import { describe, expect, test } from "bun:test";
import { extractHints, extractSection, slugify } from "../src/markdown";

describe("slugify", () => {
  test("follows GitHub's algorithm", () => {
    expect(slugify("Exercise 3.1 — `move`")).toBe("exercise-31--move");
    expect(slugify("Why this module")).toBe("why-this-module");
    expect(slugify("Rules as functions `State → State`")).toBe("rules-as-functions-state--state");
    expect(slugify("**Bold** and [a link](http://x.y)")).toBe("bold-and-a-link");
  });
});

const sample = `# Top

intro

## First

one

### Middle

middle body

\`\`\`sh
# not a heading
\`\`\`

#### Deeper

deep body

### Sibling

sibling body

## Last

end
`;

describe("extractSection", () => {
  test("returns only the middle section, including deeper headings", () => {
    const s = extractSection(sample, "middle");
    expect(s).not.toBeNull();
    expect(s!.startsWith("### Middle")).toBe(true);
    expect(s).toContain("# not a heading");
    expect(s).toContain("deep body");
    expect(s).not.toContain("sibling body");
    expect(s).not.toContain("one");
  });
  test("returns null for an unknown anchor", () => {
    expect(extractSection(sample, "nope")).toBeNull();
  });
  test("a section runs to the end of file when nothing follows", () => {
    expect(extractSection(sample, "last")).toBe("## Last\n\nend");
  });
});

describe("extractHints", () => {
  const md = `## Hints

<details><summary>Exercise 3.1 (move) — nudge</summary>

Think about direction.

</details>

<details><summary>Exercise 3.1 (move) — stronger hint</summary>

Add the delta.

</details>

<details><summary>Exercise 3.2 (inBounds) — nudge</summary>

Other.

</details>
`;
  test("returns matching blocks in order with trimmed labels", () => {
    const h = extractHints(md, "Exercise 3.1 (move)");
    expect(h.map((x) => x.label)).toEqual(["nudge", "stronger hint"]);
    expect(h[0]!.body).toBe("Think about direction.");
  });
  test("returns [] when nothing matches", () => {
    expect(extractHints(md, "Exercise 9.9")).toEqual([]);
  });
});