const API_BASE = import.meta.env.VITE_API_BASE || '';

async function request(path, { method = 'GET', body, token } = {}) {
  const headers = {};
  const options = { method, headers };

  if (body) {
    headers['Content-Type'] = 'application/json';
    options.body = JSON.stringify(body);
  }

  if (token) {
    headers['x-session-token'] = token;
  }

  const response = await fetch(`${API_BASE}${path}`, options);

  if (!response.ok) {
    const errorBody = await response.json().catch(() => ({}));
    const message = errorBody.message || 'Beklenmeyen bir hata olustu.';
    throw new Error(message);
  }

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

  return response.json();
}

export function login(credentials) {
  return request('/api/auth/login', {
    method: 'POST',
    body: credentials
  });
}

export function logout(token) {
  return request('/api/auth/logout', {
    method: 'POST',
    token
  });
}

export function fetchSession(token) {
  return request('/api/session', {
    method: 'GET',
    token
  });
}

export function listInventoryManagers(token) {
  return request('/api/inventory-managers', {
    method: 'GET',
    token
  });
}

export function createInventoryManager(token, payload) {
  return request('/api/inventory-managers', {
    method: 'POST',
    body: payload,
    token
  });
}

export function updateInventoryManager(token, id, payload) {
  return request(`/api/inventory-managers/${id}`, {
    method: 'PUT',
    body: payload,
    token
  });
}

export function deleteInventoryManager(token, id) {
  return request(`/api/inventory-managers/${id}`, {
    method: 'DELETE',
    token
  });
}

export function listVehicles(token) {
  return request('/api/vehicles', {
    method: 'GET',
    token
  });
}

export function createVehicle(token, payload) {
  return request('/api/vehicles', {
    method: 'POST',
    body: payload,
    token
  });
}

export function updateVehicle(token, id, payload) {
  return request(`/api/vehicles/${id}`, {
    method: 'PUT',
    body: payload,
    token
  });
}

export function deleteVehicle(token, id) {
  return request(`/api/vehicles/${id}`, {
    method: 'DELETE',
    token
  });
}

export function listUnits(token) {
  return request('/api/units', {
    method: 'GET',
    token
  });
}

export function createUnit(token, payload) {
  return request('/api/units', {
    method: 'POST',
    body: payload,
    token
  });
}

export function updateUnit(token, id, payload) {
  return request(`/api/units/${id}`, {
    method: 'PUT',
    body: payload,
    token
  });
}

export function deleteUnit(token, id) {
  return request(`/api/units/${id}`, {
    method: 'DELETE',
    token
  });
}

export function listFuelPersonnel(token) {
  return request('/api/fuel-personnel', {
    method: 'GET',
    token
  });
}

export function createFuelPersonnel(token, payload) {
  return request('/api/fuel-personnel', {
    method: 'POST',
    body: payload,
    token
  });
}

export function updateFuelPersonnel(token, id, payload) {
  return request(`/api/fuel-personnel/${id}`, {
    method: 'PUT',
    body: payload,
    token
  });
}

export function deleteFuelPersonnel(token, id) {
  return request(`/api/fuel-personnel/${id}`, {
    method: 'DELETE',
    token
  });
}

export function fetchFuelResources(token) {
  return request('/api/fuel/resources', {
    method: 'GET',
    token
  });
}

export function listFuelSlips(token) {
  return request('/api/fuel-slips', {
    method: 'GET',
    token
  });
}

export function createFuelSlip(token, payload) {
  return request('/api/fuel-slips', {
    method: 'POST',
    body: payload,
    token
  });
}

export async function downloadFuelSlipPdf(token, id) {
  const response = await fetch(`${API_BASE}/api/fuel-slips/${id}/pdf`, {
    method: 'GET',
    headers: {
      'x-session-token': token
    }
  });

  if (!response.ok) {
    const errorBody = await response.json().catch(() => ({}));
    const message = errorBody.message || 'PDF indirilemedi.';
    throw new Error(message);
  }

  return response.blob();
}

export function fetchAssignedFuelSlips(token) {
  return request('/api/fuel-slips/assigned', {
    method: 'GET',
    token
  });
}

export function updateFuelSlipStatus(token, id, payload) {
  return request(`/api/fuel-slips/${id}/status`, {
    method: 'PATCH',
    body: payload,
    token
  });
}