package logger

import (
	"fmt"
	"log"
	"os"
	"path/filepath"
	"runtime"
	"strings"
	"time"

	"bash_go_service/shared/pkg/constants"

	"github.com/spf13/viper"
)

// LogLevel 定义日志级别类型
type LogLevel int

const (
	OFF   LogLevel = -1
	DEBUG LogLevel = iota
	INFO
	WARN
	ERROR
)

var (
	infoLogger    *log.Logger
	debugLogger   *log.Logger
	errorLogger   *log.Logger
	warningLogger *log.Logger
	currentLevel  LogLevel
)

type LogWriter struct {
	prefix string
	color  string
	level  LogLevel
}

func (w *LogWriter) Write(p []byte) (n int, err error) {
	// 检查日志级别
	if w.level < currentLevel {
		return len(p), nil // 当前日志等级比配置的还低，不打印
	}

	_, file, line, ok := runtime.Caller(4)
	if !ok {
		file = "???"
		line = 0
	}

	filename := filepath.Base(file)
	now := time.Now().Format("2006-01-02 15:04:05.000")

	logPrefix := fmt.Sprintf("%s%s%s [%s%-7s%s] %s%s:%d%s | ",
		constants.ColorGray, now, constants.ColorReset,
		w.color, w.prefix, constants.ColorReset,
		constants.ColorBold, filename, line, constants.ColorReset,
	)

	return os.Stdout.Write([]byte(logPrefix + string(p)))
}

// getLogLevelFromConfig 从配置文件获取日志级别
func getLogLevelFromConfig() LogLevel {
	logLevel := strings.ToUpper(viper.GetString("log.level"))
	switch logLevel {
	case "DEBUG":
		return DEBUG
	case "INFO":
		return INFO
	case "WARN":
		return WARN
	case "ERROR":
		return ERROR
	default:
		return OFF // 默认INFO级别
	}
}

func init() {
	// 设置当前日志级别
	currentLevel = getLogLevelFromConfig()

	infoLogger = log.New(&LogWriter{prefix: "INFO", color: constants.ColorGreen, level: INFO}, "", 0)
	debugLogger = log.New(&LogWriter{prefix: "DEBUG", color: constants.ColorBlue, level: DEBUG}, "", 0)
	errorLogger = log.New(&LogWriter{prefix: "ERROR", color: constants.ColorRed, level: ERROR}, "", 0)
	warningLogger = log.New(&LogWriter{prefix: "WARN", color: constants.ColorYellow, level: WARN}, "", 0)
}

// UpdateLogLevel 更新日志级别
func UpdateLogLevel() {
	currentLevel = getLogLevelFromConfig()
}

// 辅助函数封装
func Info(format string, v ...interface{}) {
	if INFO >= currentLevel {
		infoLogger.Printf(format, v...)
	}
}

func Debug(format string, v ...interface{}) {
	if DEBUG >= currentLevel {
		debugLogger.Printf(format, v...)
	}
}

func Error(format string, v ...interface{}) {
	if ERROR >= currentLevel {
		errorLogger.Printf(format, v...)
	}
}

func Warn(format string, v ...interface{}) {
	if WARN >= currentLevel {
		warningLogger.Printf(format, v...)
	}
}