feat(kernel): session-index

src/kernel/session-index.ts

@@ -0,0 +1,164 @@
+/**
+ * Flow → session 轻量索引（替代 session-state.json）。
+ * 路径：.opencode/opencode-cabbage/session-index.json
+ * 作用：parentIssueNumber → sessionID 绑定；双 session 检测（R7）。
+ */
+import { mkdir, readFile, rename, writeFile } from "node:fs/promises"
+import path from "node:path"
+import { PLUGIN_ID } from "../util/paths.js"
+
+export type FlowSessionStatus = "active" | "paused" | "completed" | "cancelled"
+
+export interface FlowSessionEntry {
+  sessionID: string
+  status: FlowSessionStatus
+  continuationCount: number
+  updatedAt: number
+}
+
+export interface SessionIndex {
+  flows: Record<string, FlowSessionEntry>
+}
+
+export function sessionIndexPath(projectDir: string): string {
+  return path.join(projectDir, ".opencode", PLUGIN_ID, "session-index.json")
+}
+
+/** 读取索引；文件不存在或损坏时返回空索引。 */
+export async function readIndex(projectDir: string): Promise<SessionIndex> {
+  try {
+    const parsed = JSON.parse(await readFile(sessionIndexPath(projectDir), "utf8")) as { flows?: unknown }
+    if (parsed && typeof parsed === "object" && !Array.isArray(parsed) && parsed.flows && typeof parsed.flows === "object") {
+      return parsed as SessionIndex
+    }
+    return { flows: {} }
+  } catch {
+    return { flows: {} }
+  }
+}
+
+/** 原子写：先写临时文件再 rename。 */
+export async function writeIndex(projectDir: string, index: SessionIndex): Promise<void> {
+  const target = sessionIndexPath(projectDir)
+  const tmp = `${target}.tmp`
+  await mkdir(path.dirname(target), { recursive: true })
+  await writeFile(tmp, JSON.stringify(index, null, 2), "utf8")
+  await rename(tmp, target)
+}
+
+export function getFlowSession(index: SessionIndex, parentIssueNumber: number): FlowSessionEntry | null {
+  return index.flows[String(parentIssueNumber)] ?? null
+}
+
+export type BindSessionResult =
+  | { ok: true; entry: FlowSessionEntry }
+  | { ok: false; code: "FLOW_SESSION_CONFLICT"; message: string }
+  | { ok: false; code: "TAKEOVER_NOT_CONFIRMED"; message: string }
+
+/**
+ * 绑定 parentIssueNumber → sessionID。
+ * 双 session 检测（§10.3）：该 flow 已被另一 active session 绑定时拒绝。
+ */
+export async function bindSession(
+  projectDir: string,
+  parentIssueNumber: number,
+  sessionID: string,
+): Promise<BindSessionResult> {
+  const index = await readIndex(projectDir)
+  const key = String(parentIssueNumber)
+  const existing = index.flows[key]
+
+  if (existing && existing.sessionID !== sessionID && existing.status === "active") {
+    return {
+      ok: false,
+      code: "FLOW_SESSION_CONFLICT",
+      message: `Flow #${parentIssueNumber} is already bound to active session "${existing.sessionID}". Use flow_control takeover with user confirmation to take over.`,
+    }
+  }
+
+  const entry: FlowSessionEntry = {
+    sessionID,
+    status: "active",
+    continuationCount: existing && existing.sessionID === sessionID ? existing.continuationCount : 0,
+    updatedAt: Date.now(),
+  }
+  index.flows[key] = entry
+  await writeIndex(projectDir, index)
+  return { ok: true, entry }
+}
+
+/**
+ * 接管绑定：旧 session 置 paused，新 session 绑定 active（R7）。
+ * 旧 session 为另一 active session 时要求 userConfirmed（§10.3）；
+ * 调用方还需将旧 session 的 goal status 置 paused（goalClient 层）。
+ */
+export async function takeoverSession(
+  projectDir: string,
+  parentIssueNumber: number,
+  newSessionID: string,
+  userConfirmed: boolean,
+): Promise<BindSessionResult> {
+  const index = await readIndex(projectDir)
+  const key = String(parentIssueNumber)
+  const existing = index.flows[key]
+
+  if (existing && existing.sessionID !== newSessionID && existing.status === "active" && !userConfirmed) {
+    return {
+      ok: false,
+      code: "TAKEOVER_NOT_CONFIRMED",
+      message: `Flow #${parentIssueNumber} is bound to active session "${existing.sessionID}". Takeover requires user confirmation (user_confirmed: true).`,
+    }
+  }
+
+  if (existing) {
+    if (existing.sessionID === newSessionID) {
+      const entry: FlowSessionEntry = { ...existing, status: "active", updatedAt: Date.now() }
+      index.flows[key] = entry
+      await writeIndex(projectDir, index)
+      return { ok: true, entry }
+    }
+    existing.status = "paused"
+    existing.updatedAt = Date.now()
+  }
+
+  const entry: FlowSessionEntry = {
+    sessionID: newSessionID,
+    status: "active",
+    continuationCount: 0,
+    updatedAt: Date.now(),
+  }
+  index.flows[key] = entry
+  await writeIndex(projectDir, index)
+  return { ok: true, entry }
+}
+
+/** 更新已绑定 flow 的状态/计数；flow 未绑定时返回 null 且不创建 entry。 */
+export async function updateFlowSession(
+  projectDir: string,
+  parentIssueNumber: number,
+  patch: Partial<Pick<FlowSessionEntry, "status" | "continuationCount">>,
+): Promise<FlowSessionEntry | null> {
+  const index = await readIndex(projectDir)
+  const key = String(parentIssueNumber)
+  const existing = index.flows[key]
+  if (!existing) return null
+  const entry: FlowSessionEntry = { ...existing, ...patch, updatedAt: Date.now() }
+  index.flows[key] = entry
+  await writeIndex(projectDir, index)
+  return entry
+}
+
+/** 解绑：仅当 sessionID 与当前绑定匹配时删除 entry。 */
+export async function unbindSession(
+  projectDir: string,
+  parentIssueNumber: number,
+  sessionID: string,
+): Promise<boolean> {
+  const index = await readIndex(projectDir)
+  const key = String(parentIssueNumber)
+  const existing = index.flows[key]
+  if (!existing || existing.sessionID !== sessionID) return false
+  delete index.flows[key]
+  await writeIndex(projectDir, index)
+  return true
+}