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1/**
2 * Chat as the site draws it: which messages sit together under one name,
3 * where a day starts, what an `@…` being typed could become, and a
4 * message's text as safe blocks and spans. Pure, so it is tested on its
5 * own (chat.test.ts); the components are in components/chat.
6 *
7 * Message bodies are never HTML: they are parsed here into a small tree
8 * that React renders as text, so nothing anyone writes can run.
9 */
10import type { ChatMessage, ChatSidebarEntry, MemberProfile, Principal } from "@g1t/contracts";
11
12/** Two messages from the same author this close together share one header. */
13export const GROUP_GAP_MS = 5 * 60 * 1000;
14
15/** A message on its way: shown at once, then swapped for what the service saved. */
16export type ShownMessage = ChatMessage & { pending?: boolean; failed?: boolean; client_id?: string };
17
18export type TimelineRow =
19 | { kind: "day"; key: string; label: string }
20 | { kind: "message"; key: string; message: ShownMessage; head: boolean };
21
22function sameAuthor(a: ChatMessage["author"], b: ChatMessage["author"]): boolean {
23 return a.kind === b.kind && a.id === b.id;
24}
25
26/** The calendar day of an instant, in the reader's time zone (or `zone`). */
27export function dayKey(at: string | Date, zone?: string): string {
28 const date = typeof at === "string" ? new Date(at) : at;
29 return new Intl.DateTimeFormat("en-CA", { timeZone: zone, year: "numeric", month: "2-digit", day: "2-digit" }).format(date);
30}
31
32/** "Today", "Yesterday", or the date, for the rule between days. */
33export function dayLabel(at: string, now: Date = new Date(), zone?: string): string {
34 const key = dayKey(at, zone);
35 if (key === dayKey(now, zone)) return "Today";
36 const yesterday = new Date(now.getTime() - 86_400_000);
37 if (key === dayKey(yesterday, zone)) return "Yesterday";
38 const date = new Date(at);
39 const sameYear = dayKey(date, zone).slice(0, 4) === dayKey(now, zone).slice(0, 4);
40 return new Intl.DateTimeFormat("en-US", {
41 timeZone: zone,
42 weekday: "long",
43 month: "long",
44 day: "numeric",
45 year: sameYear ? undefined : "numeric",
46 }).format(date);
47}
48
49/**
50 * The channel's messages, oldest first, as rows: a rule where each day
51 * starts, and each message marked with whether it starts a group (and so
52 * shows its author's name and avatar). A card always starts one.
53 */
54export function timeline(messages: ShownMessage[], now: Date = new Date(), zone?: string): TimelineRow[] {
55 const rows: TimelineRow[] = [];
56 let previous: ShownMessage | null = null;
57 let day: string | null = null;
58 for (const message of messages) {
59 if (message.deleted_at) continue;
60 const today = dayKey(message.created_at, zone);
61 if (today !== day) {
62 rows.push({ kind: "day", key: `day:${today}`, label: dayLabel(message.created_at, now, zone) });
63 day = today;
64 previous = null;
65 }
66 const head =
67 previous == null ||
68 message.kind === "card" ||
69 previous.kind === "card" ||
70 !sameAuthor(previous.author, message.author) ||
71 new Date(message.created_at).getTime() - new Date(previous.created_at).getTime() > GROUP_GAP_MS;
72 rows.push({ kind: "message", key: message.client_id ?? message.id, message, head });
73 previous = message;
74 }
75 return rows;
76}
77
78/**
79 * Messages merged by id, oldest first: what the page had, what arrived
80 * live and what a reload brought. A newer copy (an edit) wins; a pending
81 * message is dropped once the saved one with its `client_id` is there.
