<?php

declare(strict_types=1);

namespace Deploymentcenter\Core;

/**
 * Minimaler Datei-Logger. Schlaegt das Schreiben fehl, wird still auf
 * error_log() ausgewichen - Logging darf niemals die Anwendung stoppen.
 */
final class Logger
{
    private static ?string $resolvedDir = null;

    public static function error(string $message, array $context = []): void
    {
        self::write('ERROR', $message, $context);
    }

    public static function warning(string $message, array $context = []): void
    {
        self::write('WARN', $message, $context);
    }

    public static function info(string $message, array $context = []): void
    {
        self::write('INFO', $message, $context);
    }

    public static function exception(\Throwable $e): void
    {
        self::write('ERROR', sprintf(
            '%s: %s in %s:%d',
            get_class($e),
            $e->getMessage(),
            $e->getFile(),
            $e->getLine()
        ), ['trace' => $e->getTraceAsString()]);
    }

    private static function write(string $level, string $message, array $context = []): void
    {
        $line = sprintf(
            "[%s] %s %s%s\n",
            gmdate('Y-m-d H:i:s'),
            $level,
            $message,
            $context !== [] ? ' ' . self::encodeContext($context) : ''
        );

        $dir = self::dir();
        if ($dir !== null) {
            $file = $dir . '/dc-' . gmdate('Y-m-d') . '.log';
            if (@file_put_contents($file, $line, FILE_APPEND | LOCK_EX) !== false) {
                return;
            }
        }

        @error_log(rtrim($line));
    }

    private static function encodeContext(array $context): string
    {
        $json = json_encode($context, JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE | JSON_INVALID_UTF8_SUBSTITUTE);
        return $json === false ? '{}' : $json;
    }

    private static function dir(): ?string
    {
        if (self::$resolvedDir !== null) {
            return self::$resolvedDir === '' ? null : self::$resolvedDir;
        }

        $dir = defined('DC_VAR') ? DC_VAR . '/log' : null;
        if ($dir === null) {
            self::$resolvedDir = '';
            return null;
        }

        if (!is_dir($dir) && !@mkdir($dir, 0775, true) && !is_dir($dir)) {
            self::$resolvedDir = '';
            return null;
        }

        if (!is_writable($dir)) {
            self::$resolvedDir = '';
            return null;
        }

        self::$resolvedDir = $dir;
        return $dir;
    }
}