CLI: add nested subcommand fuzzy selection

src/cli/program/command-selector.ts

@@ -7,6 +7,7 @@ import { getProgramContext } from "./program-context.js";
 import { getSubCliEntries, registerSubCliByName } from "./register.subclis.js";
 
 const SHOW_HELP_VALUE = "__show_help__";
+const BACK_TO_MAIN_VALUE = "__back_to_main__";
 const PATH_SEPARATOR = "\u0000";
 const MAX_RESULTS = 200;
 
@@ -21,11 +22,23 @@ type PreparedCommandSelectorCandidate = CommandSelectorCandidate & {
   searchTextLower: string;
 };
 
+type SelectorPromptResult = string[] | "back_to_main" | null;
+
 function isHiddenCommand(command: Command): boolean {
   // Commander stores hidden state on a private field.
   return Boolean((command as Command & { _hidden?: boolean })._hidden);
 }
 
+function shouldSkipCommand(command: Command, parentDepth: number): boolean {
+  if (isHiddenCommand(command) || command.name() === "help") {
+    return true;
+  }
+  if (parentDepth === 0 && command.name() === "interactive") {
+    return true;
+  }
+  return false;
+}
+
 function resolveCommandDescription(command: Command): string {
   const summary = typeof command.summary === "function" ? command.summary().trim() : "";
   if (summary) {
@@ -38,6 +51,14 @@ function resolveCommandDescription(command: Command): string {
   return "Run this command";
 }
 
+function prepareSortedCandidates(
+  raw: CommandSelectorCandidate[],
+): PreparedCommandSelectorCandidate[] {
+  const prepared = prepareSearchItems(raw);
+  prepared.sort((a, b) => a.label.localeCompare(b.label));
+  return prepared;
+}
+
 function collectCandidatesRecursive(params: {
   command: Command;
   parentPath: string[];
@@ -45,10 +66,7 @@ function collectCandidatesRecursive(params: {
   out: CommandSelectorCandidate[];
 }): void {
   for (const child of params.command.commands) {
-    if (isHiddenCommand(child) || child.name() === "help") {
-      continue;
-    }
-    if (params.parentPath.length === 0 && child.name() === "interactive") {
+    if (shouldSkipCommand(child, params.parentPath.length)) {
       continue;
     }
     const path = [...params.parentPath, child.name()];
@@ -78,9 +96,56 @@ export function collectCommandSelectorCandidates(
   const seen = new Set<string>();
   const raw: CommandSelectorCandidate[] = [];
   collectCandidatesRecursive({ command: program, parentPath: [], seen, out: raw });
-  const prepared = prepareSearchItems(raw);
-  prepared.sort((a, b) => a.label.localeCompare(b.label));
-  return prepared;
+  return prepareSortedCandidates(raw);
+}
+
+export function resolveCommandByPath(program: Command, path: string[]): Command | null {
+  let current: Command = program;
+  for (const segment of path) {
+    const next = current.commands.find((child) => child.name() === segment);
+    if (!next) {
+      return null;
+    }
+    current = next;
+  }
+  return current;
+}
+
+function hasActionHandler(command: Command): boolean {
+  return Boolean((command as Command & { _actionHandler?: unknown })._actionHandler);
+}
+
+export function commandRequiresSubcommand(command: Command): boolean {
+  const visibleChildren = command.commands.filter((child) => !shouldSkipCommand(child, 1));
+  if (visibleChildren.length === 0) {
+    return false;
+  }
+  return !hasActionHandler(command);
+}
+
+export function collectDirectSubcommandSelectorCandidates(
+  program: Command,
+  basePath: string[],
+): PreparedCommandSelectorCandidate[] {
+  const parent = resolveCommandByPath(program, basePath);
+  if (!parent) {
+    return [];
+  }
+
+  const raw: CommandSelectorCandidate[] = [];
+  for (const child of parent.commands) {
+    if (shouldSkipCommand(child, basePath.length)) {
+      continue;
+    }
+    const path = [...basePath, child.name()];
+    raw.push({
+      path,
+      label: child.name(),
+      description: resolveCommandDescription(child),
+      searchText: `${child.name()} ${path.join(" ")}`,
+    });
+  }
+  return prepareSortedCandidates(raw);
 }
 
 export function rankCommandSelectorCandidates(
@@ -115,30 +180,48 @@ async function hydrateProgramCommandsForSelector(program: Command): Promise<void
   }
 }
 
