/**
 * Binect API client
 */

const API_BASE_URL = 'https://api.binect.de';

export interface AuthToken {
  token: string;
  expiresAt: string;
}

export interface UploadResult {
  documentId: string;
  status: string;
  uploadedAt: string;
}

export class BinectAPIError extends Error {
  constructor(
    message: string,
    public statusCode?: number,
    public response?: unknown
  ) {
    super(message);
    this.name = 'BinectAPIError';
  }
}

/**
 * Authenticate with Binect API
 */
export async function authenticate(
  username: string,
  password: string
): Promise<AuthToken> {
  try {
    const response = await fetch(`${API_BASE_URL}/auth/login`, {
      method: 'POST',
      headers: {
        'Content-Type': 'application/json'
      },
      body: JSON.stringify({ username, password })
    });

    if (!response.ok) {
      if (response.status === 401) {
        throw new BinectAPIError('Invalid credentials', 401);
      }
      throw new BinectAPIError(
        `Authentication failed: ${response.statusText}`,
        response.status
      );
    }

    return await response.json();
  } catch (error) {
    if (error instanceof BinectAPIError) {
      throw error;
    }
    throw new BinectAPIError(
      `Network error: ${error instanceof Error ? error.message : 'Unknown error'}`
    );
  }
}

/**
 * Upload PDF to Binect
 */
export async function uploadPDF(
  pdfData: ArrayBuffer,
  filename: string,
  token: string
): Promise<UploadResult> {
  try {
    const formData = new FormData();
    const blob = new Blob([pdfData], { type: 'application/pdf' });
    formData.append('file', blob, filename);
    formData.append('filename', filename);

    const response = await fetch(`${API_BASE_URL}/documents/upload`, {
      method: 'POST',
      headers: {
        Authorization: `Bearer ${token}`
      },
      body: formData
    });

    if (!response.ok) {
      const errorData = await response.json().catch(() => ({}));

      if (response.status === 401) {
        throw new BinectAPIError('Authentication required', 401, errorData);
      }

      if (response.status === 400) {
        throw new BinectAPIError(
          errorData.error || 'Invalid file format',
          400,
          errorData
        );
      }

      if (response.status === 413) {
        throw new BinectAPIError('File size exceeds limit', 413, errorData);
      }

      throw new BinectAPIError(
        `Upload failed: ${response.statusText}`,
        response.status,
        errorData
      );
    }

    return await response.json();
  } catch (error) {
    if (error instanceof BinectAPIError) {
      throw error;
    }
    throw new BinectAPIError(
      `Network error: ${error instanceof Error ? error.message : 'Unknown error'}`
    );
  }
}

/**
 * Test API connectivity
 */
export async function testConnection(): Promise<boolean> {
  try {
    const response = await fetch(`${API_BASE_URL}/health`, {
      method: 'GET'
    });
    return response.ok;
  } catch {
    return false;
  }
}