#!/usr/bin/env node
/*
 * http-source.test.mjs — RoutingSource backend #2's client seam (06-04, D-01).
 * ------------------------------------------------------------------------------
 * Source-under-test: src/http-source.ts — createHttpRoutingSource(opts) turns
 * the Worker's Bearer-gated POST /api/route into a RoutingSource. The fixture
 * backend's laws carry over (fixture-source.ts is the posture reference):
 *
 *   - slug guard FIRST: a hostile destinationId never reaches the network
 *   - fail-honest (T-05-04's .catch(() => null) law, network edition): a
 *     thrown fetch, a non-200, a malformed body, or a shape violation is an
 *     honest null — the designed router-pending state (D-03), never a throw
 *     in the webview's render path
 *   - a 200 with JSON null body IS the null contract crossing HTTP — also
 *     resolves null, not an error
 *   - the Authorization header rides ONLY when the injected bearer getter
 *     returns a token (a logged-out caller still sends the request; the
 *     server's 401 then degrades to null like any other miss)
 *
 * The fetcher is INJECTED (fetchImpl) — this suite is fully offline.
 *
 * Cases:
 *   H1  happy path → RouteResult; POST + JSON body {origin, destinationId};
 *       Bearer header attached from the injected getter
 *   H2  slug guard first — off-slug destinationId → null, fetch NEVER called
 *   H3  non-200 (401/404/500) → null
 *   H4  thrown fetch → null (fail-honest)
 *   H5  malformed JSON body → null
 *   H6  200 with JSON null body (router-pending over HTTP) → null
 *   H7  shape violations → null (destination mismatch, options 0/4, non-finite
 *       summary, cumulativeDistanceM length ≠ points length, non-finite
 *       point, missing backend, steps not an array)
 *   H8  bearer() → null ⇒ request goes WITHOUT an Authorization header
 *
 * Run:  npm run routing:test   (exit 0 = all green)
 */
import { strict as assert } from "node:assert";
import { test } from "./harness.mjs";

const ENDPOINT = "https://worker.example/api/route";

const OK_RESULT = {
  destinationId: "suria-klcc",
  origin: { lat: 3.1528, lng: 101.7038 },
  options: [
    {
      geometry: {
        points: [
          { lat: 3.1528, lng: 101.7038 },
          { lat: 3.1553, lng: 101.7078 },
          { lat: 3.1578, lng: 101.7117 },
        ],
        cumulativeDistanceM: [0, 521.4, 1042.8],
      },
      summary: { distanceM: 1042.8, durationS: 62.6 },
      steps: [
        { kind: "depart", name: "Jalan Koridor Ujian", distanceM: 1042.8, geometry: "oqv_Egt~~`Ewj@_q@" },
        { kind: "arrive", geometry: "{wv_Aeb~y`E" },
      ],
    },
  ],
  backend: "engine-a",
};

const REQUEST = { origin: { lat: 3.1528, lng: 101.7038 }, destinationId: "suria-klcc" };

/** A fetchImpl returning one fixed response; records the calls it saw. */
function fetching(status, body, { throws = false } = {}) {
  const calls = [];
  const impl = async (url, init) => {
    calls.push({ url, init });
    if (throws) throw new Error("network down");
    return {
      ok: status >= 200 && status < 300,
      status,
      json: async () => JSON.parse(body),
    };
  };
  return { impl, calls };
}

async function load() {
  return import("../src/http-source.ts");
}

test("H1 happy path → RouteResult passthrough; POST JSON {origin, destinationId}; Bearer attached from the getter", async () => {
  const { createHttpRoutingSource } = await load();
  const { impl, calls } = fetching(200, JSON.stringify(OK_RESULT));
  const source = createHttpRoutingSource({ endpoint: ENDPOINT, bearer: () => "tok-123", fetchImpl: impl });
  assert.equal(source.name, "engine-a");
  const result = await source.route(REQUEST);
  assert.deepEqual(result, OK_RESULT, "the validated payload crosses as the RouteResult");
  assert.equal(calls.length, 1);
  const { url, init } = calls[0];
  assert.equal(url, ENDPOINT);
  assert.equal(init.method, "POST");
  assert.deepEqual(JSON.parse(init.body), { origin: REQUEST.origin, destinationId: REQUEST.destinationId });
  assert.equal(init.headers.authorization, "Bearer tok-123");
});

