package beaver

import (
	"fmt"
	"strings"
	"time"

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

var bold = color.New(color.Bold)

// Level defines a Beaver logging level
type Level int

const (
	TRACE Level = iota
	DEBUG
	INFO
	WARN
	ERROR
	FATAL
)

// String returns a human-friendly string
func (l Level) String() string {
	switch l {
	case TRACE:
		return "Trace"
	case DEBUG:
		return "Debug"
	case INFO:
		return "Info"
	case WARN:
		return "Warn"
	case ERROR:
		return "Error"
	case FATAL:
		return "Fatal"
	default:
		return "N/A"
	}
}

// Prefix returns a prefix for a logging level, optionally colored
func (l Level) Prefix() string {
	var letter string
	switch l {
	case TRACE:
		letter = "T"
	case DEBUG:
		letter = "D"
	case INFO:
		letter = "I"
	case WARN:
		letter = "W"
	case ERROR:
		letter = "E"
	case FATAL:
		letter = "F"
	}
	return fmt.Sprintf("[%s]", letter)
}

// Color returns a Level's color, defaulting to bold
func (l Level) Color() *color.Color {
	switch l {
	case TRACE:
		return color.Trace
	case DEBUG:
		return color.Debug
	case INFO:
		return color.Info
	case WARN:
		return color.Warn
	case ERROR:
		return color.Error
	case FATAL:
		return color.Fatal
	default:
		return bold
	}
}

// Levels returns a list of Beaver logging levels
func Levels() []Level {
	return []Level{TRACE, DEBUG, INFO, WARN, ERROR, FATAL}
}

// ParseLevel parses a string and returns a Beaver Level, defaulting to Info
func ParseLevel(level string) Level {
	switch strings.ToUpper(level) {
	case "T", "TRACE":
		return TRACE
	case "D", "DEBUG":
		return DEBUG
	case "I", "INFO":
		return INFO
	case "W", "WARN":
		return WARN
	case "E", "ERROR":
		return ERROR
	case "F", "FATAL":
		return FATAL
	}
	return INFO
}

func timePrefix(t time.Time) string {
	var buf = &[]byte{}
	year, month, day := t.Date()
	itoa(buf, int(month), 2)
	*buf = append(*buf, '/')
	itoa(buf, day, 2)
	*buf = append(*buf, '/')
	itoa(buf, year, 4)
	*buf = append(*buf, ' ')

	hour, min, sec := t.Clock()
	itoa(buf, hour, 2)
	*buf = append(*buf, ':')
	itoa(buf, min, 2)
	*buf = append(*buf, ':')
	itoa(buf, sec, 2)

	return string(*buf)
}

func itoa(buf *[]byte, i int, wid int) {
	var b [20]byte
	bp := len(b) - 1
	for i >= 10 || wid > 1 {
		wid--
		q := i / 10
		b[bp] = byte('0' + i - q*10)
		bp--
		i = q
	}
	// i < 10
	b[bp] = byte('0' + i)
	*buf = append(*buf, b[bp:]...)
}