// Filename: internal/logging/logging.go

package logging

import (
	"gemini-balancer/internal/config"
	"io"
	"os"
	"path/filepath"

	"github.com/sirupsen/logrus"
)

func NewLogger(cfg *config.Config) *logrus.Logger {
	logger := logrus.New()

	// 1. 设置日志级别
	level, err := logrus.ParseLevel(cfg.Log.Level)
	if err != nil {
		logger.WithField("configured_level", cfg.Log.Level).Warn("Invalid log level specified, defaulting to 'info'.")
		level = logrus.InfoLevel
	}
	logger.SetLevel(level)

	// 2. 设置日志格式
	if cfg.Log.Format == "json" {
		logger.SetFormatter(&logrus.JSONFormatter{
			TimestampFormat: "2006-01-02T15:04:05.000Z07:00",
			FieldMap: logrus.FieldMap{
				logrus.FieldKeyTime:  "timestamp",
				logrus.FieldKeyLevel: "level",
				logrus.FieldKeyMsg:   "message",
			},
		})
	} else {
		logger.SetFormatter(&logrus.TextFormatter{
			FullTimestamp:   true,
			TimestampFormat: "2006-01-02 15:04:05",
		})
	}

	// 3. 设置日志输出
	if cfg.Log.EnableFile {
		if cfg.Log.FilePath == "" {
			logger.Warn("Log file is enabled but no file path is specified. Logging to console only.")
			logger.SetOutput(os.Stdout)
			return logger
		}

		logDir := filepath.Dir(cfg.Log.FilePath)
		if err := os.MkdirAll(logDir, 0755); err != nil {
			logger.WithError(err).Warn("Failed to create log directory. Logging to console only.")
			logger.SetOutput(os.Stdout)
			return logger
		}

		logFile, err := os.OpenFile(cfg.Log.FilePath, os.O_CREATE|os.O_WRONLY|os.O_APPEND, 0666)
		if err != nil {
			logger.WithError(err).Warn("Failed to open log file. Logging to console only.")
			logger.SetOutput(os.Stdout)
			return logger
		}

		// 同时输出到控制台和文件
		logger.SetOutput(io.MultiWriter(os.Stdout, logFile))
		logger.WithField("log_file_path", cfg.Log.FilePath).Info("Logging is now configured to output to both console and file.")
	} else {
		// 仅输出到控制台
		logger.SetOutput(os.Stdout)
	}

	logger.Info("Root logger initialized.")
	return logger
}