/**
 * Privacy Policy Section Generators (Sections 1-4)
 *
 * Generiert die ersten 4 Abschnitte der Datenschutzerklaerung (DSI).
 * Sections 5-7 live in privacy-policy-sections-part2.ts.
 */

import {
  DataPoint,
  DataPointCategory,
  CompanyInfo,
  PrivacyPolicySection,
  SupportedLanguage,
  LocalizedText,
  RetentionMatrixEntry,
  LegalBasis,
  CATEGORY_METADATA,
  LEGAL_BASIS_INFO,
  RETENTION_PERIOD_INFO,
} from '../types'

// Re-export sections 5-7 for backward compatibility
export {
  generateRecipientsSection,
  generateRetentionSection,
  generateSpecialCategoriesSection,
  generateRightsSection,
} from './privacy-policy-sections-part2'

// =============================================================================
// KONSTANTEN
// =============================================================================

const ALL_CATEGORIES: DataPointCategory[] = [
  'MASTER_DATA', 'CONTACT_DATA', 'AUTHENTICATION', 'CONSENT',
  'COMMUNICATION', 'PAYMENT', 'USAGE_DATA', 'LOCATION',
  'DEVICE_DATA', 'MARKETING', 'ANALYTICS', 'SOCIAL_MEDIA',
  'HEALTH_DATA', 'EMPLOYEE_DATA', 'CONTRACT_DATA', 'LOG_DATA',
  'AI_DATA', 'SECURITY',
]

const ALL_LEGAL_BASES: LegalBasis[] = [
  'CONTRACT', 'CONSENT', 'EXPLICIT_CONSENT', 'LEGITIMATE_INTEREST',
  'LEGAL_OBLIGATION', 'VITAL_INTERESTS', 'PUBLIC_INTEREST',
]

// =============================================================================
// HELPER FUNCTIONS
// =============================================================================

function t(text: LocalizedText, language: SupportedLanguage): string {
  return text[language]
}

function groupByCategory(dataPoints: DataPoint[]): Map<DataPointCategory, DataPoint[]> {
  const grouped = new Map<DataPointCategory, DataPoint[]>()
  for (const dp of dataPoints) {
    const existing = grouped.get(dp.category) || []
    grouped.set(dp.category, [...existing, dp])
  }
  return grouped
}

function groupByLegalBasis(dataPoints: DataPoint[]): Map<LegalBasis, DataPoint[]> {
  const grouped = new Map<LegalBasis, DataPoint[]>()
  for (const dp of dataPoints) {
    const existing = grouped.get(dp.legalBasis) || []
    grouped.set(dp.legalBasis, [...existing, dp])
  }
  return grouped
}

function extractThirdParties(dataPoints: DataPoint[]): string[] {
  const thirdParties = new Set<string>()
  for (const dp of dataPoints) {
    for (const recipient of dp.thirdPartyRecipients) {
      thirdParties.add(recipient)
    }
  }
  return Array.from(thirdParties).sort()
}

export function formatDate(date: Date, language: SupportedLanguage): string {
  return date.toLocaleDateString(language === 'de' ? 'de-DE' : 'en-US', {
    year: 'numeric',
    month: 'long',
    day: 'numeric',
  })
}

// =============================================================================
// SECTION GENERATORS
// =============================================================================

export function generateControllerSection(
  companyInfo: CompanyInfo,
  language: SupportedLanguage
): PrivacyPolicySection {
  const title: LocalizedText = {
    de: '1. Verantwortlicher',
    en: '1. Data Controller',
  }

  const dpoSection = companyInfo.dpoName
    ? language === 'de'
      ? `\n\n**Datenschutzbeauftragter:**\n${companyInfo.dpoName}${companyInfo.dpoEmail ? `\nE-Mail: ${companyInfo.dpoEmail}` : ''}${companyInfo.dpoPhone ? `\nTelefon: ${companyInfo.dpoPhone}` : ''}`
      : `\n\n**Data Protection Officer:**\n${companyInfo.dpoName}${companyInfo.dpoEmail ? `\nEmail: ${companyInfo.dpoEmail}` : ''}${companyInfo.dpoPhone ? `\nPhone: ${companyInfo.dpoPhone}` : ''}`
    : ''

  const content: LocalizedText = {
    de: `Verantwortlich fuer die Datenverarbeitung auf dieser Website ist:

