import { test } from "node:test";
import assert from "node:assert/strict";
import { mkdtemp, readFile, readdir } from "node:fs/promises";
import { tmpdir } from "node:os";
import { join } from "node:path";

import { useBroker } from "@novox/mesh-sdk/messaging";
import { emit, on, type Event } from "@novox/mesh-sdk/events";
import { Trail } from "../dist/audit.js";
import { Spool, takeOrSpool } from "../dist/spool.js";
import { getAuditTools } from "../dist/tools/index.js";

async function lines(path: string): Promise<Record<string, any>[]> {
  const text = await readFile(path, "utf8").catch(() => "");
  return text.trim() === "" ? [] : text.trim().split("\n").map((l) => JSON.parse(l));
}

function ev(id: string, body: unknown = { n: 1 }): Event {
  return { type: "umami.site.created", id, source: "umami", node: "anchor", at: "2026-10-06T10:00:00.000Z", body };
}

async function setup() {
  const dir = await mkdtemp(join(tmpdir(), "audit-"));
  const trail = await Trail.open(join(dir, "audit.log"));
  const spool = await Spool.open(join(dir, "spool"));
  const store = { broken: false };
  const write = async (e: Event) => {
    if (store.broken) throw new Error("ENOSPC: no space left on device");
    await trail.record(e);
  };
  const said: string[] = [];
  const handle = (e: Event) => takeOrSpool(e, write, spool, (l) => said.push(l));
  return { dir, trail, spool, store, write, handle, said, path: join(dir, "audit.log") };
}

test("audit-logger records every event to the trail as one line each", async () => {
  const broker = memBroker();
  useBroker(() => broker);
  const { handle, path } = await setup();

  // The audit-logger's whole behaviour: consume everything, record it.
  await on("#", handle); // the pattern index.ts subscribes

  process.env.MESH_MODULE = "umami";
  process.env.MESH_NODE = "anchor";
  await emit("site.created", { domain: "my-app" });
  await emit("node.anchor.joined", { role: "worker" }); // a node event, not a module one

  const got = await lines(path);
  assert.equal(got.length, 2);
  // A module names its events locally (design 29); the module is the `source`, which together with
  // the type says whose event it was. This broker does no namespacing, so the type is as emitted.
  assert.deepEqual(got.map((l) => l.type), ["site.created", "node.anchor.joined"]);
  assert.equal(got[0].source, "umami");
  assert.equal(got[0].node, "anchor");
  assert.equal(got[0].body.domain, "my-app");

  delete process.env.MESH_MODULE;
  delete process.env.MESH_NODE;
});

test("a write that fails is thrown, so the bus offers the event again — and it is spooled at once", async () => {
  const broker = memBroker();
  useBroker(() => broker);
  const { handle, store, spool, path } = await setup();
  await on("#", handle);
  store.broken = true;
  await assert.rejects(emit("site.created", { domain: "x" }), /ENOSPC/);
  assert.equal(spool.size, 1, "spooled on the first failure");
  assert.equal(spool.list()[0].attempts, 1);
  assert.equal(spool.list()[0].held, false);
  assert.deepEqual(await lines(path), []);
});

test("a redelivered event is written once — also after a restart, and also when its earlier failure was spooled", async () => {
  const { handle, store, spool, path, dir } = await setup();
  await handle(ev("e1"));
  await handle(ev("e1")); // the answer was lost; the bus offers it again
  assert.equal((await lines(path)).length, 1);

  // A restart between writing and answering: the trail remembers the ids at its end.
  const again = await Trail.open(path);
  await again.record(ev("e1"));
  assert.equal((await lines(path)).length, 1);

  // Failed once, then written: the spooled copy goes.
  store.broken = true;
  await assert.rejects(handle(ev("e2")));
  assert.equal(spool.size, 1);
  store.broken = false;
  await handle(ev("e2"));
  assert.equal(spool.size, 0);
  assert.deepEqual(await readdir(join(dir, "spool")), []);
  assert.deepEqual((await lines(path)).map((l) => l.id), ["e1", "e2"]);
});

test("on its last delivery a failed event is spooled and taken", async () => {
  const { handle, store, spool, said } = await setup();
  store.broken = true;
  for (let i = 1; i < 5; i++) await assert.rejects(handle(ev("e3")), /ENOSPC/, `delivery ${i} asks again`);
  await handle(ev("e3")); // the fifth — the controller's max-deliver — returns: taken
  const [entry] = spool.list();
  assert.equal(entry.attempts, 5);
  assert.equal(entry.held, true);
  assert.match(said.at(-1)!, /spooled and taken/);
});

test("the delivery count survives a restart, because it is the spool's", async () => {
  const { handle, store, dir } = await setup();
  store.broken = true;
  for (let i = 0; i < 3; i++) await assert.rejects(handle(ev("e4")));
  const reopened = await Spool.open(join(dir, "spool"));
  assert.equal(reopened.list()[0].attempts, 3);
});

test("the spool replays into the trail once writing works, once each", async () => {
  const { handle, store, spool, write, path } = await setup();
  store.broken = true;
  for (let i = 0; i < 5; i++) await handle(ev("e5")).catch(() => {});
  for (let i = 0; i < 5; i++) await handle(ev("e6")).catch(() => {});
  assert.equal(spool.size, 2);

