const RAW_BASE = import.meta.env.VITE_API_BASE ?? '';
const DEFAULT_TIMEOUT = 15000;

/** API error carrying the HTTP status and the server's structured error code. */
export class ApiError extends Error {
  constructor(message, status, code) {
    super(message);
    this.name = 'ApiError';
    this.status = status;
    this.code = code;
  }
}

async function request(path, { method = 'GET', body, headers = {}, signal } = {}) {
  const controller = new AbortController();
  const timer = setTimeout(() => controller.abort(), DEFAULT_TIMEOUT);
  if (signal) signal.addEventListener('abort', () => controller.abort(), { once: true });

  try {
    const response = await fetch(`${RAW_BASE}${path}`, {
      method,
      headers: {
        Accept: 'application/json',
        ...(body !== undefined ? { 'Content-Type': 'application/json' } : {}),
        ...headers,
      },
      body: body === undefined ? undefined : JSON.stringify(body),
      signal: controller.signal,
    });

    if (response.status === 204) return null;

    const text = await response.text();
    let payload = null;
    if (text) {
      try {
        payload = JSON.parse(text);
      } catch {
        payload = null;
      }
    }

    if (!response.ok) {
      const code = payload?.error?.code;
      const message = payload?.error?.message ?? `${response.status} ${response.statusText}`;
      throw new ApiError(message, response.status, code);
    }
    return payload;
  } catch (error) {
    if (error instanceof ApiError) throw error;
    if (error.name === 'AbortError') {
      throw new ApiError('Request timed out or was cancelled', 0, 'timeout');
    }
    throw new ApiError(error.message || 'Network unreachable', 0, 'network');
  } finally {
    clearTimeout(timer);
  }
}

export const api = {
  health: () => request('/api/health'),
  roles: () => request('/api/roles'),
  listDocs: (query = '') =>
    request(`/api/docs${query ? `?q=${encodeURIComponent(query)}` : ''}`),
  listDocsDetailed: () => request('/api/docs?counts=1'),
  getDoc: (slug) => request(`/api/docs/${encodeURIComponent(slug)}?format=json`),
  saveDoc: (slug, content, title) => request(`/api/docs/${encodeURIComponent(slug)}`, {
    method: 'POST',
    body: { content, title },
  }),
  deleteDoc: (slug) => request(`/api/docs/${encodeURIComponent(slug)}`, { method: 'DELETE' }),
  listComments: (slug) => request(`/api/docs/${encodeURIComponent(slug)}/comments`),
  createComment: (slug, comment) =>
    request(`/api/docs/${encodeURIComponent(slug)}/comments`, { method: 'POST', body: comment }),
  deleteComment: (slug, id) =>
    request(`/api/docs/${encodeURIComponent(slug)}/comments/${encodeURIComponent(id)}`, {
      method: 'DELETE',
    }),
};

/** Audience segments mirrored from the Go engine; badges stay authoritative server-side. */
export const ROLES = [
  { role: 'user', badge: '🟢', label: 'User', hex: '#22c55e', description: 'Day-to-day workflow guidance' },
  { role: 'operator', badge: '🔵', label: 'Operator', hex: '#3b82f6', description: 'Deployment, health and rollback' },
  { role: 'developer', badge: '🔴', label: 'Developer', hex: '#ef4444', description: 'Implementation and API contracts' },
];

export function roleMeta(role) {
  return ROLES.find((r) => r.role === role) ?? { role, badge: '⚪', label: role, hex: '#94a3b8' };
}