import { readFileSync } from "node:fs";
import { join } from "node:path";
import { describe, expect, it } from "vitest";
import { render } from "@testing-library/react";
import {
  Drawer,
  EmptyState,
  ErrorState,
  Modal,
  Stat,
  Table,
  Timeline,
  ToastStack,
  UsageBar,
  type TableColumn,
} from "@agy/ui";

/**
 * The motion contract.
 *
 * These assert that animated surfaces actually carry an animation class, and
 * that every class they carry has keyframes behind it. A `className` with no
 * matching `@keyframes` is a silent no-op — nobody notices until the app feels
 * dead — so the vocabulary and the surfaces are checked together.
 *
 * Timing and feel are deliberately not asserted here: they are a design
 * decision, not behaviour, and a test that pins them down only fights the next
 * tuning pass.
 */

interface Row {
  id: string;
  name: string;
}

const columns: Array<TableColumn<Row>> = [
  { key: "name", header: "name", render: (row) => row.name },
];

const ROWS: Row[] = [
  { id: "1", name: "one" },
  { id: "2", name: "two" },
];

describe("motion vocabulary", () => {
  const globals = readFileSync(join(process.cwd(), "src/app/globals.css"), "utf-8");

  it("declares every keyframe the utilities reference", () => {
    for (const name of [
      "anim-fade-in",
      "anim-rise",
      "anim-scale-in",
      "anim-slide-up",
      "anim-drawer-in-start",
      "anim-drawer-in-start-rtl",
    ]) {
      expect(globals).toContain(`@keyframes ${name}`);
    }
  });

  it("keeps each duration behind a custom property so one override retunes the app", () => {
    for (const token of ["--anim-fast", "--anim-base", "--anim-slow", "--anim-ease"]) {
      expect(globals).toContain(token);
    }
    // Every utility must read those tokens, not a hard-coded value.
    expect(globals).not.toMatch(/animation:[^;]*\b\d+ms\b/);
  });

  it("honours prefers-reduced-motion", () => {
    expect(globals).toContain("@media (prefers-reduced-motion: reduce)");
    // Durations collapse, but the end state must still be reachable — so the
    // animation is kept at a near-zero duration rather than being removed.
    expect(globals).toMatch(/animation-duration:\s*0\.01ms !important/);
    expect(globals).toMatch(/transition-duration:\s*0\.01ms !important/);
  });

  it("never animates a property that is not also stated by the end state", () => {
    // `both` fill mode is what makes an animation land on its final frame even
    // when the element is removed mid-flight or never re-rendered.
    for (const utility of ["anim-fade-in", "anim-rise", "anim-scale-in", "anim-slide-up"]) {
      expect(globals).toMatch(
        new RegExp(`\\.${utility}\\s*\\{[^}]*both\\s*;`),
      );
    }
  });
});

describe("animated surfaces", () => {
  it("scales the modal panel in and fades its backdrop", () => {
    const { container } = render(<Modal open title="title" onClose={() => undefined} />);
    const panel = container.querySelector(".anim-scale-in");
    expect(panel).not.toBeNull();
    // The backdrop is the panel's parent: it owns the dialog role and fades.
    const backdrop = panel?.parentElement;
    expect(backdrop).toHaveAttribute("role", "dialog");
    expect(backdrop?.className).toContain("anim-fade-in");
  });

  it("slides the drawer in from its edge", () => {
    const { container } = render(
      <Drawer open title="details" onClose={() => undefined}>
        <p>body</p>
      </Drawer>,
    );
    expect(container.querySelector("aside.anim-drawer-start")).not.toBeNull();
  });

  it("slides each toast up", () => {
    const { container } = render(
      <ToastStack toasts={[{ id: "t1", title: "saved" }]} onDismiss={() => undefined} />,
    );
    expect(container.querySelector(".anim-slide-up")).not.toBeNull();
  });

  it("staggers table rows", () => {
    const { container } = render(
      <Table columns={columns} rows={ROWS} rowKey={(row) => row.id} />,
    );
    expect(container.querySelector("tbody.anim-stagger")).not.toBeNull();
  });

  it("rises the summary and async states", () => {
    const states = [
      render(<EmptyState title="nothing here" />),
      render(<ErrorState title="failed" />),
      render(<Stat label="credit" value="0" />),
    ];
    for (const { container } of states) {
      expect(container.querySelector(".anim-rise")).not.toBeNull();
    }
  });

  it("staggers the timeline and transitions the usage fill", () => {
    const timeline = render(<Timeline items={[{ id: "a", title: "event" }]} />);
    expect(timeline.container.querySelector("ol.anim-stagger")).not.toBeNull();

    const bar = render(<UsageBar used={40} total={100} />);
    expect(bar.container.querySelector(".transition-\\[width\\]")).not.toBeNull();
  });
});