test("H2 slug guard first — off-slug destinationId → null and the fetch is NEVER called", async () => {
  const { createHttpRoutingSource } = await load();
  const { impl, calls } = fetching(200, JSON.stringify(OK_RESULT));
  const source = createHttpRoutingSource({ endpoint: ENDPOINT, bearer: () => "tok", fetchImpl: impl });
  for (const bad of ["Suria KLCC", "", `${"x".repeat(65)}`, "klcc/../etc"]) {
    const result = await source.route({ origin: REQUEST.origin, destinationId: bad });
    assert.equal(result, null, `off-slug id ${JSON.stringify(bad)} is an honest null`);
  }
  assert.equal(calls.length, 0, "a hostile id never reaches the network (T-05-03 posture)");
});

test("H3 non-200 (401/404/500) → null", async () => {
  const { createHttpRoutingSource } = await load();
  for (const status of [401, 404, 500]) {
    const { impl } = fetching(status, '{"error":"x"}');
    const source = createHttpRoutingSource({ endpoint: ENDPOINT, bearer: () => "tok", fetchImpl: impl });
    assert.equal(await source.route(REQUEST), null, `HTTP ${status} degrades to null`);
  }
});

test("H4 thrown fetch → null (fail-honest, T-05-04 network edition)", async () => {
  const { createHttpRoutingSource } = await load();
  const { impl } = fetching(200, "{}", { throws: true });
  const source = createHttpRoutingSource({ endpoint: ENDPOINT, bearer: () => "tok", fetchImpl: impl });
  assert.equal(await source.route(REQUEST), null);
});

test("H5 malformed JSON body → null", async () => {
  const { createHttpRoutingSource } = await load();
  const { impl } = fetching(200, "<html>not json</html>");
  const source = createHttpRoutingSource({ endpoint: ENDPOINT, bearer: () => "tok", fetchImpl: impl });
  assert.equal(await source.route(REQUEST), null);
});

test("H6 200 with JSON null body (router-pending over HTTP) → null, not an error", async () => {
  const { createHttpRoutingSource } = await load();
  const { impl } = fetching(200, "null");
  const source = createHttpRoutingSource({ endpoint: ENDPOINT, bearer: () => "tok", fetchImpl: impl });
  assert.equal(await source.route(REQUEST), null);
});

test("H7 shape violations → null — every field defensive, the fixture-source posture", async () => {
  const { createHttpRoutingSource } = await load();
  const mutations = [
    ["destinationId mismatch", (r) => { r.destinationId = "kl-sentral"; }],
    ["options not an array", (r) => { r.options = "one"; }],
    ["zero options", (r) => { r.options = []; }],
    ["four options", (r) => { r.options = [OK_RESULT.options[0], OK_RESULT.options[0], OK_RESULT.options[0], OK_RESULT.options[0]]; }],
    ["non-finite distanceM", (r) => { r.options[0].summary.distanceM = Number.NaN; }],
    ["negative durationS", (r) => { r.options[0].summary.durationS = -5; }],
    ["cumulativeDistanceM length ≠ points length", (r) => { r.options[0].geometry.cumulativeDistanceM = [0]; }],
    ["non-finite point", (r) => { r.options[0].geometry.points[1].lat = Number.NaN; }],
    ["missing backend", (r) => { delete r.backend; }],
    ["steps not an array", (r) => { r.options[0].steps = "depart"; }],
    ["origin not a point", (r) => { r.origin = { lat: "far", lng: 101.7 }; }],
  ];
  for (const [label, mutate] of mutations) {
    const payload = structuredClone(OK_RESULT);
    mutate(payload);
    const { impl } = fetching(200, JSON.stringify(payload));
    const source = createHttpRoutingSource({ endpoint: ENDPOINT, bearer: () => "tok", fetchImpl: impl });
    const result = await source.route(REQUEST);
    assert.equal(result, null, `${label} must degrade to null`);
  }
  for (const [label, raw] of [["array payload", "[]"], ["null payload", "null"], ["string payload", '"ok"']]) {
    const { impl } = fetching(200, raw);
    const source = createHttpRoutingSource({ endpoint: ENDPOINT, bearer: () => "tok", fetchImpl: impl });
    assert.equal(await source.route(REQUEST), null, `${label} must degrade to null`);
  }
});

test("H8 bearer() → null ⇒ the request goes out WITHOUT an Authorization header (server 401 degrades like any miss)", async () => {
  const { createHttpRoutingSource } = await load();
  const { impl, calls } = fetching(401, '{"error":"unauthorized"}');
  const source = createHttpRoutingSource({ endpoint: ENDPOINT, bearer: () => null, fetchImpl: impl });
  assert.equal(await source.route(REQUEST), null);
  assert.equal(calls.length, 1, "the request still went out");
  assert.equal(calls[0].init.headers.authorization, undefined, "no Authorization header without a token");
});