Style missing worktree as red and display better error when trying to switch to them

Use a broken link icon for missing worktrees

pkg/commands/models/worktree.go

@@ -1,15 +1,22 @@
 package models
 
+import (
+	"fmt"
+	"github.com/go-errors/errors"
+	"io/fs"
+	"log"
+	"os"
+	"path/filepath"
+)
+
 // Worktree : A git worktree
 type Worktree struct {
-	Name    string
-	Main    bool
-	Current bool
-	Path    string
+	Id   int
+	Path string
 }
 
 func (w *Worktree) RefName() string {
-	return w.Name
+	return w.Name()
 }
 
 func (w *Worktree) ID() string {
@@ -19,3 +26,30 @@ func (w *Worktree) ID() string {
 func (w *Worktree) Description() string {
 	return w.RefName()
 }
+
+func (w *Worktree) Name() string {
+	return filepath.Base(w.Path)
+}
+
+func (w *Worktree) Main() bool {
+	return w.Id == 0
+}
+
+func (w *Worktree) Current() bool {
+	pwd, err := os.Getwd()
+	if err != nil {
+		log.Fatalln(err.Error())
+	}
+
+	return pwd == w.Path
+}
+
+func (w *Worktree) Missing() bool {
+	if _, err := os.Stat(w.Path); err != nil {
+		if errors.Is(err, fs.ErrNotExist) {
+			return true
+		}
+		log.Fatalln(fmt.Errorf("failed to check if worktree path `%s` exists\n%w", w.Path, err).Error())
+	}
+	return false
+}