| 1 | /** |
| 2 | * Changes made to a page's live document on the server: an agent's edit, |
| 3 | * an accepted suggestion, a restored version, a comment's anchor. Each |
| 4 | * runs in one Yjs transaction, so every open editor receives it as one |
| 5 | * update and the change merges with whatever people are typing. Pure |
| 6 | * (yjs only). |
| 7 | */ |
| 8 | import type { DocEditTarget } from "@g1t/contracts"; |
| 9 | import * as Y from "yjs"; |
| 10 | |
| 11 | import { blockGroupOf, parseMarkdown, writeBlocks } from "./blocks.ts"; |
| 12 | import { blocksMarkdown, partsOf, plainText, topContainers } from "./markdown.ts"; |
| 13 | |
| 14 | /** Top-level blocks `start` through `end - 1`; `start === end` is an insertion point. */ |
| 15 | export type Range = { start: number; end: number }; |
| 16 | |
| 17 | function norm(text: string): string { |
| 18 | return text |
| 19 | .replace(/[*_`~#]/g, "") |
| 20 | .replace(/\s+/g, " ") |
| 21 | .trim() |
| 22 | .toLowerCase(); |
| 23 | } |
| 24 | |
| 25 | /** Where a target is in the document now, or null when it is gone. */ |
| 26 | export function findTarget(fragment: Y.XmlFragment, target: DocEditTarget): Range | null { |
| 27 | const tops = topContainers(fragment); |
| 28 | switch (target.kind) { |
| 29 | case "append": |
| 30 | return { start: tops.length, end: tops.length }; |
| 31 | case "document": |
| 32 | return { start: 0, end: tops.length }; |
| 33 | case "section": { |
| 34 | const want = norm(target.heading); |
| 35 | if (!want) return null; |
| 36 | const at = tops.findIndex((c) => { |
| 37 | const content = partsOf(c).content; |
| 38 | return content?.nodeName === "heading" && norm(plainText(content)) === want; |
| 39 | }); |
| 40 | if (at < 0) return null; |
| 41 | const level = Number(partsOf(tops[at]!).content!.getAttribute("level")) || 1; |
| 42 | let end = at + 1; |
| 43 | while (end < tops.length) { |
| 44 | const content = partsOf(tops[end]!).content; |
| 45 | if (content?.nodeName === "heading" && (Number(content.getAttribute("level")) || 1) <= level) break; |
| 46 | end++; |
| 47 | } |
| 48 | return { start: at, end }; |
| 49 | } |
| 50 | case "blocks": { |
| 51 | const from = tops.findIndex((c) => c.getAttribute("id") === target.from_block); |
| 52 | const to = tops.findIndex((c) => c.getAttribute("id") === target.to_block); |
| 53 | if (from < 0 || to < 0) return null; |
| 54 | return { start: Math.min(from, to), end: Math.max(from, to) + 1 }; |
| 55 | } |
| 56 | default: |
| 57 | return null; |
| 58 | } |
| 59 | } |
| 60 | |
| 61 | /** The Markdown of a range of top-level blocks. */ |
| 62 | export function rangeMarkdown(fragment: Y.XmlFragment, range: Range): string { |
| 63 | return blocksMarkdown(topContainers(fragment).slice(range.start, range.end)); |
| 64 | } |
| 65 | |
| 66 | /** The ids of a range's top-level blocks. */ |
| 67 | export function rangeIds(fragment: Y.XmlFragment, range: Range): string[] { |
| 68 | return topContainers(fragment) |
| 69 | .slice(range.start, range.end) |
| 70 | .map((c) => String(c.getAttribute("id") ?? "")); |
| 71 | } |
| 72 | |
| 73 | /** |
| 74 | * Replaces a range of top-level blocks with Markdown, in one transaction |
| 75 | * whose origin is `origin` (who made it, for the page's history). |
| 76 | */ |
| 77 | export function replaceRange(doc: Y.Doc, fragment: Y.XmlFragment, range: Range, markdown: string, origin: unknown = null): void { |
| 78 | const specs = parseMarkdown(markdown); |
| 79 | doc.transact(() => { |
| 80 | const group = blockGroupOf(fragment); |
| 81 | // Only containers count; the group holds nothing else. |
| 82 | const count = Math.min(range.end, group.length) - range.start; |
| 83 | if (count > 0) group.delete(range.start, count); |
| 84 | if (specs.length) group.insert(range.start, writeBlocks(specs)); |
| 85 | // The editor always keeps one block. |
| 86 | if (group.length === 0) group.insert(0, writeBlocks([])); |
| 87 | }, origin); |
| 88 | } |
| 89 | |
| 90 | /** Applies an edit to a target; false when the target is gone. */ |
| 91 | export function applyEdit(doc: Y.Doc, fragment: Y.XmlFragment, target: DocEditTarget, markdown: string, origin: unknown = null): boolean { |
| 92 | const range = findTarget(fragment, target); |
| 93 | if (!range) return false; |
| 94 | replaceRange(doc, fragment, range, String(markdown ?? ""), origin); |
| 95 | return true; |
| 96 | } |
| 97 | |
| 98 | /** |
| 99 | * Makes the document's blocks what another document's were (restoring a |
| 100 | * version): the current blocks are removed and copies of the old ones put |
