import { createHash } from "node:crypto";
import {
  ANONYMOUS_PRINCIPAL,
  type ModuleDatabase,
  type ModuleRouteHandler,
  type ModuleRuntimeServices,
  parsePermissionId,
  type RegisteredModuleHttpRoute,
} from "@ekklesia/contracts";
import {
  type AuthorizationEvaluator,
  type AuthorizationStore,
  createPermissionRegistry,
} from "@ekklesia/core/authorization";
import type { EkklesiaIdentityRuntime } from "@ekklesia/core/identity";
import {
  createModuleUiPublicationRegistry,
  EMPTY_MODULE_REALTIME_REGISTRY,
} from "@ekklesia/core/modules";
import { describe, expect, it, vi } from "vitest";

// Every byte these routes serve must come from the injected startup snapshot. Any filesystem read
// while answering a request — the hallmark of a static directory — fails these tests.
const readFileMock = vi.hoisted(() => vi.fn());
vi.mock("node:fs/promises", () => ({ readFile: readFileMock }));

import { createApiApp } from "../src/app.js";
import {
  createDashboardHostAssets,
  type DashboardHostAssets,
} from "../src/dashboard-host-assets.js";
import {
  DASHBOARD_HOST_PAGE_PATH,
  DASHBOARD_HOST_SCRIPT_PATH,
  DashboardHostConfigurationError,
} from "../src/dashboard-host-routes.js";
import { DISPLAY_HOST_SCRIPT_PATH } from "../src/module-display-routes.js";
import { createInMemoryDashboardStore } from "./support/in-memory-dashboard-store.js";
import { emptyModuleConfiguration } from "./support/in-memory-module-configuration.js";
import { emptyModuleLifecycle } from "./support/in-memory-module-lifecycle.js";
import { emptyModuleStorage } from "./support/in-memory-module-storage.js";
import { readyHealth } from "./support/ready-health.js";

const trustedOrigin = "https://dashboard.example.test";
const modulePermission = parsePermissionId("dashboard.page.read");

const PAGE_HTML =
  '<!doctype html><html lang="en"><body><div id="ekklesia-host"></div><script src="/assets/ekklesia-dashboard/app.js" type="module"></script></body></html>\n';
const SCRIPT = "export const dashboard = 'built shell';\n";

function sha256Etag(text: string): string {
  return `"${createHash("sha256").update(text).digest("base64url")}"`;
}

const PAGE_ETAG = sha256Etag(PAGE_HTML);
const SCRIPT_ETAG = sha256Etag(SCRIPT);

function fakeRuntime(): EkklesiaIdentityRuntime {
  return {
    handleAuthRequest: vi.fn(),
    resolvePrincipal: vi.fn().mockResolvedValue(ANONYMOUS_PRINCIPAL),
  };
}

function fakeStore(): AuthorizationStore {
  return {
    createGrant: vi.fn(),
    grantPlatformOwner: vi.fn(),
    hasActiveGrant: vi.fn().mockResolvedValue(false),
    isPlatformOwner: vi.fn().mockResolvedValue(false),
    listGrantsForUser: vi.fn().mockResolvedValue({ grants: [] }),
    revokeGrant: vi.fn(),
    revokePlatformOwner: vi.fn(),
  };
}

function fakeModuleServices(): ModuleRuntimeServices {
  return Object.freeze({ database: Object.freeze({}) as unknown as ModuleDatabase });
}

function buildApp(
  options: {
    readonly assets?: DashboardHostAssets;
    readonly moduleRoutes?: readonly RegisteredModuleHttpRoute[];
  } = {},
) {
  const evaluator: AuthorizationEvaluator = {
    authorize: vi.fn().mockResolvedValue({ allowed: true }),
  };
  const runtime = fakeRuntime();
  const app = createApiApp({
    authorization: {
      evaluator,
      registry: createPermissionRegistry([
        { baseline: "public", description: "Test permission.", id: modulePermission },
      ]),
      store: fakeStore(),
    },
    moduleRoutes: options.moduleRoutes ?? Object.freeze([]),
    moduleRealtime: EMPTY_MODULE_REALTIME_REGISTRY,
    moduleServices: fakeModuleServices(),
    moduleUi: createModuleUiPublicationRegistry([]),
    moduleLifecycle: emptyModuleLifecycle(),
    moduleConfiguration: emptyModuleConfiguration(),
    moduleStorage: emptyModuleStorage(),
    dashboard: createInMemoryDashboardStore(),
    dashboardHostAssets: options.assets ?? createDashboardHostAssets(PAGE_HTML, SCRIPT),
    health: readyHealth(),
    runtime,
    trustedOrigins: [trustedOrigin],
  });
  return { app, evaluator, runtime };
}

function expectPageSecurityHeaders(response: Response): void {
  expect(response.headers.get("x-frame-options")).toBe("DENY");
  expect(response.headers.get("content-security-policy")).toBe("frame-ancestors 'none'");
  expect(response.headers.get("referrer-policy")).toBe("no-referrer");
  expect(response.headers.get("x-content-type-options")).toBe("nosniff");
}

