// Package logger provider std slog logger
package logger

import (
	"io"
	"log/slog"
	"os"
	"path/filepath"
	"strconv"

	"gopkg.in/natefinch/lumberjack.v2"

	"git.ifooth.com/common/pkg/config"
)

// Init 初始化 slog
func Init() {
	textHandler := slog.NewTextHandler(os.Stdout, &slog.HandlerOptions{
		AddSource:   true,
		Level:       slog.LevelInfo,
		ReplaceAttr: ReplaceSourceAttr,
	})

	logger := slog.New(textHandler)
	slog.SetDefault(logger)
}

// GetLevelByName human readable logger level
func GetLevelByName(name string) slog.Level {
	switch name {
	case "error":
		return slog.LevelError
	case "warn":
		return slog.LevelWarn
	case "info":
		return slog.LevelInfo
	case "debug":
		return slog.LevelDebug
	default:
		return slog.LevelInfo
	}
}

// NewLogger make a new logger
func NewLogger(opts *config.LogConf) *slog.Logger {
	handler := NewHandler(opts)
	logger := slog.New(handler)
	return logger
}

// NewHandler make a new handler
func NewHandler(opts *config.LogConf) slog.Handler {
	ioWriter := io.Discard

	if opts.Stdout {
		ioWriter = os.Stdout
	}

	if opts.FileName != "" {
		fileWriter := &lumberjack.Logger{
			Filename:   opts.FileName,
			MaxSize:    opts.MaxSize,
			MaxBackups: opts.MaxNum,
			LocalTime:  true,
			Compress:   false,
		}

		if ioWriter == io.Discard {
			ioWriter = fileWriter
		} else {
			ioWriter = io.MultiWriter(ioWriter, fileWriter)
		}
	}

	level := GetLevelByName(opts.Level)

	slogOpt := &slog.HandlerOptions{
		AddSource:   true,
		Level:       level,
		ReplaceAttr: ReplaceSourceAttr,
	}

	if opts.Format == "json" {
		return slog.NewJSONHandler(ioWriter, slogOpt)
	}
	return slog.NewTextHandler(ioWriter, slogOpt)
}

// ReplaceSourceAttr source 格式化为 dir/file:line 格式
func ReplaceSourceAttr(groups []string, a slog.Attr) slog.Attr {
	if a.Key != slog.SourceKey {
		return a
	}

	src, ok := a.Value.Any().(*slog.Source)
	if !ok {
		return a
	}

	a.Value = slog.StringValue(filepath.Base(src.File) + ":" + strconv.Itoa(src.Line))
	return a
}