// =============================================================================
// Privacy Policy PDF Export
// Export Datenschutzerklaerung to PDF format
// =============================================================================

import {
  GeneratedPrivacyPolicy,
  PrivacyPolicySection,
  CompanyInfo,
  SupportedLanguage,
  DataPoint,
  CATEGORY_METADATA,
  RETENTION_PERIOD_INFO,
} from '../types'

// =============================================================================
// TYPES
// =============================================================================

export interface PDFExportOptions {
  language: SupportedLanguage
  includeTableOfContents: boolean
  includeDataPointList: boolean
  companyLogo?: string
  primaryColor?: string
  pageSize?: 'A4' | 'LETTER'
  orientation?: 'portrait' | 'landscape'
  fontSize?: number
}

const DEFAULT_OPTIONS: PDFExportOptions = {
  language: 'de',
  includeTableOfContents: true,
  includeDataPointList: true,
  primaryColor: '#6366f1',
  pageSize: 'A4',
  orientation: 'portrait',
  fontSize: 11,
}

// =============================================================================
// PDF CONTENT STRUCTURE
// =============================================================================

export interface PDFSection {
  type: 'title' | 'heading' | 'subheading' | 'paragraph' | 'table' | 'list' | 'pagebreak'
  content?: string
  items?: string[]
  table?: {
    headers: string[]
    rows: string[][]
  }
  style?: {
    color?: string
    fontSize?: number
    bold?: boolean
    italic?: boolean
    align?: 'left' | 'center' | 'right'
  }
}

// =============================================================================
// PDF CONTENT GENERATION
// =============================================================================

/**
 * Generate PDF content structure for Privacy Policy
 */
export function generatePDFContent(
  policy: GeneratedPrivacyPolicy,
  companyInfo: CompanyInfo,
  dataPoints: DataPoint[],
  options: Partial<PDFExportOptions> = {}
): PDFSection[] {
  const opts = { ...DEFAULT_OPTIONS, ...options }
  const sections: PDFSection[] = []
  const lang = opts.language

  // Title page
  sections.push({
    type: 'title',
    content: lang === 'de' ? 'Datenschutzerklaerung' : 'Privacy Policy',
    style: { color: opts.primaryColor, fontSize: 28, bold: true, align: 'center' },
  })

  sections.push({
    type: 'paragraph',
    content: lang === 'de'
      ? 'gemaess Art. 13, 14 DSGVO'
      : 'according to Art. 13, 14 GDPR',
    style: { fontSize: 14, align: 'center', italic: true },
  })

  // Company information
  sections.push({
    type: 'paragraph',
    content: companyInfo.name,
    style: { fontSize: 16, bold: true, align: 'center' },
  })

  sections.push({
    type: 'paragraph',
    content: `${companyInfo.address}, ${companyInfo.postalCode} ${companyInfo.city}`,
    style: { align: 'center' },
  })

  sections.push({
    type: 'paragraph',
    content: `${lang === 'de' ? 'Stand' : 'Date'}: ${new Date(policy.generatedAt).toLocaleDateString(lang === 'de' ? 'de-DE' : 'en-US')}`,
    style: { align: 'center' },
  })

  sections.push({
    type: 'paragraph',
    content: `Version: ${policy.version}`,
    style: { align: 'center', fontSize: 10 },
  })

  sections.push({ type: 'pagebreak' })

  // Table of Contents
  if (opts.includeTableOfContents) {
    sections.push({
      type: 'heading',
      content: lang === 'de' ? 'Inhaltsverzeichnis' : 'Table of Contents',
      style: { color: opts.primaryColor },
    })

    const tocItems = policy.sections.map((section, idx) =>
      `${idx + 1}. ${section.title[lang]}`
    )

    if (opts.includeDataPointList) {
      tocItems.push(lang === 'de' ? 'Anhang: Datenpunktkatalog' : 'Appendix: Data Point Catalog')
    }

    sections.push({
      type: 'list',
      items: tocItems,
    })

    sections.push({ type: 'pagebreak' })
  }

  // Privacy Policy Sections
  policy.sections.forEach((section, idx) => {
    sections.push({
      type: 'heading',
      content: `${idx + 1}. ${section.title[lang]}`,
      style: { color: opts.primaryColor },
    })

