import pino from 'pino';
import { mkdir } from 'fs/promises';
import { dirname } from 'path';
export type { Logger } from 'pino';
export interface LoggerConfig {
consoleLevel: string;
fileLevel?: string;
filePath?: string;
pretty?: boolean;
}
/**
* Create a Pino logger with the specified configuration
*/
export function createLogger(config: LoggerConfig): pino.Logger {
const targets: pino.TransportTargetOptions[] = [];
// Console transport with graceful fallback
if (config.pretty) {
targets.push({
level: config.consoleLevel,
target: 'pino-pretty',
options: {
colorize: true,
translateTime: 'HH:MM:ss.l',
ignore: 'pid,hostname',
},
});
} else {
targets.push({
level: config.consoleLevel,
target: 'pino/file',
options: { destination: 2 }, // stderr
});
}
// File transport (if configured)
if (config.filePath && config.fileLevel) {
targets.push({
level: config.fileLevel,
target: 'pino/file',
options: { destination: config.filePath },
});
}
// Wrap initialization to handle transport errors
try {
return pino({
level: getMinLevel(config.consoleLevel, config.fileLevel),
transport: {
targets,
},
});
} catch (error) {
// Fall back to basic JSON logger if transport fails
const message = error instanceof Error ? error.message : String(error);
// Only warn if pretty was requested (otherwise it's expected behavior)
if (config.pretty) {
console.error('[Logger] pino-pretty not available, falling back to JSON logging:', message);
}
// Create fallback logger with JSON output to stderr
const fallbackTargets: pino.TransportTargetOptions[] = [
{
level: config.consoleLevel,
target: 'pino/file',
options: { destination: 2 }, // stderr
},
];
// Add file transport if configured
if (config.filePath && config.fileLevel) {
fallbackTargets.push({
level: config.fileLevel,
target: 'pino/file',
options: { destination: config.filePath },
});
}
return pino({
level: getMinLevel(config.consoleLevel, config.fileLevel),
transport: {
targets: fallbackTargets,
},
});
}
}
/**
* Create a logger for request/response logging (JSON Lines format)
*/
export function createRequestResponseLogger(filePath: string): pino.Logger {
return pino(
{
level: 'info',
timestamp: pino.stdTimeFunctions.isoTime,
},
pino.destination(filePath)
);
}
/**
* Ensure directory exists for log file
*/
export async function ensureLogDirectory(filePath: string): Promise<void> {
try {
const dir = dirname(filePath);
await mkdir(dir, { recursive: true });
} catch (error) {
throw new Error(
`Failed to create log directory for ${filePath}: ${error instanceof Error ? error.message : String(error)}`
);
}
}
/**
* Get minimum log level between console and file
*/
function getMinLevel(consoleLevel: string, fileLevel?: string): string {
const levels: Record<string, number> = {
debug: 20,
info: 30,
warn: 40,
error: 50,
};
const consoleLevelNum = levels[consoleLevel] || 30;
const fileLevelNum = fileLevel ? levels[fileLevel] || 30 : Infinity;
const minLevelNum = Math.min(consoleLevelNum, fileLevelNum);
// Return level name for minimum level number
for (const [name, num] of Object.entries(levels)) {
if (num === minLevelNum) {
return name;
}
}
return 'info';
}
