import assert from "node:assert/strict";
import fs from "node:fs";
import path from "node:path";
import test from "node:test";
import ts from "typescript";

const repoRoot = path.resolve(import.meta.dirname, "../../..");

function transpileDataUrl(filePath, replacements = new Map()) {
  const result = ts.transpileModule(fs.readFileSync(filePath, "utf8"), {
    compilerOptions: { module: ts.ModuleKind.ES2022, target: ts.ScriptTarget.ES2022 },
    fileName: filePath,
    reportDiagnostics: true,
  });
  assert.deepEqual(result.diagnostics, []);
  let source = result.outputText;
  for (const [specifier, replacement] of replacements) {
    source = source.replaceAll(`"${specifier}"`, JSON.stringify(replacement));
  }
  return `data:text/javascript;base64,${Buffer.from(source).toString("base64")}`;
}

const gatesUrl = transpileDataUrl(path.join(repoRoot, "web/protocol/capability-gates.ts"));
const selectorUrl = transpileDataUrl(
  path.join(repoRoot, "web/protocol/engine-variant.ts"),
  new Map([["./capability-gates", gatesUrl]]),
);
const bootstrapUrl = transpileDataUrl(
  path.join(repoRoot, "web/app/src/engine-client/engine-variant-bootstrap.ts"),
  new Map([["../../../protocol/engine-variant", selectorUrl]]),
);
const {
  bootstrapWebEngineRelease,
  engineVariantStatusLabel,
  EngineVariantLoadError,
} = await import(bootstrapUrl);
const manifest = JSON.parse(fs.readFileSync(
  path.join(repoRoot, "tests/golden/M6-04A/engine-manifest-v2.json"),
  "utf8",
));
const ready = { crossOriginIsolated: true, sharedArrayBuffer: true, worker: true };

class FakeSession {
  constructor(variant) {
    this.variant = variant;
    this.opened = [];
    this.disposals = 0;
    this.state = {
      handles: 1,
      workers: variant.id === "pthread" ? 1 : 0,
      timers: 0,
      pendingRequests: 0,
    };
  }

  async openProject(project) {
    this.opened.push(project);
  }

  resourceState() {
    return { ...this.state };
  }

  testOnlySeedTrackedResources() {
    this.state.timers = 1;
    this.state.pendingRequests = 1;
  }

  async dispose() {
    this.disposals += 1;
    this.state = { handles: 0, workers: 0, timers: 0, pendingRequests: 0 };
    return this.resourceState();
  }
}

function dependencies() {
  const sessions = [];
  return {
    sessions,
    initialize: async (variant) => {
      const session = new FakeSession(variant);
      sessions.push(session);
      return session;
    },
  };
}

test("M6-05A/B/C injects one pthread failure, cleans it and falls back once", async () => {
  const deps = dependencies();
  const outcome = await bootstrapWebEngineRelease(
    manifest.releaseId,
    manifest,
    "AUTO",
    ready,
    deps,
    undefined,
    { failPthreadAfterInitialize: true, seedTrackedPthreadResources: true },
  );

  assert.deepEqual(outcome.result.attempted, ["pthread", "single"]);
  assert.equal(deps.sessions.length, 2);
  assert.equal(deps.sessions[0].disposals, 1);
  assert.deepEqual(outcome.result.failedAttemptCleanup, {
    handles: 0,
    workers: 0,
    timers: 0,
    pendingRequests: 0,
  });
  assert.equal(outcome.result.selected, "single");
  assert.deepEqual(outcome.result.fallbackReason, {
    code: "PTHREAD_INITIALIZATION_FAILED",
    message: "TEST_PTHREAD_INITIALIZATION_FAILURE",
  });
  assert.equal(outcome.result.openCount, 0);
  assert.equal(deps.sessions[0].opened.length, 0);
  assert.equal(deps.sessions[1].opened.length, 0);
});

test("M6-05D opens a pending project once only after the fallback settles", async () => {
  const deps = dependencies();
  const project = { id: "pending-project" };
  const outcome = await bootstrapWebEngineRelease(
    manifest.releaseId,
    manifest,
    "AUTO",
    ready,
    deps,
    project,
    { failPthreadAfterInitialize: true },
  );

