Feature: Nested Tags (#10833)

---------

Co-authored-by: Trenton H <797416+stumpylog@users.noreply.github.com>

src-ui/src/app/utils/flatten-tags.spec.ts

@@ -0,0 +1,63 @@
+import type { Tag } from '../data/tag'
+import { flattenTags } from './flatten-tags'
+
+describe('flattenTags', () => {
+  it('returns empty array for empty input', () => {
+    expect(flattenTags([])).toEqual([])
+  })
+
+  it('orders roots and children by name (case-insensitive, numeric) and sets depth/orderIndex', () => {
+    const input: Tag[] = [
+      { id: 11, name: 'A-root' },
+      { id: 10, name: 'B-root' },
+      { id: 101, name: 'Child 10', parent: 11 },
+      { id: 102, name: 'child 2', parent: 11 },
+      { id: 201, name: 'beta', parent: 10 },
+      { id: 202, name: 'Alpha', parent: 10 },
+      { id: 103, name: 'Sub 1', parent: 102 },
+    ]
+
+    const flat = flattenTags(input)
+
+    const names = flat.map((t) => t.name)
+    expect(names).toEqual([
+      'A-root',
+      'child 2',
+      'Sub 1',
+      'Child 10',
+      'B-root',
+      'Alpha',
+      'beta',
+    ])
+
+    expect(flat.map((t) => t.depth)).toEqual([0, 1, 2, 1, 0, 1, 1])
+    expect(flat.map((t) => t.orderIndex)).toEqual([0, 1, 2, 3, 4, 5, 6])
+
+    // Children are rebuilt
+    const aRoot = flat.find((t) => t.name === 'A-root')
+    expect(new Set(aRoot.children?.map((c) => c.name))).toEqual(
+      new Set(['child 2', 'Child 10'])
+    )
+
+    const bRoot = flat.find((t) => t.name === 'B-root')
+    expect(new Set(bRoot.children?.map((c) => c.name))).toEqual(
+      new Set(['Alpha', 'beta'])
+    )
+
+    const child2 = flat.find((t) => t.name === 'child 2')
+    expect(new Set(child2.children?.map((c) => c.name))).toEqual(
+      new Set(['Sub 1'])
+    )
+  })
+
+  it('excludes orphaned nodes (with missing parent)', () => {
+    const input: Tag[] = [
+      { id: 1, name: 'Root' },
+      { id: 2, name: 'Child', parent: 1 },
+      { id: 3, name: 'Orphan', parent: 999 }, // missing parent
+    ]
+
+    const flat = flattenTags(input)
+    expect(flat.map((t) => t.name)).toEqual(['Root', 'Child'])
+  })
+})

src-ui/src/app/utils/flatten-tags.ts

@@ -0,0 +1,35 @@
+import { Tag } from '../data/tag'
+
+export function flattenTags(all: Tag[]): Tag[] {
+  const map = new Map<number, Tag>(
+    all.map((t) => [t.id, { ...t, children: [] }])
+  )
+  // rebuild children
+  for (const t of map.values()) {
+    if (t.parent) {
+      const p = map.get(t.parent)
+      p?.children.push(t)
+    }
+  }
+  const roots = Array.from(map.values()).filter((t) => !t.parent)
+  const sortByName = (a: Tag, b: Tag) =>
+    a.name.localeCompare(b.name, undefined, {
+      sensitivity: 'base',
+      numeric: true,
+    })
+  const ordered: Tag[] = []
+  let idx = 0
+  const walk = (node: Tag, depth: number) => {
+    node.depth = depth
+    node.orderIndex = idx++
+    ordered.push(node)
+    if (node.children?.length) {
+      for (const child of [...node.children].sort(sortByName)) {
+        walk(child, depth + 1)
+      }
+    }
+  }
+  roots.sort(sortByName)
+  roots.forEach((r) => walk(r, 0))
+  return ordered
+}