package config

import (
	"bytes"
	"log/slog"
	"os"

	"git.loyso.art/frx/kurious/internal/common/errors"
)

type LogFormat uint8

const (
	LogFormatText LogFormat = iota
	LogFormatJSON
)

func (f *LogFormat) UnmarshalText(data []byte) error {
	switch format := string(bytes.ToLower(data)); format {
	case "json":
		*f = LogFormatJSON
	case "text":
		*f = LogFormatText
	default:
		return errors.NewValidationError("format", "unsupported value "+format)
	}

	return nil
}

type LogLevel uint8

const (
	LogLevelDebug LogLevel = iota
	LogLevelInfo
	LogLevelWarn
	LogLevelError
)

func (lvl *LogLevel) UnmarshalText(data []byte) error {
	switch level := string(bytes.ToLower(data)); level {
	case "debug", "":
		*lvl = LogLevelDebug
	case "info":
		*lvl = LogLevelInfo
	case "warn":
		*lvl = LogLevelWarn
	case "error":
		*lvl = LogLevelError
	default:
		return errors.NewValidationError("level", "unsupported value "+level)
	}

	return nil
}

type Log struct {
	Level  LogLevel  `json:"level"`
	Format LogFormat `json:"format"`
}

func NewSLogger(config Log) *slog.Logger {
	var level slog.Level
	switch config.Level {
	case LogLevelDebug:
		level = slog.LevelDebug
	case LogLevelInfo:
		level = slog.LevelInfo
	case LogLevelWarn:
		level = slog.LevelWarn
	case LogLevelError:
		level = slog.LevelError
	}

	opts := &slog.HandlerOptions{
		Level: level,
	}

	var h slog.Handler
	switch config.Format {
	case LogFormatJSON:
		h = slog.NewJSONHandler(os.Stdout, opts)
	case LogFormatText:
		h = slog.NewTextHandler(os.Stdout, opts)
	}

	return slog.New(h)
}