import test from "node:test";
import assert from "node:assert/strict";
import {
  postDate,
  isoDate,
  limit,
  filterTagList,
  readingTime,
  extractHeadings
} from "../src/_filters/index.js";

test("Filters - postDate: formats valid dates", () => {
  assert.equal(postDate("2026-07-20"), "JUL 20, 2026");
  assert.equal(postDate(new Date("2026-12-31T00:00:00Z")), "DEC 31, 2026");
});

test("Filters - postDate: handles adversarial / invalid inputs gracefully", () => {
  assert.equal(postDate(null), "");
  assert.equal(postDate(undefined), "");
  assert.equal(postDate("invalid-date-string"), "");
  assert.equal(postDate(""), "");
});

test("Filters - isoDate: formats ISO strings", () => {
  assert.equal(isoDate("2026-07-20"), "2026-07-20");
  assert.equal(isoDate(new Date("2026-05-15T00:00:00Z")), "2026-05-15");
});

test("Filters - isoDate: handles adversarial / invalid inputs gracefully", () => {
  assert.equal(isoDate(null), "");
  assert.equal(isoDate(undefined), "");
  assert.equal(isoDate("not-a-date"), "");
});

test("Filters - limit: slices arrays correctly", () => {
  assert.deepEqual(limit([1, 2, 3, 4, 5], 3), [1, 2, 3]);
  assert.deepEqual(limit([1, 2], 5), [1, 2]);
});

test("Filters - limit: handles adversarial inputs (negative, 0, non-array)", () => {
  assert.deepEqual(limit([1, 2, 3], 0), []);
  assert.deepEqual(limit([1, 2, 3], -5), []);
  assert.deepEqual(limit(null, 3), []);
  assert.deepEqual(limit("not-an-array", 3), []);
});

test("Filters - filterTagList: removes internal system tags", () => {
  const input = ["firmware", "posts", "security", "all", "nav", "post"];
  assert.deepEqual(filterTagList(input), ["firmware", "security"]);
});

test("Filters - filterTagList: handles adversarial inputs (# prefix, casing, non-string)", () => {
  const input = ["#firmware", "#POSTS", "ALL", "#homelab", 42, null, undefined];
  assert.deepEqual(filterTagList(input), ["#firmware", "#homelab"]);
  assert.deepEqual(filterTagList(null), []);
  assert.deepEqual(filterTagList(undefined), []);
});

test("Filters - readingTime: calculates reading time from word count", () => {
  // 199 words -> 1 min
  const shortText = "word ".repeat(199);
  assert.equal(readingTime(shortText), "1 MIN READ");

  // 201 words -> 2 min
  const mediumText = "word ".repeat(201);
  assert.equal(readingTime(mediumText), "2 MIN READ");

  // 1000 words -> 5 min
  const longText = "word ".repeat(1000);
  assert.equal(readingTime(longText), "5 MIN READ");
});

test("Filters - readingTime: respects explicit frontmatter override", () => {
  assert.equal(readingTime("any text", "15 MIN READ"), "15 MIN READ");
});

test("Filters - readingTime: handles adversarial HTML tags without inflating word count", () => {
  // HTML tags should be stripped before counting words
  const htmlText = "<div><span>word</span> <p>another</p></div>";
  assert.equal(readingTime(htmlText), "1 MIN READ");
  assert.equal(readingTime(""), "1 MIN READ");
  assert.equal(readingTime(null), "1 MIN READ");
});

test("Filters - extractHeadings: extracts H2 and H3 with IDs and titles", () => {
  const html = `
    <h1>Title To Ignore</h1>
    <h2 id="section-1">1.0 First Section</h2>
    <p>Some text</p>
    <h3 id="sub-1">1.1 Sub Section</h3>
    <h4 id="h4-ignore">Ignore H4</h4>
    <h2 id="section-2">2.0 Second Section with <code>code</code> and <span class="tag">span</span></h2>
  `;

  const headings = extractHeadings(html);
  assert.equal(headings.length, 3);
  assert.deepEqual(headings[0], { level: 2, id: "section-1", title: "1.0 First Section" });
  assert.deepEqual(headings[1], { level: 3, id: "sub-1", title: "1.1 Sub Section" });
  assert.deepEqual(headings[2], { level: 2, id: "section-2", title: "2.0 Second Section with code and span" });
});

test("Filters - extractHeadings: handles adversarial HTML inputs gracefully", () => {
  assert.deepEqual(extractHeadings(""), []);
  assert.deepEqual(extractHeadings(null), []);
  assert.deepEqual(extractHeadings(undefined), []);
  assert.deepEqual(extractHeadings("<p>No headings here</p>"), []);
});