<?php
// save_lang.php
// Receives: { "lang": "fr", "translations": { "nav_home": "Accueil", ... } }
// Merges with en.php base so all keys are always present, then saves lang/fr.php

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

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

$body = json_decode(file_get_contents('php://input'), true);

if (!isset($body['lang'], $body['translations'])) {
    http_response_code(400);
    echo json_encode(['error' => 'Missing lang or translations']);
    exit;
}

$lang         = preg_replace('/[^a-z]/', '', strtolower($body['lang']));
$translations = $body['translations'];

if (strlen($lang) < 2 || strlen($lang) > 5) {
    http_response_code(400);
    echo json_encode(['error' => 'Invalid lang code']);
    exit;
}

// Load English as base — ensures every key exists even if not translated
$base = include __DIR__ . '/lang/en.php';

// Overwrite only keys that were translated
foreach ($translations as $key => $value) {
    if (array_key_exists($key, $base)) {
        $base[$key] = $value;
    }
}

// Build PHP file content
$lines = ["<?php", "return ["];
foreach ($base as $key => $value) {
    $key   = addslashes($key);
    $value = addslashes($value);
    $lines[] = "    '$key' => '$value',";
}
$lines[] = "];";
$content = implode("\n", $lines) . "\n";

$langDir = getenv('WEBSITE_LANG_WRITE_DIR') ?: (__DIR__ . '/lang');
if (!is_dir($langDir) && !mkdir($langDir, 0755, true)) {
    http_response_code(500);
    echo json_encode(['error' => 'Could not create language directory']);
    exit;
}

$path = "$langDir/$lang.php";
if (file_put_contents($path, $content) === false) {
    http_response_code(500);
    echo json_encode(['error' => 'Could not write language file']);
    exit;
}

echo json_encode(['success' => true, 'lang' => $lang]);