async function expectSanitizedNotFound(response: Response, label: string): Promise<void> {
  expect(response.status, label).toBe(404);
  expect(response.headers.get("content-type"), label).toMatch(/^application\/json/u);
  expect(await response.json(), label).toEqual({ code: "NOT_FOUND" });
}

describe("GET / (the Dashboard page)", () => {
  it("serves the exact startup HTML bytes with revalidation, a strong ETag, and the page security headers", async () => {
    const { app } = buildApp();

    const response = await app.request(DASHBOARD_HOST_PAGE_PATH);

    expect(response.status).toBe(200);
    expect(await response.text()).toBe(PAGE_HTML);
    expect(response.headers.get("content-type")).toBe("text/html; charset=utf-8");
    expect(response.headers.get("cache-control")).toBe("no-cache");
    expect(response.headers.get("etag")).toBe(PAGE_ETAG);
    expectPageSecurityHeaders(response);
    // The one CSP directive is the only one: the full policy is a separate decision.
    expect(response.headers.get("content-security-policy")).not.toContain(";");
  });

  it("serves the same page for an emailed-link landing, since the query never selects a file", async () => {
    const { app } = buildApp();

    const response = await app.request("/?ekklesia_auth=reset-password&token=abc123");

    expect(response.status).toBe(200);
    expect(await response.text()).toBe(PAGE_HTML);
    expect(response.headers.get("etag")).toBe(PAGE_ETAG);
  });

  it("answers a matching If-None-Match with an empty 304 that keeps the validator and every page security header", async () => {
    const { app } = buildApp();

    for (const ifNoneMatch of [PAGE_ETAG, `W/${PAGE_ETAG}`, `"other", ${PAGE_ETAG}`, "*"]) {
      const response = await app.request(DASHBOARD_HOST_PAGE_PATH, {
        headers: { "If-None-Match": ifNoneMatch },
      });

      expect(response.status, ifNoneMatch).toBe(304);
      expect(await response.text(), ifNoneMatch).toBe("");
      expect(response.headers.get("etag")).toBe(PAGE_ETAG);
      expect(response.headers.get("cache-control")).toBe("no-cache");
      expectPageSecurityHeaders(response);
    }
  });

  it("serves the full page again when the browser holds a different build's validator", async () => {
    const { app } = buildApp();

    const response = await app.request(DASHBOARD_HOST_PAGE_PATH, {
      headers: { "If-None-Match": sha256Etag("an older build") },
    });

    expect(response.status).toBe(200);
    expect(await response.text()).toBe(PAGE_HTML);
  });

  it("is unauthenticated and outside the API's CORS policy: it resolves no principal and reflects no origin", async () => {
    const { app, evaluator, runtime } = buildApp();

    const response = await app.request(DASHBOARD_HOST_PAGE_PATH, {
      headers: { Cookie: "better-auth.session_token=anything", Origin: trustedOrigin },
    });

    expect(response.status).toBe(200);
    expect(runtime.resolvePrincipal).not.toHaveBeenCalled();
    expect(evaluator.authorize).not.toHaveBeenCalled();
    expect(response.headers.get("access-control-allow-origin")).toBeNull();
    expect(response.headers.get("set-cookie")).toBeNull();
  });
});

describe("GET /assets/ekklesia-dashboard/app.js (the Dashboard script)", () => {
  it("serves the exact startup script bytes as JavaScript with revalidation and a strong ETag", async () => {
    const { app } = buildApp();

    const response = await app.request(DASHBOARD_HOST_SCRIPT_PATH);

    expect(response.status).toBe(200);
    expect(await response.text()).toBe(SCRIPT);
    expect(response.headers.get("content-type")).toBe("text/javascript; charset=utf-8");
    expect(response.headers.get("cache-control")).toBe("no-cache");
    expect(response.headers.get("etag")).toBe(SCRIPT_ETAG);
    expect(response.headers.get("x-content-type-options")).toBe("nosniff");
  });

  it("answers a matching If-None-Match with an empty 304 carrying the script's own validator", async () => {
    const { app } = buildApp();

    const response = await app.request(DASHBOARD_HOST_SCRIPT_PATH, {
      headers: { "If-None-Match": SCRIPT_ETAG },
    });

    expect(response.status).toBe(304);
    expect(await response.text()).toBe("");
    expect(response.headers.get("etag")).toBe(SCRIPT_ETAG);
    expect(response.headers.get("cache-control")).toBe("no-cache");
  });

  it("does not accept the page's validator as the script's", async () => {
    const { app } = buildApp();

    const response = await app.request(DASHBOARD_HOST_SCRIPT_PATH, {
      headers: { "If-None-Match": PAGE_ETAG },
    });

    expect(response.status).toBe(200);
  });
});

describe("Dashboard host boundaries", () => {
  it("serves nothing but its two exact paths, answering every other spelling with the sanitized 404", async () => {
    const { app } = buildApp();

