import { describe, expect, it, vi } from "vitest";

import { createContractHttpExecutor } from "../../src/adapters/http/http-execution-v3.ts";
import type { InstalledHttpContract } from "../../src/contracts/external-contract-runtime.ts";
import {
  TEST_CREATE_HTTP_CONTRACT,
  TEST_LIST_HTTP_CONTRACT,
} from "../helpers/external-contract-fixture.ts";

const installed: InstalledHttpContract<unknown, unknown, unknown> =
  TEST_LIST_HTTP_CONTRACT;

const scope = Object.freeze({
  generation: 1,
  fingerprint: "scope-1",
  identities: Object.freeze({}) as never,
  signal: new AbortController().signal,
  isCurrent: () => true,
});

const createInstalled: InstalledHttpContract<unknown, unknown, unknown> =
  TEST_CREATE_HTTP_CONTRACT;

function mutationIntent(
  overrides: Readonly<{
    intentId?: string;
    operationId?: string;
    idempotencyKey?: string | null;
  }> = {},
) {
  return Object.freeze({
    intentId: overrides.intentId ?? "intent-1",
    operationId: overrides.operationId ?? "TEST_CREATE_ENTITY",
    canonicalInputIdentity: "opaque-input-identity",
    ...(overrides.idempotencyKey === null
      ? {}
      : { idempotencyKey: overrides.idempotencyKey ?? "key-1" }),
    createdAtMonotonicMs: 1,
  });
}

function operation(
  overrides: Readonly<{
    deadlineMs?: number;
    responseBody?: "REQUIRED_JSON" | "OPTIONAL_JSON" | "NONE";
  }> = {},
): InstalledHttpContract<unknown, unknown, unknown> {
  return {
    ...installed,
    contract: {
      ...installed.contract,
      responseBody: overrides.responseBody ?? installed.contract.responseBody,
    },
    frontend: {
      ...installed.frontend,
      totalDeadlineMs: overrides.deadlineMs ?? installed.frontend.totalDeadlineMs,
    },
  };
}

async function flushMicrotasks(): Promise<void> {
  await Promise.resolve();
  await Promise.resolve();
  await Promise.resolve();
}

describe("descriptor-driven HTTP execution lifetime", () => {
  it.each([
    ["absent intent", () => undefined],
    ["empty key", () => mutationIntent({ idempotencyKey: "" })],
    ["control-character key", () => mutationIntent({ idempotencyKey: "key\u0000private" })],
    ["over-budget key", () => mutationIntent({ idempotencyKey: "k".repeat(257) })],
    [
      "wrong operation",
      () => mutationIntent({ operationId: "TEST_OTHER_COMMAND" }),
    ],
  ])(
    "rejects a KEYED command with %s before credentials or fetch",
    async (_label, intentFactory) => {
      const attachCredentials = vi.fn(() => ({
        kind: "READY" as const,
        headers: {},
        credentials: "omit" as const,
      }));
      const fetcher = vi.fn();
      const executor = createContractHttpExecutor({
        baseUrl: "https://api.example/",
        maxRetryAttempts: 0,
        attachCredentials,
        fetcher,
      });
      const intent = intentFactory();

      await expect(
        executor.execute(
          createInstalled,
          { name: "created" },
          { scope, ...(intent === undefined ? {} : { intent }) },
        ),
      ).resolves.toMatchObject({
        kind: "CONTRACT_VIOLATION",
        violation: {
          kind: "MISSING_IDEMPOTENCY_KEY",
          operation: "REQUEST",
        },
        effect: "NOT_STARTED",
      });
      expect(attachCredentials).not.toHaveBeenCalled();
      expect(fetcher).not.toHaveBeenCalled();
    },
  );

  it.each([
    ["an intent without a key", mutationIntent({ idempotencyKey: null })],
    ["an intent with a key", mutationIntent()],
  ])(
    "rejects a query carrying %s before credentials or fetch",
    async (_label, intent) => {
      const attachCredentials = vi.fn(() => ({
        kind: "READY" as const,
        headers: {},
        credentials: "omit" as const,
      }));
      const fetcher = vi.fn();
      const executor = createContractHttpExecutor({
        baseUrl: "https://api.example/",
        maxRetryAttempts: 0,
        attachCredentials,
        fetcher,
      });