**${companyInfo.name}**
${companyInfo.address}
${companyInfo.postalCode} ${companyInfo.city}
${companyInfo.country}

E-Mail: ${companyInfo.email}${companyInfo.phone ? `\nTelefon: ${companyInfo.phone}` : ''}${companyInfo.website ? `\nWebsite: ${companyInfo.website}` : ''}${companyInfo.registrationNumber ? `\n\nHandelsregister: ${companyInfo.registrationNumber}` : ''}${companyInfo.vatId ? `\nUSt-IdNr.: ${companyInfo.vatId}` : ''}${dpoSection}`,
    en: `The controller responsible for data processing on this website is:

**${companyInfo.name}**
${companyInfo.address}
${companyInfo.postalCode} ${companyInfo.city}
${companyInfo.country}

Email: ${companyInfo.email}${companyInfo.phone ? `\nPhone: ${companyInfo.phone}` : ''}${companyInfo.website ? `\nWebsite: ${companyInfo.website}` : ''}${companyInfo.registrationNumber ? `\n\nCommercial Register: ${companyInfo.registrationNumber}` : ''}${companyInfo.vatId ? `\nVAT ID: ${companyInfo.vatId}` : ''}${dpoSection}`,
  }

  return {
    id: 'controller',
    order: 1,
    title,
    content,
    dataPointIds: [],
    isRequired: true,
    isGenerated: false,
  }
}

export function generateDataCollectionSection(
  dataPoints: DataPoint[],
  language: SupportedLanguage
): PrivacyPolicySection {
  const title: LocalizedText = {
    de: '2. Erhobene personenbezogene Daten',
    en: '2. Personal Data We Collect',
  }

  const grouped = groupByCategory(dataPoints)
  const sections: string[] = []
  const hasSpecialCategoryData = dataPoints.some(dp => dp.isSpecialCategory || dp.category === 'HEALTH_DATA')

  for (const category of ALL_CATEGORIES) {
    const categoryData = grouped.get(category)
    if (!categoryData || categoryData.length === 0) continue

    const categoryMeta = CATEGORY_METADATA[category]
    if (!categoryMeta) continue

    const categoryTitle = t(categoryMeta.name, language)

    let categoryNote = ''
    if (category === 'HEALTH_DATA') {
      categoryNote = language === 'de'
        ? `\n\n> **Hinweis:** Diese Daten gehoeren zu den besonderen Kategorien personenbezogener Daten gemaess Art. 9 DSGVO und erfordern eine ausdrueckliche Einwilligung.`
        : `\n\n> **Note:** This data belongs to special categories of personal data under Art. 9 GDPR and requires explicit consent.`
    } else if (category === 'EMPLOYEE_DATA') {
      categoryNote = language === 'de'
        ? `\n\n> **Hinweis:** Die Verarbeitung von Beschaeftigtendaten erfolgt gemaess § 26 BDSG.`
        : `\n\n> **Note:** Processing of employee data is carried out in accordance with § 26 BDSG (German Federal Data Protection Act).`
    } else if (category === 'AI_DATA') {
      categoryNote = language === 'de'
        ? `\n\n> **Hinweis:** Die Verarbeitung von KI-bezogenen Daten unterliegt den Transparenzpflichten des AI Acts.`
        : `\n\n> **Note:** Processing of AI-related data is subject to AI Act transparency requirements.`
    }

    const dataList = categoryData
      .map((dp) => {
        const specialTag = dp.isSpecialCategory
          ? (language === 'de' ? ' *(Art. 9 DSGVO)*' : ' *(Art. 9 GDPR)*')
          : ''
        return `- **${t(dp.name, language)}**${specialTag}: ${t(dp.description, language)}`
      })
      .join('\n')

    sections.push(`### ${categoryMeta.code}. ${categoryTitle}\n\n${dataList}${categoryNote}`)
  }

  const intro: LocalizedText = {
    de: 'Wir erheben und verarbeiten die folgenden personenbezogenen Daten:',
    en: 'We collect and process the following personal data:',
  }

  const specialCategoryNote: LocalizedText = hasSpecialCategoryData
    ? {
        de: '\n\n**Wichtig:** Einige der unten aufgefuehrten Daten gehoeren zu den besonderen Kategorien personenbezogener Daten nach Art. 9 DSGVO und werden nur mit Ihrer ausdruecklichen Einwilligung verarbeitet.',
        en: '\n\n**Important:** Some of the data listed below belongs to special categories of personal data under Art. 9 GDPR and is only processed with your explicit consent.',
      }
    : { de: '', en: '' }

