// Reference detail: media block + summary + metadata + tag attach/detach + linked-from.
import { api } from '../api.js';
import { el, mount, clear, safeHref } from '../dom.js';

function mediaBlock(ref) {
  if (ref.kind === 'image' && (ref.source_url || ref.blob_path)) {
    const src = safeHref(ref.source_url || ref.blob_path);
    if (src === '#') return el('span', { class: 'muted' }, '(image url rejected by scheme check)');
    return el('img', { src, style: { maxWidth: '100%', borderRadius: '4px', border: '1px solid var(--border)' } });
  }
  if (ref.kind === 'video' && ref.source_url) {
    const yt = ref.source_url.match(/(?:youtube\.com\/watch\?v=|youtu\.be\/)([\w-]{6,})/);
    if (yt) {
      return el('iframe', {
        src: 'https://www.youtube-nocookie.com/embed/' + yt[1],
        style: { width: '100%', aspectRatio: '16/9', border: 'none', borderRadius: '4px' },
        allowfullscreen: true,
        referrerpolicy: 'no-referrer'
      });
    }
    return el('a', { href: safeHref(ref.source_url), target: '_blank', rel: 'noopener noreferrer' }, ref.source_url);
  }
  if (ref.source_url) {
    return el('a', { href: safeHref(ref.source_url), target: '_blank', rel: 'noopener noreferrer' }, ref.source_url);
  }
  return el('span', { class: 'muted' }, '(no source)');
}

function metadataTable(ref) {
  const rows = [
    ['kind', ref.kind],
    ['source_url', ref.source_url],
    ['captured_at', ref.captured_at],
    ['status', ref.status],
    ['source_kind', ref.source_kind],
    ['external_id', ref.external_id]
  ].filter(([, v]) => v);
  return el('table', { style: { width: '100%', borderCollapse: 'collapse', fontSize: '12px' } },
    el('tbody', {}, rows.map(([k, v]) =>
      el('tr', {},
        el('td', { class: 'muted', style: { padding: '4px 8px', verticalAlign: 'top', width: '120px' } }, k),
        el('td', { style: { padding: '4px 8px', wordBreak: 'break-all' } }, String(v))
      )
    ))
  );
}

async function renderTagsCard(card, ref) {
  const list = card.querySelector('.tags-list');
  clear(list);
  let tags = [];
  try { tags = await api.get(`/api/ref/${ref.id}/tags`); }
  catch { /* leave empty */ }
  for (const t of tags) {
    list.appendChild(el('span', {
      class: 'status idle',
      style: { marginRight: '6px', cursor: 'pointer' },
      title: 'click to detach',
      onclick: async () => {
        try { await api.del(`/api/ref/${ref.id}/tags/${t.id}`); renderTagsCard(card, ref); }
        catch (e) { alert('detach failed: ' + e.message); }
      }
    }, t.name));
  }
}

async function tagAttachUI(ref, onChange) {
  const input = el('input', { type: 'text', placeholder: 'Tag name', style: { flex: 1 } });
  async function attach() {
    const name = input.value.trim();
    if (!name) return;
    try {
      const tag = await api.post('/api/tags', { name });
      await api.post(`/api/ref/${ref.id}/tags`, { tag_id: tag.id });
      input.value = '';
      onChange();
    } catch (e) { alert('attach failed: ' + e.message); }
  }
  input.addEventListener('keydown', (e) => { if (e.key === 'Enter') attach(); });
  return el('div', { style: { display: 'flex', gap: '8px', marginTop: '8px' } },
    input, el('button', { class: 'primary', onclick: attach }, 'Attach')
  );
}

export async function render(main, ctx) {
  const id = ctx.params.id;
  mount(main, el('p', { class: 'view-sub muted' }, 'Loading …'));

  let ref;
  try { ref = await api.get('/api/refs/' + id); }
  catch (e) {
    mount(main,
      el('h1', { class: 'view-h1' }, 'Reference not found'),
      el('p', { class: 'view-sub muted' }, e.message)
    );
    return;
  }

  const tagsCard = el('div', { class: 'card' },
    el('h3', {}, 'Tags'),
    el('div', { class: 'tags-list' })
  );
  tagsCard.appendChild(await tagAttachUI(ref, () => renderTagsCard(tagsCard, ref)));

  const linkedFromCard = el('div', { class: 'card' },
    el('h3', {}, 'Linked from'),
    el('div', { id: 'ref-linked-from' }, el('span', { class: 'muted' }, 'Loading …'))
  );

  mount(main,
    el('h1', { class: 'view-h1' }, ref.title || '(untitled reference)'),
    el('p', { class: 'view-sub' },
      el('span', { class: 'status idle' }, ref.kind),
      ref.summary ? ' · ' + ref.summary.slice(0, 200) : ''
    ),
    el('div', { class: 'card' }, el('h3', {}, 'Media'), mediaBlock(ref)),
    ref.summary
      ? el('div', { class: 'card' }, el('h3', {}, 'Summary'), el('p', {}, ref.summary))
      : null,
    el('div', { class: 'card' }, el('h3', {}, 'Metadata'), metadataTable(ref)),
    tagsCard,
    linkedFromCard
  );

  renderTagsCard(tagsCard, ref);

  try {
    const links = await api.get('/api/links/to/ref/' + id);
    const wrap = document.getElementById('ref-linked-from');
    if (!links.length) mount(wrap, el('span', { class: 'muted' }, 'Not linked from anywhere yet.'));
    else mount(wrap,
      el('ul', { class: 'plain' }, links.map(l =>
        el('li', {},
          el('span', { class: 'status idle' }, l.from_type),
          ' ', l.from_id.slice(0, 8) + '…',
          ' ', el('span', { class: 'muted' }, 'rel: ' + l.relation)
        )
      ))
    );
  } catch (e) {
    const wrap = document.getElementById('ref-linked-from');
    if (wrap) mount(wrap, el('span', { class: 'muted' }, 'Could not load: ' + e.message));
  }
}