package other

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

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

var cliFlagLogLevel = "info"
var cliFlagLogJson = false

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",
	)
}

// Configure logging. Utilises the flags setup in [SetupFlags].
// If logWriter is not nil, will also write logs, as json objects,
// to the given writer
func ConfigureLogging(logWriter io.Writer) {
	configOutputs(logWriter)
	configLevel()
}

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", cliFlagLogLevel).Msg("New logging level set")
}

func configOutputs(logWriter io.Writer) {
	console := zerolog.ConsoleWriter{Out: os.Stderr}
	extraLogWriters := []io.Writer{console}
	if logWriter != nil {
		extraLogWriters = append(extraLogWriters, logWriter)
	}
	if !cliFlagLogJson {
		log.Logger = zerolog.New(zerolog.MultiLevelWriter(extraLogWriters...)).
			With().
			Timestamp().
			Logger()
	} else {
		log.Logger = zerolog.New(zerolog.MultiLevelWriter(
			append([]io.Writer{log.Logger}, extraLogWriters...)...,
		)).With().Timestamp().Logger()
	}
	return
}