<?php
/**
 * WEVAL Lyria 3 API — Génération musique IA souveraine
 * Endpoint: /api/lyria3-api.php
 * Usage: POST {prompt:"upbeat jazz track", duration:"clip"|"pro"}
 *        GET ?k=WEVADS2026&action=status
 */
header('Content-Type: application/json');
header('Access-Control-Allow-Origin: *');
if ($_SERVER['REQUEST_METHOD'] === 'OPTIONS') { http_response_code(200); exit; }

$GEMINI_KEY = "AIzaSyCMbYKyTldlCjg2eSCtwNONX9mMomhmIM4";

// Status check
if (($_GET['action'] ?? '') === 'status') {
    echo json_encode(["ok"=>true,"service"=>"WEVAL Lyria 3","models"=>["lyria-3-clip-preview","lyria-3-pro-preview"],"provider"=>"Google Gemini API","status"=>"active"]);
    exit;
}

// POST: Generate music
$input = json_decode(file_get_contents('php://input'), true);
$prompt = $input['prompt'] ?? $_POST['prompt'] ?? '';
$model = ($input['duration'] ?? $_POST['duration'] ?? 'clip') === 'pro' ? 'lyria-3-pro-preview' : 'lyria-3-clip-preview';

if (!$prompt) {
    echo json_encode(["ok"=>false,"error"=>"prompt required"]);
    exit;
}

// Call Gemini API with Lyria 3
$url = "https://generativelanguage.googleapis.com/v1beta/models/{$model}:generateContent?key={$GEMINI_KEY}";

$payload = json_encode([
    "contents" => [["parts" => [["text" => $prompt]]]],
    "generationConfig" => ["responseModalities" => ["AUDIO", "TEXT"]]
]);

$ch = curl_init($url);
curl_setopt_array($ch, [
    CURLOPT_POST => true,
    CURLOPT_POSTFIELDS => $payload,
    CURLOPT_HTTPHEADER => ['Content-Type: application/json'],
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_TIMEOUT => 120,
    CURLOPT_SSL_VERIFYPEER => false,
]);

$resp = curl_exec($ch);
$code = curl_getinfo($ch, CURLINFO_HTTP_CODE);
curl_close($ch);

$data = json_decode($resp, true);

if ($code !== 200 || !$data) {
    echo json_encode(["ok"=>false,"error"=>"Lyria API error","http"=>$code,"details"=>$data['error']['message'] ?? substr($resp,0,200)]);
    exit;
}

// Extract audio + lyrics from response
$audio = null;
$lyrics = null;
$parts = $data['candidates'][0]['content']['parts'] ?? [];

foreach ($parts as $part) {
    if (isset($part['inlineData'])) {
        $audio = [
            "mime" => $part['inlineData']['mimeType'] ?? 'audio/mpeg',
            "data" => $part['inlineData']['data'] ?? null, // base64
            "size" => strlen($part['inlineData']['data'] ?? '') 
        ];
    }
    if (isset($part['text'])) {
        $lyrics = ($lyrics ? $lyrics . "\n" : '') . $part['text'];
    }
}

if ($audio && $audio['data']) {
    // Save audio file
    $filename = 'lyria3_' . date('Ymd_His') . '_' . substr(md5($prompt), 0, 6) . '.mp3';
    $path = "/var/www/html/audio/{$filename}";
    @mkdir('/var/www/html/audio', 0755, true);
    file_put_contents($path, base64_decode($audio['data']));
    
    echo json_encode([
        "ok" => true,
        "model" => $model,
        "prompt" => $prompt,
        "audio_url" => "/audio/{$filename}",
        "audio_size" => filesize($path),
        "lyrics" => $lyrics,
        "mime" => $audio['mime']
    ]);
} else {
    echo json_encode([
        "ok" => false,
        "error" => "No audio in response",
        "lyrics" => $lyrics,
        "raw_parts" => count($parts)
    ]);
}