import { MODULE_UI_ABI_VERSION, type ModuleUiHostContext } from "@ekklesia/module-ui-sdk";
import { act } from "react";
import { createRoot, type Root } from "react-dom/client";
import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
import { HostApp } from "../src/browser/HostApp.js";
import { createMemoryHostHistory, type MemoryHostHistory } from "../src/browser/host-history.js";
import type { EkklesiaHostConfig } from "../src/host-protocol.js";
import { isolatedText } from "./support/isolated-dom.js";

declare global {
  // eslint-disable-next-line no-var
  var IS_REACT_ACT_ENVIRONMENT: boolean | undefined;
}

/**
 * The Dashboard's URL is the source of truth for which page is open (ADR 0057). Every test drives
 * the real shell through an in-memory history, so it can assert on the exact entries a person's
 * Back and Forward buttons would walk.
 */

const apiBaseUrl = "https://ekklesia.example.test";

let container: HTMLDivElement;
let root: Root;
let consoleError: ReturnType<typeof vi.spyOn>;

beforeEach(() => {
  globalThis.IS_REACT_ACT_ENVIRONMENT = true;
  container = document.createElement("div");
  document.body.append(container);
  root = createRoot(container);
  consoleError = vi.spyOn(console, "error").mockImplementation(() => undefined);
});

afterEach(async () => {
  await act(async () => {
    root.unmount();
  });
  container.remove();
  consoleError.mockRestore();
});

function entry(id: string, name: string, version = "0.1.0") {
  return {
    module: {
      api: { baseUrl: `/api/v1/modules/${id}` },
      contributions: [],
      display: null,
      id,
      permissions: [],
      realtime: { baseUrl: `/api/v1/module-realtime/${id}` },
      ui: { url: `/api/v1/module-ui/${id}/${version}` },
      version,
    },
    name,
  };
}

const NAVIGATION = {
  groups: [{ id: "media", label: "Media", modules: [entry("signage", "Signage")], order: 10 }],
  ungrouped: [entry("calendar", "Calendar", "2.0.0")],
};

function platform(options: { authenticated?: boolean } = {}) {
  let authenticated = options.authenticated ?? true;
  const fetchImplementation = vi.fn(async (input: RequestInfo | URL, init?: RequestInit) => {
    const url = String(input);
    if (url.endsWith("/api/auth/sign-in/email")) {
      void init;
      authenticated = true;
      return Response.json({ ok: true });
    }
    if (url.endsWith("/api/v1/principal")) {
      return Response.json(
        authenticated ? { kind: "authenticated", userId: "user-1" } : { kind: "anonymous" },
      );
    }
    if (url.endsWith("/api/v1/dashboard/navigation")) {
      return authenticated
        ? Response.json(NAVIGATION)
        : Response.json({ code: "AUTHORIZATION_DENIED" }, { status: 403 });
    }
    return Response.json({ code: "NOT_FOUND" }, { status: 404 });
  }) as unknown as typeof fetch;
  return fetchImplementation;
}

function artifactFor(url: string) {
  const id = url.includes("/calendar/") ? "calendar" : "signage";
  return {
    default: {
      abi: MODULE_UI_ABI_VERSION,
      id,
      mount(element: Element, context: ModuleUiHostContext) {
        element.textContent = `${context.moduleId} mounted`;
        return () => {
          element.textContent = "";
        };
      },
      version: id === "calendar" ? "2.0.0" : "0.1.0",
    },
  };
}

interface Rendered {
  readonly history: MemoryHostHistory;
  readonly imported: string[];
  readonly titles: string[];
}

async function render(
  path: string,
  options: { authenticated?: boolean; history?: MemoryHostHistory } = {},
): Promise<Rendered> {
  const history = options.history ?? createMemoryHostHistory(path);
  const imported: string[] = [];
  const titles: string[] = [];
  const config: EkklesiaHostConfig = { apiBaseUrl, fetch: platform(options) };
  await act(async () => {
    root.render(
      <HostApp
        config={config}
        history={history}
        importModule={async (url) => {
          imported.push(url);
          return artifactFor(url);
        }}
        setDocumentTitle={(title) => titles.push(title)}
      />,
    );
  });
  return { history, imported, titles };
}

