController extends Controller
{
    public function __construct(
        private DaemonFileRepository $fileRepository,
        private ModpackApiService $apiService
    ) {}

    /**
     * Manual version check triggered from the server console UI.
     * 
     * Rate limited to 2 requests per minute per server to prevent API abuse.
     * 
     * @param  Request  $request  The incoming HTTP request
     * @param  Server   $server   The server to check
     * @return JsonResponse
     */
    public function manualCheck(Request $request, Server $server): JsonResponse
    {
        // Rate Limiting: Max 2 requests per minute per server
        $limitKey = 'modpack_check_' . $server->uuid;
        if (RateLimiter::tooManyAttempts($limitKey, 2)) {
            $seconds = RateLimiter::availableIn($limitKey);
            return response()->json([
                'success' => false,
                'message' => "Too many requests. Please wait {$seconds} seconds before checking again."
            ], 429);
        }
        RateLimiter::hit($limitKey, 60);

        // 1. Try Egg Variables first (most reliable)
        $platform = $this->getEggVariable($server, 'MODPACK_PLATFORM');
        $modpackId = $this->getEggVariable($server, 'MODPACK_ID');

        // Also check platform-specific variables
        if (empty($modpackId)) {
            $modpackId = match($platform) {
                'curseforge' => $this->getEggVariable($server, 'CURSEFORGE_ID'),
                'modrinth' => $this->getEggVariable($server, 'MODRINTH_PROJECT_ID'),
                'ftb' => $this->getEggVariable($server, 'FTB_MODPACK_ID'),
                'technic' => $this->getEggVariable($server, 'TECHNIC_SLUG'),
                default => null
            };
        }

        // 2. If no egg variables, try file detection
        if (empty($platform) || empty($modpackId)) {
            $detected = $this->detectFromFiles($server);
            $platform = $platform ?: ($detected['platform'] ?? null);
            $modpackId = $modpackId ?: ($detected['modpack_id'] ?? null);
        }

        // 3. If still nothing, return helpful error
        if (empty($platform) || empty($modpackId)) {
            return response()->json([
                'success' => false,
                'message' => 'Could not detect modpack. Set MODPACK_PLATFORM and MODPACK_ID in startup variables.',
            ]);
        }

        // 4. Check the appropriate API using the unified Service
        try {
            $versionData = $this->apiService->fetchLatestVersion($platform, $modpackId);

            return response()->json([
                'success' => true,
                'platform' => $platform,
                'modpack_id' => $modpackId,
                'modpack_name' => $versionData['name'],
                'latest_version' => $versionData['version'],
                'status' => 'checked',
            ]);
        } catch (\Exception $e) {
            return response()->json([
                'success' => false,
                'platform' => $platform,
                'modpack_id' => $modpackId,
                'error' => $e->getMessage(),
            ]);
        }
    }

    /**
     * Retrieve an egg variable value for a specific server.
     * 
     * @param  Server  $server  The server to query
     * @param  string  $name    The environment variable name
     * @return string|null      The variable's value, or null if not set
     */
    private function getEggVariable(Server $server, string $name): ?string
    {
        $variable = $server->variables()
            ->where('env_variable', $name)
            ->first();
        return $variable?->server_value;
    }

    /**
     * Attempt to detect modpack platform and ID by reading server files.
     * 
     * Fallback method when egg variables aren't set.
     * 
     * @param  Server  $server  The server to scan
     * @return array            Contains: platform, modpack_id (all nullable)
     */
    private function detectFromFiles(Server $server): array
    {
        try {
            // Try CurseForge manifest.json
            $manifest = $this->readServerFile($server, 'manifest.json');
            if ($manifest) {
                $data = json_decode($manifest, true);
                if (isset($data['manifestType']) && $data['manifestType'] === 'minecraftModpack') {
                    return [
                        'platform' => 'curseforge',
                        'modpack_id' => $data['projectID'] ?? null,
                        'name' => $data['name'] ?? null,
                        'version' => $data['version'] ?? null,
                    ];
                }
            }

            // Try Modrinth modrinth.index.json
            $modrinthIndex = $this->readServerFile($server, 'modrinth.index.json');
            if ($modrinthIndex) {
                $data = json_decode($modrinthIndex, true);
                if (isset($data['formatVersion'])) {
                    return [
                        'platform' => 'modrinth',
                        'modpack_id' => $data['dependencies']['minecraft'] ?? null,
                        'name' => $data['name'] ?? null,
                        'version' => $data['versionId'] ?? null,
                    ];
                }
            }
        } catch (\Exception $e) {
            // File detection failed, return empty
        }

        return [];
    }

    /**
     * Read a file from the game server via the Wings daemon.
     * 
     * @param  Server  $server  The server whose files we're reading
     * @param  string  $path    Relative path from server root
     * @return string|null      File contents, or null if unreadable
     */
    private function readServerFile(Server $server, string $path): ?string
    {
        try {
            $this->fileRepository->setServer($server);
            return $this->fileRepository->getContent($path);
        } catch (\Exception $e) {
            return null;
        }
    }

    /**
     * Get cached update status for all of a user's servers.
     * 
     * THIS IS THE DASHBOARD BADGE ENDPOINT.
     * 
     * CRITICAL: This method ONLY reads from the local database cache.
     * It NEVER makes external API calls.
     * 
     * @param  Request  $request  The incoming HTTP request
     * @return JsonResponse       Keyed by server_uuid
     */
    public function getStatus(Request $request): JsonResponse
    {
        $user = $request->user();
        
        // Get all server UUIDs the user has access to
        $serverUuids = $user->accessibleServers()->pluck('uuid')->toArray();
        
        // Query our cache table for these servers
        $statuses = DB::table('modpackchecker_servers')
            ->whereIn('server_uuid', $serverUuids)
            ->get()
            ->keyBy('server_uuid');
        
        $result = [];
        foreach ($statuses as $uuid => $status) {
            $result[$uuid] = [
                'update_available' => $status->status === 'update_available',
                'modpack_name' => $status->modpack_name,
                'current_version' => $status->current_version,
                'latest_version' => $status->latest_version,
            ];
        }
        
        return response()->json($result);
    }
}