<?php

declare(strict_types=1);

namespace App\Services;

use App\Enums\GoogleService;
use App\Models\StorageRepository;
use App\Services\GoogleOAuthService;
use Illuminate\Support\Facades\Crypt;
use Illuminate\Support\Facades\Log;
use League\Flysystem\Filesystem;
use League\Flysystem\WebDAV\WebDAVAdapter;
use As247\Flysystem\GoogleDrive\GoogleDriveAdapter;
use Sabre\DAV\Client as WebDAVClient;

class StorageRepositoryService
{
    public function buildFilesystem(StorageRepository $repo): ?Filesystem
    {
        try {
            $config = $repo->getDecryptedConfig();
            // Log only the keys of the config (avoid sensitive values)
            try {
                Log::debug("StorageRepository: config keys for repo #{$repo->id}: " . json_encode(array_keys($config)));
            } catch (\Exception) {
                // ignore logging errors
            }

            return match ($repo->tipo) {
                'webdav' => $this->buildWebDAV($config),
                'google_drive' => $this->buildGoogleDrive($config),
                default => null,
            };
        } catch (\Exception $e) {
            Log::error("StorageRepository: failed to build filesystem for repo #{$repo->id} ({$repo->nome}): " . $e->getMessage());
            return null;
        }
    }

    public function testConnection(StorageRepository $repo): array
    {
        try {
            $config = $repo->getDecryptedConfig();

            if ($repo->tipo === 'google_drive') {
                if (empty($config['client_id']) || empty($config['client_secret']) || empty($config['refresh_token'])) {
                    return ['success' => false, 'message' => 'Configurazione incompleta: client_id, client_secret e refresh_token sono necessari per Google Drive.'];
                }

                $apiError = $this->checkGoogleDriveApiStatus($config);
                if ($apiError) {
                    return ['success' => false, 'message' => $apiError];
                }
            }

            $filesystem = $this->buildFilesystem($repo);
            if (!$filesystem) {
                return ['success' => false, 'message' => 'Impossibile costruire il filesystem per questo tipo di repository.'];
            }

            $rootPath = $this->normalizePath('/');
            $contents = $filesystem->listContents($rootPath, false)->toArray();
            return ['success' => true, 'message' => 'Connessione riuscita. ' . count($contents) . ' elementi trovati nella root.'];
        } catch (\Exception $e) {
            Log::error("StorageRepository: test connection failed for repo #{$repo->id} ({$repo->nome}): " . $e->getMessage());
            return ['success' => false, 'message' => 'Errore di connessione: ' . $e->getMessage()];
        }
    }

    private function checkGoogleDriveApiStatus(array $config): ?string
    {
        try {
            try {
                $oauth = app(GoogleOAuthService::class);
                $connection = $oauth->getConnection(GoogleService::Drive);
                if ($connection) {
                    $client = $oauth->buildClient(GoogleService::Drive);
                    $service = new \Google_Service_Drive($client);
                    $rootId = $config['root_folder_id'] ?? 'root';
                    $service->files->get($rootId, ['fields' => 'id']);
                    return null;
                }
            } catch (\Exception $e) {
                // fall through to config-based auth
            }

            $client = new \Google_Client();
            $client->setClientId($config['client_id']);
            $client->setClientSecret($config['client_secret']);
            $client->addScope(\Google_Service_Drive::DRIVE);
            $token = $client->refreshToken($config['refresh_token']);
            $client->setAccessToken($token);

            $service = new \Google_Service_Drive($client);

