// Knowledge Vault of Indian Environmental Laws, Policies, and IS Codes
// Comprehensive offline reference system for environmental compliance

interface LegalDocument {
  id: string;
  title: string;
  type: 'act' | 'rule' | 'policy' | 'standard' | 'guideline' | 'notification';
  authority: string;
  year: number;
  status: 'active' | 'amended' | 'superseded';
  summary: string;
  keyProvisions: string[];
  applicableTo: string[];
  penalties: string[];
  references: string[];
  lastUpdated: Date;
}

interface ISCode {
  code: string;
  title: string;
  category: string;
  year: number;
  status: 'current' | 'revised' | 'withdrawn';
  scope: string;
  keyRequirements: string[];
  testMethods: string[];
  applicableIndustries: string[];
  relatedCodes: string[];
}

interface ComplianceCheck {
  parameter: string;
  value: number;
  unit: string;
  applicable: LegalDocument[];
  compliance: 'compliant' | 'non_compliant' | 'marginal';
  recommendations: string[];
  nextReview: Date;
}

class KnowledgeVault {
  private legalDocuments: Map<string, LegalDocument> = new Map();
  private isCodes: Map<string, ISCode> = new Map();
  private searchIndex: Map<string, string[]> = new Map();

  constructor() {
    this.initializeLegalDatabase();
    this.initializeISCodes();
    this.buildSearchIndex();
  }

  // Search for legal documents
  searchLegalDocuments(query: string, filters?: {
    type?: LegalDocument['type'];
    authority?: string;
    year?: number;
  }): LegalDocument[] {
    try {
      if (!query || query.trim().length === 0) {
        return this.getAllDocuments(filters);
      }

      const searchTerms = query.toLowerCase().split(' ').filter(term => term.length > 2);
      const results = new Set<string>();

      // Search in index
      searchTerms.forEach(term => {
        const matches = this.searchIndex.get(term) || [];
        matches.forEach(docId => results.add(docId));
      });

      let documents = Array.from(results)
        .map(id => this.legalDocuments.get(id))
        .filter((doc): doc is LegalDocument => doc !== undefined);

      // Apply filters
      if (filters) {
        documents = documents.filter(doc => {
          if (filters.type && doc.type !== filters.type) return false;
          if (filters.authority && !doc.authority.toLowerCase().includes(filters.authority.toLowerCase())) return false;
          if (filters.year && doc.year !== filters.year) return false;
          return true;
        });
      }

      return documents.sort((a, b) => b.year - a.year);
    } catch (error) {
      throw new Error(`Failed to search legal documents: ${error instanceof Error ? error.message : 'Unknown error'}`);
    }
  }

  // Search IS Codes
  searchISCodes(query: string, category?: string): ISCode[] {
    try {
      if (!query || query.trim().length === 0) {
        const allCodes = Array.from(this.isCodes.values());
        return category 
          ? allCodes.filter(code => code.category.toLowerCase().includes(category.toLowerCase()))
          : allCodes;
      }

      const searchTerm = query.toLowerCase();
      return Array.from(this.isCodes.values()).filter(code =>
        code.code.toLowerCase().includes(searchTerm) ||
        code.title.toLowerCase().includes(searchTerm) ||
        code.scope.toLowerCase().includes(searchTerm) ||
        (category && code.category.toLowerCase().includes(category.toLowerCase()))
      ).sort((a, b) => b.year - a.year);
    } catch (error) {
      throw new Error(`Failed to search IS codes: ${error instanceof Error ? error.message : 'Unknown error'}`);
    }
  }

  // Check compliance for specific parameters
  checkCompliance(parameter: string, value: number, unit: string, context?: {
    industryType?: string;
    location?: string;
    dischargeTo?: string;
  }): ComplianceCheck {
    try {
      if (typeof value !== 'number' || isNaN(value)) {
        throw new Error('Invalid parameter value');
      }

      const applicableDocs = this.getApplicableRegulations(parameter, context);
      const limits = this.extractLimits(parameter, applicableDocs);
      
      let compliance: ComplianceCheck['compliance'] = 'compliant';
      const recommendations: string[] = [];

