package logsdk

import (
	"fmt"
)

// Level 日志等级
type Level int

func (level Level) String() string {
	if b, err := level.MarshalText(); err == nil {
		return string(b)
	}
	return "unknown"
}

// ParseLevel 把 level 字符串解析成 Level,
// 支持的字符串: panic, fatal, error, warn, info, debug, trace,
// 传入不支持的字符串返回 LevelInfo.
func ParseLevel(s string) Level {
	switch s {
	case LevelPanicValue:
		return LevelPanic
	case LevelFatalValue:
		return LevelFatal
	case LevelErrorValue:
		return LevelError
	case LevelWarnValue:
		return LevelWarn
	case LevelInfoValue:
		return LevelInfo
	case LevelDebugValue:
		return LevelDebug
	case LevelTraceValue:
		return LevelTrace
	default:
		return LevelInfo
	}
}

func (level Level) MarshalText() ([]byte, error) {
	switch level {
	case LevelPanic:
		return []byte(LevelPanicValue), nil
	case LevelFatal:
		return []byte(LevelFatalValue), nil
	case LevelError:
		return []byte(LevelErrorValue), nil
	case LevelWarn:
		return []byte(LevelWarnValue), nil
	case LevelInfo:
		return []byte(LevelInfoValue), nil
	case LevelDebug:
		return []byte(LevelDebugValue), nil
	case LevelTrace:
		return []byte(LevelTraceValue), nil
	case LevelDisabled:
		return []byte(levelDisabledValue), nil
	}
	return nil, fmt.Errorf("not a valid log level %d", level)
}

const (
	// LevelCount 日志等级的个数
	LevelCount = 7

	// levelOffset 是把 LevelInfo 等级的日志值偏移到零值的偏移量
	levelOffset = 4
)

const (
	// LevelDisabled 表示不处理任何等级的日志,
	// 其他日志等级的值越小表示日志严重程度越高.
	LevelDisabled Level = iota - levelOffset - 1
	LevelPanic
	LevelFatal
	LevelError
	LevelWarn
	LevelInfo
	LevelDebug
	LevelTrace
)

const (
	LevelPanicValue = "panic"
	LevelFatalValue = "fatal"
	LevelErrorValue = "error"
	LevelWarnValue  = "warn"
	LevelInfoValue  = "info"
	LevelDebugValue = "debug"
	LevelTraceValue = "trace"

	levelDisabledValue = "disabled"
)

var AllLevels = []Level{
	LevelPanic,
	LevelFatal,
	LevelError,
	LevelWarn,
	LevelInfo,
	LevelDebug,
	LevelTrace,
}