import { test } from "node:test";
import assert from "node:assert/strict";
import { readdirSync } from "node:fs";
import { parseScenario } from "../src/declaration/parse.ts";
import { loadScenario } from "../src/declaration/parse.ts";
import { planRouters } from "../src/lifecycle/router.ts";

/** Every rejection below is a fault that would otherwise be silent at runtime. */
function refuses(yaml: string, pattern: RegExp): void {
  assert.throws(() => parseScenario(yaml), (err: Error) => {
    assert.match(err.message, pattern);
    return true;
  });
}

test("the shipped scenarios are valid", () => {
  // **Every one of them**, not a chosen two. Thirty-odd scenarios were rewritten in one pass when
  // the lab's registry was removed, and a scenario nobody loads is a scenario nobody validates —
  // which is how a bed goes unraisable for weeks and is only found when somebody wants it.
  const files = readdirSync("scenarios").filter((f) => f.endsWith(".yml"));
  assert.ok(files.length > 20, `only ${files.length} scenarios found — is the path right?`);
  for (const file of files) {
    assert.doesNotThrow(() => loadScenario(`scenarios/${file}`), `scenarios/${file}`);
  }
});

test("a public segment on a private range is refused — the mesh would silently never form", () => {
  refuses(
    `scenario: x
segments: { net: { kind: public, cidr: [10.99.1.0/24] } }
machines: { a: { at: { segment: net, address: [10.99.1.1] } } }`,
    /not documentation space/,
  );
});

test("a public segment on a real routable range is refused", () => {
  refuses(
    `scenario: x
segments: { net: { kind: public, cidr: [8.8.8.0/24] } }
machines: { a: { at: { segment: net, address: [8.8.8.8] } } }`,
    /not documentation space/,
  );
});

test("a private segment may use any range, including someone else's RFC 1918", () => {
  assert.doesNotThrow(() =>
    parseScenario(`scenario: x
segments:
  pub: { kind: public, cidr: [192.0.2.0/24] }
  cafe: { kind: private, cidr: [10.50.0.0/16], gateway: { to: pub, address: [192.0.2.5], nat: [v4], forwardable: false } }
machines: { a: { at: { segment: cafe, address: [10.50.0.9] } } }`),
  );
});

test("publishing through an unforwardable gateway is refused — that is the constraint", () => {
  refuses(
    `scenario: x
segments:
  pub: { kind: public, cidr: [192.0.2.0/24] }
  cafe: { kind: private, cidr: [10.50.0.0/16], gateway: { to: pub, address: [192.0.2.5], nat: [v4], forwardable: false } }
machines:
  a:
    at: { segment: cafe, address: [10.50.0.9] }
    published: [{ port: 443, on: cafe }]`,
    /not forwardable/,
  );
});

test("a gateway address must be on the PARENT segment, not the one behind it", () => {
  refuses(
    `scenario: x
segments:
  pub: { kind: public, cidr: [192.0.2.0/24] }
  home: { kind: private, cidr: [10.99.1.0/24], gateway: { to: pub, address: [10.99.1.1], nat: [v4] } }
machines: { a: { at: { segment: home, address: [10.99.1.9] } } }`,
    /is not within 'pub'/,
  );
});

test("a machine address outside its segment is refused", () => {
  refuses(
    `scenario: x
segments: { net: { kind: public, cidr: [192.0.2.0/24] } }
machines: { a: { at: { segment: net, address: [203.0.113.9] } } }`,
    /is not within segment 'net'/,
  );
});

test("an unknown segment reference is refused", () => {
  refuses(
    `scenario: x
segments: { net: { kind: public, cidr: [192.0.2.0/24] } }
machines: { a: { at: { segment: nope, address: [192.0.2.1] } } }`,
    /unknown segment 'nope'/,
  );
});

test("a gateway loop is refused rather than raised forever", () => {
  refuses(
    `scenario: x
segments:
  a: { kind: private, cidr: [10.0.0.0/24], gateway: { to: b, address: [10.0.1.1], nat: [] } }
  b: { kind: private, cidr: [10.0.1.0/24], gateway: { to: a, address: [10.0.0.1], nat: [] } }
machines: { m: { at: { segment: a, address: [10.0.0.9] } } }`,
    /loops through/,
  );
});