      // Check against limits
      for (const limit of limits) {
        if (value > limit.maxValue) {
          compliance = 'non_compliant';
          recommendations.push(`Exceeds ${limit.standard} limit of ${limit.maxValue} ${unit}`);
        } else if (value > limit.maxValue * 0.8) {
          compliance = 'marginal';
          recommendations.push(`Approaching ${limit.standard} limit - monitor closely`);
        }
      }

      if (compliance === 'compliant') {
        recommendations.push('Parameter within acceptable limits');
      }

      const nextReview = new Date();
      nextReview.setMonth(nextReview.getMonth() + 6); // 6 months from now

      return {
        parameter,
        value,
        unit,
        applicable: applicableDocs,
        compliance,
        recommendations,
        nextReview
      };
    } catch (error) {
      throw new Error(`Failed to check compliance: ${error instanceof Error ? error.message : 'Unknown error'}`);
    }
  }

  // Get applicable regulations for parameter
  getApplicableRegulations(parameter: string, context?: any): LegalDocument[] {
    const parameterKey = parameter.toLowerCase();
    const regulations: LegalDocument[] = [];

    this.legalDocuments.forEach(doc => {
      const isApplicable = doc.keyProvisions.some(provision =>
        provision.toLowerCase().includes(parameterKey) ||
        provision.toLowerCase().includes('water') ||
        provision.toLowerCase().includes('air') ||
        provision.toLowerCase().includes('emission')
      );

      if (isApplicable) {
        regulations.push(doc);
      }
    });

    return regulations;
  }

  // Get environmental clearance requirements
  getEnvironmentalClearanceInfo(projectType: string, projectCapacity?: number): {
    category: 'A' | 'B1' | 'B2' | 'exempted';
    authority: string;
    requirements: string[];
    timeline: string;
    fees: string;
    validity: string;
  } {
    try {
      const projectTypeLower = projectType.toLowerCase();
      
      // Simplified categorization based on EIA Notification 2006
      let category: 'A' | 'B1' | 'B2' | 'exempted';
      let authority: string;
      let requirements: string[];
      let timeline: string;
      let fees: string;

      if (projectTypeLower.includes('thermal power') && (projectCapacity || 0) >= 500) {
        category = 'A';
        authority = 'MoEF&CC, New Delhi';
        timeline = '210 days';
        fees = '₹5-50 lakhs';
      } else if (projectTypeLower.includes('cement') && (projectCapacity || 0) >= 1.0) {
        category = 'A';
        authority = 'MoEF&CC, New Delhi';
        timeline = '210 days';
        fees = '₹10-25 lakhs';
      } else if (projectTypeLower.includes('steel') || projectTypeLower.includes('iron')) {
        category = (projectCapacity || 0) >= 5.0 ? 'A' : 'B1';
        authority = category === 'A' ? 'MoEF&CC, New Delhi' : 'State Environment Impact Assessment Authority';
        timeline = category === 'A' ? '210 days' : '105 days';
        fees = category === 'A' ? '₹15-40 lakhs' : '₹2-10 lakhs';
      } else {
        category = 'B2';
        authority = 'State Environment Impact Assessment Authority';
        timeline = '105 days';
        fees = '₹50,000-5 lakhs';
      }

      requirements = this.getECRequirements(category);

      return {
        category,
        authority,
        requirements,
        timeline,
        fees,
        validity: '30 years (renewable)'
      };
    } catch (error) {
      throw new Error(`Failed to get EC information: ${error instanceof Error ? error.message : 'Unknown error'}`);
    }
  }

  // Get consent to operate requirements
  getConsentRequirements(industryType: string, pollutionCategory: 'red' | 'orange' | 'green' | 'white'): {
    authority: string;
    validity: string;
    requirements: string[];
    fees: string;
    monitoring: string[];
  } {
    try {
      const requirements = [
        'Valid Environmental Clearance (if applicable)',
        'Consent to Establish',
        'Pollution control equipment installation certificates',
        'Effluent/emission monitoring reports',
        'Waste management plan',
        'Emergency response plan'
      ];

      const monitoring = [
        'Monthly stack emission monitoring',
        'Daily effluent monitoring',
        'Quarterly ambient air quality monitoring',
        'Annual environmental audit'
      ];

      let validity: string;
      let fees: string;

      switch (pollutionCategory) {
        case 'red':
          validity = '5 years';
          fees = '₹25,000-10 lakhs';
          monitoring.push('Continuous emission monitoring system (CEMS)');
          break;
        case 'orange':
          validity = '5 years';
          fees = '₹10,000-5 lakhs';
          break;
        case 'green':
          validity = '5 years';
          fees = '₹5,000-1 lakh';
          break;
        default:
          validity = '5 years';
          fees = '₹2,500-25,000';
      }

      return {
        authority: 'State Pollution Control Board',
        validity,
        requirements,
        fees,
        monitoring
      };
    } catch (error) {
      throw new Error(`Failed to get consent requirements: ${error instanceof Error ? error.message : 'Unknown error'}`);
    }
  }