function query(testId: string): HTMLElement | null {
  return container.querySelector<HTMLElement>(`[data-testid="${testId}"]`);
}

async function click(element: Element | null, init: MouseEventInit = {}): Promise<MouseEvent> {
  if (!element) {
    throw new Error("missing element");
  }
  const event = new MouseEvent("click", { bubbles: true, button: 0, cancelable: true, ...init });
  await act(async () => {
    element.dispatchEvent(event);
  });
  return event;
}

async function go(history: MemoryHostHistory, delta: number): Promise<void> {
  await act(async () => {
    history.go(delta);
  });
}

describe("the Dashboard opens on the page its URL names", () => {
  it("lands on the Overview at the root, and mounts no module", async () => {
    const { imported, titles } = await render("/");

    expect(query("host-overview")).not.toBeNull();
    expect(query("host-overview")?.querySelector("h1")?.textContent).toBe("Overview");
    expect(query("module-container")).toBeNull();
    expect(imported).toEqual([]);
    expect(query("select-overview")?.getAttribute("aria-current")).toBe("page");
    expect(titles.at(-1)).toBe("Overview");
  });

  it("opens a module's page directly from its deep link — what a refresh or a bookmark does", async () => {
    const { imported, titles } = await render("/modules/calendar");

    expect(imported).toEqual([`${apiBaseUrl}/api/v1/module-ui/calendar/2.0.0`]);
    expect(isolatedText(query("module-container"))).toBe("calendar mounted");
    expect(query("select-calendar")?.getAttribute("aria-current")).toBe("page");
    expect(query("select-overview")?.getAttribute("aria-current")).toBeNull();
    expect(query("host-overview")).toBeNull();
    expect(titles.at(-1)).toBe("Calendar");
  });

  it("opens a module from inside a group exactly as one outside it", async () => {
    const { imported } = await render("/modules/signage");

    expect(imported).toEqual([`${apiBaseUrl}/api/v1/module-ui/signage/0.1.0`]);
    expect(query("select-signage")?.getAttribute("aria-current")).toBe("page");
  });

  it("says a module page is unavailable when no navigable module has that id, and loads nothing", async () => {
    const { imported, titles } = await render("/modules/disabled-module");

    expect(query("host-module-unavailable")).not.toBeNull();
    expect(query("module-container")).toBeNull();
    expect(imported).toEqual([]);
    // The address is never echoed back into the page.
    expect(container.textContent).not.toContain("disabled-module");
    expect(titles.at(-1)).toBe("This page isn’t available");
    expect(query("host-go-to-overview")?.getAttribute("href")).toBe("/");
  });

  it("shows a host-owned not-found page for an address inside the Dashboard it does not know", async () => {
    for (const path of ["/settings/displays", "/modules/calendar/events", "/account"]) {
      await act(async () => {
        root.unmount();
      });
      root = createRoot(container);
      const { imported, titles } = await render(path);

      expect(query("host-not-found"), path).not.toBeNull();
      expect(imported, path).toEqual([]);
      expect(titles.at(-1), path).toBe("Page not found");
      // Nothing in the navigation claims to be the open page.
      expect(container.querySelector('[aria-current="page"]'), path).toBeNull();
    }
  });

  it("corrects a trailing slash to the canonical address in place, adding no history entry", async () => {
    const { history, imported } = await render("/modules/calendar/");

    expect(history.entries).toEqual(["/modules/calendar"]);
    expect(imported).toHaveLength(1);
  });

  it("opens the deep link it was given once the person signs in, with no redirect", async () => {
    const history = createMemoryHostHistory("/modules/calendar");
    const { imported } = await render("/modules/calendar", { authenticated: false, history });
    expect(query("host-login")).not.toBeNull();

    const email = query("login-email") as HTMLInputElement;
    const password = query("login-password") as HTMLInputElement;
    const setter = Object.getOwnPropertyDescriptor(HTMLInputElement.prototype, "value")?.set;
    await act(async () => {
      setter?.call(email, "owner@example.test");
      email.dispatchEvent(new Event("input", { bubbles: true }));
      setter?.call(password, "correct password");
      password.dispatchEvent(new Event("input", { bubbles: true }));
    });
    await act(async () => {
      query("host-login")
        ?.querySelector("form")
        ?.dispatchEvent(new Event("submit", { bubbles: true, cancelable: true }));
    });

