// Package logger provides structured logging for the application.
package logger

import (
	"log/slog"
	"os"

	"git.eeqj.de/sneak/chat/internal/globals"
	"go.uber.org/fx"
)

// Params defines the dependencies for creating a Logger.
type Params struct {
	fx.In

	Globals *globals.Globals
}

// Logger wraps slog with application-specific configuration.
type Logger struct {
	log    *slog.Logger
	level  *slog.LevelVar
	params Params
}

// New creates a new Logger with appropriate handler
// based on terminal detection.
func New(
	_ fx.Lifecycle, params Params,
) (*Logger, error) {
	logger := new(Logger)
	logger.level = new(slog.LevelVar)
	logger.level.Set(slog.LevelInfo)

	tty := false

	if fileInfo, _ := os.Stdout.Stat(); (fileInfo.Mode() & os.ModeCharDevice) != 0 {
		tty = true
	}

	opts := &slog.HandlerOptions{ //nolint:exhaustruct // ReplaceAttr optional
		Level:     logger.level,
		AddSource: true,
	}

	var handler slog.Handler
	if tty {
		handler = slog.NewTextHandler(os.Stdout, opts)
	} else {
		handler = slog.NewJSONHandler(os.Stdout, opts)
	}

	logger.log = slog.New(handler)
	logger.params = params

	return logger, nil
}

// EnableDebugLogging switches the log level to debug.
func (logger *Logger) EnableDebugLogging() {
	logger.level.Set(slog.LevelDebug)
	logger.log.Debug(
		"debug logging enabled", "debug", true,
	)
}

// Get returns the underlying slog.Logger.
func (logger *Logger) Get() *slog.Logger {
	return logger.log
}

// Identify logs the application name and version at startup.
func (logger *Logger) Identify() {
	logger.log.Info("starting",
		"appname", logger.params.Globals.Appname,
		"version", logger.params.Globals.Version,
	)
}