  // Export knowledge base
  exportKnowledgeBase(): string {
    try {
      const exportData = {
        legalDocuments: Array.from(this.legalDocuments.values()),
        isCodes: Array.from(this.isCodes.values()),
        exportDate: new Date().toISOString(),
        version: '1.0'
      };

      return JSON.stringify(exportData, null, 2);
    } catch (error) {
      throw new Error(`Failed to export knowledge base: ${error instanceof Error ? error.message : 'Unknown error'}`);
    }
  }

  // Private initialization methods
  private initializeLegalDatabase(): void {
    // Water-related regulations
    this.addLegalDocument({
      id: 'water_act_1974',
      title: 'Water (Prevention and Control of Pollution) Act, 1974',
      type: 'act',
      authority: 'Parliament of India',
      year: 1974,
      status: 'active',
      summary: 'Provides for the prevention and control of water pollution and maintaining or restoring of wholesomeness of water.',
      keyProvisions: [
        'Prohibition of discharge of pollutants into water bodies without consent',
        'Establishment of Central and State Pollution Control Boards',
        'Power to take samples and analyze water',
        'Penalties for violation of provisions'
      ],
      applicableTo: ['Industries', 'Municipalities', 'Commercial establishments'],
      penalties: ['Imprisonment up to 6 years', 'Fine up to ₹1 lakh', 'Daily fine of ₹5,000'],
      references: ['Water Act 1974', 'Water Rules 1975']
    });

    this.addLegalDocument({
      id: 'air_act_1981',
      title: 'Air (Prevention and Control of Pollution) Act, 1981',
      type: 'act',
      authority: 'Parliament of India',
      year: 1981,
      status: 'active',
      summary: 'Provides for the prevention, control and abatement of air pollution.',
      keyProvisions: [
        'Prohibition of air polluting industries in air pollution control areas',
        'Consent required for establishment and operation',
        'Power to give directions for closure of industries',
        'Standards for emission of air pollutants'
      ],
      applicableTo: ['Industries', 'Vehicles', 'Commercial establishments'],
      penalties: ['Imprisonment up to 6 years', 'Fine up to ₹1 lakh', 'Daily fine of ₹5,000'],
      references: ['Air Act 1981', 'Air Rules 1982']
    });

    this.addLegalDocument({
      id: 'environment_protection_act_1986',
      title: 'Environment (Protection) Act, 1986',
      type: 'act',
      authority: 'Parliament of India',
      year: 1986,
      status: 'active',
      summary: 'Umbrella legislation providing for protection and improvement of environment.',
      keyProvisions: [
        'General powers to Central Government for environmental protection',
        'Appointment of officers and authorities',
        'Power to direct closure of industries',
        'Environmental standards and guidelines'
      ],
      applicableTo: ['All activities affecting environment'],
      penalties: ['Imprisonment up to 5 years', 'Fine up to ₹1 lakh', 'Daily fine'],
      references: ['EPA 1986', 'Environment Rules 1986']
    });

    this.addLegalDocument({
      id: 'eia_notification_2006',
      title: 'Environmental Impact Assessment Notification, 2006',
      type: 'notification',
      authority: 'Ministry of Environment, Forest and Climate Change',
      year: 2006,
      status: 'amended',
      summary: 'Mandates prior environmental clearance for specified activities.',
      keyProvisions: [
        'Categorization of projects (Category A and B)',
        'Screening and scoping procedures',
        'Public consultation requirements',
        'Monitoring and compliance procedures'
      ],
      applicableTo: ['Mining', 'Thermal power', 'Industrial projects', 'Infrastructure'],
      penalties: ['Project closure', 'Penalty up to ₹1 crore', 'Legal action'],
      references: ['EIA Notification 2006', 'EIA Amendment 2020']
    });

    this.addLegalDocument({
      id: 'swm_rules_2016',
      title: 'Solid Waste Management Rules, 2016',
      type: 'rule',
      authority: 'Ministry of Environment, Forest and Climate Change',
      year: 2016,
      status: 'active',
      summary: 'Comprehensive rules for management of solid waste.',
      keyProvisions: [
        'Waste segregation at source',
        'Extended producer responsibility',
        'Processing and treatment of waste',
        'Waste to energy recovery'
      ],
      applicableTo: ['Urban local bodies', 'Waste generators', 'Bulk generators'],
      penalties: ['Fine as per local bye-laws', 'Spot fine up to ₹500'],
      references: ['SWM Rules 2016', 'SWM Amendment 2018']
    });

