// Package config loads application configuration from
// environment variables, .env files, and config files.
package config

import (
	"errors"
	"log/slog"

	"sneak.berlin/go/netwatch/internal/globals"
	"sneak.berlin/go/netwatch/internal/logger"

	_ "github.com/joho/godotenv/autoload" // loads .env file
	"github.com/spf13/viper"
	"go.uber.org/fx"
)

// Params defines the dependencies for Config.
type Params struct {
	fx.In

	Globals *globals.Globals
	Logger  *logger.Logger
}

// Config holds the resolved application configuration.
type Config struct {
	DataDir         string
	Debug           bool
	MetricsPassword string
	MetricsUsername string
	Port            int
	SentryDSN       string
	log             *slog.Logger
	params          *Params
}

// New loads configuration from env, .env files, and config
// files, returning a fully resolved Config.
func New(
	_ fx.Lifecycle,
	params Params,
) (*Config, error) {
	log := params.Logger.Get()
	name := params.Globals.Appname

	viper.SetConfigName(name)
	viper.SetConfigType("yaml")
	viper.AddConfigPath("/etc/" + name)
	viper.AddConfigPath("$HOME/.config/" + name)

	viper.AutomaticEnv()

	viper.SetDefault("DATA_DIR", "./data/reports")
	viper.SetDefault("DEBUG", "false")
	viper.SetDefault("PORT", "8080")
	viper.SetDefault("SENTRY_DSN", "")
	viper.SetDefault("METRICS_USERNAME", "")
	viper.SetDefault("METRICS_PASSWORD", "")

	err := viper.ReadInConfig()
	if err != nil {
		var notFound viper.ConfigFileNotFoundError
		if !errors.As(err, &notFound) {
			log.Error("config file malformed", "error", err)
			panic(err)
		}
	}

	s := &Config{
		DataDir:         viper.GetString("DATA_DIR"),
		Debug:           viper.GetBool("DEBUG"),
		MetricsPassword: viper.GetString("METRICS_PASSWORD"),
		MetricsUsername: viper.GetString("METRICS_USERNAME"),
		Port:            viper.GetInt("PORT"),
		SentryDSN:       viper.GetString("SENTRY_DSN"),
		log:             log,
		params:          &params,
	}

	if s.Debug {
		params.Logger.EnableDebugLogging()
		s.log = params.Logger.Get()
	}

	return s, nil
}