package config

import (
	"errors"
	"fmt"
	"path/filepath"
	"time"

	"ddc/internal/preferences"
)

const (
	minPasswordLength   = 12
	defaultLibraryRoots = "/media/blob/TeaNet/Plex;/media/blob/ChaiNet/Plex"
)

type Settings struct {
	ListenAddr        string
	Username          string
	Password          string
	CookieSecure      bool
	SessionTTL        time.Duration
	TrustProxyHeaders bool
	DownloadDir       string
	LibraryRoots      []string
	LogLevel          string
	LogFormat         string
	Defaults          preferences.Preferences
}

func Load() (Settings, error) {
	reader := &envReader{}
	settings := Settings{
		ListenAddr:        reader.text("LISTEN_ADDR", ":8080"),
		Username:          reader.text("AUTH_USERNAME", ""),
		Password:          reader.text("AUTH_PASSWORD", ""),
		CookieSecure:      reader.boolean("COOKIE_SECURE", true),
		SessionTTL:        time.Duration(reader.integer("SESSION_TTL_HOURS", 12)) * time.Hour,
		TrustProxyHeaders: reader.boolean("TRUST_PROXY_HEADERS", false),
		DownloadDir:       filepath.Clean(reader.text("DOWNLOAD_DIR", "/data/downloads")),
		LogLevel:          reader.text("LOG_LEVEL", "info"),
		LogFormat:         reader.text("LOG_FORMAT", "text"),
		Defaults: preferences.Preferences{
			MaxConcurrentDownloads: reader.integer("MAX_CONCURRENT_DOWNLOADS", 2),
			ConnectionsPerDownload: reader.integer("CONNECTIONS_PER_DOWNLOAD", 4),
			MinFreeGB:              reader.integer("MIN_FREE_GB", 10),
			AllowedPorts:           reader.ports("ALLOWED_PORTS", "80,443"),
			AutoExtract:            true,
			CleanupAfterMove:       true,
		},
	}
	rawRoots := reader.text("LIBRARY_ROOTS", defaultLibraryRoots)
	if reader.err != nil {
		return Settings{}, reader.err
	}

	roots, err := parseLibraryRoots(rawRoots)
	if err != nil {
		return Settings{}, err
	}
	settings.LibraryRoots = roots

	return settings, settings.validate()
}

func (settings Settings) validate() error {
	switch {
	case settings.Username == "":
		return errors.New("AUTH_USERNAME is required")
	case len(settings.Password) < minPasswordLength:
		return fmt.Errorf("AUTH_PASSWORD must be at least %d characters", minPasswordLength)
	case !filepath.IsAbs(settings.DownloadDir):
		return errors.New("DOWNLOAD_DIR must be an absolute path")
	case settings.SessionTTL <= 0:
		return errors.New("SESSION_TTL_HOURS must be greater than zero")
	}
	return settings.Defaults.Validate()
}