import { describe, expect, test } from "bun:test";
import { extractHeadings, makeAnchor } from "../../src/lib/headings.ts";

describe("makeAnchor", () => {
	test("slugifies plain text", () => {
		const seen = new Map<string, number>();
		expect(makeAnchor("Hello World", seen)).toBe("hello-world");
	});

	test("suffixes repeats with -1, -2, ...", () => {
		const seen = new Map<string, number>();
		expect(makeAnchor("Intro", seen)).toBe("intro");
		expect(makeAnchor("Intro", seen)).toBe("intro-1");
		expect(makeAnchor("Intro", seen)).toBe("intro-2");
	});

	test("returns empty for text that slugifies to empty", () => {
		const seen = new Map<string, number>();
		expect(makeAnchor("   ", seen)).toBe("");
	});
});

describe("extractHeadings", () => {
	test("returns empty for no headings", () => {
		expect(extractHeadings("just paragraphs\n\nmore text")).toEqual([]);
		expect(extractHeadings("")).toEqual([]);
	});

	test("captures level, text, and anchor", () => {
		const md = "# One\n\n## Two\n\n### Three";
		expect(extractHeadings(md)).toEqual([
			{ text: "One", level: 1, anchor: "one" },
			{ text: "Two", level: 2, anchor: "two" },
			{ text: "Three", level: 3, anchor: "three" },
		]);
	});

	test("strips trailing ATX closing hashes", () => {
		expect(extractHeadings("# Title ##")[0]?.text).toBe("Title");
	});

	test("requires a space after the hashes", () => {
		expect(extractHeadings("#notaheading")).toEqual([]);
	});

	test("ignores headings inside fenced code blocks", () => {
		const md = "# Real\n\n```\n# Fake\n```\n\n## AlsoReal";
		const out = extractHeadings(md);
		expect(out.map((h) => h.text)).toEqual(["Real", "AlsoReal"]);
	});

	test("handles tilde fences", () => {
		const md = "~~~\n# Fake\n~~~\n# Real";
		expect(extractHeadings(md).map((h) => h.text)).toEqual(["Real"]);
	});

	test("ignores YAML comments in frontmatter", () => {
		const md = "---\n# not a heading\ntitle: x\n---\n\n# Real";
		expect(extractHeadings(md).map((h) => h.text)).toEqual(["Real"]);
	});

	test("disambiguates duplicate anchors", () => {
		const md = "# Intro\n\n## Intro\n\n### Intro";
		expect(extractHeadings(md).map((h) => h.anchor)).toEqual([
			"intro",
			"intro-1",
			"intro-2",
		]);
	});
});