another big refactor to make code more manageable

backend/app.go

@@ -0,0 +1,92 @@
+package backend
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"log"
+	"path"
+	"supersonic/player"
+
+	"github.com/20after4/configdir"
+	"github.com/zalando/go-keyring"
+)
+
+const (
+	AppName    = "supersonic"
+	configFile = "config.toml"
+)
+
+var (
+	ErrNoServers = errors.New("no servers set up")
+)
+
+type App struct {
+	Config          *Config
+	ServerManager   *ServerManager
+	ImageManager    *ImageManager
+	LibraryManager  *LibraryManager
+	PlaybackManager *PlaybackManager
+	Player          *player.Player
+
+	bgrndCtx context.Context
+	cancel   context.CancelFunc
+}
+
+func StartupApp() (*App, error) {
+	a := &App{}
+	a.bgrndCtx, a.cancel = context.WithCancel(context.Background())
+
+	a.readConfig()
+
+	if err := a.initMPV(); err != nil {
+		return nil, err
+	}
+
+	a.ServerManager = NewServerManager()
+	a.PlaybackManager = NewPlaybackManager(a.bgrndCtx, a.ServerManager, a.Player)
+	a.LibraryManager = NewLibraryManager(a.ServerManager)
+	a.ImageManager = NewImageManager(a.ServerManager, configdir.LocalCache(AppName))
+
+	return a, nil
+}
+
+func (a *App) readConfig() {
+	configdir.MakePath(configdir.LocalConfig(AppName))
+	cfg, err := ReadConfigFile(configPath())
+	if err != nil {
+		log.Printf("Error reading app config file: %v", err)
+		cfg = DefaultConfig()
+	}
+	a.Config = cfg
+}
+
+func (a *App) initMPV() error {
+	p := player.NewWithClientName(AppName)
+	if err := p.Init(); err != nil {
+		return fmt.Errorf("failed to initialize mpv player: %s", err.Error())
+	}
+	a.Player = p
+	return nil
+}
+
+func (a *App) LoginToDefaultServer() error {
+	serverCfg := a.Config.GetDefaultServer()
+	if serverCfg == nil {
+		return ErrNoServers
+	}
+	pass, err := keyring.Get(AppName, serverCfg.ID.String())
+	if err != nil {
+		return fmt.Errorf("error reading keyring credentials: %v", err)
+	}
+	return a.ServerManager.ConnectToServer(serverCfg, pass)
+}
+
+func (a *App) Shutdown() {
+	a.cancel()
+	a.Player.Destroy()
+}
+
+func configPath() string {
+	return path.Join(configdir.LocalConfig(AppName), configFile)
+}