package config

import (
	"math/rand"

	"github.com/joho/godotenv"
	"github.com/kelseyhightower/envconfig"
	log "github.com/sirupsen/logrus"
	"github.com/usefathom/fathom/pkg/datastore/sqlstore"
)

type Config struct {
	Database *sqlstore.Config

	Secret string
}

func Parse(file string) *Config {
	var cfg Config
	var err error

	if file != "" {
		err = godotenv.Load(file)
		if err != nil && file != ".env" {
			log.Fatalf("error parsing config file: %s", err)
		}
	}

	err = envconfig.Process("Fathom", &cfg)
	if err != nil {
		log.Fatalf("error parsing config from environment values: %s", err)
	}

	// alias sqlite to sqlite3
	if cfg.Database.Driver == "sqlite" {
		cfg.Database.Driver = "sqlite3"
	}

	// if secret key is empty, use a randomly generated one
	if cfg.Secret == "" {
		cfg.Secret = randomString(40)
	}

	return &cfg
}

func randomString(len int) string {
	bytes := make([]byte, len)
	for i := 0; i < len; i++ {
		bytes[i] = byte(65 + rand.Intn(25)) //A=65 and Z = 65+25
	}

	return string(bytes)
}