82 */
83export function mergeMessages(current: ShownMessage[], incoming: ShownMessage[]): ShownMessage[] {
84 const byId = new Map<string, ShownMessage>();
85 for (const message of [...current, ...incoming]) {
86 const key = message.id;
87 const had = byId.get(key);
88 if (!had || !message.pending || had.pending) byId.set(key, message);
89 }
90 const saved = new Set([...byId.values()].filter((m) => !m.pending).map((m) => m.client_id).filter(Boolean));
91 return [...byId.values()]
92 .filter((message) => !(message.pending && message.client_id && saved.has(message.client_id)))
93 .sort((a, b) => (a.pending === b.pending ? (a.id < b.id ? -1 : a.id > b.id ? 1 : 0) : a.pending ? 1 : -1));
94}
95
96/** Someone who can be mentioned: a person by username, an agent by handle. */
97export type Mentionable = {
98 kind: "user" | "agent";
99 /** What follows the `@`: lowercased, as it is kept. */
100 name: string;
101 /** A person's username as they wrote it, when that differs from `name`. */
102 display_username?: string | null;
103 display_name: string;
104 avatar: string | null;
105 /** An agent's role, shown beside it. */
106 role?: string | null;
107};
108
109export type MentionQuery = { start: number; typed: string; options: Mentionable[] };
110
111/** Most suggestions at once. */
112export const MAX_MENTIONS = 6;
113
114/**
115 * The `@…` just before the caret and who it could be: names that start with
116 * what is typed first, then display names with a word that does. Null when
117 * the caret is not in a mention, or nothing fits.
118 */
119export function mentionQuery(text: string, caret: number, people: readonly Mentionable[]): MentionQuery | null {
120 const match = /(?:^|[\s(])@([\w.-]{0,40})$/.exec(text.slice(0, caret));
121 if (!match) return null;
122 const typed = match[1]!.toLowerCase();
123 const start = caret - match[1]!.length - 1;
124 const first: Mentionable[] = [];
125 const then: Mentionable[] = [];
126 for (const person of people) {
127 const name = person.name.toLowerCase();
128 if (name === typed) continue;
129 if (name.startsWith(typed)) first.push(person);
130 else if (typed && person.display_name.toLowerCase().split(/\s+/).some((word) => word.startsWith(typed))) then.push(person);
131 }
132 const options = [...first, ...then].slice(0, MAX_MENTIONS);
133 return options.length > 0 ? { start, typed, options } : null;
134}
135
136// ---------------------------------------------------------------------------
137// A message's text: its Markdown, parsed by the rule every part of g1t reads it with.
138
139export { type Block, type Span, blocks, inline, plainText, safeHref, spansText } from "@g1t/contracts/chat-markdown";
140
141/** Whether a message is only emoji, a few of them: shown larger, as people expect. */
142export function onlyEmoji(text: string): boolean {
143 const trimmed = text.trim();
144 if (!trimmed || trimmed.length > 24) return false;
145 return /^(?:\p{Extended_Pictographic}|\p{Emoji_Component}|‍|️|\s)+$/u.test(trimmed) && /\p{Extended_Pictographic}/u.test(trimmed);
146}
147
148// ---------------------------------------------------------------------------
149// The sidebar.
150
151export type ChatFilter = "all" | "unread" | "mentions";
152
153/** The sidebar's rows that pass the filter and the "Jump to" text. */
154export function filterEntries(entries: ChatSidebarEntry[], filter: ChatFilter, query: string): ChatSidebarEntry[] {
155 const q = query.trim().toLowerCase().replace(/^[#@]/, "");
156 return entries.filter((entry) => {
157 if (filter === "unread" && entry.unread === 0 && entry.mentions === 0) return false;
158 if (filter === "mentions" && entry.mentions === 0) return false;
159 if (!q) return true;
160 if (entry.title.toLowerCase().includes(q)) return true;
161 return entry.others.some((member) => member.name.toLowerCase().includes(q) || member.display_name.toLowerCase().includes(q));
162 });
163}
164
165/** The agent a conversation is a direct message with, when it is with one agent alone; else null. */
166export function agentDmOf(entry: ChatSidebarEntry): string | null {
167 const only = entry.others.length === 1 ? entry.others[0]! : null;
168 return entry.channel.kind === "dm" && only?.kind === "agent" ? only.id : null;
169}
170
171/**
172 * The sidebar's sections, in the order they show: what is pinned (the
173 * `starred` preference), channels, and direct messages, the latest first,
174 * with people and agents alike (an agent is a member you message like
175 * anyone). `agentDms` finds the direct message with each agent, by agent
176 * id, so the Agents section lists only the agents you have not talked to.