      await expect(
        executor.execute(installed, { limit: 20 }, { scope, intent }),
      ).resolves.toMatchObject({
        kind: "CONTRACT_VIOLATION",
        violation: {
          kind: "UNEXPECTED_IDEMPOTENCY_KEY",
          operation: "REQUEST",
        },
        effect: "NOT_STARTED",
      });
      expect(attachCredentials).not.toHaveBeenCalled();
      expect(fetcher).not.toHaveBeenCalled();
    },
  );

  it.each([
    {
      label: "query with the canonical reserved header",
      operation: installed,
      input: { limit: 20 },
      context: { scope },
      headerName: "Idempotency-Key",
    },
    {
      label: "valid KEYED command with a case-variant reserved header",
      operation: createInstalled,
      input: { name: "created" },
      context: { scope, intent: mutationIntent() },
      headerName: "iDeMpOtEnCy-KeY",
    },
  ])(
    "rejects a credential patch for $label before fetch",
    async ({ operation, input, context, headerName }) => {
      const attachCredentials = vi.fn(() => ({
        kind: "READY" as const,
        headers: { [headerName]: "credential-owned-key" },
        credentials: "omit" as const,
      }));
      const fetcher = vi.fn();
      const executor = createContractHttpExecutor({
        baseUrl: "https://api.example/",
        maxRetryAttempts: 0,
        attachCredentials,
        fetcher,
      });

      await expect(
        executor.execute(operation, input, context),
      ).resolves.toMatchObject({
        kind: "CONTRACT_VIOLATION",
        violation: {
          kind: "UNEXPECTED_IDEMPOTENCY_KEY",
          operation: "REQUEST",
        },
        effect: "NOT_STARTED",
      });
      expect(attachCredentials).toHaveBeenCalledOnce();
      expect(fetcher).not.toHaveBeenCalled();
    },
  );

  it("reuses one supplied idempotency key across every physical retry", async () => {
    const observedKeys: Array<string | null> = [];
    let attempt = 0;
    const fetcher = vi.fn((_input: RequestInfo | URL, init?: RequestInit) => {
      observedKeys.push(new Headers(init?.headers).get("Idempotency-Key"));
      attempt += 1;
      if (attempt === 1) throw new TypeError("synchronous pre-dispatch failure");
      return Promise.resolve(
        Response.json(
          { id: "created", name: "Created" },
          { status: 201 },
        ),
      );
    });
    const executor = createContractHttpExecutor({
      baseUrl: "https://api.example/",
      maxRetryAttempts: 1,
      attachCredentials: () => ({
        kind: "READY",
        headers: {},
        credentials: "omit",
      }),
      fetcher,
      sleep: async () => {},
      random: () => 0,
    });
    const retryingCreate = {
      ...createInstalled,
      frontend: {
        ...createInstalled.frontend,
        retryBudget: 1 as const,
      },
    };

    await expect(
      executor.execute(
        retryingCreate,
        { name: "created" },
        { scope, intent: mutationIntent({ idempotencyKey: "logical-key" }) },
      ),
    ).resolves.toMatchObject({ kind: "SUCCESS" });
    expect(fetcher).toHaveBeenCalledTimes(2);
    expect(observedKeys).toEqual(["logical-key", "logical-key"]);
  });

  it("never emits a mutation idempotency header for a query", async () => {
    const observedKeys: Array<string | null> = [];
    const fetcher = vi.fn(
      async (_input: RequestInfo | URL, init?: RequestInit) => {
        observedKeys.push(
          new Headers(init?.headers).get("Idempotency-Key"),
        );
        return Response.json([]);
      },
    );
    const executor = createContractHttpExecutor({
      baseUrl: "https://api.example/",
      maxRetryAttempts: 0,
      attachCredentials: () => ({
        kind: "READY",
        headers: {},
        credentials: "omit",
      }),
      fetcher,
    });

