package internal

import (
	"io"
	"log/slog"
	"strings"
)

func parseLogLevel(levelStr string) slog.Level {
	switch strings.ToUpper(levelStr) {
	case "DEBUG":
		return slog.LevelDebug
	case "INFO":
		return slog.LevelInfo
	case "WARN":
		return slog.LevelWarn
	case "ERROR":
		return slog.LevelError
	default:
		return slog.LevelInfo // Default level
	}
}

// InitLoggging initializes global structured logging for the entire application
//
// Stderr is used for diagnostics and logging. Stdout is used for program
// output. Stderr should be used since it will have greater likely hood of being
// seen if a programs output is being redirected.
func InitLogging(level string, w io.Writer) *slog.Logger {
	parsedLogLevel := parseLogLevel(level)
	loggerHandler := slog.NewJSONHandler(w, &slog.HandlerOptions{Level: parsedLogLevel, AddSource: true})
	logger := slog.New(loggerHandler)
	slog.SetDefault(logger)
	return logger
}