    for (const path of [
      "/index.html",
      "/app.js",
      "/app.js.map",
      "/assets/ekklesia-dashboard/app.js.map",
      "/assets/ekklesia-dashboard/",
      "/assets/ekklesia-dashboard",
      "/assets/ekklesia-dashboard/app.js/",
      "/assets/ekklesia-dashboard/index.html",
      "/assets/",
      "/assets/ekklesia-dashboard/APP.JS",
      "/dashboard",
      "/login",
    ]) {
      await expectSanitizedNotFound(await app.request(path), path);
    }
  });

  it("cannot be walked out of: encoded traversal, separators, and double slashes reach no file", async () => {
    const { app } = buildApp();

    for (const path of [
      "/assets/ekklesia-dashboard/%2e%2e/%2e%2e/package.json",
      "/assets/ekklesia-dashboard/..%2fapp.js.map",
      "/assets/ekklesia-dashboard/%2e%2e%2fapp.js.map",
      "/assets/ekklesia-dashboard/app.js%2f..%2f..%2fpackage.json",
      "/assets/ekklesia-dashboard/..%5c..%5cpackage.json",
      "/%2e%2e/%2e%2e/etc/passwd",
      "/../../etc/passwd",
      "//assets/ekklesia-dashboard/app.js",
      "/assets//ekklesia-dashboard/app.js",
      "/assets/ekklesia-dashboard/app.js%00.map",
    ]) {
      const response = await app.request(path);
      expect(await response.text(), path).not.toContain(SCRIPT);
      expect(response.status, path).toBe(404);
    }
    expect(readFileMock).not.toHaveBeenCalled();
  });

  it("never touches the filesystem while answering, even across every served path", async () => {
    const { app } = buildApp();

    await app.request(DASHBOARD_HOST_PAGE_PATH);
    await app.request(DASHBOARD_HOST_SCRIPT_PATH);
    await app.request("/assets/ekklesia-dashboard/app.js.map");

    expect(readFileMock).not.toHaveBeenCalled();
  });

  it("serves GET (and Hono's implicit HEAD) only; every other method is the ordinary 404", async () => {
    const { app } = buildApp();

    const head = await app.request(DASHBOARD_HOST_PAGE_PATH, { method: "HEAD" });
    expect(head.status).toBe(200);
    expect(head.headers.get("etag")).toBe(PAGE_ETAG);
    expect(await head.text()).toBe("");

    for (const path of [DASHBOARD_HOST_PAGE_PATH, DASHBOARD_HOST_SCRIPT_PATH]) {
      for (const method of ["POST", "PUT", "PATCH", "DELETE"]) {
        await expectSanitizedNotFound(await app.request(path, { method }), `${method} ${path}`);
      }
    }
  });

  it("leaves the API, the display host's namespace, and module routes exactly where they were", async () => {
    const moduleHandler = vi.fn<ModuleRouteHandler>(
      async () => new Response("module", { status: 200 }),
    );
    const { app } = buildApp({
      moduleRoutes: [
        Object.freeze({
          bodyMode: "buffered",
          handler: moduleHandler,
          maxBodyBytes: 1024,
          method: "GET",
          moduleId: "dashboard",
          path: "/",
          permission: modulePermission,
        }) as RegisteredModuleHttpRoute,
      ],
    });

    expect(await (await app.request("/api/v1/principal")).json()).toEqual({ kind: "anonymous" });
    expect(await (await app.request("/api/v1/health/live")).json()).toEqual({ status: "live" });
    expect(await (await app.request("/api/v1/modules/dashboard")).text()).toBe("module");
    await expectSanitizedNotFound(await app.request("/api/v1/unknown"), "/api/v1/unknown");
    // No display is published here, so the display host's script is absent rather than answered
    // by the Dashboard's.
    await expectSanitizedNotFound(
      await app.request(DISPLAY_HOST_SCRIPT_PATH),
      DISPLAY_HOST_SCRIPT_PATH,
    );
    expect(DASHBOARD_HOST_SCRIPT_PATH.startsWith("/assets/ekklesia-display/")).toBe(false);
    expect(await (await app.request(DASHBOARD_HOST_PAGE_PATH)).text()).toBe(PAGE_HTML);
    expect(moduleHandler).toHaveBeenCalledTimes(1);
  });

  it("refuses at composition a snapshot whose validator does not match its bytes, or empty bytes", () => {
    const consistent = createDashboardHostAssets(PAGE_HTML, SCRIPT);

    for (const assets of [
      { ...consistent, html: `${PAGE_HTML}<!-- tampered -->` },
      { ...consistent, scriptEtag: PAGE_ETAG },
      { html: "", htmlEtag: sha256Etag(""), script: SCRIPT, scriptEtag: SCRIPT_ETAG },
    ]) {
      expect(() => buildApp({ assets })).toThrow(DashboardHostConfigurationError);
    }
  });
});