// Default to '' (relative URLs) so any production-style build - whether
// done inside Docker (Dockerfile sets REACT_APP_API_URL=) or on the host
// without that env var - hits the same origin that served the page. This
// avoids the cross-origin trap where a `npm run build` on the host
// without REACT_APP_API_URL would silently bake `http://localhost:8000`
// into the bundle and break every API call from a Docker deployment.
//
// If you want the CRA dev server (`npm start` on :3000) to talk to a
// FastAPI backend on :8000, set REACT_APP_API_URL=http://localhost:8000
// in `frontend/.env.development` or your shell.
const API_BASE = process.env.REACT_APP_API_URL !== undefined
  ? process.env.REACT_APP_API_URL
  : '';

export async function fetchModels() {
  const resp = await fetch(`${API_BASE}/api/models`, { cache: 'no-store' });
  if (!resp.ok) throw new Error(`Failed to fetch models: ${resp.status}`);
  return resp.json();
}

export async function fetchPersonas() {
  const resp = await fetch(`${API_BASE}/api/personas`, { cache: 'no-store' });
  if (!resp.ok) throw new Error(`Failed to fetch personas: ${resp.status}`);
  return resp.json();
}

export async function fetchDemoQuestions() {
  const resp = await fetch(`${API_BASE}/api/demo-questions`, { cache: 'no-store' });
  if (!resp.ok) throw new Error(`Failed to fetch demo questions: ${resp.status}`);
  return resp.json();
}

export async function generateRole({
  name,
  profile,
  identity,
  samples,
  role_style,
  orchestrator_model_id,
}) {
  const resp = await fetch(`${API_BASE}/api/chat/generate-role`, {
    method: 'POST',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify({
      name,
      profile,
      identity,
      samples,
      role_style,
      orchestrator_model_id,
    }),
  });
  if (!resp.ok) {
    const err = await resp.json().catch(() => ({ detail: resp.statusText }));
    throw new Error(err.detail || 'Role generation failed');
  }
  return resp.json();
}

export async function generateRoleFreeform({
  name,
  text,
  role_style,
  orchestrator_model_id,
}) {
  const resp = await fetch(`${API_BASE}/api/chat/generate-role-freeform`, {
    method: 'POST',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify({
      name,
      text,
      role_style,
      orchestrator_model_id,
    }),
  });
  if (!resp.ok) {
    const err = await resp.json().catch(() => ({ detail: resp.statusText }));
    throw new Error(err.detail || 'Role generation failed');
  }
  return resp.json();
}

/**
 * Suggest an LLM for an Expert Persona from the builder's live model list.
 *
 * Body: { persona_name, source_text, role_prompt, available_models,
 *         panel_context, orchestrator_model_id }
 *
 * Returns: { recommended_model_id, rationale }
 */
export async function suggestModel({
  persona_name,
  source_text,
  role_prompt,
  available_models,
  panel_context,
  orchestrator_model_id,
}) {
  const resp = await fetch(`${API_BASE}/api/chat/suggest-model`, {
    method: 'POST',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify({
      persona_name,
      source_text,
      role_prompt,
      available_models,
      panel_context,
      orchestrator_model_id,
    }),
  });
  if (!resp.ok) {
    const err = await resp.json().catch(() => ({ detail: resp.statusText }));
    const detail = err.detail;
    const message = typeof detail === 'string'
      ? detail
      : Array.isArray(detail)
        ? detail.map(d => d.msg || JSON.stringify(d)).join('; ')
        : 'Model suggestion failed';
    throw new Error(message);
  }
  return resp.json();
}

/**
 * Start a CCAI conversation and consume the SSE stream.
 *
 * Body: { question, participants[], expert_personas[], model_assignments,
 *         orchestrator_model_id, summarizer_model_id, max_participants }
 */
export async function startChat(body, handlers, abortSignal) {
  const resp = await fetch(`${API_BASE}/api/chat/start`, {
    method: 'POST',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify(body),
    signal: abortSignal,
  });

  if (!resp.ok) {
    const err = await resp.json().catch(() => ({ detail: resp.statusText }));
    throw new Error(err.detail || 'Chat start failed');
  }

  const reader = resp.body.getReader();
  const decoder = new TextDecoder();
  let buffer = '';

  try {
    while (true) {
      if (abortSignal?.aborted) break;
      const { value, done } = await reader.read();
      if (done) break;
      buffer += decoder.decode(value, { stream: true });

      const parts = buffer.split('\n\n');
      buffer = parts.pop();

      for (const part of parts) {
        const lines = part.trim().split('\n');
        let eventType = 'message';
        let data = '';
        for (const line of lines) {
          if (line.startsWith('event: ')) eventType = line.slice(7).trim();
          else if (line.startsWith('data: ')) data = line.slice(6);
        }
        if (!data) continue;
        try {
          const parsed = JSON.parse(data);
          const handler = handlers[eventHandlerKey(eventType)];
          if (handler) handler(parsed);
        } catch (e) {
          console.warn('SSE parse error', e, data);
        }
      }
    }
  } finally {
    reader.releaseLock();
  }
  handlers.onDone?.();
}