test("a detached machine cannot publish", () => {
  refuses(
    `scenario: x
segments: { net: { kind: public, cidr: [192.0.2.0/24] } }
machines: { a: { at: detached, published: [{ port: 443, on: net }] } }`,
    /detached but declares published/,
  );
});

test("publishing on a segment the machine is not attached to is refused", () => {
  refuses(
    `scenario: x
segments:
  pub: { kind: public, cidr: [192.0.2.0/24] }
  home: { kind: private, cidr: [10.99.1.0/24], gateway: { to: pub, address: [192.0.2.5], nat: [v4] } }
machines:
  a:
    at: { segment: pub, address: [192.0.2.10] }
    published: [{ port: 443, on: home }]`,
    /not attached to it/,
  );
});

test("two addresses of one family on one attachment is refused", () => {
  refuses(
    `scenario: x
segments: { net: { kind: public, cidr: [192.0.2.0/24] } }
machines: { a: { at: { segment: net, address: [192.0.2.1, 192.0.2.2] } } }`,
    /two v4 addresses/,
  );
});

test("place naming a machine that does not exist is refused", () => {
  refuses(
    `scenario: x
segments: { net: { kind: public, cidr: [192.0.2.0/24] } }
machines: { a: { at: { segment: net, address: [192.0.2.1] } } }
place: { ghost: [host] }`,
    /'ghost' is not a machine/,
  );
});

test("every problem is reported, not just the first", () => {
  try {
    parseScenario(`scenario: x
segments: { net: { kind: public, cidr: [192.168.0.0/24] } }
machines: { a: { at: { segment: nope, address: [1.2.3.4] } } }
place: { ghost: [host] }`);
    assert.fail("should have thrown");
  } catch (err) {
    const problems = (err as { problems: string[] }).problems;
    assert.ok(problems.length >= 3, `expected several problems, got ${problems.length}`);
  }
});

test("a detached machine is valid", () => {
  assert.doesNotThrow(() =>
    parseScenario(`scenario: x
segments: { net: { kind: public, cidr: [192.0.2.0/24] } }
machines:
  a: { at: { segment: net, address: [192.0.2.1] } }
  roamer: { at: detached }`),
  );
});

test("a multi-homed machine is valid", () => {
  assert.doesNotThrow(() =>
    parseScenario(`scenario: x
segments:
  pub: { kind: public, cidr: [192.0.2.0/24] }
  home: { kind: private, cidr: [10.99.1.0/24], gateway: { to: pub, address: [192.0.2.5], nat: [v4] } }
machines:
  border:
    at:
      - { segment: pub, address: [192.0.2.60] }
      - { segment: home, address: [10.99.1.2] }`),
  );
});

test("an isolated private segment with no gateway is valid — a site with no internet", () => {
  assert.doesNotThrow(() =>
    parseScenario(`scenario: x
segments: { island: { kind: private, cidr: [10.9.0.0/24] } }
machines: { a: { at: { segment: island, address: [10.9.0.1] } } }`),
  );
});

test("two gateways sharing an address are one gateway, not two", () => {
  // Modelled on the real thing: a bridged modem, one gateway holding the public address,
  // everything behind it. Two routers on one address is not a topology, it is a collision —
  // and the lab raised it happily, with the address resolving to whichever container
  // answered ARP last.
  const scenario = parseScenario(`
scenario: shared-gateway
segments:
  isp:
    kind: public
    cidr: [198.51.100.0/24, "2001:db8:b::/48"]
  home:
    kind: private
    cidr: [10.99.1.0/24]
    gateway: { to: isp, address: [198.51.100.7, "2001:db8:b::7"], nat: [v4], forwardable: true, mapping_ttl: 120s }
  devices:
    kind: private
    cidr: [192.168.30.0/24]
    gateway: { to: isp, address: [198.51.100.7], nat: [v4], forwardable: true, mapping_ttl: 120s }
machines:
  thermostat:
    at: { segment: devices, address: [192.168.30.20] }
`);
  const plans = planRouters(scenario, "test");
  assert.equal(plans.length, 1, `expected one gateway, got ${plans.map((p) => p.inside.join("+")).join(" / ")}`);
  assert.deepEqual([...plans[0]!.inside].sort(), ["devices", "home"]);
  // The union: a v6 address declared on only one of the segments it serves is still carried.
  assert.deepEqual([...plans[0]!.outsideAddresses].sort(), ["198.51.100.7", "2001:db8:b::7"]);
});

