// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.
package log

import (
	"encoding/json"
	"fmt"
	"log"
	"os"
	"runtime/debug"
	"strings"
	"sync"
	"time"

	"qoobing.com/gomod/str"
)

const (
	PANIC       logLevel = 0
	FATAL       logLevel = 1
	ERROR       logLevel = 2
	NOTICE      logLevel = 3
	WARNING     logLevel = 4
	INFO        logLevel = 5
	DEBUG       logLevel = 9
	ErrLogPanic          = "~~~~panic~~~~~~"
)

var (
	golog        *log.Logger        = nil
	mylog        *Logger            = nil
	logidCreator LogidCreator       = nil
	modulelogs   map[string]*Logger = map[string]*Logger{}
)

type logLevel int
type Logger struct {
	module   string
	golog    *log.Logger
	loglevel logLevel
}

type LogidCreator interface {
	Cleanup()
	GetLogid() string
	SetLogid(logid string)
}

func New(module string) *Logger {
	if module == "" {
		module = "undefine"
	}
	if _, ok := modulelogs[module]; ok {
		return modulelogs[module]
	} else {
		modulelogs[module] = &Logger{
			module:   module,
			golog:    golog,
			loglevel: DEBUG,
		}
		return modulelogs[module]
	}
}

// ////////////////////////////////////////////////////////////////
func (log *Logger) SetLogLevel(newlv logLevel) (oldlv logLevel) {
	oldlv = log.loglevel
	log.loglevel = newlv
	return oldlv
}

func (log *Logger) Print(prefix string, v interface{}) {
	preety, _ := json.Marshal(v)
	log.logwrite(DEBUG, 3, prefix+"%s\n", preety)
}

func (log *Logger) PrintPretty(prefix string, v interface{}) {
	preety, _ := json.MarshalIndent(v, "==", "    ")
	log.logwrite(DEBUG, 3, prefix+"%s\n", preety)
}

func (log *Logger) Debugf(format string, v ...interface{}) {
	log.logwrite(DEBUG, 3, format, v...)
}

func (log *Logger) DebugfWithDepth(calldepth int, format string, v ...interface{}) {
	calldepth += 3
	log.logwrite(DEBUG, calldepth, format, v...)
}

func (log *Logger) Noticef(format string, v ...interface{}) {
	log.logwrite(NOTICE, 3, format, v...)
}

func (log *Logger) NoticefWithDepth(calldepth int, format string, v ...interface{}) {
	calldepth += 3
	log.logwrite(NOTICE, calldepth, format, v...)
}

func (log *Logger) Warningf(format string, v ...interface{}) {
	log.logwrite(WARNING, 3, format, v...)
}

func (log *Logger) Infof(format string, v ...interface{}) {
	log.logwrite(INFO, 3, format, v...)
}

func (log *Logger) Errorf(format string, v ...interface{}) {
	log.logwrite(ERROR, 3, format, v...)
}

func (log *Logger) Fatalf(format string, v ...interface{}) {
	log.logwrite(FATAL, 3, format, v...)
}

func (log *Logger) Panicf(format string, v ...interface{}) {
	log.logwrite(PANIC, 3, format, v...)
}

func (log *Logger) GetLogidStr(format string) string {
	if logidCreator != nil {
		return fmt.Sprintf(format, logidCreator.GetLogid())
	}
	return ""
}

func (log *Logger) logwrite(typ logLevel, calldepth int, format string, v ...interface{}) {
	if typ > log.loglevel {
		return
	}

	var (
		idstr  = log.GetLogidStr("[%s] ")
		prestr = idstr // + "[" + log.module + "] "
	)

	format = strings.Trim(format, "\n")
	switch typ {
	case PANIC:
		log.golog.SetPrefix("\x1b[31m" + "PANI ")
	case FATAL:
		log.golog.SetPrefix("\x1b[31m" + "FATA ")
	case WARNING:
		log.golog.SetPrefix("\x1b[32m" + "WARN ")
	case ERROR:
		log.golog.SetPrefix("\x1b[32m" + "ERRO ")
	case INFO:
		log.golog.SetPrefix("INFO ")
	case NOTICE:
		log.golog.SetPrefix("NOTI ")
	case DEBUG:
		log.golog.SetPrefix("DBUG ")
	default:
		log.golog.SetPrefix("UNKN ")
	}

	if mylog == log {
		calldepth = calldepth + 1
	}

	if typ == FATAL || typ == WARNING || typ == ERROR {
		log.golog.Output(calldepth, prestr+fmt.Sprintf(format+"\x1b[0m\n", v...))
	} else if typ == NOTICE {
		calldepth = calldepth + 2
		log.golog.Output(calldepth, prestr+fmt.Sprintf(format+"\n", v...))
	} else if typ == PANIC {
		stack := strings.Replace(string(debug.Stack()), "\n", "\n==    ", -1)
		stack = str.SkipLine(stack, calldepth*2+1)
		v = append(v, stack)
		panicstr := fmt.Sprintf(prestr+format+"\x1b[0m. Panic stack:\n%s\n", v...)
		log.golog.Output(calldepth, panicstr)
		panic(ErrLogPanic)
	} else {
		log.golog.Output(calldepth, prestr+fmt.Sprintf(format+"\n", v...))
	}
}

func needWriteLogToFile() bool {
	if cls, ok := os.LookupEnv("QOOLOG_CLOSE_FILELOG"); ok && cls != "N" && cls != "n" {
		return false
	} else if ink8s, ok := os.LookupEnv("KUBERNETES_PORT"); ok && ink8s != "" {
		return false
	}
	return true
}

// //////////////////////////////////////////////////////////////////////////////////
// ///////////////////////Initialize/////////////////////////////////////////////////
// //////////////////////////////////////////////////////////////////////////////////
var once sync.Once = sync.Once{}

// init
func init() {
	once.Do(initlog)
}

// initlog
func initlog() {
	// Step 1. create base writer & cache writer for ALL log
	var (
		logDir          = "./logs/"
		logName         = getExeFilename()
		logDirsOptional = []string{"./log", "/var/log"}
		logSplitTag     = "20060102" //20060102150405
		baseWriter      = NewBaseWriter(nil, os.Stdout, nil)
		gologFlags      = log.Ldate | log.Lmicroseconds | log.Lshortfile
	)

	// Step 2. init golog(golang std logger) & mylog(myself defined logger)
	golog = log.New(NewCacheWriter(baseWriter), "", gologFlags)
	mylog = New("system")

	// Step 3. backgroud split log (log rotate) if need
	if needWriteLogToFile() {
		go func() {
			baseWriter.OpenLogFile(logDir, logName, logDirsOptional)
			for {
				tag := time.Now().Local().Format(logSplitTag)
				baseWriter.TryBackupLogFile(tag)
				time.Sleep(2 * time.Minute)
			}
		}()
	}
}