/**
 * PDF Generation API
 * Handles PDF generation using tinypdf-plus backend
 */

import { Capacitor } from '@capacitor/core';

const API_BASE_URL = Capacitor.isNativePlatform()
  ? 'https://veridian.runfoo.run'
  : (import.meta.env.VITE_API_URL || '');

export interface TextPDFOptions {
  content: string;
  options?: {
    width?: number;
    height?: number;
    margin?: number;
  };
}

export interface CertificatePDFData {
  title: string;
  recipientName: string;
  description: string;
  date: string;
  certificateNumber: string;
  authorizedBy?: string;
}

export interface LabelPDFData {
  title: string;
  subtitle?: string;
  qrCode?: string;
  details: Array<{
    label: string;
    value: string;
  }>;
}

/**
 * Helper function to download PDF blob
 */
function downloadPDF(blob: Blob, filename: string) {
  const url = window.URL.createObjectURL(blob);
  const link = document.createElement('a');
  link.href = url;
  link.download = filename;
  document.body.appendChild(link);
  link.click();
  document.body.removeChild(link);
  window.URL.revokeObjectURL(url);
}

/**
 * Generate a simple text PDF
 */
export async function generateTextPDF(data: TextPDFOptions, filename = 'document.pdf'): Promise<void> {
  const token = localStorage.getItem('token');
  const headers: Record<string, string> = {
    'Content-Type': 'application/json',
  };
  if (token) {
    headers.Authorization = `Bearer ${token}`;
  }

  const response = await fetch(`${API_BASE_URL}/api/pdf/text`, {
    method: 'POST',
    headers,
    body: JSON.stringify(data),
  });

  if (!response.ok) {
    throw new Error(`Failed to generate PDF: ${response.statusText}`);
  }

  const blob = await response.blob();
  downloadPDF(blob, filename);
}

/**
 * Generate a certificate PDF
 */
export async function generateCertificatePDF(
  data: CertificatePDFData,
  filename?: string
): Promise<void> {
  const token = localStorage.getItem('token');
  const headers: Record<string, string> = {
    'Content-Type': 'application/json',
  };
  if (token) {
    headers.Authorization = `Bearer ${token}`;
  }

  const response = await fetch(`${API_BASE_URL}/api/pdf/certificate`, {
    method: 'POST',
    headers,
    body: JSON.stringify(data),
  });

  if (!response.ok) {
    throw new Error(`Failed to generate certificate: ${response.statusText}`);
  }

  const blob = await response.blob();
  const defaultFilename = `certificate-${data.certificateNumber}.pdf`;
  downloadPDF(blob, filename || defaultFilename);
}

/**
 * Generate a label PDF (for plants, batches, etc.)
 */
export async function generateLabelPDF(data: LabelPDFData, filename = 'label.pdf'): Promise<void> {
  const token = localStorage.getItem('token');
  const headers: Record<string, string> = {
    'Content-Type': 'application/json',
  };
  if (token) {
    headers.Authorization = `Bearer ${token}`;
  }

  const response = await fetch(`${API_BASE_URL}/api/pdf/label`, {
    method: 'POST',
    headers,
    body: JSON.stringify(data),
  });

  if (!response.ok) {
    throw new Error(`Failed to generate label: ${response.statusText}`);
  }

  const blob = await response.blob();
  downloadPDF(blob, filename);
}

/**
 * Check PDF service health
 */
export async function checkPDFHealth(): Promise<{ status: string; service: string; timestamp: string }> {
  const response = await fetch(`${API_BASE_URL}/api/pdf/health`);
  if (!response.ok) {
    throw new Error(`PDF health check failed: ${response.statusText}`);
  }
  return response.json();
}