// Shared CHAT-03 fixture setup (#1507). Every fixture lives in its own temp
// directory: fixture root, project, session file, claim root and socket
// directory. Nothing here touches a live session.

import { mkdtempSync, mkdirSync, writeFileSync, readFileSync, rmSync } from "node:fs";
import { tmpdir } from "node:os";
import { join, resolve } from "node:path";
import { spawnSync } from "node:child_process";
import { Controller } from "../src/controller.mjs";
import { ConversationClient } from "../src/client.mjs";
import { AUTHORITY } from "../src/cohort.mjs";
import { FixtureVerifier } from "../src/records.mjs";
import { FakeLauncher } from "./fake-pi.mjs";

export const REPO = resolve(import.meta.dirname, "..", "..", "..");
export const SESSION_ID = "0f5e1c2a-1111-4222-8333-944455556666";
export const FAST = Object.freeze({ ack: 1500, state: 1500, start: 1500, clear: 1500, abort: 3000, settle: 3000, grace: 50, write: 1500, maxRounds: 3 });
export const time = (i) => new Date(Date.UTC(2026, 9, 4, 12, 0, 0) + i * 1000).toISOString();

const tmp = mkdtempSync(join(tmpdir(), "chat03-"));
let serial = 0;

export function cleanupAll() {
  spawnSync("chmod", ["-R", "u+rwx", tmp]);
  rmSync(tmp, { recursive: true, force: true });
}

export const header = (cwd) => ({ type: "session", version: 3, id: SESSION_ID, timestamp: time(0), cwd });
export const userEntry = (id, parentId, text, i = 1) => ({ type: "message", id, parentId, timestamp: time(i), message: { role: "user", content: [{ type: "text", text }] } });
// Pi writes this when it creates a session (sdk.js 247–251), so a session Pi
// created and prompted carries one. Pi appends at startup to a session with
// messages and no thinking entry, and to any session with no messages.
export const thinkingEntry = (id = "f0e1d2c3", parentId = null) => ({ type: "thinking_level_change", id, parentId, timestamp: time(0), thinkingLevel: "off" });
export const assistantEntry = (id, parentId, text, i = 2) => ({ type: "message", id, parentId, timestamp: time(i), message: { role: "assistant", content: [{ type: "text", text }], stopReason: "stop" } });

// A fixture tree with one session file. `entries` default to one exchange.
export function fixture({ seat = "fixture-seat", name = "s1.jsonl", entries } = {}) {
  const base = join(tmp, `f${++serial}`);
  const proj = join(base, "proj");
  const sessions = join(proj, ".pi", "state", seat, "sessions");
  mkdirSync(sessions, { recursive: true });
  const sessionFile = join(sessions, name);
  const list = entries ?? [thinkingEntry(), userEntry("a1b2c3d4", "f0e1d2c3", "hello"), assistantEntry("b2c3d4e5", "a1b2c3d4", "hi")];
  writeFileSync(sessionFile, [header(proj), ...list].map((v) => JSON.stringify(v) + "\n").join(""));
  return { base, proj, sessions, sessionFile, seat, claimRoot: join(base, "claims"), socketDir: join(base, "sock") };
}

export const noUnits = Object.freeze({ lookup: async () => ({ state: "absent" }) });

// A controller on the in-process fake engine.
export function controllerFor(fx, { launcher = new FakeLauncher(), verifier = new FixtureVerifier({ authorities: [AUTHORITY] }), timeouts = FAST, ...opts } = {}) {
  const ctrl = new Controller({
    fixtureRoot: fx.base, claimRoot: fx.claimRoot, socketDir: fx.socketDir, sessionFile: fx.sessionFile, seat: fx.seat,
    launcher, verifier, units: noUnits, timeouts, ...opts,
  });
  return { ctrl, launcher, verifier };
}

// Starts a controller and connects `n` clients; the first takes control.
export async function started(opts = {}) {
  const fx = opts.fx ?? fixture(opts.fixture);
  const { ctrl, launcher, verifier } = controllerFor(fx, opts);
  const started = await ctrl.start();
  const clients = [];
  for (let i = 0; i < (opts.clients ?? 1); i++) {
    const c = new ConversationClient({ socketPath: ctrl.socketPath });
    await c.connect();
    clients.push(c);
  }
  if (opts.control !== false && clients[0]) {
    const r = await clients[0].takeover();
    if (r.outcome !== "transferred") throw new Error(`takeover: ${JSON.stringify(r)}`);
  }
  const close = async () => {
    for (const c of clients) c.close();
    await ctrl.close({ killEngine: true });
  };
  return { fx, ctrl, launcher, verifier, started, clients, client: clients[0], engine: launcher.last, close };
}

