import test from "node:test";
import assert from "node:assert/strict";

import { extractVersionNotes } from "../lib/extract-version-notes.mjs";

const changelog = `# Fusion changelog

## 1.2.0

### @runfusion/fusion

#### Patch Changes

- Added release integration.

## 1.1.0

### @runfusion/fusion

#### Patch Changes

- Fixed parser bug.

## 1.0.0

### @runfusion/fusion

#### Patch Changes

- Initial release.
`;

test("extracts correct section for known version", () => {
  const notes = extractVersionNotes(changelog, "1.1.0");
  assert.match(notes, /Fixed parser bug\./);
  assert.doesNotMatch(notes, /Added release integration\./);
});

test("returns full multiline body including sub-headings", () => {
  const notes = extractVersionNotes(changelog, "1.2.0");
  assert.match(notes, /^### @runfusion\/fusion/m);
  assert.match(notes, /^#### Patch Changes/m);
  assert.match(notes, /- Added release integration\./);
});

test("returns fallback when version not found", () => {
  const notes = extractVersionNotes(changelog, "9.9.9");
  assert.equal(notes, "Release v9.9.9");
});

test("returns fallback when changelog content is empty", () => {
  const notes = extractVersionNotes("", "1.2.0");
  assert.equal(notes, "Release v1.2.0");
});

test("handles version as last section with no trailing heading", () => {
  const notes = extractVersionNotes(changelog, "1.0.0");
  assert.match(notes, /Initial release\./);
});

test("handles single-version changelog", () => {
  const single = `# Changelog\n\n## 2.0.0\n\n### pkg\n\n#### Patch Changes\n\n- Solo entry.\n`;
  const notes = extractVersionNotes(single, "2.0.0");
  assert.match(notes, /Solo entry\./);
});

test("does not bleed into adjacent version sections", () => {
  const notes = extractVersionNotes(changelog, "1.1.0");
  assert.doesNotMatch(notes, /Initial release\./);
  assert.doesNotMatch(notes, /Added release integration\./);
});