package beaver

import (
	"fmt"
	"io"
	"os"
	"runtime"
	"strings"
	"time"

	"go.jolheiser.com/beaver/color"
)

// Logger is a base Beaver logger
type Logger struct {
	Writer io.Writer
	Level  Level
	Format FormatOptions
	skip   int
}

// FormatOptions defines formatting options for a logger
type FormatOptions struct {
	TimePrefix   bool
	StackPrefix  bool
	StackLimit   int
	LevelPrefix  bool
	LevelColor   bool
	MessageColor bool
}

// New returns a new Beaver logger
func New(writer io.Writer, level Level, opts FormatOptions) *Logger {
	return &Logger{
		Writer: writer,
		Level:  level,
		Format: opts,
		skip:   3,
	}
}

func (l *Logger) write(level Level, text string) {
	if l.Level <= level {
		_, file, line, _ := runtime.Caller(l.skip)
		var message string
		if l.Format.TimePrefix {
			message += color.Time.Format(timePrefix(time.Now())) + " "
		}
		if l.Format.StackPrefix {
			idx := len(file) - l.Format.StackLimit
			if l.Format.StackLimit <= 0 {
				idx = 0
			}
			if idx > 0 {
				file = fmt.Sprintf("...%s", file[idx:])
			}
			message += color.Stack.Format(fmt.Sprintf("%s:%d", file, line)) + " "
		}
		if l.Format.LevelPrefix {
			if l.Format.LevelColor {
				message += level.Color().Format(level.Prefix())
			} else {
				message += level.Prefix()
			}
			message += " "
		}
		if l.Format.MessageColor {
			message += level.Color().Format(text)
		} else {
			message += text
		}
		message += "\n"
		_, _ = l.Writer.Write([]byte(message))
	}
}

func (l *Logger) log(level Level, v ...interface{}) {
	var args = make([]string, len(v))
	for i := 0; i < len(v); i++ {
		args[i] = fmt.Sprintf("%v", v[i])
	}
	text := strings.Join(args, " ")
	l.write(level, text)
}

func (l *Logger) logf(level Level, format string, v ...interface{}) {
	text := fmt.Sprintf(format, v...)
	l.write(level, text)
}

// Low-Level Log
func (l *Logger) Log(level Level, v ...interface{}) {
	l.log(level, v...)
}

// Low-Level formatted Log
func (l *Logger) Logf(level Level, format string, v ...interface{}) {
	l.logf(level, format, v...)
}

// Trace logs at TRACE Level
func (l *Logger) Trace(v ...interface{}) {
	l.log(TRACE, v...)
}

// Tracef formats logs at TRACE Level
func (l *Logger) Tracef(format string, v ...interface{}) {
	l.logf(TRACE, format, v...)
}

// Debug logs at DEBUG Level
func (l *Logger) Debug(v ...interface{}) {
	l.log(DEBUG, v...)
}

// Debugf formats logs at DEBUG Level
func (l *Logger) Debugf(format string, v ...interface{}) {
	l.logf(DEBUG, format, v...)
}

// Info logs at INFO Level
func (l *Logger) Info(v ...interface{}) {
	l.log(INFO, v...)
}

// Infof formats logs at INFO Level
func (l *Logger) Infof(format string, v ...interface{}) {
	l.logf(INFO, format, v...)
}

// Warn logs at WARN Level
func (l *Logger) Warn(v ...interface{}) {
	l.log(WARN, v...)
}

// Warnf formats logs at WARN Level
func (l *Logger) Warnf(format string, v ...interface{}) {
	l.logf(WARN, format, v...)
}

// Error logs at ERROR Level
func (l *Logger) Error(v ...interface{}) {
	l.log(ERROR, v...)
}

// Errorf formats logs at ERROR Level
func (l *Logger) Errorf(format string, v ...interface{}) {
	l.logf(ERROR, format, v...)
}

// Fatal logs at FATAL Level
func (l *Logger) Fatal(v ...interface{}) {
	l.log(FATAL, v...)
	os.Exit(1)
}

// Fatalf formats logs at FATAL Level
func (l *Logger) Fatalf(format string, v ...interface{}) {
	l.logf(FATAL, format, v...)
	os.Exit(1)
}