test("one box cannot behave two ways", () => {
  // If two gateways share an address they are the same box, so a disagreement about what
  // that box does is a contradiction — refused rather than silently resolved one way.
  assert.throws(
    () =>
      parseScenario(`
scenario: contradictory-gateway
segments:
  isp:
    kind: public
    cidr: [198.51.100.0/24]
  home:
    kind: private
    cidr: [10.99.1.0/24]
    gateway: { to: isp, address: [198.51.100.7], nat: [v4], forwardable: true }
  devices:
    kind: private
    cidr: [192.168.30.0/24]
    gateway: { to: isp, address: [198.51.100.7], nat: [v4], forwardable: false }
machines:
  thermostat:
    at: { segment: devices, address: [192.168.30.20] }
`),
    /one gateway.*disagree.*forwardable/s,
  );
});

test("a detached machine cannot declare egress", () => {
  refuses(`scenario: x
segments: { net: { kind: public, cidr: [192.0.2.0/24] } }
machines: { a: { at: detached, egress: true } }`,
    /detached but declares egress/);
});

/**
 * `images:` is the mesh's own images and nothing else.
 *
 * **The rule that replaced the lab's registry.** Anything with somewhere to be fetched from is
 * fetched from there, by the machine, over its uplink. Serving it from inside the scenario instead
 * is what hid the bootstrap faults this lab exists to find — so it is refused rather than quietly
 * done, or the fiction comes back one convenient line at a time.
 */
test("a third-party image in images: is refused, because nothing loads it", () => {
  for (const image of ["postgres:17-alpine", "gitea/gitea:1.22", "ghcr.io/mailu/admin:1.9"]) {
    refuses(`scenario: x
segments: { net: { kind: public, cidr: [192.0.2.0/24] } }
machines: { a: { at: { segment: net, address: [192.0.2.1] }, egress: true } }
images: ["${image}"]
place: { all: [runtime] }`,
      /is not one of the mesh's own images/);
  }
});

test("one of ours in images: is accepted", () => {
  assert.doesNotThrow(() => parseScenario(`scenario: x
segments: { net: { kind: public, cidr: [192.0.2.0/24] } }
machines: { a: { at: { segment: net, address: [192.0.2.1] }, egress: true } }
images: [mesh-controller:development, mesh-route-proxy:development]
place: { all: [runtime] }`));
});

test("images: is named by tag — an image ID is not knowable until the image is built", () => {
  refuses(`scenario: x
segments: { net: { kind: public, cidr: [192.0.2.0/24] } }
machines: { a: { at: { segment: net, address: [192.0.2.1] }, egress: true } }
images: ["mesh-controller@sha256:${"0".repeat(64)}"]
place: { all: [runtime] }`,
    /is pinned by digest/);
});

test("a machine cannot be handed an image the scenario does not have", () => {
  // Ignoring it silently would be a machine missing a runtime, failing several minutes later
  // inside an apply, as a container that will not start.
  refuses(`scenario: x
segments: { net: { kind: public, cidr: [192.0.2.0/24] } }
machines:
  a:
    at: { segment: net, address: [192.0.2.1] }
    egress: true
    images: [mesh-runtime-redis:development]
images: [mesh-controller:development]
place: { all: [runtime] }`,
    /is not in this scenario's images/);
});

test("a segment may not be named 'uplink' — the lab claims that name for egress", () => {
  refuses(`scenario: x
segments: { uplink: { kind: public, cidr: [192.0.2.0/24] } }
machines: { a: { at: { segment: uplink, address: [192.0.2.1] }, egress: true } }`,
    /reserved for the lab's own NAT bridge/);
});