            $rootId = $config['root_folder_id'] ?? 'root';
            $service->files->get($rootId, ['fields' => 'id']);

            return null;
        } catch (\Google\Service\Exception $e) {
            $errors = $e->getErrors();
            $reason = $errors[0]['reason'] ?? '';
            $message = $errors[0]['message'] ?? $e->getMessage();

            if ($reason === 'accessNotConfigured' || str_contains($message, 'Drive API has not been used')) {
                $projectNumber = explode('-', $config['client_id'] ?? '')[0] ?? '';
                return 'Google Drive API non abilitata. Vai su https://console.developers.google.com/apis/api/drive.googleapis.com/overview?project=' . $projectNumber . ' e clicca "Enable".';
            }

            if ($e->getCode() === 404) {
                return 'Cartella root non trovata (ID: ' . ($config['root_folder_id'] ?? 'root') . '). Verifica che il folder ID sia corretto.';
            }

            return 'Errore API Google Drive: ' . $message;
        } catch (\Exception $e) {
            return 'Errore di connessione Google Drive: ' . $e->getMessage();
        }
    }

    public function listContents(StorageRepository $repo, string $path = '/'): array
    {
        try {
            $config = $repo->getDecryptedConfig();

            if ($repo->tipo === 'google_drive') {
                if (empty($config['client_id']) || empty($config['client_secret']) || empty($config['refresh_token'])) {
                    Log::warning("StorageRepository: listContents failed for repo #{$repo->id} ({$repo->nome}): credenziali Google Drive mancanti");
                    return [];
                }
            }

            $filesystem = $this->buildFilesystem($repo);
            if (!$filesystem) {
                return [];
            }

            $normalizedPath = $this->normalizePath($path);
            $items = $filesystem->listContents($normalizedPath, false)->toArray();
            $result = [];
            foreach ($items as $item) {
                $path = method_exists($item, 'path') ? $item->path() : (is_array($item) && isset($item['path']) ? $item['path'] : null);
                $type = method_exists($item, 'type') ? $item->type() : (is_array($item) && isset($item['type']) ? $item['type'] : null);
                $basename = $path ? basename($path) : '';
                $lastModified = method_exists($item, 'lastModified') ? $item->lastModified() : (is_array($item) && isset($item['lastmodified']) ? $item['lastmodified'] : null);
                $fileSize = method_exists($item, 'fileSize') ? $item->fileSize() : (is_array($item) && isset($item['filesize']) ? $item['filesize'] : null);
                $mimeType = method_exists($item, 'mimeType') ? $item->mimeType() : (is_array($item) && isset($item['mimetype']) ? $item['mimetype'] : null);

                $result[] = [
                    'path' => $path,
                    'type' => $type,
                    'basename' => $basename,
                    'lastModified' => $lastModified,
                    'fileSize' => $fileSize,
                    'mimeType' => $mimeType,
                ];
            }

            usort($result, fn($a, $b) => ($a['type'] === 'dir' && $b['type'] !== 'dir') ? -1 : (($b['type'] === 'dir' && $a['type'] !== 'dir') ? 1 : strcasecmp($a['basename'], $b['basename'])));

            Log::debug("StorageRepository: listContents repo #{$repo->id} tipo={$repo->tipo} path='{$normalizedPath}' results=" . count($result));

            return $result;
        } catch (\Exception $e) {
            Log::error("StorageRepository: listContents failed for repo #{$repo->id} path '{$path}': " . $e->getMessage());
            return [];
        }
    }

    public function encryptSensitiveConfig(array $config, string $tipo, array $existingConfig = []): array
    {
        $sensitiveFields = match ($tipo) {
            'webdav' => ['password'],
            'google_drive' => ['client_secret', 'refresh_token'],
            default => [],
        };

        foreach ($sensitiveFields as $field) {
            if (!empty($config[$field]) && !$this->isEncrypted($config[$field])) {
                $config[$field] = Crypt::encryptString($config[$field]);
            } elseif (empty($config[$field]) && !empty($existingConfig[$field])) {
                $config[$field] = $existingConfig[$field];
            }
        }

        return $config;
    }

    public function normalizePath(string $path): string
    {
        $path = trim($path);
        if ($path === '' || $path === '\\') {
            return '';
        }
        if ($path === '/') {
            return '';
        }
        return ltrim($path, '/\\');
    }

    private function isEncrypted(string $value): bool
    {
        return str_starts_with($value, 'ey') || str_contains($value, ':');
    }

    private function buildWebDAV(array $config): ?Filesystem
    {
        $fullBaseUri = rtrim($config['base_uri'] ?? '', '/') . '/';