  // Still broken: the pass stops at the first failure and keeps everything.
  let r = await spool.replay(write);
  assert.equal(r.replayed, 0);
  assert.equal(spool.size, 2);

  store.broken = false;
  r = await spool.replay(write);
  assert.deepEqual(r, { replayed: 2, left: 0 });
  await handle(ev("e5")); // a late redelivery after the replay
  assert.deepEqual((await lines(path)).map((l) => l.id), ["e5", "e6"]);
});

test("over its bound the spool keeps the event but does not take it, so the bus gives it up and says so", async () => {
  const dir = await mkdtemp(join(tmpdir(), "audit-"));
  const spool = await Spool.open(join(dir, "spool"), { boundCount: 1 });
  const failing = async () => {
    throw new Error("down");
  };
  for (let i = 0; i < 5; i++) await takeOrSpool(ev("a"), failing, spool, () => {}).catch(() => {});
  assert.equal(spool.list()[0].held, true, "within the bound: taken");
  for (let i = 1; i < 5; i++) await assert.rejects(takeOrSpool(ev("b"), failing, spool, () => {}));
  await assert.rejects(takeOrSpool(ev("b"), failing, spool, () => {}), /down/, "over the bound: asked again on its last");
  assert.equal(spool.size, 2, "and still spooled");
  const st = spool.standing();
  assert.equal(st.overBound, true);
  assert.equal(st.spooled, 2);
  assert.equal(st.held, 1);
  assert.match(st.why!, /more than 1/);
});

test("an event without a body, or without an id, is recorded once", async () => {
  const { handle, path } = await setup();
  await handle(ev("e7", null));
  await handle(ev("", undefined));
  await handle(ev("", undefined));
  const got = await lines(path);
  assert.equal(got.length, 2);
  assert.equal(got[0].body, null);
});

test("an event waiting longer than the bound puts the spool over it", async () => {
  const dir = await mkdtemp(join(tmpdir(), "audit-"));
  let now = new Date("2026-10-06T10:00:00Z");
  const spool = await Spool.open(join(dir, "spool"), { now: () => now });
  await takeOrSpool(ev("old"), async () => { throw new Error("down"); }, spool, () => {}).catch(() => {});
  assert.equal(spool.standing().overBound, false);
  now = new Date("2026-10-06T10:31:00Z");
  assert.match(spool.standing().why!, /longer than 30 minutes/);
});

test("audit_status says what waits in the spool, read from disk by the tool's own process", async () => {
  const { handle, store, dir } = await setup();
  store.broken = true;
  for (let i = 0; i < 5; i++) await handle(ev("s1")).catch(() => {});
  await handle(ev("s2")).catch(() => {});
  const [tool] = getAuditTools({ AUDIT_LOG: join(dir, "audit.log"), AUDIT_SPOOL: join(dir, "spool") });
  assert.equal(tool.name, "audit_status");
  const got = (await tool.run({}, {} as never)) as { spool: { spooled: number; held: number; lastError: string } };
  assert.equal(got.spool.spooled, 2);
  assert.equal(got.spool.held, 1);
  assert.match(got.spool.lastError, /ENOSPC/);
});

function memBroker() {
  const subs: { pattern: string; handler: (env: { key: string; node: string; body: unknown }) => Promise<void> }[] = [];
  return {
    async request() {
      throw new Error("unused");
    },
    async handle() {
      return () => {};
    },
    async publish<T>(env: { key: string; node: string; body: T }): Promise<void> {
      for (const s of subs) if (match(s.pattern, env.key)) await s.handler(env);
    },
    async subscribe<T>(pattern: string, handler: (env: { key: string; node: string; body: T }) => Promise<void>): Promise<() => void> {
      subs.push({ pattern, handler: handler as (env: { key: string; node: string; body: unknown }) => Promise<void> });
      return () => {};
    },
    async close() {},
  };
}

function match(pattern: string, key: string): boolean {
  return pattern === "#" || pattern === key;
}