package other

import (
	"flag"
	"io"
	"os"
	"strings"

	"github.com/rs/zerolog"
	"github.com/rs/zerolog/log"
)

var cliFlagLogLevel = "info"
var cliFlagLogJson = false
var cliFlagLogFile = ""

func SetupFlags() {
	flag.StringVar(
		&cliFlagLogLevel,
		"loglevel",
		"info",
		"Set the logging level. Valid values (case insensitive) are: debug, info, warn, error, fatal",
	)
	flag.BoolVar(
		&cliFlagLogJson,
		"logjson",
		false,
		"Log json objects to stderr instead of nicely formatted ones",
	)
	flag.StringVar(
		&cliFlagLogFile,
		"logfile",
		"",
		"Set the file to write json formatted log messages to",
	)
}

func ConfigureLoggingFromCliArgs() {
	configLevel()
	configOutputs()
}

func configLevel() {
	switch strings.ToLower(*&cliFlagLogLevel) {
	case "trace":
		zerolog.SetGlobalLevel(zerolog.TraceLevel)
	case "debug":
		zerolog.SetGlobalLevel(zerolog.DebugLevel)
	case "info":
		zerolog.SetGlobalLevel(zerolog.InfoLevel)
	case "warn":
		zerolog.SetGlobalLevel(zerolog.WarnLevel)
	case "error":
		zerolog.SetGlobalLevel(zerolog.ErrorLevel)
	case "fatal":
		zerolog.SetGlobalLevel(zerolog.FatalLevel)
	default:
		zerolog.SetGlobalLevel(zerolog.InfoLevel)
	}
	log.Info().Str("new-level", *flagLogLevel).Msg("New logging level set")
}

func configOutputs() {
	extraLogWriters := []io.Writer{}
	if cliFlagLogFile != "" {
		file, err := os.OpenFile(cliFlagLogFile, os.O_APPEND|os.O_CREATE, os.ModeAppend)
		if err != nil {
			log.Fatal().Err(err).Msg("Failed to open log file")
		}
		// NOTE: Technically this leaks a file handle
		// Shouldn't matter though since the log file should be open until the very end
		// Sooooo, eh. Don't care about adding an elaborate system to close the file at the very end.
		// OS will do that anyway
		extraLogWriters = append(extraLogWriters, file)
	}
	if !cliFlagLogJson {
		console := zerolog.ConsoleWriter{Out: os.Stderr}
		log.Logger = zerolog.New(zerolog.MultiLevelWriter(append([]io.Writer{console}, extraLogWriters...)...)).
			With().
			Timestamp().
			Logger()
	} else {
		log.Logger = zerolog.New(zerolog.MultiLevelWriter(
			append([]io.Writer{log.Logger}, extraLogWriters...)...,
		)).With().Timestamp().Logger()
	}
}