| 101 | * in, as one change that every open editor merges. |
| 102 | */ |
| 103 | export function restoreFrom(doc: Y.Doc, fragment: Y.XmlFragment, old: Y.XmlFragment, origin: unknown = null): void { |
| 104 | const oldGroup = old.toArray().find((n): n is Y.XmlElement => n instanceof Y.XmlElement && n.nodeName === "blockGroup"); |
| 105 | doc.transact(() => { |
| 106 | const group = blockGroupOf(fragment); |
| 107 | if (group.length) group.delete(0, group.length); |
| 108 | const copies = (oldGroup?.toArray() ?? []).filter((n): n is Y.XmlElement => n instanceof Y.XmlElement).map((n) => n.clone()); |
| 109 | group.insert(0, copies.length ? copies : writeBlocks([])); |
| 110 | }, origin); |
| 111 | } |
| 112 | |
| 113 | /** Every text in the document, in document order. */ |
| 114 | function texts(node: Y.XmlFragment | Y.XmlElement, out: Y.XmlText[] = []): Y.XmlText[] { |
| 115 | for (const child of node.toArray()) { |
| 116 | if (child instanceof Y.XmlText) out.push(child); |
| 117 | else if (child instanceof Y.XmlElement) texts(child, out); |
| 118 | } |
| 119 | return out; |
| 120 | } |
| 121 | |
| 122 | /** The mark key y-prosemirror uses for a comment (overlapping marks carry an 8-character suffix). */ |
| 123 | export function commentMarkKey(threadId: string): string { |
| 124 | let h = 0x811c9dc5; |
| 125 | for (let i = 0; i < threadId.length; i++) { |
| 126 | h ^= threadId.charCodeAt(i); |
| 127 | h = Math.imul(h, 0x01000193); |
| 128 | } |
| 129 | const bytes = [h >>> 24, (h >>> 16) & 255, (h >>> 8) & 255, h & 255, threadId.length & 255, 0x2a]; |
| 130 | return `comment--${btoa(String.fromCharCode(...bytes))}`; |
| 131 | } |
| 132 | |
| 133 | /** |
| 134 | * Marks the text between two positions with a comment thread, the way the |
| 135 | * editor does: the `comment` mark on every character in between, across |
| 136 | * blocks if need be. Returns the text marked (the thread's quote), or null |
| 137 | * when the positions are not in this document's text. |
| 138 | */ |
| 139 | export function anchorThread(doc: Y.Doc, fragment: Y.XmlFragment, anchor: unknown, head: unknown, threadId: string): string | null { |
| 140 | let a: Y.AbsolutePosition | null = null; |
| 141 | let b: Y.AbsolutePosition | null = null; |
| 142 | try { |
| 143 | a = Y.createAbsolutePositionFromRelativePosition(Y.createRelativePositionFromJSON(anchor), doc); |
| 144 | b = Y.createAbsolutePositionFromRelativePosition(Y.createRelativePositionFromJSON(head), doc); |
| 145 | } catch { |
| 146 | return null; |
| 147 | } |
| 148 | if (!a || !b || !(a.type instanceof Y.XmlText) || !(b.type instanceof Y.XmlText)) return null; |
| 149 | const all = texts(fragment); |
| 150 | let from = { at: all.indexOf(a.type as Y.XmlText), index: a.index }; |
| 151 | let to = { at: all.indexOf(b.type as Y.XmlText), index: b.index }; |
| 152 | if (from.at < 0 || to.at < 0) return null; |
| 153 | if (from.at > to.at || (from.at === to.at && from.index > to.index)) [from, to] = [to, from]; |
| 154 | const key = commentMarkKey(threadId); |
| 155 | const value = { orphan: false, threadId }; |
| 156 | let quote = ""; |
| 157 | doc.transact(() => { |
| 158 | for (let t = from.at; t <= to.at; t++) { |
| 159 | const text = all[t]!; |
| 160 | const start = t === from.at ? from.index : 0; |
| 161 | const end = t === to.at ? to.index : text.length; |
| 162 | if (end > start) { |
| 163 | text.format(start, end - start, { [key]: value }); |
| 164 | quote += |
| 165 | (quote ? " " : "") + |
| 166 | text |
| 167 | .toString() |
| 168 | .replace(/<[^>]+>/g, "") |
| 169 | .slice(start, end); |
| 170 | } |
| 171 | } |
| 172 | }); |
| 173 | return quote || null; |
| 174 | } |
| 175 | |
| 176 | /** Takes a deleted thread's mark off the text it was on. */ |
| 177 | export function unanchorThread(doc: Y.Doc, fragment: Y.XmlFragment, threadId: string): void { |
| 178 | const key = commentMarkKey(threadId); |
| 179 | doc.transact(() => { |
| 180 | for (const text of texts(fragment)) { |
| 181 | let at = 0; |
| 182 | for (const d of text.toDelta() as { insert: string | object; attributes?: Record<string, { threadId?: string }> }[]) { |
| 183 | const length = typeof d.insert === "string" ? d.insert.length : 1; |
| 184 | for (const [name, attrs] of Object.entries(d.attributes ?? {})) { |
| 185 | if (name.startsWith("comment") && attrs?.threadId === threadId) text.format(at, length, { [name]: null, [key]: null }); |
| 186 | } |
| 187 | at += length; |
| 188 | } |
| 189 | } |
| 190 | }); |
| 191 | } |