feat: archive session descendants

src/server/sessions/sessionArchiveTree.ts

@@ -0,0 +1,47 @@
+export interface SessionArchiveTreeCandidate {
+  id: string;
+  path: string;
+  archived: boolean;
+  parentSessionPath?: string;
+}
+
+export interface SessionArchiveTreePlan<T extends SessionArchiveTreeCandidate> {
+  targets: T[];
+  unarchivedTargets: T[];
+  skippedAlreadyArchivedCount: number;
+}
+
+export function findArchiveCandidateByIdOrPrefix<T extends SessionArchiveTreeCandidate>(candidates: readonly T[], sessionId: string): T | undefined {
+  return candidates.find((candidate) => candidate.id === sessionId) ?? candidates.find((candidate) => candidate.id.startsWith(sessionId));
+}
+
+export function planSessionArchiveTree<T extends SessionArchiveTreeCandidate>(root: T, candidates: readonly T[]): SessionArchiveTreePlan<T> {
+  const targets = sessionArchiveSubtree(root, candidates);
+  const unarchivedTargets = targets.filter((target) => !target.archived);
+  return {
+    targets,
+    unarchivedTargets,
+    skippedAlreadyArchivedCount: targets.length - unarchivedTargets.length,
+  };
+}
+
+function sessionArchiveSubtree<T extends SessionArchiveTreeCandidate>(root: T, candidates: readonly T[]): T[] {
+  const childrenByParentPath = new Map<string, T[]>();
+  for (const candidate of candidates) {
+    if (candidate.parentSessionPath === undefined) continue;
+    const children = childrenByParentPath.get(candidate.parentSessionPath) ?? [];
+    children.push(candidate);
+    childrenByParentPath.set(candidate.parentSessionPath, children);
+  }
+
+  const result: T[] = [];
+  const visit = (candidate: T, seenPaths: Set<string>) => {
+    if (seenPaths.has(candidate.path)) return;
+    result.push(candidate);
+    const nextSeenPaths = new Set(seenPaths);
+    nextSeenPaths.add(candidate.path);
+    for (const child of childrenByParentPath.get(candidate.path) ?? []) visit(child, nextSeenPaths);
+  };
+  visit(root, new Set());
+  return result;
+}