    // Convert markdown-like content to paragraphs
    const content = section.content[lang]
    const paragraphs = content.split('\n\n')

    for (const para of paragraphs) {
      if (para.startsWith('- ')) {
        // List items
        const items = para.split('\n').filter(l => l.startsWith('- ')).map(l => l.substring(2))
        sections.push({
          type: 'list',
          items,
        })
      } else if (para.startsWith('### ')) {
        sections.push({
          type: 'subheading',
          content: para.substring(4),
        })
      } else if (para.startsWith('## ')) {
        sections.push({
          type: 'subheading',
          content: para.substring(3),
          style: { bold: true },
        })
      } else if (para.trim()) {
        sections.push({
          type: 'paragraph',
          content: para.replace(/\*\*(.*?)\*\*/g, '$1'), // Remove markdown bold for plain text
        })
      }
    }

    // Add related data points if this section has them
    if (section.dataPointIds.length > 0 && opts.includeDataPointList) {
      const relatedDPs = dataPoints.filter(dp => section.dataPointIds.includes(dp.id))
      if (relatedDPs.length > 0) {
        sections.push({
          type: 'paragraph',
          content: lang === 'de'
            ? `Betroffene Datenkategorien: ${relatedDPs.map(dp => dp.name[lang]).join(', ')}`
            : `Affected data categories: ${relatedDPs.map(dp => dp.name[lang]).join(', ')}`,
          style: { italic: true, fontSize: 10 },
        })
      }
    }
  })

  // Data Point Catalog Appendix
  if (opts.includeDataPointList && dataPoints.length > 0) {
    sections.push({ type: 'pagebreak' })

    sections.push({
      type: 'heading',
      content: lang === 'de' ? 'Anhang: Datenpunktkatalog' : 'Appendix: Data Point Catalog',
      style: { color: opts.primaryColor },
    })

    sections.push({
      type: 'paragraph',
      content: lang === 'de'
        ? 'Die folgende Tabelle zeigt alle verarbeiteten personenbezogenen Daten:'
        : 'The following table shows all processed personal data:',
    })

    // Group by category
    const categories = [...new Set(dataPoints.map(dp => dp.category))]

    for (const category of categories) {
      const categoryDPs = dataPoints.filter(dp => dp.category === category)
      const categoryMeta = CATEGORY_METADATA[category]

      sections.push({
        type: 'subheading',
        content: `${categoryMeta.code}. ${categoryMeta.name[lang]}`,
      })

      sections.push({
        type: 'table',
        table: {
          headers: lang === 'de'
            ? ['Code', 'Datenpunkt', 'Zweck', 'Loeschfrist']
            : ['Code', 'Data Point', 'Purpose', 'Retention'],
          rows: categoryDPs.map(dp => [
            dp.code,
            dp.name[lang],
            dp.purpose[lang].substring(0, 50) + (dp.purpose[lang].length > 50 ? '...' : ''),
            RETENTION_PERIOD_INFO[dp.retentionPeriod]?.label[lang] || dp.retentionPeriod,
          ]),
        },
      })
    }
  }

  // Footer
  sections.push({
    type: 'paragraph',
    content: lang === 'de'
      ? `Generiert am ${new Date().toLocaleDateString('de-DE')} mit dem Datenschutzerklaerung-Generator`
      : `Generated on ${new Date().toLocaleDateString('en-US')} with the Privacy Policy Generator`,
    style: { italic: true, align: 'center', fontSize: 9 },
  })

  return sections
}

// =============================================================================
// PDF BLOB GENERATION
// =============================================================================

/**
 * Generate a PDF file as a Blob
 * This generates HTML that can be printed to PDF or used with a PDF library
 */
export async function generatePDFBlob(
  policy: GeneratedPrivacyPolicy,
  companyInfo: CompanyInfo,
  dataPoints: DataPoint[],
  options: Partial<PDFExportOptions> = {}
): Promise<Blob> {
  const content = generatePDFContent(policy, companyInfo, dataPoints, options)
  const opts = { ...DEFAULT_OPTIONS, ...options }

  // Generate HTML for PDF conversion
  const html = generateHTMLFromContent(content, opts)

  return new Blob([html], { type: 'text/html' })
}

/**
 * Generate printable HTML from PDF content
 */
function generateHTMLFromContent(
  content: PDFSection[],
  options: PDFExportOptions
): string {
  const pageWidth = options.pageSize === 'A4' ? '210mm' : '8.5in'
  const pageHeight = options.pageSize === 'A4' ? '297mm' : '11in'

  let html = `
<!DOCTYPE html>
<html lang="${options.language}">
<head>
  <meta charset="utf-8">
  <title>${options.language === 'de' ? 'Datenschutzerklaerung' : 'Privacy Policy'}</title>
  <style>
    @page {
      size: ${pageWidth} ${pageHeight};
      margin: 20mm;
    }

    body {
      font-family: 'Segoe UI', Calibri, Arial, sans-serif;
      font-size: ${options.fontSize}pt;
      line-height: 1.6;
      color: #1e293b;
      max-width: 800px;
      margin: 0 auto;
      padding: 20px;
    }

