import assert from 'node:assert/strict';
import { test } from 'node:test';
import {
  findCaption,
  findMetaMedia,
  mediaFromMetaNode,
  mediaFromOpenGraph,
} from '../src/platforms/meta-media.ts';
import { fixture } from './helpers.ts';

const REFERER = 'https://www.threads.com/';

test('a Threads image post normalizes to one image with referrer headers', () => {
  const node = fixture<Parameters<typeof mediaFromMetaNode>[0]>('threads/image.json');
  const media = mediaFromMetaNode(node, REFERER);
  assert.equal(media.length, 1);
  assert.equal(media[0]?.kind, 'image');
  assert.equal(media[0]?.fetchHeaders?.['Referer'], REFERER);
});

test('a second real Threads post normalizes the same way', () => {
  // Two captures, so the walk is not quietly fitted to one payload.
  const media = mediaFromMetaNode(fixture('threads/second.json'), REFERER);
  assert.equal(media.length, 1);
  assert.equal(media[0]?.kind, 'image');
});

test('the largest candidate wins', () => {
  const media = mediaFromMetaNode(
    {
      image_versions2: {
        candidates: [
          { url: 'https://cdn/small.jpg', width: 320, height: 320 },
          { url: 'https://cdn/large.jpg', width: 1440, height: 1440 },
        ],
      },
    },
    REFERER,
  );
  assert.equal(media[0]?.url, 'https://cdn/large.jpg');
});

test('a carousel flattens to its children', () => {
  const media = mediaFromMetaNode(
    {
      carousel_media: [
        { image_versions2: { candidates: [{ url: 'https://cdn/1.jpg', width: 100 }] } },
        {
          image_versions2: { candidates: [{ url: 'https://cdn/poster.jpg', width: 100 }] },
          video_versions: [{ url: 'https://cdn/2.mp4', width: 720 }],
        },
      ],
    },
    REFERER,
  );
  assert.deepEqual(media.map((m) => m.kind), ['image', 'video']);
});

test('the media node is found however deeply it is buried', () => {
  const real = { image_versions2: { candidates: [{ url: 'https://cdn/i.jpg', width: 100 }] }, tag: 'me' };
  const found = findMetaMedia({ a: [{ b: { c: real } }] });
  assert.equal((found as { tag?: string })?.tag, 'me');
});

test('a stub node with no candidates is not mistaken for the post', () => {
  // These payloads are full of empty placeholders; picking one used to make
  // a real post look like it had no media at all.
  assert.equal(findMetaMedia({ image_versions2: { candidates: [] }, carousel_media: null }), undefined);
});

test('the caption is found the same way, and an empty one is not a caption', () => {
  assert.equal(findCaption({ x: { caption: { text: 'hello' } } }), 'hello');
  assert.equal(findCaption({ x: { caption: { text: '' } } }), undefined);
  assert.equal(findCaption({ x: { caption: null } }), undefined);
});

test('the link preview stands in for the post when there is nothing better', () => {
  const image = mediaFromOpenGraph({ 'og:image': 'https://image.example/a.jpg' }, REFERER);
  assert.deepEqual(image.map((item) => [item.kind, item.url]), [['image', 'https://image.example/a.jpg']]);
  assert.equal(image[0]?.fetchHeaders?.['Referer'], REFERER);
});

test('a preview naming a video is a video, and its image is the poster', () => {
  const media = mediaFromOpenGraph(
    { 'og:video': 'https://video.example/a.mp4', 'og:image': 'https://image.example/a.jpg' },
    REFERER,
  );
  assert.equal(media[0]?.kind, 'video');
  assert.equal(media[0]?.kind === 'video' ? media[0].poster?.url : undefined, 'https://image.example/a.jpg');
});

test('a page with no preview at all yields no media rather than an empty asset', () => {
  assert.deepEqual(mediaFromOpenGraph({ 'og:title': 'just a title' }, REFERER), []);
});