package fslog

import (
	"go.uber.org/zap"
	"go.uber.org/zap/zapcore"
	"os"
	"path/filepath"
	"runtime/debug"
	"strings"
	"sync"
)

const (
	LoggerLevelInfo  = "info"
	LoggerLevelError = "error"
	LoggerLevelDebug = "debug"
	LoggerLevelWarn  = "Warn"
)

var LoggerLever = LoggerLevelDebug

func chooseLoggerLever() zapcore.Level {
	switch LoggerLever {
	case LoggerLevelInfo:
		return zapcore.InfoLevel
	case LoggerLevelError:
		return zapcore.ErrorLevel
	case LoggerLevelDebug:
		return zapcore.DebugLevel
	case LoggerLevelWarn:
		return zapcore.WarnLevel
	default:
		return zapcore.DebugLevel
	}
}

var logger *zap.Logger
var initLoggerOnce sync.Once

const logDir = "logs"

func lazyInitialize() {
	initLoggerOnce.Do(func() {
		if !pathExists(logDir) {
			err := os.MkdirAll(logDir, os.ModeDir|os.ModePerm)
			if err != nil {
				panic(err)
			}
		}

		logFilePath := filepath.Join(logDir, "log")
		file, err := os.Create(logFilePath)
		if err != nil {
			panic(err)
		}

		developmentEncoderConfig := zap.NewDevelopmentEncoderConfig()

		encoder := zapcore.NewConsoleEncoder(developmentEncoderConfig)
		core := zapcore.NewTee(
			zapcore.NewCore(encoder, zapcore.AddSync(file), chooseLoggerLever()),
			zapcore.NewCore(encoder, zapcore.AddSync(os.Stdout), chooseLoggerLever()),
		)

		logger = zap.New(core, zap.AddCaller())
	})
}

func Info(serviceName string, funcName string, callName string, message string) {
	lazyInitialize()
	callerFields := getCallerInfoForLog(serviceName, funcName, callName)
	logger.Info(message, callerFields...)
}

func Error(serviceName string, funcName string, callName string, message string) {
	lazyInitialize()
	callerFields := getCallerInfoForLog(serviceName, funcName, callName)
	logger.Error(message+"\n"+string(debug.Stack()), callerFields...)
}

func Debug(serviceName string, funcName string, callName string, message string) {
	lazyInitialize()
	callerFields := getCallerInfoForLog(serviceName, funcName, callName)
	logger.Debug(message, callerFields...)
}

func Warn(serviceName string, funcName string, callName string, message string) {
	lazyInitialize()
	callerFields := getCallerInfoForLog(serviceName, funcName, callName)
	logger.Warn(message, callerFields...)
}

func getCallerInfoForLog(serviceName string, funcName string, callName string) []zap.Field {
	fields := make([]zap.Field, 0)

	if strings.Trim(serviceName, " ") != "" {
		fields = append(fields, zap.String("service", serviceName))
	}

	if strings.Trim(funcName, " ") != "" {
		fields = append(fields, zap.String("function", funcName))
	}

	if strings.Trim(callName, " ") != "" {
		fields = append(fields, zap.String("call", callName))
	}

	return fields
}

func pathExists(path string) bool {
	_, err := os.Stat(path)
	if err == nil {
		return true
	}

	if os.IsNotExist(err) {
		return false
	}

	return false
}