<?php

namespace com\fwdekker\deathnotifier;

use Exception;
use Monolog\ErrorHandler;
use Monolog\Handler\StreamHandler;
use Monolog\Logger;


/**
 * Helper functions.
 */
class Util
{
    /**
     * Sets HTTP status code and exits the script.
     *
     * @param int $status the HTTP status code to set
     * @return never
     */
    static function http_exit(int $status): never
    {
        http_response_code($status);
        exit(1);
    }


    /**
     * Reads the configuration file and overrides it with the user's custom values.
     *
     * @return array<string, array<string, mixed>>|null the configuration
     */
    static function read_config(): ?array
    {
        // TODO: Check permissions, return `null` if too permissive
        $config = parse_ini_file("config.default.ini.php", process_sections: true, scanner_mode: INI_SCANNER_TYPED);
        if ($config === false) return null;

        if (file_exists("config.ini.php")) {
            $config_custom = parse_ini_file("config.ini.php", process_sections: true, scanner_mode: INI_SCANNER_TYPED);
            if ($config_custom === false) return null;

            $config = array_replace_recursive($config, $config_custom);
        }

        return $config;
    }

    /**
     * Creates the main logger instance.
     *
     * @param array<string, mixed> $logger_config the logger section of the configuration
     * @return Logger the main logger instance
     */
    static function create_logger(array $logger_config): Logger
    {
        $logger = new Logger("main");
        $logger->pushHandler(new StreamHandler($logger_config["file"], $logger_config["level"]));
        ErrorHandler::register($logger);

        return $logger;
    }

    /**
     * Parses POST values from JSON-based inputs.
     *
     * @return array<string, mixed>|null the parsed POST-ed values
     */
    static function parse_post(): ?array
    {
        $output = $_POST;

        $post_input = file_get_contents("php://input");
        if ($post_input !== false)
            $output = json_decode($post_input, associative: true);

        return $output;
    }


    /**
     * Generates an appropriate CSRF token.
     *
     * @return string the generated CSRF token
     * @throws Exception if the CSRF token could not be generated
     */
    static function generate_csrf_token(): string
    {
        return bin2hex(random_bytes(32));
    }
}