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/mimeapps.go

@@ -0,0 +1,226 @@
+package desktop
+
+import (
+	"bufio"
+	"bytes"
+	"fmt"
+	"os"
+	"path/filepath"
+	"slices"
+	"sort"
+	"strings"
+	"sync"
+
+	"github.com/AvengeMedia/DankMaterialShell/core/internal/utils"
+)
+
+var mimeappsWriteMu sync.Mutex
+
+const (
+	groupDefaults = "Default Applications"
+	groupAdded    = "Added Associations"
+	groupRemoved  = "Removed Associations"
+)
+
+type MimeAssociations struct {
+	Defaults map[string]string
+	Added    map[string][]string
+	Removed  map[string][]string
+}
+
+func newAssociations() *MimeAssociations {
+	return &MimeAssociations{
+		Defaults: make(map[string]string),
+		Added:    make(map[string][]string),
+		Removed:  make(map[string][]string),
+	}
+}
+
+func mimeappsSearchPaths() []string {
+	var paths []string
+	seen := make(map[string]bool)
+
+	add := func(p string) {
+		if p == "" || seen[p] {
+			return
+		}
+		seen[p] = true
+		paths = append(paths, p)
+	}
+
+	add(filepath.Join(utils.XDGConfigHome(), "mimeapps.list"))
+
+	if env := os.Getenv("XDG_CONFIG_DIRS"); env != "" {
+		for d := range strings.SplitSeq(env, ":") {
+			add(filepath.Join(strings.TrimSpace(d), "mimeapps.list"))
+		}
+	} else {
+		add("/etc/xdg/mimeapps.list")
+	}
+
+	add(filepath.Join(utils.XDGDataHome(), "applications", "mimeapps.list"))
+
+	if env := os.Getenv("XDG_DATA_DIRS"); env != "" {
+		for d := range strings.SplitSeq(env, ":") {
+			add(filepath.Join(strings.TrimSpace(d), "applications", "mimeapps.list"))
+		}
+	} else {
+		add("/usr/local/share/applications/mimeapps.list")
+		add("/usr/share/applications/mimeapps.list")
+	}
+
+	return paths
+}
+
+func mimeappsWritePath() string {
+	return filepath.Join(utils.XDGConfigHome(), "mimeapps.list")
+}
+
+func readAssociations(path string) (*MimeAssociations, error) {
+	data, err := os.ReadFile(path)
+	if err != nil {
+		return nil, err
+	}
+
+	groups := parseGroups(data)
+	assoc := newAssociations()
+
+	if g := groups[groupDefaults]; g != nil {
+		for mime, val := range g.keys {
+			parts := splitList(val)
+			if len(parts) > 0 {
+				assoc.Defaults[mime] = parts[0]
+			}
+		}
+	}
+
+	if g := groups[groupAdded]; g != nil {
+		for mime, val := range g.keys {
+			assoc.Added[mime] = splitList(val)
+		}
+	}
+
+	if g := groups[groupRemoved]; g != nil {
+		for mime, val := range g.keys {
+			assoc.Removed[mime] = splitList(val)
+		}
+	}
+
+	return assoc, nil
+}
+
+func mergedAssociations() *MimeAssociations {
+	merged := newAssociations()
+
+	for _, path := range mimeappsSearchPaths() {
+		assoc, err := readAssociations(path)
+		if err != nil {
+			continue
+		}
+		for mime, app := range assoc.Defaults {
+			if _, ok := merged.Defaults[mime]; !ok {
+				merged.Defaults[mime] = app
+			}
+		}
+		for mime, apps := range assoc.Added {
+			merged.Added[mime] = append(merged.Added[mime], apps...)
+		}
+		for mime, apps := range assoc.Removed {
+			merged.Removed[mime] = append(merged.Removed[mime], apps...)
+		}
+	}
+
+	return merged
+}
+
+func writeUserMimeapps(update func(*MimeAssociations)) error {
+	mimeappsWriteMu.Lock()
+	defer mimeappsWriteMu.Unlock()
+
+	path := mimeappsWritePath()
+
+	assoc, err := readAssociations(path)
+	if err != nil {
+		if !os.IsNotExist(err) {
+			return err
+		}
+		assoc = newAssociations()
+	}
+
+	update(assoc)
+
+	var buf bytes.Buffer
+	w := bufio.NewWriter(&buf)
+
+	writeSection := func(name string, entries map[string]string) {
+		fmt.Fprintf(w, "[%s]\n", name)
+		keys := make([]string, 0, len(entries))
+		for k := range entries {
+			keys = append(keys, k)
+		}
+		sort.Strings(keys)
+		for _, k := range keys {
+			fmt.Fprintf(w, "%s=%s\n", k, entries[k])
+		}
+		fmt.Fprintln(w)
+	}
+
+	flatten := func(m map[string][]string) map[string]string {
+		out := make(map[string]string, len(m))
+		for k, list := range m {
+			out[k] = strings.Join(list, ";") + ";"
+		}
+		return out
+	}
+
+	writeSection(groupDefaults, assoc.Defaults)
+	writeSection(groupAdded, flatten(assoc.Added))
+	writeSection(groupRemoved, flatten(assoc.Removed))
+
+	if err := w.Flush(); err != nil {
+		return err
+	}
+
+	if err := os.MkdirAll(filepath.Dir(path), 0o755); err != nil {
+		return err
+	}
+	return os.WriteFile(path, buf.Bytes(), 0o644)
+}
+
+func setDefaultAssociation(mimeType, desktopID string) error {
+	return setDefaultAssociations([]string{mimeType}, desktopID)
+}
+
+func setDefaultAssociations(mimeTypes []string, desktopID string) error {
+	if !strings.HasSuffix(desktopID, ".desktop") {
+		desktopID += ".desktop"
+	}
+	return writeUserMimeapps(func(assoc *MimeAssociations) {
+		for _, mimeType := range mimeTypes {
+			if mimeType == "" {
+				continue
+			}
+			assoc.Defaults[mimeType] = desktopID
+			existing := assoc.Added[mimeType]
+			if !slices.Contains(existing, desktopID) {
+				assoc.Added[mimeType] = append(existing, desktopID)
+			}
+			removed, ok := assoc.Removed[mimeType]
+			if !ok {
+				continue
+			}
+			filtered := removed[:0]
+			for _, id := range removed {
+				if id != desktopID {
+					filtered = append(filtered, id)
+				}
+			}
+			switch {
+			case len(filtered) == 0:
+				delete(assoc.Removed, mimeType)
+			default:
+				assoc.Removed[mimeType] = filtered
+			}
+		}
+	})
+}