// Use VITE_API_URL if set at build time, otherwise derive from current origin
const API_URL = import.meta.env.VITE_API_URL || `${window.location.origin}/api`;

export interface ParticipantAPI {
  id: string;
  name: string;
  email: string;
  timezone: string;
  ics_url: string | null;
  created_at: string;
  updated_at: string;
}

export interface TimeSlotAPI {
  day: string;
  hour: number;
  start_time: string;
  availability: 'full' | 'partial' | 'none';
  availableParticipants: string[];
}

export interface CreateParticipantRequest {
  name: string;
  email: string;
  timezone: string;
  ics_url?: string;
}

export interface UpdateParticipantRequest {
  timezone?: string;
  ics_url?: string;
}

async function handleResponse<T>(response: Response): Promise<T> {
  if (!response.ok) {
    const error = await response.json().catch(() => ({ detail: 'Request failed' }));
    throw new Error(error.detail || 'Request failed');
  }
  return response.json();
}

export async function fetchParticipants(): Promise<ParticipantAPI[]> {
  const response = await fetch(`${API_URL}/api/participants`);
  return handleResponse<ParticipantAPI[]>(response);
}

export async function createParticipant(data: CreateParticipantRequest): Promise<ParticipantAPI> {
  const response = await fetch(`${API_URL}/api/participants`, {
    method: 'POST',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify(data),
  });
  return handleResponse<ParticipantAPI>(response);
}

export async function updateParticipant(id: string, data: UpdateParticipantRequest): Promise<ParticipantAPI> {
  const response = await fetch(`${API_URL}/api/participants/${id}`, {
    method: 'PATCH',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify(data),
  });
  return handleResponse<ParticipantAPI>(response);
}

export async function deleteParticipant(id: string): Promise<void> {
  const response = await fetch(`${API_URL}/api/participants/${id}`, {
    method: 'DELETE',
  });
  if (!response.ok) {
    throw new Error('Failed to delete participant');
  }
}

export async function fetchAvailability(participantIds: string[]): Promise<TimeSlotAPI[]> {
  const response = await fetch(`${API_URL}/api/availability`, {
    method: 'POST',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify({ participant_ids: participantIds }),
  });
  const data = await handleResponse<{ slots: TimeSlotAPI[] }>(response);
  return data.slots;
}

export async function syncCalendars(): Promise<void> {
  const response = await fetch(`${API_URL}/api/sync`, { method: 'POST' });
  if (!response.ok) {
    throw new Error('Failed to sync calendars');
  }
}

export async function syncParticipant(id: string): Promise<void> {
  const response = await fetch(`${API_URL}/api/sync/${id}`, { method: 'POST' });
  if (!response.ok) {
    throw new Error('Failed to sync participant calendar');
  }
}

export async function scheduleMeeting(
  participantIds: string[],
  title: string,
  description: string,
  startTime: string,
  endTime: string,
): Promise<{ email_sent: boolean; zulip_sent: boolean }> {
  const response = await fetch(`${API_URL}/api/schedule`, {
    method: 'POST',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify({
      participant_ids: participantIds,
      title,
      description,
      start_time: startTime,
      end_time: endTime,
    }),
  });
  return handleResponse(response);
}