    expect(isolatedText(query("module-container"))).toBe("calendar mounted");
    expect(imported).toEqual([`${apiBaseUrl}/api/v1/module-ui/calendar/2.0.0`]);
    expect(history.entries).toEqual(["/modules/calendar"]);
  });
});

describe("moving between pages", () => {
  it("renders navigation as real links to canonical addresses", async () => {
    await render("/");

    for (const [testId, href] of [
      ["select-overview", "/"],
      ["select-signage", "/modules/signage"],
      ["select-calendar", "/modules/calendar"],
    ] as const) {
      const link = query(testId);
      expect(link?.tagName, testId).toBe("A");
      expect(link?.getAttribute("href"), testId).toBe(href);
    }
    expect(container.querySelector('nav[aria-label="Dashboard"]')).not.toBeNull();
  });

  it("opens a page in place on an ordinary click, adding one history entry", async () => {
    const { history, imported } = await render("/");

    const event = await click(query("select-calendar"));

    expect(event.defaultPrevented).toBe(true);
    expect(history.entries).toEqual(["/", "/modules/calendar"]);
    expect(imported).toEqual([`${apiBaseUrl}/api/v1/module-ui/calendar/2.0.0`]);
    expect(isolatedText(query("module-container"))).toBe("calendar mounted");
  });

  it("leaves a modified or middle click to the browser, so a page can open in a new tab", async () => {
    const { history } = await render("/");

    for (const init of [
      { ctrlKey: true },
      { metaKey: true },
      { shiftKey: true },
      { altKey: true },
      { button: 1 },
    ]) {
      const event = await click(query("select-calendar"), init);
      expect(event.defaultPrevented, JSON.stringify(init)).toBe(false);
    }
    expect(history.entries).toEqual(["/"]);
  });

  it("adds no entry when the open page's own link is clicked again", async () => {
    const { history } = await render("/modules/calendar");

    await click(query("select-calendar"));

    expect(history.entries).toEqual(["/modules/calendar"]);
  });

  it("walks Back and Forward through exactly the pages that were open", async () => {
    const { history, imported } = await render("/");
    await click(query("select-signage"));
    await click(query("select-calendar"));

    await go(history, -1);
    expect(isolatedText(query("module-container"))).toBe("signage mounted");
    expect(query("select-signage")?.getAttribute("aria-current")).toBe("page");

    await go(history, -1);
    expect(query("host-overview")).not.toBeNull();
    expect(query("module-container")).toBeNull();

    await go(history, 1);
    expect(isolatedText(query("module-container"))).toBe("signage mounted");
    expect(imported).toEqual([
      `${apiBaseUrl}/api/v1/module-ui/signage/0.1.0`,
      `${apiBaseUrl}/api/v1/module-ui/calendar/2.0.0`,
      `${apiBaseUrl}/api/v1/module-ui/signage/0.1.0`,
      `${apiBaseUrl}/api/v1/module-ui/signage/0.1.0`,
    ]);
  });

  it("returns to the Overview from an unavailable page through its own link", async () => {
    const { history } = await render("/modules/missing");

    await click(query("host-go-to-overview"));

    expect(history.entries).toEqual(["/modules/missing", "/"]);
    expect(query("host-overview")).not.toBeNull();
  });

  it("moves focus to the new page's content after a page change, but not on first load", async () => {
    await render("/");
    const main = container.querySelector("main");
    expect(main?.getAttribute("tabindex")).toBe("-1");
    expect(document.activeElement).not.toBe(main);

    await click(query("select-calendar"));

    expect(document.activeElement).toBe(main);
    expect(main?.getAttribute("aria-label")).toBe("Calendar");
  });

  it("names the browser tab after each page as it opens", async () => {
    const { titles } = await render("/");
    await click(query("select-signage"));
    await click(query("select-overview"));

    expect(titles).toEqual(["Overview", "Signage", "Overview"]);
  });
});