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

import { initPasswordValidation, loadPasswordRules } from "./password_validation";

// The checklist is display-only (the server enforces), but it gates the
// submit button and mirrors the ACTIVE server rules — these tests pin the
// rules matrix, the fetch fallback behavior, and the submit gating.

function buildDom(): void {
  document.body.innerHTML = `
    <input id="password" />
    <input id="confirm-password" />
    <input id="username" />
    <input id="email" />
    <div id="password-requirements"></div>
    <button id="register-btn">Register</button>
  `;
}

function setPassword(value: string): void {
  (document.getElementById("password") as HTMLInputElement).value = value;
  (document.getElementById("password") as HTMLInputElement).dispatchEvent(new Event("input"));
}

const submitButton = (): HTMLButtonElement =>
  document.getElementById("register-btn") as HTMLButtonElement;

describe("loadPasswordRules", () => {
  afterEach(() => {
    vi.unstubAllGlobals();
  });

  it("adopts fetched rules", async () => {
    vi.stubGlobal(
      "fetch",
      vi.fn(
        async () =>
          new Response(JSON.stringify({ min_length: 12, require_upper: false }), { status: 200 }),
      ),
    );
    const rules = await loadPasswordRules();
    expect(rules).toEqual({
      min_length: 12,
      require_upper: false,
      require_lower: true,
      require_number: true,
      require_special: true,
    });
  });

  it("falls back to defaults when the endpoint fails", async () => {
    vi.stubGlobal(
      "fetch",
      vi.fn(async () => new Response("nope", { status: 500 })),
    );
    const rules = await loadPasswordRules();
    expect(rules).toEqual({
      min_length: 8,
      require_upper: true,
      require_lower: true,
      require_number: true,
      require_special: true,
    });
  });

  it("falls back to defaults on invalid payloads", async () => {
    vi.stubGlobal(
      "fetch",
      vi.fn(async () => new Response(JSON.stringify({ min_length: -5 }), { status: 200 })),
    );
    const rules = await loadPasswordRules();
    expect(rules.min_length).toBe(8);
  });
});

describe("initPasswordValidation", () => {
  beforeEach(() => {
    // Deterministic rules: fetch failure lands on the historical defaults.
    vi.stubGlobal(
      "fetch",
      vi.fn(async () => new Response("nope", { status: 500 })),
    );
  });

  afterEach(() => {
    vi.unstubAllGlobals();
  });

  // initPasswordValidation debounces through window.setTimeout, which under
  // jsdom is a distinct timer from the faked global — so these tests wait
  // out the real 100ms debounce instead of advancing fake clocks.
  const settleDebounce = (): Promise<void> => new Promise((resolve) => setTimeout(resolve, 150));

  it("generates one checklist row per active rule plus the match row", async () => {
    buildDom();
    await loadPasswordRules();
    initPasswordValidation({});

    const rows = document.querySelectorAll("#password-requirements li");
    expect(rows.length).toBe(6); // length, upper, lower, number, special, match
  });

  it("starts with the submit button disabled for an empty password", async () => {
    buildDom();
    await loadPasswordRules();
    initPasswordValidation({});

    expect(submitButton().disabled).toBe(true);
  });

  it("enables submit when all requirements pass", async () => {
    buildDom();
    await loadPasswordRules();
    initPasswordValidation({});

    setPassword("Abcdef1!");
    (document.getElementById("confirm-password") as HTMLInputElement).value = "Abcdef1!";
    (document.getElementById("confirm-password") as HTMLInputElement).dispatchEvent(
      new Event("input"),
    );
    (document.getElementById("username") as HTMLInputElement).value = "user";
    (document.getElementById("username") as HTMLInputElement).dispatchEvent(new Event("input"));
    (document.getElementById("email") as HTMLInputElement).value = "user@example.com";
    (document.getElementById("email") as HTMLInputElement).dispatchEvent(new Event("input"));
    await settleDebounce();

    expect(submitButton().disabled).toBe(false);
  });

  it("keeps submit disabled on a confirmation mismatch", async () => {
    buildDom();
    await loadPasswordRules();
    initPasswordValidation({});

    setPassword("Abcdef1!");
    (document.getElementById("confirm-password") as HTMLInputElement).value = "Different1!";
    (document.getElementById("confirm-password") as HTMLInputElement).dispatchEvent(
      new Event("input"),
    );
    await settleDebounce();

    expect(submitButton().disabled).toBe(true);
  });

  it("does not require username/email when requireUsernameEmail is false", async () => {
    buildDom();
    await loadPasswordRules();
    initPasswordValidation({ requireUsernameEmail: false });

    setPassword("Abcdef1!");
    (document.getElementById("confirm-password") as HTMLInputElement).value = "Abcdef1!";
    (document.getElementById("confirm-password") as HTMLInputElement).dispatchEvent(
      new Event("input"),
    );
    await settleDebounce();

    expect(submitButton().disabled).toBe(false);
  });
});