block-patch-store.ts

block-patch-store.tsapps/web/src/stores/block-patch-store.tsraw ← stores4,568 B← Back to the app
1"use client";
2 
3/**
4 * Realtime block-patch store: last-writer-wins overlay on top of the TanStack
5 * Query block cache, fed by the page's realtime channel (lib/realtime.ts).
6 * Query is the source of truth at rest; this store keeps the editor
7 * sub-200 ms (PRODUCT-SPEC §26) without refetching on every remote edit.
8 */
9import { create } from "zustand";
10import type { Block, BlockPatch, Presence } from "@/lib/types";
11 
12interface BlockPatchState {
13  /** pageId → blockId → pending patch (remote or optimistic). */
14  patches: Record<string, Record<string, BlockPatch>>;
15  /** pageId → fully-upserted remote blocks (not yet in the query cache). */
16  upserts: Record<string, Record<string, Block>>;
17  /** pageId → remote-deleted block ids. */
18  deleted: Record<string, string[]>;
19  /** pageId → userId → current peer state (the fold of the per-peer
20   *  `presence` frames seen since subscribing, minus `presence-leave` —
21   *  TASK-0093). */
22  presence: Record<string, Record<string, Presence>>;
23  upsert: (pageId: string, blocks: Block[]) => void;
24  patch: (pageId: string, blockId: string, p: BlockPatch) => void;
25  delete: (pageId: string, blockIds: string[]) => void;
26  /** Apply one peer's state (a `presence` frame). */
27  upsertPresence: (pageId: string, peer: Presence) => void;
28  /** Drop a peer (a `presence-leave` frame / the client's own prune). */
29  removePresence: (pageId: string, userId: string) => void;
30  /** Merge all overlay state for a page into a flat block list. */
31  merged: (pageId: string, base: readonly Block[]) => Block[];
32  /** Drop the BLOCK overlay for a page (call after a refetch/invalidation).
33   *  Unlike `reset`, this keeps the page's PRESENCE (a block change must
34   *  not wipe who's online). */
35  clearBlocks: (pageId: string) => void;
36  /** Drop the overlay for a page (call after a refetch/invalidation). */
37  reset: (pageId: string) => void;
38}
39 
40function applyPatch(block: Block, p: BlockPatch): Block {
41  return { ...block, ...p, properties: { ...block.properties, ...(p.properties ?? {}) } };
42}
43 
44export const useBlockPatchStore = create<BlockPatchState>()((set, get) => ({
45  patches: {},
46  upserts: {},
47  deleted: {},
48  presence: {},
49 
50  upsert: (pageId, blocks) => {
51    const cur = get().upserts[pageId] ?? {};
52    const next: Record<string, Block> = { ...cur };
53    for (const b of blocks) next[b.id] = b;
54    set({ upserts: { ...get().upserts, [pageId]: next } });
55  },
56 
57  patch: (pageId, blockId, p) => {
58    const page = get().patches[pageId] ?? {};
59    set({
60      patches: { ...get().patches, [pageId]: { ...page, [blockId]: { ...page[blockId], ...p } } },
61    });
62  },
63 
64  delete: (pageId, blockIds) => {
65    const cur = get().deleted[pageId] ?? [];
66    const page = get().upserts[pageId] ?? {};
67    const nextPage: Record<string, Block> = { ...page };
68    for (const id of blockIds) delete nextPage[id];
69    set({
70      deleted: { ...get().deleted, [pageId]: [...new Set([...cur, ...blockIds])] },
71      upserts: { ...get().upserts, [pageId]: nextPage },
72    });
73  },
74 
75  upsertPresence: (pageId, peer) => {
76    const page = get().presence[pageId] ?? {};
77    set({ presence: { ...get().presence, [pageId]: { ...page, [peer.userId]: peer } } });
78  },
79 
80  removePresence: (pageId, userId) => {
81    const page = get().presence[pageId];
82    if (page === undefined || page[userId] === undefined) return;
83    const next = { ...page };
84    delete next[userId];
85    set({ presence: { ...get().presence, [pageId]: next } });
86  },
87 
88  merged: (pageId, base) => {
89    const { patches, upserts, deleted } = get();
90    const removed = new Set(deleted[pageId] ?? []);
91    const pagePatches = patches[pageId] ?? {};
92    const pageUpserts = upserts[pageId] ?? {};
93    const out: Block[] = [];
94    for (const b of base) {
95      if (removed.has(b.id)) continue;
96      out.push(pagePatches[b.id] ? applyPatch(b, pagePatches[b.id] as BlockPatch) : b);
97    }
98    for (const b of Object.values(pageUpserts)) {
99      if (removed.has(b.id)) continue;
100      out.push(pagePatches[b.id] ? applyPatch(b, pagePatches[b.id] as BlockPatch) : b);
101    }
102    return out;
103  },
104 
105  clearBlocks: (pageId) => {
106    set({
107      patches: { ...get().patches, [pageId]: {} },
108      upserts: { ...get().upserts, [pageId]: {} },
109      deleted: { ...get().deleted, [pageId]: [] },
110    });
111  },
112 
113  reset: (pageId) => {
114    set({
115      patches: { ...get().patches, [pageId]: {} },
116      upserts: { ...get().upserts, [pageId]: {} },
117      deleted: { ...get().deleted, [pageId]: [] },
118      presence: { ...get().presence, [pageId]: {} },
119    });
120  },
121}));
122