-export async function runInteractiveCommandSelector(program: Command): Promise<string[] | null> {
-  await hydrateProgramCommandsForSelector(program);
+function serializePath(path: string[]): string {
+  return path.join(PATH_SEPARATOR);
+}
 
-  const candidates = collectCommandSelectorCandidates(program);
-  if (candidates.length === 0) {
-    return null;
-  }
+function deserializePath(value: string): string[] {
+  return value
+    .split(PATH_SEPARATOR)
+    .map((segment) => segment.trim())
+    .filter(Boolean);
+}
 
+async function promptForCommandSelection(params: {
+  message: string;
+  placeholder: string;
+  candidates: PreparedCommandSelectorCandidate[];
+  includeBackToMain?: boolean;
+}): Promise<SelectorPromptResult> {
   const selection = await clackAutocomplete<string>({
-    message: stylePromptMessage("Find and run a command") ?? "Find and run a command",
-    placeholder: "Type to fuzzy-search (e.g. msg snd)",
+    message: params.message,
+    placeholder: params.placeholder,
     maxItems: 10,
     // We pre-rank the list with our fuzzy scorer, then opt out of clack's own
     // filter so item order stays stable and score-based.
     filter: () => true,
     options() {
       const query = this.userInput.trim();
-      const ranked = rankCommandSelectorCandidates(candidates, query).slice(0, MAX_RESULTS);
+      const ranked = rankCommandSelectorCandidates(params.candidates, query).slice(0, MAX_RESULTS);
       return [
         ...ranked.map((candidate) => ({
-          value: candidate.path.join(PATH_SEPARATOR),
+          value: serializePath(candidate.path),
           label: candidate.label,
           hint: stylePromptHint(candidate.description),
         })),
+        ...(params.includeBackToMain
+          ? [
+              {
+                value: BACK_TO_MAIN_VALUE,
+                label: "../",
+                hint: stylePromptHint("Back to main command selector"),
+              },
+            ]
+          : []),
         {
           value: SHOW_HELP_VALUE,
           label: "Show help",
@@ -151,9 +234,62 @@ export async function runInteractiveCommandSelector(program: Command): Promise<s
   if (isCancel(selection) || selection === SHOW_HELP_VALUE) {
     return null;
   }
-
-  return selection
-    .split(PATH_SEPARATOR)
-    .map((segment) => segment.trim())
-    .filter(Boolean);
+  if (selection === BACK_TO_MAIN_VALUE) {
+    return "back_to_main";
+  }
+  return deserializePath(selection);
+}
+
+export async function runInteractiveCommandSelector(program: Command): Promise<string[] | null> {
+  await hydrateProgramCommandsForSelector(program);
+
+  const mainCandidates = collectCommandSelectorCandidates(program);
+  if (mainCandidates.length === 0) {
+    return null;
+  }
+
+  while (true) {
+    const mainSelection = await promptForCommandSelection({
+      message: stylePromptMessage("Find and run a command") ?? "Find and run a command",
+      placeholder: "Type to fuzzy-search (e.g. msg snd)",
+      candidates: mainCandidates,
+    });
+    if (!mainSelection || mainSelection === "back_to_main") {
+      return null;
+    }
+
+    let selectedPath = mainSelection;
+    let selectedCommand = resolveCommandByPath(program, selectedPath);
+    if (!selectedCommand || !commandRequiresSubcommand(selectedCommand)) {
+      return selectedPath;
+    }
+
+    while (true) {
+      const subcommandCandidates = collectDirectSubcommandSelectorCandidates(program, selectedPath);
+      if (subcommandCandidates.length === 0) {
+        return selectedPath;
+      }
+
+      const subSelection = await promptForCommandSelection({
+        message:
+          stylePromptMessage(`Select subcommand for ${selectedPath.join(" ")}`) ??
+          `Select subcommand for ${selectedPath.join(" ")}`,
+        placeholder: "Type to fuzzy-search subcommands",
+        candidates: subcommandCandidates,
+        includeBackToMain: true,
+      });
+      if (!subSelection) {
+        return null;
+      }
+      if (subSelection === "back_to_main") {
+        break;
+      }
+
+      selectedPath = subSelection;
+      selectedCommand = resolveCommandByPath(program, selectedPath);
+      if (!selectedCommand || !commandRequiresSubcommand(selectedCommand)) {
+        return selectedPath;
+      }
+    }
+  }
 }