// Package config provides application configuration via environment and files.
package config

import (
	"errors"
	"log/slog"

	"git.eeqj.de/sneak/chat/internal/globals"
	"git.eeqj.de/sneak/chat/internal/logger"
	"github.com/spf13/viper"
	"go.uber.org/fx"

	_ "github.com/joho/godotenv/autoload" // loads .env file
)

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

	Globals *globals.Globals
	Logger  *logger.Logger
}

// Config holds all application configuration values.
type Config struct {
	DBURL              string
	Debug              bool
	MaintenanceMode    bool
	MetricsPassword    string
	MetricsUsername    string
	Port               int
	SentryDSN          string
	MaxHistory         int
	SessionTimeout     int
	MaxMessageSize     int
	MOTD               string
	ServerName         string
	FederationKey      string
	SessionIdleTimeout string
	params             *Params
	log                *slog.Logger
}

// New creates a new Config by reading from files and environment variables.
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("DEBUG", "false")
	viper.SetDefault("MAINTENANCE_MODE", "false")
	viper.SetDefault("PORT", "8080")
	viper.SetDefault("DBURL", "file:./data.db?_journal_mode=WAL")
	viper.SetDefault("SENTRY_DSN", "")
	viper.SetDefault("METRICS_USERNAME", "")
	viper.SetDefault("METRICS_PASSWORD", "")
	viper.SetDefault("MAX_HISTORY", "10000")
	viper.SetDefault("SESSION_TIMEOUT", "86400")
	viper.SetDefault("MAX_MESSAGE_SIZE", "4096")
	viper.SetDefault("MOTD", "")
	viper.SetDefault("SERVER_NAME", "")
	viper.SetDefault("FEDERATION_KEY", "")
	viper.SetDefault("SESSION_IDLE_TIMEOUT", "24h")

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

	cfg := &Config{
		DBURL:              viper.GetString("DBURL"),
		Debug:              viper.GetBool("DEBUG"),
		Port:               viper.GetInt("PORT"),
		SentryDSN:          viper.GetString("SENTRY_DSN"),
		MaintenanceMode:    viper.GetBool("MAINTENANCE_MODE"),
		MetricsUsername:    viper.GetString("METRICS_USERNAME"),
		MetricsPassword:    viper.GetString("METRICS_PASSWORD"),
		MaxHistory:         viper.GetInt("MAX_HISTORY"),
		SessionTimeout:     viper.GetInt("SESSION_TIMEOUT"),
		MaxMessageSize:     viper.GetInt("MAX_MESSAGE_SIZE"),
		MOTD:               viper.GetString("MOTD"),
		ServerName:         viper.GetString("SERVER_NAME"),
		FederationKey:      viper.GetString("FEDERATION_KEY"),
		SessionIdleTimeout: viper.GetString("SESSION_IDLE_TIMEOUT"),
		log:                log,
		params:             &params,
	}

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

	return cfg, nil
}