// ── API Calls ──

async function apiChat(messages, sessionId) {
  return fetch('/api/chat', {
    method: 'POST',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify({ messages, sessionId })
  });
}

// ── Agent API ──

async function apiGetAgents() {
  const resp = await fetch('/api/agents');
  return resp.json();
}

async function apiGetAgent(agentId) {
  const resp = await fetch(`/api/agents/${agentId}`);
  if (!resp.ok) return null;
  return resp.json();
}

async function apiCreateAgent(data) {
  const resp = await fetch('/api/agents', {
    method: 'POST',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify(data)
  });
  return resp.json();
}

async function apiUpdateAgent(agentId, data) {
  const resp = await fetch(`/api/agents/${agentId}`, {
    method: 'PUT',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify(data)
  });
  return resp.json();
}

async function apiDeleteAgent(agentId) {
  return fetch(`/api/agents/${agentId}`, { method: 'DELETE' });
}

async function apiHistory(sessionId) {
  const resp = await fetch(`/api/history?sessionId=${sessionId}`);
  return resp.json();
}

async function apiHistoryPoll(sessionId, afterId) {
  const resp = await fetch(`/api/history/poll?sessionId=${sessionId}&afterId=${afterId}`);
  return resp.json();
}

async function apiArchive(sessionId) {
  const resp = await fetch(`/api/archive?sessionId=${sessionId}`, { method: 'POST' });
  if (resp.status === 204) return null;
  return resp.json();
}

async function apiListArchives(sessionId) {
  const resp = await fetch(`/api/archives?sessionId=${sessionId}`);
  return resp.json();
}

async function apiGetArchive(archiveId) {
  const resp = await fetch(`/api/archive/${archiveId}`);
  return resp.json();
}

// ── Session API ──

async function apiGetSessions() {
  const resp = await fetch('/api/sessions');
  return resp.json();
}

async function apiCreateSession(data = {}) {
  const resp = await fetch('/api/sessions', {
    method: 'POST',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify(data)
  });
  return resp.json();
}

async function apiGetSession(sessionId) {
  const resp = await fetch(`/api/sessions/${sessionId}`);
  if (!resp.ok) return null;
  return resp.json();
}

async function apiDeleteSession(sessionId) {
  return fetch(`/api/sessions/${sessionId}`, { method: 'DELETE' });
}

async function apiUpdateSession(sessionId, data) {
  const resp = await fetch(`/api/sessions/${sessionId}`, {
    method: 'PUT',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify(data)
  });
  return resp.json();
}

async function apiExecCommand(sessionId, command) {
  return fetch(`/api/sessions/${sessionId}/exec`, {
    method: 'POST',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify({ command })
  });
}

async function apiGetSystemPrompt(sessionId) {
  const resp = await fetch(`/api/sessions/${sessionId}/system-prompt`);
  if (!resp.ok) throw new Error('System-Prompt konnte nicht geladen werden');
  return resp.text();
}

async function apiIsStreaming(sessionId) {
  const resp = await fetch(`/api/sessions/${sessionId}/streaming`);
  return resp.json();
}

async function apiGetChain(chainId) {
  const resp = await fetch(`/api/chains/${chainId}`);
  if (!resp.ok) return null;
  return resp.json();
}

async function apiBackupDb() {
  const resp = await fetch('/api/backup', { method: 'POST' });
  if (!resp.ok) throw new Error('Backup fehlgeschlagen');
  const blob = await resp.blob();
  const cd = resp.headers.get('content-disposition') || '';
  const filename = cd.match(/filename\*=UTF-8''(.+?)(?:;|$)/i)?.[1]
    || cd.match(/filename="?([^";]+)"?/)?.[1]
    || 'gott-backup.tar.gz';
  const url = URL.createObjectURL(blob);
  const a = document.createElement('a');
  a.href = url;
  a.download = filename;
  document.body.appendChild(a);
  a.click();
  a.remove();
  URL.revokeObjectURL(url);
}