/**
* ロガーユーティリティ
* ログレベル制御と構造化ログ出力をサポート
*/
export type LogLevel = 'debug' | 'info' | 'warn' | 'error';
interface LogConfig {
level: LogLevel;
structured: boolean;
}
const LOG_LEVELS: Record<LogLevel, number> = {
debug: 0,
info: 1,
warn: 2,
error: 3,
};
let config: LogConfig = {
level: (process.env.LOG_LEVEL as LogLevel) || 'info',
structured: process.env.LOG_FORMAT === 'json',
};
function shouldLog(level: LogLevel): boolean {
return LOG_LEVELS[level] >= LOG_LEVELS[config.level];
}
function formatMessage(level: LogLevel, message: string, meta?: Record<string, unknown>): string {
if (config.structured) {
return JSON.stringify({
timestamp: new Date().toISOString(),
level,
message,
...meta,
});
}
const metaStr = meta && Object.keys(meta).length > 0 ? ` ${JSON.stringify(meta)}` : '';
return `[${level.toUpperCase()}] ${message}${metaStr}`;
}
export function info(message: string, meta?: Record<string, unknown>): void {
if (shouldLog('info')) {
console.error(formatMessage('info', message, meta));
}
}
export function warn(message: string, meta?: Record<string, unknown>): void {
if (shouldLog('warn')) {
console.error(formatMessage('warn', message, meta));
}
}
export function error(message: string, meta?: Record<string, unknown>): void {
if (shouldLog('error')) {
console.error(formatMessage('error', message, meta));
}
}
export function debug(message: string, meta?: Record<string, unknown>): void {
// DEBUG環境変数が設定されているか、ログレベルがdebugの場合に出力
if (process.env.DEBUG || shouldLog('debug')) {
console.error(formatMessage('debug', message, meta));
}
}
/**
* ログ設定を変更
*/
export function setLogConfig(newConfig: Partial<LogConfig>): void {
config = { ...config, ...newConfig };
}
/**
* 現在のログ設定を取得
*/
export function getLogConfig(): LogConfig {
return { ...config };
}
/**
* ログ設定をリセット
*/
export function resetLogConfig(): void {
config = {
level: (process.env.LOG_LEVEL as LogLevel) || 'info',
structured: process.env.LOG_FORMAT === 'json',
};
}
/**
* パフォーマンス計測用タイマー
*/
export class PerformanceTimer {
private startTime: number;
constructor(private label: string) {
this.startTime = Date.now();
}
end(): number {
const elapsed = Date.now() - this.startTime;
debug(this.label, { elapsed_ms: elapsed });
return elapsed;
}
}