  assert.equal(outcome.result.openCount, 1);
  assert.deepEqual(deps.sessions[0].opened, []);
  assert.deepEqual(deps.sessions[1].opened, [project]);
});

test("M6-05E exposes selected, attempted and fallbackReason without pthread READY UI", async () => {
  const deps = dependencies();
  const outcome = await bootstrapWebEngineRelease(
    manifest.releaseId,
    manifest,
    "AUTO",
    ready,
    deps,
    undefined,
    { failPthreadAfterInitialize: true },
  );
  const label = engineVariantStatusLabel(outcome.result);

  assert.deepEqual(
    {
      selected: outcome.result.selected,
      attempted: outcome.result.attempted,
      fallbackReason: outcome.result.fallbackReason?.code,
    },
    {
      selected: "single",
      attempted: ["pthread", "single"],
      fallbackReason: "PTHREAD_INITIALIZATION_FAILED",
    },
  );
  assert.equal(label, "Runtime: single (pthread fallback: PTHREAD_INITIALIZATION_FAILED)");
  assert.doesNotMatch(label, /pthread\s+ready/i);
});

test("M6-08E treats a manifest hash mismatch as fatal without fallback or project open", async () => {
  const initialized = [];
  const project = { id: "must-stay-unopened" };
  await assert.rejects(
    bootstrapWebEngineRelease(
      manifest.releaseId,
      manifest,
      "AUTO",
      ready,
      {
        initialize: async (variant) => {
          initialized.push(variant.id);
          if (variant.id === "pthread") {
            throw new EngineVariantLoadError("ENGINE_VARIANT_RESOURCE_HASH_MISMATCH", variant.resources.wasm.url);
          }
          return new FakeSession(variant);
        },
      },
      project,
    ),
    (error) => error?.code === "ENGINE_VARIANT_INTEGRITY_FAILED" &&
      error.cause?.code === "ENGINE_VARIANT_RESOURCE_HASH_MISMATCH" &&
      JSON.stringify(error.attempted) === JSON.stringify(["pthread"]),
  );
  assert.deepEqual(initialized, ["pthread"]);
});

test("M6-08D returns refresh-required before initialization or project open", async () => {
  let initializationCount = 0;
  const outcome = await bootstrapWebEngineRelease(
    "blender-wasm-previous",
    manifest,
    "AUTO",
    ready,
    {
      initialize: async (variant) => {
        initializationCount += 1;
        return new FakeSession(variant);
      },
    },
    { id: "must-stay-unopened" },
  );

  assert.deepEqual(outcome, {
    result: {
      status: "REFRESH_REQUIRED",
      expectedReleaseId: "blender-wasm-previous",
      actualReleaseId: manifest.releaseId,
      manifest: null,
    },
    session: null,
  });
  assert.equal(initializationCount, 0);
});

test("M6-08E normalizes a fallback variant hash mismatch and never opens the project", async () => {
  const initialized = [];
  const pthreadSession = new FakeSession(manifest.variants[1]);
  await assert.rejects(
    bootstrapWebEngineRelease(
      manifest.releaseId,
      manifest,
      "AUTO",
      ready,
      {
        initialize: async (variant) => {
          initialized.push(variant.id);
          if (variant.id === "single") {
            throw new EngineVariantLoadError("ENGINE_VARIANT_RESOURCE_HASH_MISMATCH", variant.resources.wasm.url);
          }
          return pthreadSession;
        },
      },
      { id: "must-stay-unopened" },
      { failPthreadAfterInitialize: true },
    ),
    (error) => error?.code === "ENGINE_VARIANT_INTEGRITY_FAILED" &&
      error.cause?.code === "ENGINE_VARIANT_RESOURCE_HASH_MISMATCH" &&
      JSON.stringify(error.attempted) === JSON.stringify(["pthread", "single"]),
  );
  assert.deepEqual(initialized, ["pthread", "single"]);
  assert.equal(pthreadSession.disposals, 1);
  assert.deepEqual(pthreadSession.opened, []);
});