import { readFile } from "node:fs/promises";

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

import { SESSION_COOKIE_NAME, shouldUseSecureAuthCookie } from "@/lib/auth/config";
import {
  chunkCookieValue,
  chunkedCookieNames,
  createSignedJsonValue,
  parseSessionCookieValue,
} from "@/lib/auth/session";
import {
  clearSessionCookieValues,
  setSessionCookieValue,
} from "@/lib/server/auth/session-cookie";

type CookieContract = {
  name: string;
  chunkSize: number;
  maxChunks: number;
  maxValueLength: number;
  chunkNames: string[];
  writeExample: {
    valueCharacter: string;
    valueLength: number;
    chunkLengths: number[];
    expiresAtUnix: number;
  };
  attributes: {
    httpOnly: boolean;
    sameSite: "lax";
    path: string;
    productionSecure: boolean;
  };
  clear: {
    value: string;
    maxAgeSeconds: number;
  };
  secureResolutionCases: Array<{
    name: string;
    explicit: string;
    publicBaseUrl: string;
    requestUrl: string;
    expected: boolean;
  }>;
};

type SessionCookieFixture = {
  version: 1;
  cookie: CookieContract;
  secret: string;
  rawJson: string;
  payload: string;
  signature: string;
  cookieValue: string;
};

const fixtureUrl = new URL("../contracts/auth/session-cookie-v1.json", import.meta.url);
const cookieEnvironmentKeys = [
  "ZHINIAN_AUTH_COOKIE_SECURE",
  "NEXT_PUBLIC_APP_URL",
  "ZHINIAN_PUBLIC_BASE_URL",
] as const;
const originalCookieEnvironment = new Map(
  cookieEnvironmentKeys.map((key) => [key, process.env[key]])
);

type RecordedCookie = {
  name: string;
  value: string;
  options: Record<string, unknown>;
};

afterEach(() => {
  for (const key of cookieEnvironmentKeys) {
    const value = originalCookieEnvironment.get(key);
    if (value === undefined) delete process.env[key];
    else process.env[key] = value;
  }
});

async function loadFixture(): Promise<SessionCookieFixture> {
  return JSON.parse(await readFile(fixtureUrl, "utf8")) as SessionCookieFixture;
}

function cookieRecorder() {
  const writes: RecordedCookie[] = [];
  const response = {
    cookies: {
      set(name: string, value: string, options: Record<string, unknown>) {
        writes.push({ name, value, options });
      },
    },
  } as unknown as Parameters<typeof setSessionCookieValue>[0];
  return { response, writes };
}

function configureCookieEnvironment(explicit: string, publicBaseUrl: string) {
  delete process.env.ZHINIAN_AUTH_COOKIE_SECURE;
  delete process.env.NEXT_PUBLIC_APP_URL;
  delete process.env.ZHINIAN_PUBLIC_BASE_URL;
  if (explicit) process.env.ZHINIAN_AUTH_COOKIE_SECURE = explicit;
  if (publicBaseUrl) process.env.NEXT_PUBLIC_APP_URL = publicBaseUrl;
}

describe("session Cookie v1 cross-language contract", () => {
  it("matches the language-neutral HMAC and payload golden vector", async () => {
    const fixture = await loadFixture();
    const rawSession = JSON.parse(fixture.rawJson) as unknown;

    expect(fixture.version).toBe(1);
    expect(await createSignedJsonValue(rawSession, fixture.secret)).toBe(fixture.cookieValue);
    expect(fixture.cookieValue).toBe(`${fixture.payload}.${fixture.signature}`);
    await expect(parseSessionCookieValue(fixture.cookieValue, fixture.secret, 150)).resolves.toMatchObject({
      version: 1,
      authMode: "admin",
      expiresAt: 200,
      user: {
        id: "auth:customPC:1",
        clientId: "customPC",
        displayName: "张三",
      },
    });
  });

  it("freezes cookie names, chunk boundaries, attributes, and stale-chunk clearing", async () => {
    const { cookie } = await loadFixture();
    const value = cookie.writeExample.valueCharacter.repeat(cookie.writeExample.valueLength);
    const expires = new Date(cookie.writeExample.expiresAtUnix * 1000);
    const { response, writes } = cookieRecorder();
    configureCookieEnvironment("true", "");

    expect(SESSION_COOKIE_NAME).toBe(cookie.name);
    expect(chunkedCookieNames(cookie.name, cookie.maxChunks)).toEqual(cookie.chunkNames);
    expect(chunkCookieValue(value, cookie.chunkSize).map((chunk) => chunk.length)).toEqual(
      cookie.writeExample.chunkLengths
    );

    setSessionCookieValue(response, "http://127.0.0.1:3000", value, expires);

    expect(writes.map(({ name }) => name)).toEqual(cookie.chunkNames);
    expect(writes.slice(0, cookie.writeExample.chunkLengths.length).map(({ value: part }) => part.length)).toEqual(
      cookie.writeExample.chunkLengths
    );
    for (const write of writes.slice(0, cookie.writeExample.chunkLengths.length)) {
      expect(write.options).toMatchObject({
        httpOnly: cookie.attributes.httpOnly,
        sameSite: cookie.attributes.sameSite,
        secure: cookie.attributes.productionSecure,
        path: cookie.attributes.path,
        expires,
      });
      expect(write.options).not.toHaveProperty("maxAge");
    }
    for (const write of writes.slice(cookie.writeExample.chunkLengths.length)) {
      expect(write.value).toBe(cookie.clear.value);
      expect(write.options).toMatchObject({
        httpOnly: cookie.attributes.httpOnly,
        sameSite: cookie.attributes.sameSite,
        secure: cookie.attributes.productionSecure,
        path: cookie.attributes.path,
        maxAge: cookie.clear.maxAgeSeconds,
      });
      expect(write.options).not.toHaveProperty("expires");
    }
  });

  it("rejects values beyond the 20-chunk read ceiling before writing", async () => {
    const { cookie } = await loadFixture();
    const { response, writes } = cookieRecorder();

    expect(() =>
      setSessionCookieValue(
        response,
        "https://app.example.test",
        "x".repeat(cookie.maxValueLength + 1),
        new Date(cookie.writeExample.expiresAtUnix * 1000)
      )
    ).toThrow(/maximum supported size/i);
    expect(writes).toEqual([]);
  });

  it("clears every possible chunk on logout with the legacy attributes", async () => {
    const { cookie } = await loadFixture();
    const { response, writes } = cookieRecorder();
    configureCookieEnvironment("true", "");

    clearSessionCookieValues(response, "http://127.0.0.1:3000");

    expect(writes.map(({ name }) => name)).toEqual(cookie.chunkNames);
    expect(writes).toHaveLength(cookie.maxChunks);
    for (const write of writes) {
      expect(write.value).toBe(cookie.clear.value);
      expect(write.options).toEqual({
        httpOnly: cookie.attributes.httpOnly,
        sameSite: cookie.attributes.sameSite,
        secure: cookie.attributes.productionSecure,
        path: cookie.attributes.path,
        maxAge: cookie.clear.maxAgeSeconds,
      });
    }
  });

  it("uses the shared Secure resolution precedence", async () => {
    const { cookie } = await loadFixture();
    for (const testCase of cookie.secureResolutionCases) {
      configureCookieEnvironment(testCase.explicit, testCase.publicBaseUrl);
      expect(shouldUseSecureAuthCookie(testCase.requestUrl), testCase.name).toBe(testCase.expected);
    }
  });
});