package logger

import (
	"flag"
	"fmt"
	"io"
	"log"
	"os"
	"path"
	"runtime"
	"runtime/debug"
	"strings"
)

var stdlogger *log.Logger
var errlogger *log.Logger
var _ = flag.Bool("logfile", false, "")

func init() {
	binpath, _ := os.Executable()
	binname := path.Base(strings.ReplaceAll(binpath, "\\", "/"))

	var outWriter io.Writer
	var errWriter io.Writer
	outWriter = os.Stdout
	errWriter = os.Stderr

	args := os.Args
	useLogFile := false
	for _, arg := range args {
		if arg == "-logfile" {
			useLogFile = true
			break
		}
	}

	if useLogFile {
		ext := path.Ext(binname)
		if len(ext) > 0 {
			binname = binname[:len(binname)-len(ext)]
		}

		logFile, err := os.Create(fmt.Sprintf("%s.log", binname))
		if err != nil {
			os.Stdout.Write([]byte(err.Error()))
			panic(err)
		}

		outWriter = io.MultiWriter(outWriter, logFile)
		errWriter = io.MultiWriter(errWriter, logFile)
	}

	stdlogger = log.New(outWriter, "", log.LstdFlags)
	errlogger = log.New(errWriter, "", log.LstdFlags)
}

func Println(v ...interface{}) {
	stdlogger.Output(2, fmt.Sprintln(v...))
}

func Printf(format string, v ...interface{}) {
	stdlogger.Output(2, fmt.Sprintf(format, v...))
}

func Error(v ...interface{}) {
	errlogger.Output(2, fmt.Sprintln(v...))
	errlogger.Output(2, string(debug.Stack()))
}

func Errorf(format string, v ...interface{}) {
	errlogger.Output(2, fmt.Sprintf(format, v...))
	errlogger.Output(2, string(debug.Stack()))
}

func Fatal(v ...interface{}) {
	errlogger.Output(2, fmt.Sprint(v...))
	errlogger.Output(2, string(debug.Stack()))
	os.Exit(1)
}
func Fatalln(v ...interface{}) {
	errlogger.Output(2, fmt.Sprintln(v...))
	errlogger.Output(2, string(debug.Stack()))
	os.Exit(1)
}
func Panic(v ...interface{}) {
	s := fmt.Sprint(v...)
	errlogger.Output(2, s)
	errlogger.Output(2, string(debug.Stack()))
	panic(s)
}

func Panicf(format string, v ...interface{}) {
	s := fmt.Sprintf(format, v...)
	errlogger.Output(2, s)
	errlogger.Output(2, string(debug.Stack()))
	panic(s)
}

func Panicln(v ...interface{}) {
	s := fmt.Sprintln(v...)
	errlogger.Output(2, s)
	errlogger.Output(2, string(debug.Stack()))
	panic(s)
}

type errWithCallstack struct {
	inner  error
	frames []*runtime.Frame
}

func (ecs *errWithCallstack) Error() string {
	if ecs.frames == nil {
		return ecs.inner.Error()
	}

	out := make([]string, 0, len(ecs.frames)+1)
	out = append(out, ecs.inner.Error())
	for i := len(ecs.frames) - 1; i >= 0; i-- {
		frame := ecs.frames[i]
		out = append(out, fmt.Sprintf("%s\n\t%s:%d", frame.Function, frame.File, frame.Line))
	}

	return strings.Join(out, "\n")
}

func ErrorWithCallStack(err error) error {
	var frames []*runtime.Frame

	if recur, ok := err.(*errWithCallstack); ok {
		err = recur.inner
		frames = recur.frames
	}

	pc, _, _, ok := runtime.Caller(1)
	if ok {
		curframes := runtime.CallersFrames([]uintptr{pc})
		f, _ := curframes.Next()
		frames = append(frames, &f)
	}

	return &errWithCallstack{
		inner:  err,
		frames: frames,
	}
}