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

import (
	"errors"
	"log/slog"

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

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

const defaultMOTD = ` _ __   ___  ___  (_)_ __ ___
| '_ \ / _ \/ _ \ | | '__/ __|
| | | |  __/ (_) || | | | (__
|_| |_|\___|\___/ |_|_|  \___|

Welcome to NeoIRC — IRC semantics over HTTP.
Type /help for available commands.`

// 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
	MessageMaxAge      string
	MaxMessageSize     int
	QueueMaxAge        string
	MOTD               string
	ServerName         string
	FederationKey      string
	SessionIdleTimeout string
	HashcashBits       int
	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:///var/lib/neoirc/state.db?_journal_mode=WAL")
	viper.SetDefault("SENTRY_DSN", "")
	viper.SetDefault("METRICS_USERNAME", "")
	viper.SetDefault("METRICS_PASSWORD", "")
	viper.SetDefault("MESSAGE_MAX_AGE", "720h")
	viper.SetDefault("MAX_MESSAGE_SIZE", "4096")
	viper.SetDefault("QUEUE_MAX_AGE", "720h")
	viper.SetDefault("MOTD", defaultMOTD)
	viper.SetDefault("SERVER_NAME", "")
	viper.SetDefault("FEDERATION_KEY", "")
	viper.SetDefault("SESSION_IDLE_TIMEOUT", "720h")
	viper.SetDefault("NEOIRC_HASHCASH_BITS", "20")

	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"),
		MessageMaxAge:      viper.GetString("MESSAGE_MAX_AGE"),
		MaxMessageSize:     viper.GetInt("MAX_MESSAGE_SIZE"),
		QueueMaxAge:        viper.GetString("QUEUE_MAX_AGE"),
		MOTD:               viper.GetString("MOTD"),
		ServerName:         viper.GetString("SERVER_NAME"),
		FederationKey:      viper.GetString("FEDERATION_KEY"),
		SessionIdleTimeout: viper.GetString("SESSION_IDLE_TIMEOUT"),
		HashcashBits:       viper.GetInt("NEOIRC_HASHCASH_BITS"),
		log:                log,
		params:             &params,
	}

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

	return cfg, nil
}