package logger

import (
	"go.uber.org/zap"
	"go.uber.org/zap/buffer"
	"go.uber.org/zap/zapcore"
	"gopkg.in/natefinch/lumberjack.v2"
	"os"
	"path"
	"strings"
)

type (
	LogConf struct {
		Path       string         // 日志路径
		Encoder    string         // 编码器选择
		Level      *zapcore.Level // 日志级别
		MaxSize    int            // 每个日志文件的最大大小（MB）
		MaxBackups int            // 保留的旧日志文件个数
		RotateDays int            // 日志文件的最大保留天数
	}
	logItem struct {
		FileName string
		Level    zap.LevelEnablerFunc
	}
	Encoder interface {
		Config() zapcore.Encoder
		WithKey(key string) Encoder
		WithField(key, val string) Encoder
		Debug(msg string)
		Debugf(format string, v ...interface{})
		Info(msg string)
		Infof(format string, v ...interface{})
		Warn(msg string)
		Warnf(format string, v ...interface{})
		Error(msg string)
		Errorf(format string, v ...interface{})
		Fatal(msg string)
		Fatalf(format string, v ...interface{})
	}
)

var (
	maxSize    = 200 // 每个日志文件最大尺寸200M
	maxBackups = 2   // 日志文件最多保存20个备份
	maxAge     = 5   // 保留最大天数
	logLevel   = zapcore.WarnLevel
	_logger    *zap.Logger
	_pool      = buffer.NewPool()

	ConsoleEncoder = "console" // 控制台输出
	JsonEncoder    = "json"    // json输出
)

// Init 初始化日志.
func Init(conf LogConf) {
	if conf.Level == nil {
		conf.Level = &logLevel
	}
	if conf.Path == "" {
		conf.Path = "server.log"
	}
	if conf.RotateDays == 0 {
		conf.RotateDays = 15
	}
	prefix, suffix := getFileSuffixPrefix(conf.Path)

	logPath := path.Join(prefix + suffix)
	items := []logItem{
		{
			FileName: logPath,
			Level: func(level zapcore.Level) bool {
				return level >= *conf.Level
			},
		},
	}

	NewLogger(items, conf)
}

// NewLogger 日志.
func NewLogger(items []logItem, conf LogConf) {
	var (
		cfg   zapcore.Encoder
		cores []zapcore.Core
	)
	switch conf.Encoder {
	case JsonEncoder:
		cfg = NewJsonLog().Config()
	case ConsoleEncoder:
		cfg = NewConsoleLog().Config()
	default:
		cfg = NewConsoleLog().Config()
	}

	if conf.RotateDays == 0 {
		conf.RotateDays = maxAge
	}
	if conf.MaxBackups == 0 {
		conf.MaxBackups = maxBackups
	}
	if conf.MaxSize == 0 {
		conf.MaxSize = maxSize
	}

	for _, v := range items {
		hook := lumberjack.Logger{
			Filename:   v.FileName,
			MaxSize:    conf.MaxSize,    // 每个日志文件保存的最大尺寸 单位：M
			MaxBackups: conf.MaxBackups, // 日志文件最多保存多少个备份
			MaxAge:     conf.RotateDays, // 文件最多保存多少天
			Compress:   true,            // 是否压缩
			LocalTime:  true,            // 备份文件名本地/UTC时间
		}
		core := zapcore.NewCore(
			cfg, // 编码器配置;
			zapcore.NewMultiWriteSyncer(zapcore.AddSync(os.Stdout), zapcore.AddSync(&hook)), // 打印到控制台和文件
			v.Level, // 日志级别
		)
		cores = append(cores, core)
	}

	// 开启开发模式，堆栈跟踪
	caller := zap.AddCaller()
	// 开发模式
	development := zap.Development()
	// 二次封装
	skip := zap.AddCallerSkip(1)
	// 构造日志
	_logger = zap.New(zapcore.NewTee(cores...), caller, development, skip)
	return
}

// GetEncoder 获取自定义编码器.
func GetEncoder(conf LogConf) Encoder {
	switch conf.Encoder {
	case JsonEncoder:
		return NewJsonLog()
	case ConsoleEncoder:
		return NewConsoleLog()
	default:
		return NewConsoleLog()
	}
}

// GetLogger 获取日志记录器.
func GetLogger() *zap.Logger {
	return _logger
}

// getFileSuffixPrefix 文件路径切割
func getFileSuffixPrefix(fileName string) (prefix, suffix string) {
	paths, _ := path.Split(fileName)
	base := path.Base(fileName)
	suffix = path.Ext(fileName)
	prefix = strings.TrimSuffix(base, suffix)
	prefix = path.Join(paths, prefix)
	return
}

// getFilePath 自定义获取文件路径.
func getFilePath(ec zapcore.EntryCaller) string {
	if !ec.Defined {
		return "undefined"
	}
	buf := _pool.Get()
	buf.AppendString(ec.Function)
	buf.AppendByte(':')
	buf.AppendInt(int64(ec.Line))
	caller := buf.String()
	buf.Free()
	return caller
}