        $parsedUrl = parse_url($fullBaseUri);
        $schemeHost = ($parsedUrl['scheme'] ?? 'https') . '://' . ($parsedUrl['host'] ?? 'localhost');
        $basePath = rawurldecode($parsedUrl['path'] ?? '/');

        $root = '/' . trim($config['root'] ?? '/', '/') . '/';
        $prefix = rtrim($basePath, '/') . $root;

        $authType = match ($config['auth_type'] ?? 'basic') {
            'basic' => WebDAVClient::AUTH_BASIC,
            'digest' => WebDAVClient::AUTH_DIGEST,
            'ntlm' => WebDAVClient::AUTH_NTLM,
            default => WebDAVClient::AUTH_BASIC,
        };

        $client = new WebDAVClient([
            'baseUri' => $schemeHost . '/',
            'userName' => $config['username'] ?? '',
            'password' => $config['password'] ?? '',
            'authType' => $authType,
        ]);

        $adapter = new WebDAVAdapter($client, $prefix);

        return new Filesystem($adapter);
    }

    private function buildGoogleDrive(array $config): ?Filesystem
    {
        if (empty($config['client_id']) || empty($config['client_secret']) || empty($config['refresh_token'])) {
            throw new \InvalidArgumentException('Google Drive richiede client_id, client_secret e refresh_token per l\'autenticazione.');
        }

        $client = new \Google_Client();
        $client->setClientId($config['client_id']);
        $client->setClientSecret($config['client_secret']);
        $client->addScope(\Google_Service_Drive::DRIVE);
        
        // Refresh token per ottenere un access token valido
        $token = $client->refreshToken($config['refresh_token']);
        $client->setAccessToken($token);

        $service = new \Google_Service_Drive($client);

        $rootFolderId = $config['root_folder_id'] ?? 'root';
        $adapter = new GoogleDriveAdapter($service, $rootFolderId);

        return new Filesystem($adapter);
    }

    public function readGoogleDriveFile(StorageRepository $repo, string $normalizedPath, string $basename): array
    {
        $config = $repo->getDecryptedConfig();

        try {
            $oauth = app(GoogleOAuthService::class);
            $connection = $oauth->getConnection(GoogleService::Drive);
            if ($connection) {
                $client = $oauth->buildClient(GoogleService::Drive);
                $service = new \Google_Service_Drive($client);
                return $this->readGoogleDriveFileWithService($service, $config, $normalizedPath, $basename);
            }
        } catch (\Exception $e) {
            \Illuminate\Support\Facades\Log::warning('Central Google Drive OAuth failed in readGoogleDriveFile, falling back: ' . $e->getMessage());
        }

        $client = new \Google_Client();
        $client->setClientId($config['client_id']);
        $client->setClientSecret($config['client_secret']);
        $client->addScope(\Google_Service_Drive::DRIVE);
        $token = $client->refreshToken($config['refresh_token']);
        $client->setAccessToken($token);

        $service = new \Google_Service_Drive($client);
        $rootFolderId = $config['root_folder_id'] ?? 'root';

        $fileId = $this->findGoogleDriveFileId($service, $rootFolderId, $normalizedPath);
        $file = $service->files->get($fileId, ['fields' => 'id,name,mimeType,size']);

        $mimeType = $file->getMimeType();

        if ($mimeType && str_starts_with($mimeType, 'application/vnd.google-apps.')) {
            return $this->exportGoogleDriveDoc($service, $fileId, $mimeType, $basename);
        }

        $response = $service->files->get($fileId, ['alt' => 'media']);
        $body = $response->getBody();
        $stream = $body instanceof \Psr\Http\Message\StreamInterface ? $body->detach() : null;

        if (!$stream) {
            $stream = fopen('php://temp', 'r+');
            fwrite($stream, (string) $body);
            rewind($stream);
        }

