feat: wip web admin for mapping and crud

1 files changed, 64 insertions, 0 deletions

diff --git a/internal/admin/id_alloc.go b/internal/admin/id_alloc.go
new file mode 100644
index 0000000..d79718b
--- /dev/null
+++ b/internal/admin/id_alloc.go
@@ -0,0 +1,64 @@
+package admin
+
+import (
+	"os"
+	"path/filepath"
+	"strconv"
+)
+
+func nextRoomIDInDir(dataDir string, fromRoomID int) (int, string, error) {
+	base := filepath.Join(dataDir, "rooms")
+	subdir, err := findRoomSubdir(base, fromRoomID)
+	if err != nil {
+		subdir = base
+	}
+	used := map[int]bool{}
+	scanDir(subdir, used)
+	if len(used) == 0 {
+		return 1, subdir, nil
+	}
+	minID := 1<<31 - 1
+	for id := range used {
+		if id < minID {
+			minID = id
+		}
+	}
+	id := minID
+	for used[id] {
+		id++
+	}
+	return id, subdir, nil
+}
+
+func findRoomSubdir(base string, roomID int) (string, error) {
+	fileName := strconv.Itoa(roomID) + ".yaml"
+	var found string
+	filepath.WalkDir(base, func(path string, d os.DirEntry, err error) error {
+		if err != nil || found != "" {
+			return nil
+		}
+		if !d.IsDir() && d.Name() == fileName {
+			found = filepath.Dir(path)
+		}
+		return nil
+	})
+	if found == "" {
+		return "", os.ErrNotExist
+	}
+	return found, nil
+}
+
+func scanDir(dir string, used map[int]bool) {
+	entries, err := os.ReadDir(dir)
+	if err != nil {
+		return
+	}
+	for _, e := range entries {
+		if !e.IsDir() && filepath.Ext(e.Name()) == ".yaml" {
+			idStr := e.Name()[:len(e.Name())-5]
+			if id, err := strconv.Atoi(idStr); err == nil && id > 0 {
+				used[id] = true
+			}
+		}
+	}
+}