const API_BASE_URL = import.meta.env.VITE_API_URL || 'http://localhost:3000/api';

export interface UploadError {
  row: number;
  field?: string;
  message: string;
  data?: Record<string, unknown>;
}

export interface UploadResult {
  total: number;
  inserted: number;
  updated: number;
  errors: UploadError[];
}

export interface ApiResponse {
  success: boolean;
  message: string;
  data?: UploadResult;
}

/**
 * Upload meters CSV file
 */
export async function uploadMetersCSV(file: File): Promise<ApiResponse> {
  const formData = new FormData();
  formData.append('file', file);

  const response = await fetch(`${API_BASE_URL}/csv-upload/meters`, {
    method: 'POST',
    body: formData,
  });

  return response.json();
}

/**
 * Upload readings CSV file
 */
export async function uploadReadingsCSV(file: File): Promise<ApiResponse> {
  const formData = new FormData();
  formData.append('file', file);

  const response = await fetch(`${API_BASE_URL}/csv-upload/readings`, {
    method: 'POST',
    body: formData,
  });

  return response.json();
}

/**
 * Download meters CSV template
 */
export function downloadMetersTemplate(): void {
  window.open(`${API_BASE_URL}/csv-upload/meters/template`, '_blank');
}

/**
 * Download readings CSV template
 */
export function downloadReadingsTemplate(): void {
  window.open(`${API_BASE_URL}/csv-upload/readings/template`, '_blank');
}