        $fileSize = $file->getSize();

        return [
            'stream' => $stream,
            'mimeType' => $mimeType,
            'basename' => $basename,
            'fileSize' => $fileSize !== null ? (int) $fileSize : null,
        ];
    }


    private function readGoogleDriveFileWithService(\Google_Service_Drive $service, array $config, string $normalizedPath, string $basename): array
    {
        $rootFolderId = $config['root_folder_id'] ?? 'root';

        $fileId = $this->findGoogleDriveFileId($service, $rootFolderId, $normalizedPath);
        $file = $service->files->get($fileId, ['fields' => 'id,name,mimeType,size']);

        $mimeType = $file->getMimeType();

        if ($mimeType && str_starts_with($mimeType, 'application/vnd.google-apps.')) {
            return $this->exportGoogleDriveDoc($service, $fileId, $mimeType, $basename);
        }

        $response = $service->files->get($fileId, ['alt' => 'media']);
        $body = $response->getBody();
        $stream = $body instanceof \Psr\Http\Message\StreamInterface ? $body->detach() : null;

        if (!$stream) {
            $stream = fopen('php://temp', 'r+');
            fwrite($stream, (string) $body);
            rewind($stream);
        }

        $fileSize = $file->getSize();

        return [
            'stream' => $stream,
            'mimeType' => $mimeType,
            'basename' => $basename,
            'fileSize' => $fileSize !== null ? (int) $fileSize : null,
        ];
    }

    private function exportGoogleDriveDoc(\Google_Service_Drive $service, string $fileId, string $googleMimeType, string $originalBasename): array
    {
        $exportMap = [
            'application/vnd.google-apps.document' => [
                'mime' => 'application/vnd.openxmlformats-officedocument.wordprocessingml.document',
                'ext' => 'docx',
            ],
            'application/vnd.google-apps.spreadsheet' => [
                'mime' => 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet',
                'ext' => 'xlsx',
            ],
            'application/vnd.google-apps.presentation' => [
                'mime' => 'application/vnd.openxmlformats-officedocument.presentationml.presentation',
                'ext' => 'pptx',
            ],
            'application/vnd.google-apps.drawing' => [
                'mime' => 'image/png',
                'ext' => 'png',
            ],
        ];

        $format = $exportMap[$googleMimeType] ?? ['mime' => 'application/pdf', 'ext' => 'pdf'];

        $response = $service->files->export($fileId, $format['mime'], ['alt' => 'media']);
        $body = $response->getBody();
        $stream = $body instanceof \Psr\Http\Message\StreamInterface ? $body->detach() : null;

        if (!$stream) {
            $stream = fopen('php://temp', 'r+');
            fwrite($stream, (string) $body);
            rewind($stream);
        }

        $nameWithoutExt = pathinfo($originalBasename, PATHINFO_FILENAME);
        $newBasename = $nameWithoutExt . '.' . $format['ext'];

        Log::info("StorageRepository: exported Google Drive file {$fileId} from {$googleMimeType} to {$format['mime']} as {$newBasename}");

        return [
            'stream' => $stream,
            'mimeType' => $format['mime'],
            'basename' => $newBasename,
            'fileSize' => null,
        ];
    }

    private function findGoogleDriveFileId(\Google_Service_Drive $service, string $rootFolderId, string $path): string
    {
        $path = trim($path, '/');
        if ($path === '') {
            return $rootFolderId;
        }

        $parts = explode('/', $path);
        $currentParentId = $rootFolderId;

        foreach ($parts as $name) {
            $optParams = [
                'q' => sprintf("trashed = false and '%s' in parents and name = '%s'",
                    str_replace("'", "\\'", $currentParentId),
                    str_replace("'", "\\'", $name)
                ),
                'fields' => 'files(id, name, mimeType)',
                'pageSize' => 1,
            ];

            $results = $service->files->listFiles($optParams);
            $files = $results->getFiles();

            if (empty($files)) {
                throw new \RuntimeException("Elemento non trovato su Google Drive: {$name} (path: {$path})");
            }

            $currentParentId = $files[0]->getId();
        }

        return $currentParentId;
    }
}