final: refactor for removal of system package and reduction of interactions to state package

State query command has been moved to main where it belongs, "system" information are now fetched in app.New and stored in *App with accessors for relevant values. Exit (cleanup-related) functions are separated into its dedicated "final" package.

Signed-off-by: Ophestra Umiker <cat@ophivana.moe>

internal/app/setup.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"os"
 	"os/user"
+	"path"
 	"strconv"
 
 	"git.ophivana.moe/cat/fortify/internal/state"
@@ -12,18 +13,25 @@ import (
 	"git.ophivana.moe/cat/fortify/internal/verbose"
 )
 
+const (
+	xdgRuntimeDir = "XDG_RUNTIME_DIR"
+)
+
 type App struct {
-	launchOptionText string
+	uid     int      // assigned
+	env     []string // modified via AppendEnv
+	command []string // set on initialisation
 
-	uid     int
-	env     []string
-	command []string
+	launchOptionText string // set on initialisation
+	launchOption     uint8  // assigned
 
-	launchOption uint8
-	toolPath     string
+	sharePath   string // set on initialisation
+	runtimePath string // assigned
+	runDirPath  string // assigned
+	toolPath    string // assigned
 
-	enablements state.Enablements
-	*user.User
+	enablements state.Enablements // set via setEnablement
+	*user.User                    // assigned
 
 	// absolutely *no* method of this type is thread-safe
 	// so don't treat it as if it is
@@ -33,6 +41,10 @@ func (a *App) LaunchOption() uint8 {
 	return a.launchOption
 }
 
+func (a *App) RunDir() string {
+	return a.runDirPath
+}
+
 func (a *App) setEnablement(e state.Enablement) {
 	if a.enablements.Has(e) {
 		panic("enablement " + e.String() + " set twice")
@@ -42,8 +54,25 @@ func (a *App) setEnablement(e state.Enablement) {
 }
 
 func New(userName string, args []string, launchOptionText string) *App {
-	a := &App{command: args, launchOptionText: launchOptionText}
+	a := &App{
+		command:          args,
+		launchOptionText: launchOptionText,
+		sharePath:        path.Join(os.TempDir(), "fortify."+strconv.Itoa(os.Geteuid())),
+	}
 
+	// runtimePath, runDirPath
+	if r, ok := os.LookupEnv(xdgRuntimeDir); !ok {
+		fmt.Println("Env variable", xdgRuntimeDir, "unset")
+
+		// too early for fatal
+		os.Exit(1)
+	} else {
+		a.runtimePath = r
+		a.runDirPath = path.Join(a.runtimePath, "fortify")
+		verbose.Println("Runtime directory at", a.runDirPath)
+	}
+
+	// *user.User
 	if u, err := user.Lookup(userName); err != nil {
 		if errors.As(err, new(user.UnknownUserError)) {
 			fmt.Println("unknown user", userName)
@@ -58,6 +87,7 @@ func New(userName string, args []string, launchOptionText string) *App {
 		a.User = u
 	}
 
+	// uid
 	if u, err := strconv.Atoi(a.Uid); err != nil {
 		// usually unreachable
 		panic("uid parse")
@@ -70,6 +100,7 @@ func New(userName string, args []string, launchOptionText string) *App {
 		verbose.Println("System booted with systemd as init system (PID 1).")
 	}
 
+	// launchOption, toolPath
 	switch a.launchOptionText {
 	case "sudo":
 		a.launchOption = LaunchMethodSudo