177 */
178export function sections(entries: ChatSidebarEntry[]): {
179 pinned: ChatSidebarEntry[];
180 channels: ChatSidebarEntry[];
181 agentDms: Map<string, ChatSidebarEntry>;
182 dms: ChatSidebarEntry[];
183} {
184 const byName = (a: ChatSidebarEntry, b: ChatSidebarEntry) => a.title.localeCompare(b.title);
185 // Direct messages: the latest conversation first, as people scan them.
186 const byRecent = (a: ChatSidebarEntry, b: ChatSidebarEntry) =>
187 (b.channel.last_message_at ?? b.channel.created_at).localeCompare(a.channel.last_message_at ?? a.channel.created_at);
188 const agentDms = new Map<string, ChatSidebarEntry>();
189 for (const entry of entries) {
190 const agent = agentDmOf(entry);
191 if (agent) agentDms.set(agent, entry);
192 }
193 return {
194 pinned: entries.filter((e) => e.starred).sort(byName),
195 channels: entries.filter((e) => !e.starred && e.channel.kind === "channel").sort(byName),
196 agentDms,
197 dms: entries.filter((e) => !e.starred && e.channel.kind === "dm").sort(byRecent),
198 };
199}
200
201/** Where a conversation is, under the workspace. */
202export function channelPath(slug: string, channel: { id: string; kind: "channel" | "dm"; name: string | null }): string {
203 return channel.kind === "dm" || !channel.name ? `/${slug}/-/chat/dm/${channel.id}` : `/${slug}/-/chat/${channel.name}`;
204}
205
206/** Unread across the sidebar, leaving out what is muted: the rail's badge. */
207export function unreadTotals(entries: ChatSidebarEntry[]): { unread: number; mentions: number } {
208 let unread = 0;
209 let mentions = 0;
210 for (const entry of entries) {
211 mentions += entry.mentions;
212 if (!entry.muted) unread += entry.unread;
213 }
214 return { unread, mentions };
215}
216
217/** Channel names: lowercase words and digits joined by dashes, as people type them. */
218export function channelName(typed: string): string {
219 return typed
220 .toLowerCase()
221 .replace(/^#/, "")
222 .replace(/[\s_]+/g, "-")
223 .replace(/[^a-z0-9-]/g, "")
224 .replace(/-{2,}/g, "-")
225 .slice(0, 80);
226}
227
228/** Paths under `-/chat/` that are pages, not channels: never a channel's name. */
229export const RESERVED_CHANNEL_NAMES = ["dm", "browse", "live", "api", "new"] as const;
230
231/** A principal as a form field carries it: `user:<username>` or `agent:<id>`. */
232export function principalField(kind: Principal["kind"], key: string): string {
233 return `${kind}:${key}`;
234}
235
236/**
237 * A member's handle as it shows after `@`: a person's username in its
238 * chosen case, an agent's handle. The same rule as `memberHandle` in
239 * @g1t/contracts, kept here so this file stays pure for its tests.
240 */
241export function shownHandle(member: { name: string; display_username?: string | null }): string {
242 const display = member.display_username;
243 return display && display.toLowerCase() === member.name.toLowerCase() ? display : member.name;
244}
245
246/**
247 * The name shown for a member, everywhere in chat (messages, the sidebar,
248 * typing, cards): their display name, else their handle in its chosen
249 * case. The same rule as `memberName` in @g1t/contracts, which the chat
250 * service and its notifications follow.
251 */
252export function shownName(member: Pick<MemberProfile, "display_name" | "name"> & { display_username?: string | null }): string {
253 return member.display_name?.trim() || shownHandle(member);
254}
255
256/**
257 * Who each lowercased handle is, for drawing `@name` as the name people
258 * know: the workspace's people and agents.
259 */
260export function mentionNames(people: readonly Mentionable[]): Map<string, string> {
261 const names = new Map<string, string>();
262 for (const person of people) names.set(person.name.toLowerCase(), shownName(person));
263 return names;
264}
265
266/** Reconnect delays for the live socket: doubling from one second to thirty, with jitter. */
267export function backoff(attempt: number, random: () => number = Math.random): number {
268 const base = Math.min(30_000, 1000 * 2 ** Math.max(0, attempt));
269 return Math.round(base * (0.75 + random() * 0.5));
270}