    await expect(
      executor.execute(
        installed,
        { limit: 20 },
        { scope },
      ),
    ).resolves.toMatchObject({ kind: "SUCCESS" });
    expect(fetcher).toHaveBeenCalledOnce();
    expect(observedKeys).toEqual([null]);
  });

  it("keeps intent identities out of request URLs and safe observations", async () => {
    const urls: string[] = [];
    const observations: unknown[] = [];
    const executor = createContractHttpExecutor({
      baseUrl: "https://api.example/",
      maxRetryAttempts: 0,
      attachCredentials: () => ({
        kind: "READY",
        headers: {},
        credentials: "omit",
      }),
      fetcher: vi.fn(async (input) => {
        urls.push(String(input));
        return Response.json(
          { id: "created", name: "Created" },
          { status: 201 },
        );
      }),
      observe: (observation) => observations.push(observation),
    });

    await expect(
      executor.execute(
        createInstalled,
        { name: "created" },
        {
          scope,
          intent: Object.freeze({
            intentId: "private-intent-id",
            operationId: "TEST_CREATE_ENTITY",
            canonicalInputIdentity: "private-canonical-input",
            idempotencyKey: "private-idempotency-key",
            createdAtMonotonicMs: 1,
          }),
        },
      ),
    ).resolves.toMatchObject({ kind: "SUCCESS" });

    const safeEvidence = JSON.stringify({ urls, observations });
    expect(urls).toEqual(["https://api.example/api/test-entities"]);
    expect(observations).toHaveLength(1);
    expect(safeEvidence).not.toContain("private-intent-id");
    expect(safeEvidence).not.toContain("private-canonical-input");
    expect(safeEvidence).not.toContain("private-idempotency-key");
  });

  it.each([
    [{}, "limit=20"],
    [{ limit: "7" }, "limit=7"],
  ])("projects the canonical validated input %#", async (input, expectedQuery) => {
    const fetcher = vi.fn(async () => Response.json([]));
    const executor = createContractHttpExecutor({
      baseUrl: "https://api.example/",
      maxRetryAttempts: 0,
      attachCredentials: () => ({
        kind: "READY",
        headers: {},
        credentials: "omit",
      }),
      fetcher,
    });

    await expect(executor.execute(installed, input, { scope })).resolves.toMatchObject({
      kind: "SUCCESS",
    });
    expect(String((fetcher.mock.calls as unknown[][])[0]?.[0])).toContain(
      expectedQuery,
    );
  });

  it("contains throwing and malformed external request projections", async () => {
    const executor = createContractHttpExecutor({
      baseUrl: "https://api.example/",
      maxRetryAttempts: 0,
      attachCredentials: () => ({
        kind: "READY",
        headers: {},
        credentials: "omit",
      }),
      fetcher: vi.fn(),
    });
    const throwing = {
      ...installed,
      contract: {
        ...installed.contract,
        projectRequest: () => {
          throw new Error("external descriptor defect");
        },
      },
    };
    const malformed = {
      ...installed,
      contract: {
        ...installed.contract,
        projectRequest: () => ({ pathValues: {}, queryEntries: [["limit"]], body: null }),
      },
    } as unknown as typeof installed;

    await expect(executor.execute(throwing, { limit: 20 }, { scope })).resolves.toMatchObject({
      kind: "CONTRACT_VIOLATION",
      effect: "NOT_APPLICABLE",
    });
    await expect(executor.execute(malformed, { limit: 20 }, { scope })).resolves.toMatchObject({
      kind: "CONTRACT_VIOLATION",
      effect: "NOT_APPLICABLE",
    });
  });

  it("preserves MAYBE_APPLIED for a malformed command response after dispatch", async () => {
    const executor = createContractHttpExecutor({
      baseUrl: "https://api.example/",
      maxRetryAttempts: 0,
      attachCredentials: () => ({
        kind: "READY",
        headers: {},
        credentials: "omit",
      }),
      fetcher: vi.fn(async () => Response.json({ malformed: true }, { status: 201 })),
    });

