/**
 * agents-coord.ts — SSE event stream for the Live Coordination page.
 *
 * Reads owner, repoSlug, and cursor from the #page-data JSON block and
 * connects to the /coord/watch SSE endpoint, appending rows to the stream panel.
 *
 * Registered as: window.MusePages['agents-coord']
 */

interface AgentsCoordData {
  owner: string;
  repoSlug: string;
  cursor: number;
}

const MAX_ROWS = 60;

const KIND_DOT_CLASS: Record<string, string> = {
  reservation: 'agents-stream-dot--reservation',
  heartbeat:   'agents-stream-dot--heartbeat',
  claim:       'agents-stream-dot--claim',
  release:     'agents-stream-dot--release',
  task:        'agents-stream-dot--task',
  intent:      'agents-stream-dot--intent',
};

function setStatus(state: 'live' | 'error' | 'connecting'): void {
  const dot   = document.getElementById('sse-dot');
  const label = document.getElementById('sse-label');
  if (!dot || !label) return;
  if (state === 'live') {
    dot.style.background  = 'var(--color-success, #3fb950)';
    dot.style.boxShadow   = '0 0 6px var(--color-success, #3fb950)';
    label.textContent     = 'LIVE';
  } else if (state === 'error') {
    dot.style.background  = 'var(--color-danger, #f85149)';
    dot.style.boxShadow   = 'none';
    label.textContent     = 'RECONNECTING';
  } else {
    dot.style.background  = 'var(--color-warning, #e3b341)';
    dot.style.boxShadow   = 'none';
    label.textContent     = 'CONNECTING';
  }
}

function appendRow(body: Element, kind: string, detail: string): void {
  const row = document.createElement('div');
  row.className = 'agents-stream-row';

  const dotEl = document.createElement('span');
  dotEl.className = 'agents-stream-dot ' + (KIND_DOT_CLASS[kind] ?? 'agents-stream-dot--default');

  const kindEl = document.createElement('span');
  kindEl.className = 'agents-stream-kind';
  kindEl.textContent = kind;

  const detailEl = document.createElement('span');
  detailEl.className = 'agents-stream-detail';
  detailEl.textContent = detail;

  row.appendChild(dotEl);
  row.appendChild(kindEl);
  row.appendChild(detailEl);
  body.appendChild(row);

  while (body.children.length > MAX_ROWS) {
    body.removeChild(body.firstChild!);
  }
  (body as HTMLElement).scrollTop = (body as HTMLElement).scrollHeight;
}

function connect(owner: string, repoSlug: string, initialCursor: number): void {
  const body      = document.getElementById('stream-body');
  const cursorEl  = document.getElementById('stream-cursor');
  if (!body) return;

  let cursor = initialCursor;
  let watchUrl = `/${owner}/${repoSlug}/coord/watch?since_id=${cursor}`;

  setStatus('connecting');

  const es = new EventSource(watchUrl);

  es.addEventListener('coord_record', (e: MessageEvent) => {
    setStatus('live');
    try {
      const rec = JSON.parse(e.data as string) as Record<string, unknown>;
      cursor = (rec['id'] as number) || cursor;
      if (cursorEl) cursorEl.textContent = `cursor: ${cursor}`;
      watchUrl = `/${owner}/${repoSlug}/coord/watch?since_id=${cursor}`;

      const kind    = (rec['kind'] as string) || 'unknown';
      const runId   = ((rec['run_id'] as string) || '').substring(0, 22);
      const payload = (rec['payload'] as Record<string, unknown>) || {};
      let addr      = '';
      const addrs   = payload['addresses'] as string[] | undefined;
      if (addrs && addrs.length) addr = addrs[0];
      else if (payload['symbol_address']) addr = payload['symbol_address'] as string;
      else if (payload['task_id']) addr = 'task:' + ((payload['task_id'] as string).substring(0, 8));
      const detail = runId + (addr ? '  · ' + addr.substring(0, 40) : '');
      appendRow(body, kind, detail);
    } catch { /* ignore parse errors */ }
  });

  es.onerror = () => {
    setStatus('error');
    es.close();
    setTimeout(() => connect(owner, repoSlug, cursor), 3000);
  };
}

export function initAgentsCoord(data: Record<string, unknown>): void {
  const cfg = data as unknown as AgentsCoordData;
  const owner     = String(cfg.owner     ?? '');
  const repoSlug  = String(cfg.repoSlug  ?? '');
  const cursor    = Number(cfg.cursor    ?? 0);
  if (!owner || !repoSlug) return;
  connect(owner, repoSlug, cursor);
}