import * as path from 'path';
import { promises as fs } from 'fs';
import { EInvoice } from '../../ts/einvoice.js';
import type { TInvoice } from '../../ts/interfaces/common.js';
import { InvoiceFormat } from '../../ts/interfaces/common.js';
import { business, finance } from '../../ts/plugins.js';
import { CorpusLoader } from './corpus.loader.js';
import { PerformanceTracker } from './performance.tracker.js';

// Re-export helpers for convenience
export { CorpusLoader, PerformanceTracker };

/**
 * Test utilities for EInvoice testing
 */

/**
 * Test file categories based on the corpus
 */
export const TestFileCategories = {
  CII_XMLRECHNUNG: 'test/assets/corpus/XML-Rechnung/CII',
  UBL_XMLRECHNUNG: 'test/assets/corpus/XML-Rechnung/UBL',
  ZUGFERD_V1_CORRECT: 'test/assets/corpus/ZUGFeRDv1/correct',
  ZUGFERD_V1_FAIL: 'test/assets/corpus/ZUGFeRDv1/fail',
  ZUGFERD_V2_CORRECT: 'test/assets/corpus/ZUGFeRDv2/correct',
  ZUGFERD_V2_FAIL: 'test/assets/corpus/ZUGFeRDv2/fail',
  PEPPOL: 'test/assets/corpus/PEPPOL/Valid/Qvalia',
  FATTURAPA: 'test/assets/corpus/fatturaPA',
  EN16931_UBL_INVOICE: 'test/assets/eInvoicing-EN16931/test/Invoice-unit-UBL',
  EN16931_UBL_CREDITNOTE: 'test/assets/eInvoicing-EN16931/test/CreditNote-unit-UBL',
  EN16931_EXAMPLES_CII: 'test/assets/eInvoicing-EN16931/cii/examples',
  EN16931_EXAMPLES_UBL: 'test/assets/eInvoicing-EN16931/ubl/examples',
  EN16931_EXAMPLES_EDIFACT: 'test/assets/eInvoicing-EN16931/edifact/examples'
} as const;

/**
 * Test data factory for creating test invoices
 */
export class TestInvoiceFactory {
  /**
   * Creates a minimal valid test invoice
   */
  static createMinimalInvoice(): Partial<TInvoice> {
    return {
      id: 'TEST-' + Date.now(),
      accountingDocId: 'INV-TEST-001',
      accountingDocType: 'invoice',
      type: 'accounting-doc',
      date: Date.now(),
      accountingDocStatus: 'draft',
      subject: 'Test Invoice',
      from: {
        name: 'Test Seller Company',
        type: 'company',
        description: 'Test seller',
        address: {
          streetName: 'Test Street',
          houseNumber: '1',
          city: 'Test City',
          country: 'Germany',
          postalCode: '12345'
        },
        status: 'active',
        foundedDate: { year: 2020, month: 1, day: 1 },
        registrationDetails: {
          vatId: 'DE123456789',
          registrationId: 'HRB 12345',
          registrationName: 'Test Registry'
        }
      },
      to: {
        name: 'Test Buyer Company',
        type: 'company',
        description: 'Test buyer',
        address: {
          streetName: 'Buyer Street',
          houseNumber: '2',
          city: 'Buyer City',
          country: 'France',
          postalCode: '75001'
        },
        status: 'active',
        foundedDate: { year: 2019, month: 6, day: 15 },
        registrationDetails: {
          vatId: 'FR987654321',
          registrationId: 'RCS 98765',
          registrationName: 'French Registry'
        }
      },
      items: [{
        position: 1,
        name: 'Test Product',
        articleNumber: 'TEST-001',
        unitType: 'EA',
        unitQuantity: 1,
        unitNetPrice: 100,
        vatPercentage: 19
      }],
      currency: 'EUR',
      language: 'en',
      objectActions: [],
      versionInfo: {
        type: 'draft',
        version: '1.0.0'
      }
    };
  }