    await expect(
      executor.execute(
        createInstalled,
        { name: "created" },
        {
          scope,
          intent: mutationIntent(),
        },
      ),
    ).resolves.toMatchObject({
      kind: "CONTRACT_VIOLATION",
      violation: { kind: "SUCCESS_SCHEMA_INVALID" },
      effect: "MAYBE_APPLIED",
    });
  });

  it("preserves MAYBE_APPLIED when a command response arrives after its scope fence", async () => {
    let current = true;
    const lifetime = new AbortController();
    const fencedScope = Object.freeze({
      ...scope,
      signal: lifetime.signal,
      isCurrent: () => current,
    });
    const executor = createContractHttpExecutor({
      baseUrl: "https://api.example/",
      maxRetryAttempts: 0,
      attachCredentials: () => ({
        kind: "READY",
        headers: {},
        credentials: "omit",
      }),
      fetcher: vi.fn(async () => {
        current = false;
        lifetime.abort();
        return Response.json(
          { id: "created", name: "Created" },
          { status: 201 },
        );
      }),
    });

    await expect(
      executor.execute(
        createInstalled,
        { name: "created" },
        {
          scope: fencedScope,
          intent: mutationIntent({ intentId: "intent-2", idempotencyKey: "key-2" }),
        },
      ),
    ).resolves.toMatchObject({
      kind: "CONTRACT_VIOLATION",
      violation: { kind: "SCOPE_FENCED" },
      effect: "MAYBE_APPLIED",
    });
  });

  it("settles a credential hang at the total operation deadline", async () => {
    vi.useFakeTimers();
    let settled = false;
    const executor = createContractHttpExecutor({
      baseUrl: "https://api.example/",
      maxRetryAttempts: 0,
      attachCredentials: () => new Promise(() => {}),
    });

    const result = executor
      .execute(operation({ deadlineMs: 5 }), { limit: 20 }, { scope })
      .then((outcome) => {
        settled = true;
        return outcome;
      });
    await vi.advanceTimersByTimeAsync(5);
    await flushMicrotasks();

    expect(settled).toBe(true);
    await expect(result).resolves.toMatchObject({
      kind: "TRANSPORT_FAILURE",
      failure: { kind: "TIMEOUT" },
    });
    vi.useRealTimers();
  });

  it("cancels a non-cooperative retry sleep when the caller aborts", async () => {
    const caller = new AbortController();
    let sleepSignal: AbortSignal | undefined;
    let settled = false;
    const executor = createContractHttpExecutor({
      baseUrl: "https://api.example/",
      maxRetryAttempts: 2,
      attachCredentials: () => ({
        kind: "READY",
        headers: {},
        credentials: "omit",
      }),
      fetcher: vi.fn(async () =>
        Response.json(
          { type: "about:blank", title: "temporary", status: 503 },
          { status: 503 },
        ),
      ),
      sleep: (_ms, signal) => {
        sleepSignal = signal;
        return new Promise(() => {});
      },
      random: () => 0,
    });

    const result = executor
      .execute(installed, { limit: 20 }, { scope, signal: caller.signal })
      .then((outcome) => {
        settled = true;
        return outcome;
      });
    await vi.waitFor(() => expect(sleepSignal).toBeDefined());
    caller.abort();
    await flushMicrotasks();

    expect(sleepSignal?.aborted).toBe(true);
    expect(settled).toBe(true);
    await expect(result).resolves.toMatchObject({ kind: "CANCELLED" });
  });

  it("treats an unreadable forbidden-body probe as a transport failure", async () => {
    const body = new ReadableStream<Uint8Array>({
      pull(controller) {
        controller.error(new TypeError("stream failed"));
      },
    });
    const executor = createContractHttpExecutor({
      baseUrl: "https://api.example/",
      maxRetryAttempts: 0,
      attachCredentials: () => ({
        kind: "READY",
        headers: {},
        credentials: "omit",
      }),
      fetcher: vi.fn(async () => new Response(body, { status: 200 })),
    });

    await expect(
      executor.execute(
        operation({ responseBody: "NONE" }),
        { limit: 20 },
        { scope },
      ),
    ).resolves.toMatchObject({
      kind: "TRANSPORT_FAILURE",
      failure: { kind: "RESPONSE_STREAM_FAILURE" },
    });
  });
});