<?php
// Temporary error logging
ini_set('display_errors', 1);
ini_set('display_startup_errors', 1);
error_reporting(E_ALL);
ini_set('log_errors', 1);
ini_set('error_log', __DIR__ . '/error_log.txt');

// Simple success/error JSON response
function json_response($status, $message, $data = null) {
    header('Content-Type: application/json');
    echo json_encode([
        'status' => $status,
        'message' => $message,
        'data' => $data
    ]);
    exit;
}

if ($_SERVER['REQUEST_METHOD'] !== 'POST') {
    json_response('error', 'Invalid request method.');
}

if (!isset($_FILES['document']) || $_FILES['document']['error'] == UPLOAD_ERR_NO_FILE) {
    json_response('error', 'No file was uploaded.');
}

$file = $_FILES['document'];

// Check for upload errors
if ($file['error'] !== UPLOAD_ERR_OK) {
    $upload_errors = [
        UPLOAD_ERR_INI_SIZE   => 'The uploaded file exceeds the upload_max_filesize directive in php.ini.',
        UPLOAD_ERR_FORM_SIZE  => 'The uploaded file exceeds the MAX_FILE_SIZE directive that was specified in the HTML form.',
        UPLOAD_ERR_PARTIAL    => 'The uploaded file was only partially uploaded.',
        UPLOAD_ERR_NO_FILE    => 'No file was uploaded.',
        UPLOAD_ERR_NO_TMP_DIR => 'Missing a temporary folder.',
        UPLOAD_ERR_CANT_WRITE => 'Failed to write file to disk.',
        UPLOAD_ERR_EXTENSION  => 'A PHP extension stopped the file upload.',
    ];
    $error_message = $upload_errors[$file['error']] ?? 'Unknown upload error.';
    json_response('error', $error_message);
}

$upload_dir = __DIR__ . '/uploads/';
if (!is_dir($upload_dir)) {
    if (!mkdir($upload_dir, 0775, true)) {
        json_response('error', 'Failed to create upload directory.');
    }
}

$file_name = basename($file['name']);
$target_path = $upload_dir . $file_name;

// Move the file to the uploads directory
if (move_uploaded_file($file['tmp_name'], $target_path)) {
    // AI Translation Step
    try {
        require_once __DIR__ . '/ai/LocalAIApi.php';

        $source_lang = $_POST['source_lang'] ?? 'auto-detect';
        $target_lang = $_POST['target_lang'] ?? 'English';
        $file_path_for_ai = 'uploads/' . $file_name;

        // Read the file content and base64 encode it
        $file_content = file_get_contents($target_path);
        $base64_image = base64_encode($file_content);
        
        // Check if mime_content_type function exists
        if (function_exists('mime_content_type')) {
            $mime_type = mime_content_type($target_path);
        } else {
            // Fallback to a generic MIME type if the function doesn't exist
            $mime_type = 'application/octet-stream';
        }

        $resp = LocalAIApi::createResponse([
            'input' => [
                [
                    'role' => 'user',
                    'content' => [
                        [
                            'type' => 'text',
                            'text' => "You are an expert document translator. Please perform the following tasks:\n" \
                                . "1. **OCR Extraction:** Extract all visible text from the attached image.\n" \
                                . "2. **Translation:** Translate the extracted text from `{$source_lang}` to `{$target_lang}`.\n" \
                                . "3. **Output:** Return ONLY the translated text as a single block of plain text. Do not include any explanations, apologies, or introductory phrases. Just the translation."
                        ],
                        [
                            'type' => 'image',
                            'source' => [
                                'type' => 'base64',
                                'media_type' => $mime_type,
                                'data' => $base64_image,
                            ],
                        ],
                    ],
                ],
            ],
        ]);

        if (!empty($resp['success'])) {
            $translated_text = LocalAIApi::extractText($resp);
            if ($translated_text === '') {
                // Handle cases where the AI returns a non-text response or empty text
                $decoded = LocalAIApi::decodeJsonFromResponse($resp);
                $error_details = $decoded ? json_encode($decoded, JSON_PRETTY_PRINT) : 'AI returned an empty or invalid response.';
                json_response('error', 'AI processing failed. Details: ' . $error_details);
            } else {
                json_response('success', 'File translated successfully.', [
                    'filePath' => $file_path_for_ai,
                    'translatedText' => $translated_text
                ]);
            }
        } else {
            $error_message = $resp['error'] ?? 'Unknown AI error.';
            json_response('error', 'Failed to get response from AI service: ' . $error_message);
        }

    } catch (Exception $e) {
        json_response('error', 'An exception occurred during AI processing: ' . $e->getMessage());
    }

} else {
    json_response('error', 'Failed to move uploaded file.');
}

?>