import { render, screen, waitFor, within } from "@testing-library/react";
import userEvent from "@testing-library/user-event";
import { describe, expect, it, vi } from "vitest";
import { CandidateLab } from "../../src/components/CandidateLab";
import { createEmptyPuzzle, normalizePuzzle } from "../../src/domain";
import type { CandidateOverlay } from "../../src/helpers";

function mask(...values: number[]): number {
  return values.reduce((result, value) => result | (1 << (value - 1)), 0);
}

const puzzle = normalizePuzzle(createEmptyPuzzle(4));

describe("candidate lab", () => {
  it("inspects selected cells, filters digits and focuses a link overlay", async () => {
    const user = userEvent.setup();
    const overlays: (CandidateOverlay | undefined)[] = [];
    const candidateMasks = new Array<number>(16).fill(0);
    candidateMasks[0] = mask(1, 2);
    candidateMasks[1] = mask(1, 2);

    render(
      <CandidateLab
        puzzle={puzzle}
        values={puzzle.givens}
        candidateMasks={candidateMasks}
        selectedCells={[0]}
        onOverlayChange={(overlay) => overlays.push(overlay)}
      />,
    );

    const selected = screen.getByRole("heading", {
      name: "Selected cells",
    }).parentElement!;
    expect(within(selected).getByText("r1c1")).toBeInTheDocument();
    expect(within(selected).getByText("1 2")).toBeInTheDocument();

    await user.click(
      screen.getByRole("button", { name: "Filter candidate 1" }),
    );
    await waitFor(() => {
      expect(overlays.at(-1)?.activeValues).toEqual([1]);
      expect(overlays.at(-1)?.candidateCells).toEqual([0, 1]);
    });

    const link = screen.getByRole("button", { name: /r1c1\(1\).*r1c2\(1\)/u });
    await user.click(link);
    await waitFor(() => expect(overlays.at(-1)?.links).toHaveLength(1));
    expect(link).toHaveAttribute("aria-pressed", "true");
    await user.click(screen.getByRole("button", { name: "Show all" }));
    expect(link).toHaveAttribute("aria-pressed", "false");
  });

  it("reveals weak links on demand within a chosen house", async () => {
    const user = userEvent.setup();
    const candidateMasks = new Array<number>(16).fill(0);
    candidateMasks[0] = mask(3);
    candidateMasks[1] = mask(3);
    candidateMasks[2] = mask(3);

    render(
      <CandidateLab
        puzzle={puzzle}
        values={puzzle.givens}
        candidateMasks={candidateMasks}
        selectedCells={[0]}
      />,
    );

    await user.selectOptions(
      screen.getByLabelText("Candidate house scope"),
      "unit:0",
    );
    await user.click(
      screen.getByRole("button", { name: "Filter candidate 3" }),
    );
    expect(screen.getByText(/No links match this scope/u)).toBeInTheDocument();
    await user.click(screen.getByRole("checkbox", { name: "Weak links" }));

    expect(
      screen.getAllByRole("button", { name: /weak · Row 1/u }),
    ).toHaveLength(3);
  });

  it("clears the board overlay when it unmounts", async () => {
    const onOverlayChange = vi.fn();
    const { unmount } = render(
      <CandidateLab
        puzzle={puzzle}
        values={puzzle.givens}
        candidateMasks={new Array<number>(16).fill(0)}
        selectedCells={[0]}
        onOverlayChange={onOverlayChange}
      />,
    );
    await waitFor(() => expect(onOverlayChange).toHaveBeenCalled());
    unmount();
    expect(onOverlayChange).toHaveBeenLastCalledWith(undefined);
  });
});