// Package logging provides a process-wide slog JSON logger for EvoBGP binaries.
package logging

import (
	"log/slog"
	"os"
	"strings"
	"sync"
)

var (
	once   sync.Once
	logger *slog.Logger
)

// Default returns the process JSON slog logger (stdout). Level from EVOBGP_LOG_LEVEL (debug|info|warn|error).
func Default() *slog.Logger {
	once.Do(func() {
		level := slog.LevelInfo
		switch strings.ToLower(strings.TrimSpace(os.Getenv("EVOBGP_LOG_LEVEL"))) {
		case "debug":
			level = slog.LevelDebug
		case "warn", "warning":
			level = slog.LevelWarn
		case "error":
			level = slog.LevelError
		}
		handler := slog.NewJSONHandler(os.Stdout, &slog.HandlerOptions{Level: level})
		logger = slog.New(handler)
		slog.SetDefault(logger)
	})
	return logger
}

// With returns Default().With(args...).
func With(args ...any) *slog.Logger {
	return Default().With(args...)
}