| 1 | /** |
| 2 | * Ask g1t's conversation, as the composer keeps it (components/ask-composer): |
| 3 | * where the person is, the turns so far, and reading the answer as it |
| 4 | * streams. Pure, so it is tested on its own. |
| 5 | * |
| 6 | * A conversation lives in the browser tab for now (the composer keeps it in |
| 7 | * session storage); keeping conversations on the server comes later. |
| 8 | */ |
| 9 | import type { AskEvent, AskMessage, AskPage } from "@g1t/contracts"; |
| 10 | |
| 11 | /** First path segments that are g1t's own pages, never a workspace. */ |
| 12 | const RESERVED = new Set([ |
| 13 | "settings", "u", "auth", "oauth", "integrations", "new", "invite", "workspaces", "device", "verify", |
| 14 | "confirm-email", "login", "register", "logout", "forgot", "reset", "search", "status", "avatars", "docs", "-", |
| 15 | ]); |
| 16 | |
| 17 | /** Where the person is: the page, and the repository, issue or pull request on it. */ |
| 18 | export function askPage(pathname: string): AskPage { |
| 19 | const path = pathname.split(/[?#]/)[0] ?? ""; |
| 20 | const parts = path.split("/").filter(Boolean).map((part) => decodeURIComponent(part)); |
| 21 | const page: AskPage = { path: path || "/" }; |
| 22 | const [owner, name, section, number] = parts; |
| 23 | if (!owner || !name || RESERVED.has(owner.toLowerCase()) || name === "-") return page; |
| 24 | page.repo = { namespace: owner.toLowerCase(), name }; |
| 25 | const numbered = number && /^\d+$/.test(number) ? Number(number) : null; |
| 26 | if (numbered != null && section === "issues") page.issue = numbered; |
| 27 | if (numbered != null && section === "pull") page.pull = numbered; |
| 28 | return page; |
| 29 | } |
| 30 | |
| 31 | export type TurnStatus = "streaming" | "done" | "stopped" | "error"; |
| 32 | |
| 33 | export type Turn = { |
| 34 | id: string; |
| 35 | role: "user" | "assistant"; |
| 36 | content: string; |
| 37 | status: TurnStatus; |
| 38 | /** Who answered: the provider's name and the model. */ |
| 39 | provider?: string; |
| 40 | model?: string; |
| 41 | /** What went wrong, for an answer that did not come. */ |
| 42 | error?: string; |
| 43 | /** `max_tokens`, `length`: the answer was cut off at its limit. */ |
| 44 | stopReason?: string | null; |
| 45 | }; |
| 46 | |
| 47 | export type AskState = { turns: Turn[]; busy: boolean }; |
| 48 | |
| 49 | export const EMPTY_ASK: AskState = { turns: [], busy: false }; |
| 50 | |
| 51 | export type AskAction = |
| 52 | | { type: "ask"; question: string; id: string } |
| 53 | | { type: "event"; event: AskEvent } |
| 54 | | { type: "stop" } |
| 55 | | { type: "failed"; message: string } |
| 56 | | { type: "reset" } |
| 57 | | { type: "restore"; state: AskState }; |
| 58 | |
| 59 | /** The answer being written, if one is. */ |
| 60 | function answering(state: AskState): Turn | null { |
| 61 | const last = state.turns.at(-1); |
| 62 | return last?.role === "assistant" && last.status === "streaming" ? last : null; |
| 63 | } |
| 64 | |
| 65 | function withLast(state: AskState, change: (turn: Turn) => Turn, busy: boolean): AskState { |
| 66 | const last = answering(state); |
| 67 | if (!last) return state; |
| 68 | return { turns: [...state.turns.slice(0, -1), change(last)], busy }; |
| 69 | } |
| 70 | |
| 71 | export function askReducer(state: AskState, action: AskAction): AskState { |
| 72 | switch (action.type) { |
| 73 | case "ask": { |
| 74 | const question = action.question.trim(); |
| 75 | if (state.busy || !question) return state; |
| 76 | return { |
| 77 | busy: true, |
| 78 | turns: [ |
| 79 | ...state.turns, |
| 80 | { id: `${action.id}-q`, role: "user", content: question, status: "done" }, |
| 81 | { id: `${action.id}-a`, role: "assistant", content: "", status: "streaming" }, |
| 82 | ], |
| 83 | }; |
| 84 | } |
| 85 | case "event": { |
| 86 | const { event } = action; |
| 87 | switch (event.type) { |