// Waits for a receipt to reach one of `states` (or outcome unknown).
export async function receiptState(client, receiptId, states, ms = 4000) {
  const want = new Set(Array.isArray(states) ? states : [states]);
  const ok = await client.waitFor(() => {
    const r = client.receipt(receiptId);
    return r && want.has(r.state);
  }, ms);
  if (!ok) throw new Error(`receipt ${receiptId} stayed ${client.receipt(receiptId)?.state}; wanted ${[...want]}`);
  return client.receipt(receiptId);
}

export function outcomeUnknownPush(client, receiptId) {
  return client.pushes.find((p) => p.kind === "receipt" && p.receipt.id === receiptId && p.outcomeUnknown === true) ?? null;
}

export const sessionText = (fx) => readFileSync(fx.sessionFile, "utf8");
export const tick = (ms = 0) => new Promise((r) => setTimeout(r, ms));
export { tmp };

// ---- controller in a child process -----------------------------------------

import { spawn } from "node:child_process";

const CHILD = join(import.meta.dirname, "ctrl-child.mjs");
const childPids = new Set();

export function killChildren() {
  for (const pid of childPids) {
    try {
      process.kill(pid, "SIGKILL");
    } catch {
      // gone
    }
  }
  childPids.clear();
}

// Spawns ctrl-child.mjs. `msgs` collects its JSON lines; `next(pred)` waits
// for one.
export function spawnController(cfg) {
  const proc = spawn(process.execPath, [CHILD, JSON.stringify({ timeouts: FAST, ...cfg })], { stdio: ["pipe", "pipe", "pipe"] });
  childPids.add(proc.pid);
  const msgs = [];
  const waiters = new Set();
  let buf = "";
  let stderr = "";
  proc.stderr.on("data", (c) => (stderr += c));
  proc.stdout.on("data", (c) => {
    buf += c;
    let i;
    while ((i = buf.indexOf("\n")) >= 0) {
      const line = buf.slice(0, i);
      buf = buf.slice(i + 1);
      try {
        msgs.push(JSON.parse(line));
      } catch {
        msgs.push({ raw: line });
      }
      for (const w of [...waiters]) w();
    }
  });
  const exited = new Promise((r) => proc.on("exit", (code, signal) => {
    childPids.delete(proc.pid);
    r({ code, signal });
    for (const w of [...waiters]) w();
  }));
  let done = false;
  exited.then(() => (done = true));
  const next = (pred, ms = 8000) => new Promise((resolve, reject) => {
    const check = () => {
      const hit = msgs.find(pred);
      if (hit) {
        waiters.delete(check);
        clearTimeout(t);
        resolve(hit);
      } else if (done) {
        waiters.delete(check);
        clearTimeout(t);
        reject(new Error(`controller child exited; lines ${JSON.stringify(msgs)} stderr ${stderr.slice(-2000)}`));
      }
    };
    const t = setTimeout(() => {
      waiters.delete(check);
      reject(new Error(`timeout; lines ${JSON.stringify(msgs)} stderr ${stderr.slice(-2000)}`));
    }, ms);
    waiters.add(check);
    check();
  });
  return { proc, msgs, next, exited, send: (line) => proc.stdin.write(line + "\n"), stderr: () => stderr };
}

// Stops every scope and kills every pgroup engine a fixture's claim records
// name, so a crashed controller leaves nothing running.
import { readdirSync as lsdir } from "node:fs";
import { processStart } from "../../discord/src/journal.mjs";

export function claimRecords(fx) {
  const out = [];
  const walk = (dir) => {
    let names = [];
    try {
      names = lsdir(dir, { withFileTypes: true });
    } catch {
      return;
    }
    for (const d of names) {
      const p = join(dir, d.name);
      if (d.isDirectory()) walk(p);
      else if (/^r\d{10}\.json$/.test(d.name)) {
        try {
          out.push({ path: p, record: JSON.parse(readFileSync(p, "utf8")) });
        } catch {
          out.push({ path: p, record: null });
        }
      }
    }
  };
  walk(fx.claimRoot);
  return out;
}

export function reap(fx) {
  const units = new Set(), engines = new Map();
  for (const { record } of claimRecords(fx)) {
    if (!record) continue;
    if (record.unitName && record.spawnMarker) units.add(record.unitName);
    if (record.engine?.kind === "pgroup" && record.engine.pid) engines.set(record.engine.pid, record.engine.start);
  }
  for (const u of units) spawnSync("systemctl", ["--user", "kill", "--signal=SIGKILL", `${u}.scope`], { stdio: "ignore", timeout: 5000 });
  for (const u of units) spawnSync("systemctl", ["--user", "stop", `${u}.scope`], { stdio: "ignore", timeout: 5000 });
  for (const [pid, start] of engines) {
    if (processStart(pid) !== start) continue;
    try {
      process.kill(-pid, "SIGKILL");
    } catch {
      // gone
    }
  }
}