<?php

namespace App\Libraries;

use Aws\S3\S3Client;
use Aws\Exception\AwsException;
use CodeIgniter\HTTP\ResponseInterface;

class S3Service
{
    protected $s3Client;
    protected $bucket;
    protected $region;
    protected $baseUrl;

    public function __construct()
    {
        $this->bucket = getenv('AWS_BUCKET');
        $this->region = getenv('AWS_DEFAULT_REGION');
        
        $this->s3Client = new S3Client([
            'version' => 'latest',
            'region' => $this->region,
            'credentials' => [
                'key' => getenv('AWS_ACCESS_KEY_ID'),
                'secret' => getenv('AWS_SECRET_ACCESS_KEY'),
            ],
        ]);

        $this->baseUrl = "https://{$this->bucket}.s3.{$this->region}.amazonaws.com/";
        // echo $this->baseUrl;die();
    }

    /**
     * Upload file to S3
     * 
     * @param mixed $file File object or file path
     * @param string $folder Folder path in S3 bucket (optional)
     * @param string $fileName Custom file name (optional)
     * @return array ['success' => bool, 'url' => string, 'key' => string, 'message' => string]
     */
    public function upload($file, string $folder = '', string $fileName = null): array
    {
        try {
            // Handle CodeIgniter file upload object
            if (is_object($file) && method_exists($file, 'isValid')) {
                if (!$file->isValid()) {
                    return [
                        'success' => false,
                        'message' => 'Invalid file upload',
                        'url' => null,
                        'key' => null
                    ];
                }
                $filePath = $file->getTempName();
                $originalName = $fileName ?? $file->getClientName();
            } else {
                // Handle file path string
                $filePath = $file;
                $originalName = $fileName ?? basename($file);
            }

            // Generate unique file name
            $extension = pathinfo($originalName, PATHINFO_EXTENSION);
            // $uniqueName = pathinfo($originalName, PATHINFO_FILENAME) . '_' . time() . '.' . $extension;
            $uniqueName = pathinfo($originalName, PATHINFO_FILENAME)  . '.' . $extension;
            
            // Build S3 key (path)
            $key = $folder ? rtrim($folder, '/') . '/' . $uniqueName : $uniqueName;

            // Upload to S3
            // NEW - Faster with streaming and proper content type
            $finfo = finfo_open(FILEINFO_MIME_TYPE);
            $mimeType = finfo_file($finfo, $filePath);
            finfo_close($finfo);

            $result = $this->s3Client->putObject([
                'Bucket' => $this->bucket,
                'Key' => $key,
                'Body' => fopen($filePath, 'rb'), // Stream instead of loading into memory
                'ContentType' => $mimeType,
                // 'ACL' => 'public-read',
            ]);

            return [
                'success' => true,
                'url' => $this->baseUrl . $key,
                'key' => $key,
                'message' => 'File uploaded successfully'
            ];

        } catch (AwsException $e) {
            log_message('error', 'S3 Upload Error: ' . $e->getMessage());
            return [
                'success' => false,
                'message' => 'Upload failed: ' . $e->getMessage(),
                'url' => null,
                'key' => null
            ];
        }
    }

    /**
     * Download file from S3
     * 
     * @param string $key S3 object key (file path in bucket)
     * @param string $savePath Local path to save the file (optional)
     * @return array ['success' => bool, 'path' => string, 'content' => string, 'message' => string]
     */
    public function download(string $key, string $savePath = null): array
    {
        try {
            $result = $this->s3Client->getObject([
                'Bucket' => $this->bucket,
                'Key' => $key,
            ]);

            $content = (string) $result['Body'];

            // If save path is provided, save to local file
            if ($savePath) {
                $directory = dirname($savePath);
                if (!is_dir($directory)) {
                    mkdir($directory, 0755, true);
                }
                file_put_contents($savePath, $content);
                
                return [
                    'success' => true,
                    'path' => $savePath,
                    'content' => $content,
                    'message' => 'File downloaded successfully'
                ];
            }

            return [
                'success' => true,
                'path' => null,
                'content' => $content,
                'message' => 'File content retrieved successfully'
            ];

        } catch (AwsException $e) {
            log_message('error', 'S3 Download Error: ' . $e->getMessage());
            return [
                'success' => false,
                'path' => null,
                'content' => null,
                'message' => 'Download failed: ' . $e->getMessage()
            ];
        }
    }

    /**
     * Get a pre-signed URL for temporary access to a private file
     * 
     * @param string $key S3 object key
     * @param int $expiration Expiration time in minutes (default: 60)
     * @return array ['success' => bool, 'url' => string, 'message' => string]
     */
    public function getPresignedUrl(string $key, int $expiration = 60): array
    {
        try {
            $cmd = $this->s3Client->getCommand('GetObject', [
                'Bucket' => $this->bucket,
                'Key' => $key
            ]);

            $request = $this->s3Client->createPresignedRequest($cmd, "+{$expiration} minutes");
            $presignedUrl = (string) $request->getUri();

            return [
                'success' => true,
                'url' => $presignedUrl,
                'message' => 'Pre-signed URL generated successfully'
            ];

        } catch (AwsException $e) {
            log_message('error', 'S3 Presigned URL Error: ' . $e->getMessage());
            return [
                'success' => false,
                'url' => null,
                'message' => 'Failed to generate URL: ' . $e->getMessage()
            ];
        }
    }

    /**
     * Delete file from S3
     * 
     * @param string $key S3 object key
     * @return array ['success' => bool, 'message' => string]
     */
    public function delete(string $key): array
    {
        try {
            $this->s3Client->deleteObject([
                'Bucket' => $this->bucket,
                'Key' => $key,
            ]);

            return [
                'success' => true,
                'message' => 'File deleted successfully'
            ];

        } catch (AwsException $e) {
            log_message('error', 'S3 Delete Error: ' . $e->getMessage());
            return [
                'success' => false,
                'message' => 'Delete failed: ' . $e->getMessage()
            ];
        }
    }

    /**
     * Check if file exists in S3
     * 
     * @param string $key S3 object key
     * @return bool
     */
    public function exists(string $key): bool
    {
        return $this->s3Client->doesObjectExist($this->bucket, $key);
    }

    /**
     * List files in S3 bucket
     * 
     * @param string $prefix Folder prefix (optional)
     * @return array ['success' => bool, 'files' => array, 'message' => string]
     */
    public function listFiles(string $prefix = ''): array
    {
        try {
            $result = $this->s3Client->listObjectsV2([
                'Bucket' => $this->bucket,
                'Prefix' => $prefix,
            ]);

            $files = [];
            if (isset($result['Contents'])) {
                foreach ($result['Contents'] as $object) {
                    $files[] = [
                        'key' => $object['Key'],
                        'size' => $object['Size'],
                        'last_modified' => $object['LastModified']->format('Y-m-d H:i:s'),
                        'url' => $this->baseUrl . $object['Key']
                    ];
                }
            }

            return [
                'success' => true,
                'files' => $files,
                'message' => 'Files retrieved successfully'
            ];

        } catch (AwsException $e) {
            log_message('error', 'S3 List Error: ' . $e->getMessage());
            return [
                'success' => false,
                'files' => [],
                'message' => 'Failed to list files: ' . $e->getMessage()
            ];
        }
    }
}