<?php
// Composition Plan Generation Endpoint for ElevenLabs Music API

header('Content-Type: application/json');

// Load configuration
$config = require_once 'config.php';

if ($_SERVER['REQUEST_METHOD'] !== 'POST') {
    http_response_code(405);
    echo json_encode(['success' => false, 'error' => 'Method not allowed']);
    exit;
}

$prompt = $_POST['prompt'] ?? '';
$musicLengthMs = (int)($_POST['music_length_ms'] ?? 0);
$apiKey = $config['elevenlabs_api_key'];

if (empty($prompt)) {
    echo json_encode(['success' => false, 'error' => 'Prompt is required']);
    exit;
}

if (empty($apiKey) || $apiKey === 'your-api-key-here') {
    echo json_encode(['success' => false, 'error' => 'ElevenLabs API key not configured']);
    exit;
}

// Generate composition plan
$planResult = generateCompositionPlan($prompt, $musicLengthMs, $apiKey);

if ($planResult['success']) {
    echo json_encode(['success' => true, 'plan' => $planResult['plan']]);
} else {
    echo json_encode(['success' => false, 'error' => $planResult['error']]);
}

function generateCompositionPlan($prompt, $musicLengthMs, $apiKey) {
    $url = 'https://api.elevenlabs.io/v1/music/plan';
    
    $data = [
        'prompt' => $prompt,
        'model_id' => 'music_v1'
    ];
    
    // Add music length if specified (minimum 10 seconds)
    if ($musicLengthMs >= 10000) {
        $data['music_length_ms'] = $musicLengthMs;
    }
    
    $ch = curl_init();
    curl_setopt($ch, CURLOPT_URL, $url);
    curl_setopt($ch, CURLOPT_POST, true);
    curl_setopt($ch, CURLOPT_POSTFIELDS, json_encode($data));
    curl_setopt($ch, CURLOPT_HTTPHEADER, [
        'xi-api-key: ' . $apiKey,
        'Content-Type: application/json'
    ]);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
    curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
    curl_setopt($ch, CURLOPT_TIMEOUT, 60);
    
    $response = curl_exec($ch);
    $httpCode = curl_getinfo($ch, CURLINFO_HTTP_CODE);
    
    if (curl_error($ch)) {
        curl_close($ch);
        return ['success' => false, 'error' => 'Connection error: ' . curl_error($ch)];
    }
    
    curl_close($ch);
    
    if ($httpCode === 200) {
        $planData = json_decode($response, true);
        if ($planData) {
            return ['success' => true, 'plan' => $planData];
        } else {
            return ['success' => false, 'error' => 'Invalid response format'];
        }
    } else {
        $errorResponse = json_decode($response, true);
        $errorMessage = $errorResponse['detail'] ?? 'Unknown error occurred';
        return ['success' => false, 'error' => 'API Error (' . $httpCode . '): ' . $errorMessage];
    }
}
?>