| 88 | case "meta": |
| 89 | return withLast(state, (turn) => ({ ...turn, provider: event.provider_label, model: event.model }), true); |
| 90 | case "text": |
| 91 | return withLast(state, (turn) => ({ ...turn, content: turn.content + event.text }), true); |
| 92 | case "done": |
| 93 | return withLast(state, (turn) => ({ ...turn, status: "done", stopReason: event.stop_reason }), false); |
| 94 | case "error": |
| 95 | return withLast(state, (turn) => ({ ...turn, status: "error", error: event.message }), false); |
| 96 | } |
| 97 | return state; |
| 98 | } |
| 99 | case "stop": |
| 100 | return withLast(state, (turn) => ({ ...turn, status: "stopped" }), false); |
| 101 | case "failed": |
| 102 | return withLast(state, (turn) => ({ ...turn, status: "error", error: action.message }), false); |
| 103 | case "reset": |
| 104 | return EMPTY_ASK; |
| 105 | case "restore": |
| 106 | return restorable(action.state); |
| 107 | } |
| 108 | } |
| 109 | |
| 110 | /** |
| 111 | * A conversation kept in the tab, made safe to show again: an answer that |
| 112 | * was still coming when the page went away is marked stopped. |
| 113 | */ |
| 114 | export function restorable(state: unknown): AskState { |
| 115 | if (!state || typeof state !== "object" || !Array.isArray((state as AskState).turns)) return EMPTY_ASK; |
| 116 | const turns = (state as AskState).turns |
| 117 | .filter((turn) => turn && (turn.role === "user" || turn.role === "assistant") && typeof turn.content === "string") |
| 118 | .map((turn) => (turn.status === "streaming" ? { ...turn, status: "stopped" as const } : turn)); |
| 119 | return { turns, busy: false }; |
| 120 | } |
| 121 | |
| 122 | /** |
| 123 | * What to send with a new question: every question that got an answer, and |
| 124 | * the answer (as far as it got, if it was stopped), then the new question. |
| 125 | * A question whose answer failed or never started is left out, so the turns |
| 126 | * alternate. |
| 127 | */ |
| 128 | export function history(turns: Turn[], question: string): AskMessage[] { |
| 129 | const messages: AskMessage[] = []; |
| 130 | for (let at = 0; at < turns.length; at++) { |
| 131 | const turn = turns[at]!; |
| 132 | const next = turns[at + 1]; |
| 133 | if (turn.role !== "user") continue; |
| 134 | if (next?.role === "assistant" && next.status !== "error" && next.content.trim()) { |
| 135 | messages.push({ role: "user", content: turn.content }, { role: "assistant", content: next.content }); |
| 136 | at++; |
| 137 | } |
| 138 | } |
| 139 | messages.push({ role: "user", content: question.trim() }); |
| 140 | return messages; |
| 141 | } |
| 142 | |
| 143 | /** |
| 144 | * Reads newline-delimited JSON as it arrives: each whole line's event, and |
| 145 | * what is left of a line still coming. Lines that are not events are |
| 146 | * skipped. |
| 147 | */ |
| 148 | export function readLines(pending: string, chunk: string): { events: AskEvent[]; rest: string } { |
| 149 | const text = pending + chunk; |
| 150 | const lines = text.split("\n"); |
| 151 | const rest = lines.pop() ?? ""; |
| 152 | const events: AskEvent[] = []; |
| 153 | for (const line of lines) { |
| 154 | const event = parseEvent(line); |
| 155 | if (event) events.push(event); |
| 156 | } |
| 157 | return { events, rest }; |
| 158 | } |
| 159 | |
| 160 | export function parseEvent(line: string): AskEvent | null { |
| 161 | if (!line.trim()) return null; |
| 162 | try { |
| 163 | const event = JSON.parse(line) as AskEvent; |
| 164 | return event && typeof event === "object" && ["meta", "text", "done", "error"].includes(event.type) ? event : null; |
| 165 | } catch { |
| 166 | return null; |
| 167 | } |
| 168 | } |
| 169 | |
| 170 | /** Whether an answer was cut off at its length limit. */ |
| 171 | export function cutOff(turn: Turn): boolean { |
| 172 | return turn.stopReason === "max_tokens" || turn.stopReason === "length"; |
| 173 | } |