    this.addLegalDocument({
      id: 'hwm_rules_2016',
      title: 'Hazardous and Other Wastes Management Rules, 2016',
      type: 'rule',
      authority: 'Ministry of Environment, Forest and Climate Change',
      year: 2016,
      status: 'active',
      summary: 'Rules for management of hazardous and other wastes.',
      keyProvisions: [
        'Authorization for hazardous waste management',
        'Manifest system for waste tracking',
        'Treatment and disposal standards',
        'Liability and compensation provisions'
      ],
      applicableTo: ['Industries generating hazardous waste', 'Treatment facilities'],
      penalties: ['Closure directions', 'Fine up to ₹1 crore', 'Criminal liability'],
      references: ['HWM Rules 2016', 'HWM Amendment 2019']
    });
  }

  private initializeISCodes(): void {
    // Water quality standards
    this.addISCode({
      code: 'IS 10500:2012',
      title: 'Drinking Water — Specification',
      category: 'Water Quality',
      year: 2012,
      status: 'current',
      scope: 'Specifies requirements for drinking water quality',
      keyRequirements: [
        'pH: 6.5-8.5',
        'TDS: 500 mg/L (acceptable), 2000 mg/L (permissible)',
        'Turbidity: 1 NTU (acceptable), 5 NTU (permissible)',
        'Chloride: 250 mg/L (acceptable), 1000 mg/L (permissible)'
      ],
      testMethods: ['IS 3025 series for water testing'],
      applicableIndustries: ['Water supply', 'Bottled water', 'Food industry'],
      relatedCodes: ['IS 3025', 'IS 14543']
    });

    this.addISCode({
      code: 'IS 3025:2009',
      title: 'Methods of Sampling and Test (Physical and Chemical) for Water and Wastewater',
      category: 'Testing Methods',
      year: 2009,
      status: 'current',
      scope: 'Standard methods for water and wastewater analysis',
      keyRequirements: [
        'Sample collection procedures',
        'Preservation techniques',
        'Analytical methods for various parameters',
        'Quality control measures'
      ],
      testMethods: ['Gravimetric', 'Titrimetric', 'Spectrophotometric', 'Chromatographic'],
      applicableIndustries: ['Laboratories', 'Water treatment', 'Environmental monitoring'],
      relatedCodes: ['IS 10500', 'IS 2490']
    });

    // Air quality standards
    this.addISCode({
      code: 'IS 5182:2006',
      title: 'Methods for Measurement of Air Pollution',
      category: 'Air Quality',
      year: 2006,
      status: 'current',
      scope: 'Methods for measurement of ambient air quality',
      keyRequirements: [
        'Sampling methods for particulate matter',
        'Gas sampling techniques',
        'Calibration procedures',
        'Data validation methods'
      ],
      testMethods: ['Gravimetric analysis', 'Spectrophotometry', 'Gas chromatography'],
      applicableIndustries: ['Environmental monitoring', 'Industrial hygiene', 'Research'],
      relatedCodes: ['IS 11255', 'IS 9969']
    });

    // Structural codes
    this.addISCode({
      code: 'IS 456:2000',
      title: 'Plain and Reinforced Concrete - Code of Practice',
      category: 'Structural Engineering',
      year: 2000,
      status: 'current',
      scope: 'Requirements for design and construction of concrete structures',
      keyRequirements: [
        'Material specifications',
        'Design methods and principles',
        'Construction practices',
        'Quality control requirements'
      ],
      testMethods: ['Concrete strength testing', 'Durability tests', 'Non-destructive testing'],
      applicableIndustries: ['Construction', 'Infrastructure', 'Industrial structures'],
      relatedCodes: ['IS 875', 'IS 1893', 'IS 13920']
    });

    this.addISCode({
      code: 'IS 875:1987',
      title: 'Code of Practice for Design Loads (Other than Earthquake) for Buildings and Structures',
      category: 'Structural Engineering',
      year: 1987,
      status: 'current',
      scope: 'Design loads for buildings and structures',
      keyRequirements: [
        'Dead load calculations',
        'Live load specifications',
        'Wind load calculations',
        'Snow load considerations'
      ],
      testMethods: ['Load testing', 'Material property testing'],
      applicableIndustries: ['Building construction', 'Industrial structures', 'Infrastructure'],
      relatedCodes: ['IS 456', 'IS 800', 'IS 1893']
    });