    h1 {
      font-size: 24pt;
      color: ${options.primaryColor};
      border-bottom: 2px solid ${options.primaryColor};
      padding-bottom: 10px;
      margin-top: 30px;
    }

    h2 {
      font-size: 16pt;
      color: ${options.primaryColor};
      margin-top: 24px;
    }

    h3 {
      font-size: 13pt;
      color: #334155;
      margin-top: 18px;
    }

    p {
      margin: 12px 0;
      text-align: justify;
    }

    .title {
      font-size: 28pt;
      text-align: center;
      color: ${options.primaryColor};
      font-weight: bold;
      margin-bottom: 10px;
    }

    .subtitle {
      text-align: center;
      font-style: italic;
      color: #64748b;
    }

    .center {
      text-align: center;
    }

    table {
      width: 100%;
      border-collapse: collapse;
      margin: 16px 0;
      font-size: 10pt;
    }

    th, td {
      border: 1px solid #e2e8f0;
      padding: 8px 12px;
      text-align: left;
    }

    th {
      background-color: ${options.primaryColor};
      color: white;
      font-weight: 600;
    }

    tr:nth-child(even) {
      background-color: #f8fafc;
    }

    ul {
      margin: 12px 0;
      padding-left: 24px;
    }

    li {
      margin: 6px 0;
    }

    .pagebreak {
      page-break-after: always;
    }

    .footer {
      margin-top: 40px;
      padding-top: 20px;
      border-top: 1px solid #e2e8f0;
      font-size: 9pt;
      color: #94a3b8;
      text-align: center;
    }

    @media print {
      body {
        padding: 0;
      }
      .pagebreak {
        page-break-after: always;
      }
    }
  </style>
</head>
<body>
`

  for (const section of content) {
    switch (section.type) {
      case 'title':
        html += `<div class="title" style="${getStyleString(section.style)}">${escapeHtml(section.content || '')}</div>\n`
        break

      case 'heading':
        html += `<h1 style="${getStyleString(section.style)}">${escapeHtml(section.content || '')}</h1>\n`
        break

      case 'subheading':
        html += `<h3 style="${getStyleString(section.style)}">${escapeHtml(section.content || '')}</h3>\n`
        break

      case 'paragraph':
        const alignClass = section.style?.align === 'center' ? ' class="center"' : ''
        html += `<p${alignClass} style="${getStyleString(section.style)}">${escapeHtml(section.content || '')}</p>\n`
        break

      case 'list':
        html += '<ul>\n'
        for (const item of section.items || []) {
          html += `  <li>${escapeHtml(item)}</li>\n`
        }
        html += '</ul>\n'
        break

      case 'table':
        if (section.table) {
          html += '<table>\n<thead><tr>\n'
          for (const header of section.table.headers) {
            html += `  <th>${escapeHtml(header)}</th>\n`
          }
          html += '</tr></thead>\n<tbody>\n'
          for (const row of section.table.rows) {
            html += '<tr>\n'
            for (const cell of row) {
              html += `  <td>${escapeHtml(cell)}</td>\n`
            }
            html += '</tr>\n'
          }
          html += '</tbody></table>\n'
        }
        break

      case 'pagebreak':
        html += '<div class="pagebreak"></div>\n'
        break
    }
  }

  html += '</body></html>'
  return html
}

function getStyleString(style?: PDFSection['style']): string {
  if (!style) return ''

  const parts: string[] = []
  if (style.color) parts.push(`color: ${style.color}`)
  if (style.fontSize) parts.push(`font-size: ${style.fontSize}pt`)
  if (style.bold) parts.push('font-weight: bold')
  if (style.italic) parts.push('font-style: italic')
  if (style.align) parts.push(`text-align: ${style.align}`)

  return parts.join('; ')
}

function escapeHtml(text: string): string {
  return text
    .replace(/&/g, '&amp;')
    .replace(/</g, '&lt;')
    .replace(/>/g, '&gt;')
    .replace(/"/g, '&quot;')
    .replace(/'/g, '&#039;')
}

// =============================================================================
// FILENAME GENERATION
// =============================================================================

/**
 * Generate a filename for the PDF export
 */
export function generatePDFFilename(
  companyInfo: CompanyInfo,
  language: SupportedLanguage = 'de'
): string {
  const companyName = companyInfo.name.replace(/[^a-zA-Z0-9]/g, '-') || 'unknown'
  const date = new Date().toISOString().split('T')[0]
  const prefix = language === 'de' ? 'Datenschutzerklaerung' : 'Privacy-Policy'
  return `${prefix}-${companyName}-${date}.html`
}