function eventHandlerKey(eventType) {
  switch (eventType) {
    case 'session': return 'onSession';
    case 'message': return 'onMessage';
    case 'message_stream_start': return 'onMessageStreamStart';
    case 'message_delta': return 'onMessageDelta';
    case 'orchestrator': return 'onOrchestrator';
    case 'system': return 'onSystem';
    case 'status': return 'onStatus';
    case 'error': return 'onError';
    case 'done': return 'onDone';
    case 'failsafe_pause': return 'onFailsafePause';
    case 'orchestrator_cap_pause': return 'onOrchestratorCapPause';
    case 'participant_error': return 'onParticipantError';
    case 'participant_substituted': return 'onParticipantSubstituted';
    case 'participant_replaced': return 'onParticipantReplaced';
    case 'vote_cast': return 'onVoteCast';
    case 'vote_tally': return 'onVoteTally';
    case 'credentials_updated': return 'onCredentialsUpdated';
    case 'human_turn_needed': return 'onHumanTurnNeeded';
    case 'human_turn_cleared': return 'onHumanTurnCleared';
    default: return null;
  }
}

export async function continueChat(sessionId, reason) {
  const resp = await fetch(
    `${API_BASE}/api/chat/${sessionId}/continue?reason=${encodeURIComponent(reason)}`,
    { method: 'POST' },
  );
  if (!resp.ok) throw new Error('Continue failed');
  return resp.json();
}

export async function getOrchestrator() {
  const resp = await fetch(`${API_BASE}/api/chat/orchestrator`);
  if (!resp.ok) throw new Error('Failed to get orchestrator');
  return resp.json();
}

export async function setOrchestrator(modelId) {
  const resp = await fetch(`${API_BASE}/api/chat/orchestrator`, {
    method: 'PUT',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify({ model_id: modelId }),
  });
  if (!resp.ok) throw new Error('Failed to set orchestrator');
  return resp.json();
}

export async function getSpeedPriority() {
  const resp = await fetch(`${API_BASE}/api/chat/speed-priority`);
  if (!resp.ok) throw new Error('Failed to get speed priority');
  return resp.json();
}

export async function setSpeedPriority(enabled) {
  const resp = await fetch(`${API_BASE}/api/chat/speed-priority`, {
    method: 'PUT',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify({ enabled }),
  });
  if (!resp.ok) throw new Error('Failed to set speed priority');
  return resp.json();
}

/**
 * Fetch the catalog of available conversation structures and
 * decision-making methods. The Settings menu's "Conversation format"
 * accordion populates from this so adding a new plugin server-side
 * doesn't require frontend code changes.
 *
 * Returns: { structures: [{id, name, description}, ...],
 *            decisions: [{id, name, description}, ...],
 *            default_structure_id, default_decision_id }
 */
export async function fetchConversationFormats() {
  const resp = await fetch(`${API_BASE}/api/chat/conversation-formats`, { cache: 'no-store' });
  if (!resp.ok) throw new Error('Failed to fetch conversation formats');
  return resp.json();
}

export async function exportChat(sessionId, fmt = 'txt') {
  const resp = await fetch(`${API_BASE}/api/chat/${sessionId}/export?fmt=${fmt}`);
  if (!resp.ok) throw new Error('Export failed');
  return resp.json();
}

export async function exportApiLog(sessionId) {
  const resp = await fetch(`${API_BASE}/api/chat/${sessionId}/api-log`);
  if (!resp.ok) throw new Error('API log export failed');
  return resp.json();
}

export async function fetchTableView(sessionId) {
  const resp = await fetch(`${API_BASE}/api/chat/${sessionId}/table`);
  if (!resp.ok) throw new Error('Table view fetch failed');
  return resp.json();
}

/**
 * Fetch the catalog of every prompt template the orchestrator and
 * participants use, grouped by phase and annotated with purpose and
 * runtime variables. Backs the "View current chat prompts" modal.
 */
export async function fetchPromptCatalog() {
  const resp = await fetch(`${API_BASE}/api/chat/prompts/catalog`, { cache: 'no-store' });
  if (!resp.ok) throw new Error('Failed to fetch prompt catalog');
  return resp.json();
}

/**
 * Ask the backend to pick the top `count` participants from the
 * candidate pool by relevance to the question. Used by the
 * "Select N Automatically" toggle in the participants dropdown.
 *
 * Returns: { selected: [participant_id, ...], rationale: "..." }
 */
export async function autoSelectParticipants({ question, count, candidates, orchestrator_model_id }) {
  const resp = await fetch(`${API_BASE}/api/chat/auto-select-participants`, {
    method: 'POST',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify({ question, count, candidates, orchestrator_model_id }),
  });
  if (!resp.ok) {
    const err = await resp.json().catch(() => ({ detail: resp.statusText }));
    throw new Error(err.detail || 'Auto-select failed');
  }
  return resp.json();
}