  const content: LocalizedText = {
    de: `${intro.de}${specialCategoryNote.de}\n\n${sections.join('\n\n')}`,
    en: `${intro.en}${specialCategoryNote.en}\n\n${sections.join('\n\n')}`,
  }

  return {
    id: 'data-collection',
    order: 2,
    title,
    content,
    dataPointIds: dataPoints.map((dp) => dp.id),
    isRequired: true,
    isGenerated: true,
  }
}

export function generatePurposesSection(
  dataPoints: DataPoint[],
  language: SupportedLanguage
): PrivacyPolicySection {
  const title: LocalizedText = {
    de: '3. Zwecke der Datenverarbeitung',
    en: '3. Purposes of Data Processing',
  }

  const purposes = new Map<string, DataPoint[]>()
  for (const dp of dataPoints) {
    const purpose = t(dp.purpose, language)
    const existing = purposes.get(purpose) || []
    purposes.set(purpose, [...existing, dp])
  }

  const purposeList = Array.from(purposes.entries())
    .map(([purpose, dps]) => {
      const dataNames = dps.map((dp) => t(dp.name, language)).join(', ')
      return `- **${purpose}**\n  Betroffene Daten: ${dataNames}`
    })
    .join('\n\n')

  const content: LocalizedText = {
    de: `Wir verarbeiten Ihre personenbezogenen Daten fuer folgende Zwecke:\n\n${purposeList}`,
    en: `We process your personal data for the following purposes:\n\n${purposeList}`,
  }

  return {
    id: 'purposes',
    order: 3,
    title,
    content,
    dataPointIds: dataPoints.map((dp) => dp.id),
    isRequired: true,
    isGenerated: true,
  }
}

export function generateLegalBasisSection(
  dataPoints: DataPoint[],
  language: SupportedLanguage
): PrivacyPolicySection {
  const title: LocalizedText = {
    de: '4. Rechtsgrundlagen der Verarbeitung',
    en: '4. Legal Basis for Processing',
  }

  const grouped = groupByLegalBasis(dataPoints)
  const sections: string[] = []

  for (const basis of ALL_LEGAL_BASES) {
    const basisData = grouped.get(basis)
    if (!basisData || basisData.length === 0) continue

    const basisInfo = LEGAL_BASIS_INFO[basis]
    if (!basisInfo) continue

    const basisTitle = `${t(basisInfo.name, language)} (${basisInfo.article})`
    const basisDesc = t(basisInfo.description, language)

    let additionalWarning = ''
    if (basis === 'EXPLICIT_CONSENT') {
      additionalWarning = language === 'de'
        ? `\n\n> **Wichtig:** Fuer die Verarbeitung dieser besonderen Kategorien personenbezogener Daten (Art. 9 DSGVO) ist eine separate, ausdrueckliche Einwilligung erforderlich, die Sie jederzeit widerrufen koennen.`
        : `\n\n> **Important:** Processing of these special categories of personal data (Art. 9 GDPR) requires a separate, explicit consent that you can withdraw at any time.`
    }

    const dataLabel = language === 'de' ? 'Betroffene Daten' : 'Affected Data'
    const dataList = basisData
      .map((dp) => {
        const specialTag = dp.isSpecialCategory
          ? (language === 'de' ? ' *(Art. 9 DSGVO)*' : ' *(Art. 9 GDPR)*')
          : ''
        return `- ${t(dp.name, language)}${specialTag}: ${t(dp.legalBasisJustification, language)}`
      })
      .join('\n')

    sections.push(`### ${basisTitle}\n\n${basisDesc}${additionalWarning}\n\n**${dataLabel}:**\n${dataList}`)
  }

  const content: LocalizedText = {
    de: `Die Verarbeitung Ihrer personenbezogenen Daten erfolgt auf Grundlage folgender Rechtsgrundlagen:\n\n${sections.join('\n\n')}`,
    en: `The processing of your personal data is based on the following legal grounds:\n\n${sections.join('\n\n')}`,
  }

  return {
    id: 'legal-basis',
    order: 4,
    title,
    content,
    dataPointIds: dataPoints.map((dp) => dp.id),
    isRequired: true,
    isGenerated: true,
  }
}