feat: /last and bind button for previous Q/A context (v0.3.4)

After attaching a session, show a button and /last command that load the latest human/assistant turn via session.history so phone users can continue with context.

Co-authored-by: Cursor <cursoragent@cursor.com>

src/history.ts

@@ -0,0 +1,131 @@
+import { randomUUID } from 'node:crypto'
+import type { Context } from '@deepseek-ai/cordis'
+import type { Agent } from '@deepseek-ai/dsh-agent'
+import type { ContentBlock, TextBlock } from '@deepseek-ai/dsh-llm/types'
+import { resolveApiProxy } from './apiproxy.js'
+
+export interface LastTurn {
+  userText?: string
+  assistantText?: string
+}
+
+type ApiFn = (req: { rpcId: string; payload: unknown }) => Promise<unknown>
+
+function unwrap<T>(res: unknown): T | undefined {
+  const r = res as { result?: { ok?: boolean; value?: T; error?: { message?: string } } } | undefined
+  if (r?.result?.ok === true) return r.result.value
+  return undefined
+}
+
+function contentToText(content: unknown): string {
+  if (!Array.isArray(content)) return ''
+  return (content as ContentBlock[])
+    .filter((block): block is TextBlock => block?.type === 'text' && typeof block.text === 'string')
+    .map((block) => block.text)
+    .join('')
+    .trim()
+}
+
+type LooseEvent = {
+  type?: string
+  data?: {
+    source?: { kind?: string }
+    content?: unknown
+    message?: { content?: unknown; source?: { kind?: string } }
+    text?: string
+  }
+}
+
+/** Extract the latest human Q + assistant A from a session event list. */
+export function extractLastTurn(events: readonly LooseEvent[]): LastTurn {
+  let lastUser: string | undefined
+  let lastAssistant: string | undefined
+
+  for (const ev of events) {
+    if (ev.type === 'user/message') {
+      const sourceKind = ev.data?.source?.kind ?? ev.data?.message?.source?.kind
+      // Prefer real human prompts; skip plugin-injected context noise.
+      if (sourceKind && sourceKind !== 'user') continue
+      const text = contentToText(ev.data?.content ?? ev.data?.message?.content)
+      if (text) {
+        lastUser = text
+        // New user turn resets prior assistant for pairing.
+        lastAssistant = undefined
+      }
+      continue
+    }
+    if (ev.type === 'assistant/message') {
+      const text = contentToText(ev.data?.message?.content ?? ev.data?.content)
+      if (text) lastAssistant = text
+      continue
+    }
+    if (ev.type === 'compaction/summary') {
+      const text = typeof ev.data?.text === 'string' ? ev.data.text.trim() : ''
+      if (text && !lastAssistant) lastAssistant = `（摘要）${text}`
+    }
+  }
+
+  return { userText: lastUser, assistantText: lastAssistant }
+}
+
+export function formatLastTurn(turn: LastTurn, maxEach = 3500): string {
+  if (!turn.userText && !turn.assistantText) {
+    return '暂无上次问答（会话可能为空或尚未产生用户回合）。'
+  }
+  const clip = (s: string) => {
+    const chars = [...s]
+    if (chars.length <= maxEach) return s
+    return `${chars.slice(0, maxEach - 1).join('')}…`
+  }
+  const parts: string[] = ['—— 上次对话 ——']
+  if (turn.userText) {
+    parts.push('', '【用户】', clip(turn.userText))
+  }
+  if (turn.assistantText) {
+    parts.push('', '【助手】', clip(turn.assistantText))
+  }
+  return parts.join('\n')
+}
+
+async function historyViaApi(ctx: Context, sessionId: string): Promise<LooseEvent[] | undefined> {
+  const api = resolveApiProxy(ctx)
+  const history = api?.sessions?.history as ApiFn | undefined
+  if (typeof history !== 'function') return undefined
+  const raw = await history({
+    rpcId: randomUUID(),
+    payload: { sessionId, maxMessages: 8 },
+  })
+  const value = unwrap<{ events: Array<{ event?: LooseEvent } | LooseEvent> }>(raw)
+  if (!value?.events) return undefined
+  return value.events.map((entry) => {
+    if (entry && typeof entry === 'object' && 'event' in entry && entry.event) {
+      return entry.event
+    }
+    return entry as LooseEvent
+  })
+}
+
+function historyViaAgent(agent: Agent | undefined): LooseEvent[] | undefined {
+  const events = (agent as { session?: { events?: readonly LooseEvent[] } } | undefined)?.session?.events
+  if (!events || events.length === 0) return undefined
+  return [...events]
+}
+
+/** Load last Q/A for a bound session (apiProxy history, else live agent events). */
+export async function loadLastTurn(
+  ctx: Context,
+  sessionId: string,
+  agent?: Agent,
+): Promise<LastTurn> {
+  let events: LooseEvent[] | undefined
+  try {
+    events = await historyViaApi(ctx, sessionId)
+  } catch {
+    events = undefined
+  }
+  if (!events || events.length === 0) {
+    events = historyViaAgent(agent)
+  }
+  if (!events || events.length === 0) return {}
+  return extractLastTurn(events)
+}