app picker: extend App Picker to integrate with mime overrides

- Adds "DMS Opener" as an option (dms-open.desktop)
- Add mime type GO utils
- Add rememberance to App Picker modal

core/internal/desktop/entries.go

@@ -0,0 +1,203 @@
+package desktop
+
+import (
+	"os"
+	"path/filepath"
+	"strings"
+	"sync"
+	"time"
+
+	"github.com/AvengeMedia/DankMaterialShell/core/internal/utils"
+)
+
+type Entry struct {
+	ID         string
+	Path       string
+	Name       string
+	Exec       string
+	Icon       string
+	Categories []string
+	MimeTypes  []string
+	NoDisplay  bool
+	Hidden     bool
+	Terminal   bool
+}
+
+type cachedEntry struct {
+	entry   *Entry
+	modTime time.Time
+	size    int64
+}
+
+var (
+	entryCache   = make(map[string]cachedEntry)
+	entryCacheMu sync.Mutex
+
+	listingCache   []*Entry
+	listingExpires time.Time
+	listingCacheMu sync.Mutex
+)
+
+const listingTTL = 5 * time.Second
+
+func applicationDirs() []string {
+	seen := make(map[string]bool)
+	var dirs []string
+
+	add := func(path string) {
+		if path == "" {
+			return
+		}
+		abs, err := filepath.Abs(path)
+		if err != nil {
+			abs = path
+		}
+		if seen[abs] {
+			return
+		}
+		seen[abs] = true
+		dirs = append(dirs, abs)
+	}
+
+	add(filepath.Join(utils.XDGDataHome(), "applications"))
+
+	if env := os.Getenv("XDG_DATA_DIRS"); env != "" {
+		for d := range strings.SplitSeq(env, ":") {
+			add(filepath.Join(strings.TrimSpace(d), "applications"))
+		}
+	} else {
+		add("/usr/local/share/applications")
+		add("/usr/share/applications")
+	}
+
+	home, _ := os.UserHomeDir()
+	if home != "" {
+		add(filepath.Join(home, ".local", "share", "flatpak", "exports", "share", "applications"))
+	}
+	add("/var/lib/flatpak/exports/share/applications")
+	add("/var/lib/snapd/desktop/applications")
+
+	return dirs
+}
+
+func parseEntry(path string, id string) (*Entry, error) {
+	info, err := os.Stat(path)
+	if err != nil {
+		return nil, err
+	}
+
+	entryCacheMu.Lock()
+	if c, ok := entryCache[path]; ok && c.modTime.Equal(info.ModTime()) && c.size == info.Size() {
+		entryCacheMu.Unlock()
+		return c.entry, nil
+	}
+	entryCacheMu.Unlock()
+
+	data, err := os.ReadFile(path)
+	if err != nil {
+		return nil, err
+	}
+
+	groups := parseGroups(data)
+	g, ok := groups["Desktop Entry"]
+	if !ok {
+		return nil, nil
+	}
+
+	entry := &Entry{
+		ID:         id,
+		Path:       path,
+		Name:       g.keys["Name"],
+		Exec:       g.keys["Exec"],
+		Icon:       g.keys["Icon"],
+		Categories: splitList(g.keys["Categories"]),
+		MimeTypes:  splitList(g.keys["MimeType"]),
+		NoDisplay:  parseBool(g.keys["NoDisplay"]),
+		Hidden:     parseBool(g.keys["Hidden"]),
+		Terminal:   parseBool(g.keys["Terminal"]),
+	}
+
+	if t := g.keys["Type"]; t != "" && t != "Application" {
+		return nil, nil
+	}
+
+	entryCacheMu.Lock()
+	entryCache[path] = cachedEntry{entry: entry, modTime: info.ModTime(), size: info.Size()}
+	entryCacheMu.Unlock()
+
+	return entry, nil
+}
+
+func relativeID(root, path string) string {
+	rel, err := filepath.Rel(root, path)
+	if err != nil {
+		return filepath.Base(path)
+	}
+	return strings.ReplaceAll(rel, string(filepath.Separator), "-")
+}
+
+func AllEntries() []*Entry {
+	listingCacheMu.Lock()
+	if time.Now().Before(listingExpires) && listingCache != nil {
+		out := listingCache
+		listingCacheMu.Unlock()
+		return out
+	}
+	listingCacheMu.Unlock()
+
+	seen := make(map[string]bool)
+	var entries []*Entry
+
+	for _, dir := range applicationDirs() {
+		_ = filepath.WalkDir(dir, func(path string, d os.DirEntry, err error) error {
+			if err != nil || d.IsDir() {
+				return nil
+			}
+			if !strings.HasSuffix(path, ".desktop") {
+				return nil
+			}
+			id := relativeID(dir, path)
+			if seen[id] {
+				return nil
+			}
+			seen[id] = true
+
+			entry, err := parseEntry(path, id)
+			if err != nil || entry == nil {
+				return nil
+			}
+			entries = append(entries, entry)
+			return nil
+		})
+	}
+
+	listingCacheMu.Lock()
+	listingCache = entries
+	listingExpires = time.Now().Add(listingTTL)
+	listingCacheMu.Unlock()
+
+	return entries
+}
+
+func EntryByID(id string) *Entry {
+	if !strings.HasSuffix(id, ".desktop") {
+		id += ".desktop"
+	}
+	for _, entry := range AllEntries() {
+		if entry.ID == id {
+			return entry
+		}
+	}
+	return nil
+}
+
+func InvalidateCache() {
+	entryCacheMu.Lock()
+	entryCache = make(map[string]cachedEntry)
+	entryCacheMu.Unlock()
+
+	listingCacheMu.Lock()
+	listingCache = nil
+	listingExpires = time.Time{}
+	listingCacheMu.Unlock()
+}