<?php

header('Content-Type: application/json');
require_once __DIR__ . '/default.php';


function readConfig() {
    if (!file_exists(CONFIG_FILE)) {
        return ['defaultModel' => ''];
    }

    $content = file_get_contents(CONFIG_FILE);
    if ($content === false) {
        return ['defaultModel' => ''];
    }

    $data = json_decode($content, true);
    if (!is_array($data)) {
        return ['defaultModel' => ''];
    }

    return [
        'defaultModel' => isset($data['defaultModel']) ? (string) $data['defaultModel'] : ''
    ];
}

function writeConfig($config) {
    $data = json_encode($config, JSON_PRETTY_PRINT | JSON_UNESCAPED_UNICODE);
    return file_put_contents(CONFIG_FILE, $data) !== false;
}

$action = $_GET['action'] ?? '';

switch ($action) {
    case 'load':
        echo json_encode(readConfig());
        exit;

    case 'save':
        if ($_SERVER['REQUEST_METHOD'] !== 'POST') {
            echo json_encode(['error' => 'POST required.']);
            exit;
        }

        $input = json_decode(file_get_contents('php://input'), true);
        if (!is_array($input)) {
            echo json_encode(['error' => 'Invalid JSON.']);
            exit;
        }

        $config = readConfig();
        $config['defaultModel'] = isset($input['defaultModel']) ? (string) $input['defaultModel'] : '';

        if (!writeConfig($config)) {
            echo json_encode(['error' => 'Unable to save config.']);
            exit;
        }

        echo json_encode(['success' => true, 'defaultModel' => $config['defaultModel']]);
        exit;

    default:
        echo json_encode(['error' => 'Unknown action.']);
        exit;
}