    // Environmental engineering codes
    this.addISCode({
      code: 'IS 4764:2017',
      title: 'Code of Practice for Concrete Structures for the Storage of Liquids',
      category: 'Environmental Engineering',
      year: 2017,
      status: 'current',
      scope: 'Design and construction of liquid storage structures',
      keyRequirements: [
        'Structural design criteria',
        'Waterproofing requirements',
        'Joint design and sealing',
        'Quality control procedures'
      ],
      testMethods: ['Water tightness testing', 'Structural load testing'],
      applicableIndustries: ['Water treatment', 'Chemical storage', 'Sewage treatment'],
      relatedCodes: ['IS 456', 'IS 3370', 'IS 875']
    });
  }

  private addLegalDocument(doc: Omit<LegalDocument, 'lastUpdated'>): void {
    const document: LegalDocument = {
      ...doc,
      lastUpdated: new Date()
    };
    this.legalDocuments.set(doc.id, document);
  }

  private addISCode(code: ISCode): void {
    this.isCodes.set(code.code, code);
  }

  private buildSearchIndex(): void {
    // Build search index for legal documents
    this.legalDocuments.forEach(doc => {
      const searchableText = [
        doc.title,
        doc.summary,
        ...doc.keyProvisions,
        ...doc.applicableTo
      ].join(' ').toLowerCase();

      const words = searchableText.split(/\W+/).filter(word => word.length > 2);
      
      words.forEach(word => {
        if (!this.searchIndex.has(word)) {
          this.searchIndex.set(word, []);
        }
        const docIds = this.searchIndex.get(word)!;
        if (!docIds.includes(doc.id)) {
          docIds.push(doc.id);
        }
      });
    });
  }

  private getAllDocuments(filters?: any): LegalDocument[] {
    let documents = Array.from(this.legalDocuments.values());
    
    if (filters) {
      documents = documents.filter(doc => {
        if (filters.type && doc.type !== filters.type) return false;
        if (filters.authority && !doc.authority.toLowerCase().includes(filters.authority.toLowerCase())) return false;
        if (filters.year && doc.year !== filters.year) return false;
        return true;
      });
    }
    
    return documents.sort((a, b) => b.year - a.year);
  }

  private extractLimits(parameter: string, documents: LegalDocument[]): Array<{
    standard: string;
    maxValue: number;
    unit: string;
  }> {
    // Simplified limit extraction - in a real implementation, this would parse the documents
    const limits: Array<{ standard: string; maxValue: number; unit: string }> = [];
    
    const paramLower = parameter.toLowerCase();
    
    if (paramLower.includes('ph')) {
      limits.push({ standard: 'IS 10500:2012', maxValue: 8.5, unit: 'pH units' });
    } else if (paramLower.includes('bod')) {
      limits.push({ standard: 'CPCB Standards', maxValue: 30, unit: 'mg/L' });
    } else if (paramLower.includes('cod')) {
      limits.push({ standard: 'CPCB Standards', maxValue: 250, unit: 'mg/L' });
    } else if (paramLower.includes('tds')) {
      limits.push({ standard: 'IS 10500:2012', maxValue: 500, unit: 'mg/L' });
    } else if (paramLower.includes('pm2.5')) {
      limits.push({ standard: 'CPCB NAAQS', maxValue: 40, unit: 'μg/m³' });
    } else if (paramLower.includes('pm10')) {
      limits.push({ standard: 'CPCB NAAQS', maxValue: 60, unit: 'μg/m³' });
    }
    
    return limits;
  }

  private getECRequirements(category: string): string[] {
    const baseRequirements = [
      'Project proposal with detailed technical specifications',
      'Environmental Impact Assessment report',
      'Environmental Management Plan',
      'Risk assessment and disaster management plan',
      'Details of public consultation (for Category A & B1)'
    ];

    if (category === 'A') {
      return [
        ...baseRequirements,
        'Approved Terms of Reference from MoEF&CC',
        'Comprehensive EIA by accredited consultants',
        'Expert Appraisal Committee presentation',
        'State government recommendation'
      ];
    } else if (category === 'B1') {
      return [
        ...baseRequirements,
        'State level expert appraisal',
        'District Collector certificate'
      ];
    } else {
      return [
        'Simplified project information',
        'Environmental clearance from SEIAA',
        'No public consultation required'
      ];
    }
  }
}

export const knowledgeVault = new KnowledgeVault();
export { LegalDocument, ISCode, ComplianceCheck };