// logger.js
const winston = require('winston');

/**
 * 配置winston日志
 */
const DailyRotateFile = require('winston-daily-rotate-file');
const fs = require('fs');
const path = require('path');

const baseDir = (typeof process !== 'undefined' && process.pkg) ? path.dirname(process.execPath) : __dirname;
const logsDir = path.join(baseDir, 'logs');
if (!fs.existsSync(logsDir)) {
    fs.mkdirSync(logsDir);
}

const logger = winston.createLogger({
    level: process.env.LOG_LEVEL || 'info',
    format: winston.format.combine(
        winston.format.timestamp({
            format: 'YYYY-MM-DD HH:mm:ss'
        }),
        winston.format.errors({ stack: true }),
        winston.format.splat(),
        winston.format.json()
    ),
    defaultMeta: { service: 'dialysis-server' },
    transports: [
        new DailyRotateFile({
            dirname: logsDir,
            filename: 'error-%DATE%.log',
            datePattern: 'YYYY-MM-DD',
            level: 'error',
            zippedArchive: true,
            maxFiles: '10d',
        }),
        new DailyRotateFile({
            dirname: logsDir,
            filename: 'combined-%DATE%.log',
            datePattern: 'YYYY-MM-DD',
            zippedArchive: true,
            maxFiles: '10d',
        }),
    ]
});

// 如果不是生产环境，也输出到控制台
if (process.env.NODE_ENV !== 'production') {
    logger.add(new winston.transports.Console({
        format: winston.format.combine(
            winston.format.colorize(),
            winston.format.timestamp({ format: 'YYYY-MM-DD HH:mm:ss' }),
            winston.format.printf(({ level, message, timestamp, ...meta }) => {
                try {
                    return `${level}: ${message} ${JSON.stringify(meta)}`;
                } catch (_) {
                    return `${level}: ${message}`;
                }
            })
        )
    }));
}

// 提供按设备序列号的子 logger，便于按设备追踪
logger.forDevice = (deviceSerial, ip, clientId) => logger.child({ deviceSerial, ip, clientId });

module.exports = logger;