/**
 * Fetch the user-tunable conversation-limit defaults, bounds, and
 * descriptions. The frontend uses this to render the "Conversation
 * limits" settings modal entirely from the server schema, so adding
 * a new knob in the backend doesn't require a frontend change.
 *
 * Shape: { defaults: {field: int}, bounds: {field: {min, max}},
 *          descriptions: {field: {group, label, help}} }
 */
export async function fetchConversationLimitsDefaults() {
  const resp = await fetch(`${API_BASE}/api/chat/limits/defaults`, { cache: 'no-store' });
  if (!resp.ok) throw new Error('Failed to fetch conversation-limit defaults');
  return resp.json();
}

export async function fetchCredentials(sessionId) {
  const resp = await fetch(
    `${API_BASE}/api/chat/${sessionId}/credentials`,
    { cache: 'no-store' },
  );
  if (!resp.ok) throw new Error('Credentials fetch failed');
  return resp.json();
}

/**
 * Submit the human participant's response to the orchestrator for the
 * currently pending turn. `skip=true` flips the turn into a "declined
 * to comment" note rather than a message.
 */
export async function submitHumanResponse(sessionId, { text, skip = false } = {}) {
  const resp = await fetch(`${API_BASE}/api/chat/${sessionId}/human-response`, {
    method: 'POST',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify({ text: text || '', skip: !!skip }),
  });
  if (!resp.ok) {
    const err = await resp.json().catch(() => ({ detail: resp.statusText }));
    throw new Error(err.detail || 'Submit failed');
  }
  return resp.json();
}

/**
 * Patch the in-the-loop human's credential summary. Used by the
 * CredentialSummaryModal's edit affordance on the human's row. The
 * backend rejects fields it doesn't know about; we send only the
 * fields the user actually changed (sparse patch).
 */
export async function patchHumanCredential(sessionId, patch) {
  const resp = await fetch(`${API_BASE}/api/chat/${sessionId}/credentials/human`, {
    method: 'PATCH',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify(patch),
  });
  if (!resp.ok) {
    const err = await resp.json().catch(() => ({ detail: resp.statusText }));
    throw new Error(err.detail || 'Edit failed');
  }
  return resp.json();
}

/**
 * Start the AI-assisted credential intake Q&A flow. Returns either a
 * first question or (rarely) a final summary if the LLM bails. The
 * draft_id is needed for subsequent /answer calls.
 */
/**
 * Generate a structured credential summary from a human's freeform
 * profile text (experience, personality, etc.). Uses the orchestrator
 * the same way it assesses an LLM participant's role prompt.
 */
export async function generateHumanCredentialFromProfile({
  name, question, profile_text, participant_id, orchestrator_model_id,
}) {
  const resp = await fetch(`${API_BASE}/api/chat/credentials/from-profile`, {
    method: 'POST',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify({
      name,
      question,
      profile_text,
      participant_id: participant_id || '',
      orchestrator_model_id: orchestrator_model_id || null,
    }),
  });
  if (!resp.ok) {
    const err = await resp.json().catch(() => ({ detail: resp.statusText }));
    throw new Error(err.detail || 'Credential generation failed');
  }
  return resp.json();
}

export async function startCredentialDraft({
  name, question, max_questions = 6, orchestrator_model_id = null,
}) {
  const resp = await fetch(`${API_BASE}/api/chat/credentials/draft`, {
    method: 'POST',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify({ name, question, max_questions, orchestrator_model_id }),
  });
  if (!resp.ok) {
    const err = await resp.json().catch(() => ({ detail: resp.statusText }));
    throw new Error(err.detail || 'Credential draft start failed');
  }
  return resp.json();
}

export async function answerCredentialDraft(draftId, answer) {
  const resp = await fetch(`${API_BASE}/api/chat/credentials/draft/${draftId}/answer`, {
    method: 'POST',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify({ answer: answer || '' }),
  });
  if (!resp.ok) {
    const err = await resp.json().catch(() => ({ detail: resp.statusText }));
    throw new Error(err.detail || 'Credential draft answer failed');
  }
  return resp.json();
}

export async function cancelCredentialDraft(draftId) {
  try {
    await fetch(`${API_BASE}/api/chat/credentials/draft/${draftId}`, {
      method: 'DELETE',
    });
  } catch (_) { /* fire-and-forget cleanup; ignore */ }
}

export async function getAuthStatus() {
  const resp = await fetch(`${API_BASE}/api/auth/status`, { credentials: 'include' });
  if (!resp.ok) return { logged_in: false, remaining_conversations: -1 };
  return resp.json();
}

export async function getRateLimitStatus() {
  const resp = await fetch(`${API_BASE}/api/rate-limit/status`, { credentials: 'include' });
  if (!resp.ok) return { remaining: -1, daily_limit: 30 };
  return resp.json();
}