package mq

import (
	"fmt"
	"log"
)

// LogLevel 日志级别
type LogLevel string

const (
	LevelInfo  LogLevel = "INFO"
	LevelError LogLevel = "ERROR"
	LevelWarn  LogLevel = "WARN"
)

// Logger 简单的结构化日志封装
// 格式: [Component] [Level] Message key1=value1 key2=value2
type Logger struct {
	Component string
}

func NewLogger(component string) *Logger {
	return &Logger{Component: component}
}

func (l *Logger) Info(msg string, keysAndValues ...interface{}) {
	l.log(LevelInfo, msg, keysAndValues...)
}

func (l *Logger) Warn(msg string, keysAndValues ...interface{}) {
	l.log(LevelWarn, msg, keysAndValues...)
}

func (l *Logger) Error(msg string, keysAndValues ...interface{}) {
	l.log(LevelError, msg, keysAndValues...)
}

func (l *Logger) log(level LogLevel, msg string, args ...interface{}) {
	// 构建 key=value 字符串
	var kvStr string
	for i := 0; i < len(args); i += 2 {
		key := args[i]
		var val interface{} = ""
		if i+1 < len(args) {
			val = args[i+1]
		}
		if kvStr != "" {
			kvStr += " "
		}
		kvStr += logFormatKV(key, val)
	}

	if kvStr != "" {
		log.Printf("[%s] [%s] %s %s", l.Component, level, msg, kvStr)
	} else {
		log.Printf("[%s] [%s] %s", l.Component, level, msg)
	}
}

func logFormatKV(key, val interface{}) string {
	return logStr(key) + "=" + logStr(val)
}

func logStr(v interface{}) string {
	return fmt.Sprint(v)
}