  /**
   * Creates a complex test invoice with multiple items and features
   */
  static createComplexInvoice(): Partial<TInvoice> {
    const baseInvoice = this.createMinimalInvoice();
    return {
      ...baseInvoice,
      items: [
        {
          position: 1,
          name: 'Professional Service',
          articleNumber: 'SERV-001',
          unitType: 'HUR',
          unitQuantity: 8,
          unitNetPrice: 150,
          vatPercentage: 19,
          // description: 'Consulting services'
        },
        {
          position: 2,
          name: 'Software License',
          articleNumber: 'SOFT-001',
          unitType: 'EA',
          unitQuantity: 5,
          unitNetPrice: 200,
          vatPercentage: 19,
          // description: 'Annual software license'
        },
        {
          position: 3,
          name: 'Training',
          articleNumber: 'TRAIN-001',
          unitType: 'DAY',
          unitQuantity: 2,
          unitNetPrice: 800,
          vatPercentage: 19,
          // description: 'On-site training'
        }
      ],
      paymentOptions: {
        description: 'Payment due within 30 days',
        sepaConnection: {
          iban: 'DE89370400440532013000',
          bic: 'COBADEFFXXX'
        },
        payPal: { email: 'test@example.com' }
      },
      notes: [
        'This is a test invoice for validation purposes',
        'All amounts are in EUR'
      ],
      periodOfPerformance: {
        from: Date.now() - 30 * 24 * 60 * 60 * 1000, // 30 days ago
        to: Date.now()
      },
      deliveryDate: Date.now(),
      buyerReference: 'PO-2024-001',
      dueInDays: 30,
      reverseCharge: false
    };
  }
}

/**
 * Test file helpers
 */
export class TestFileHelpers {
  /**
   * Gets all test files from a directory
   */
  static async getTestFiles(directory: string, pattern: string = '*'): Promise<string[]> {
    const basePath = path.join(process.cwd(), directory);
    const files: string[] = [];
    try {
      const entries = await fs.readdir(basePath, { withFileTypes: true });
      for (const entry of entries) {
        if (entry.isFile()) {
          const fileName = entry.name;
          if (pattern === '*' || fileName.match(pattern.replace('*', '.*'))) {
            files.push(path.join(directory, fileName));
          }
        }
      }
    } catch (error) {
      console.error(`Error reading directory ${basePath}:`, error);
    }
    return files;
  }

  /**
   * Loads a test file
   */
  static async loadTestFile(filePath: string): Promise<Buffer> {
    const fullPath = path.join(process.cwd(), filePath);
    return fs.readFile(fullPath);
  }

  /**
   * Gets corpus statistics
   */
  static async getCorpusStats(): Promise<{
    totalFiles: number;
    byFormat: Record<string, number>;
    byCategory: Record<string, number>;
  }> {
    const stats = {
      totalFiles: 0,
      byFormat: {} as Record<string, number>,
      byCategory: {} as Record<string, number>
    };

    for (const [category, path] of Object.entries(TestFileCategories)) {
      const files = await this.getTestFiles(path, '*.xml');
      const pdfFiles = await this.getTestFiles(path, '*.pdf');
      
      const totalCategoryFiles = files.length + pdfFiles.length;
      stats.totalFiles += totalCategoryFiles;
      stats.byCategory[category] = totalCategoryFiles;
    }

    return stats;
  }
}

/**
 * Test assertions for invoice validation
 */
export class InvoiceAssertions {
  /**
   * Asserts that an invoice has all required fields
   */
  static assertRequiredFields(invoice: EInvoice): void {
    const requiredFields = ['id', 'invoiceId', 'from', 'to', 'items', 'date'];
    
    for (const field of requiredFields) {
      if (!invoice[field as keyof EInvoice]) {
        throw new Error(`Required field '${field}' is missing`);
      }
    }
    
    // Check nested required fields
    if (!invoice.from.name || !invoice.from.address) {
      throw new Error('Seller information incomplete');
    }
    
    if (!invoice.to.name || !invoice.to.address) {
      throw new Error('Buyer information incomplete');
    }
    
    if (!invoice.items || invoice.items.length === 0) {
      throw new Error('Invoice must have at least one item');
    }
  }

  /**
   * Asserts that format detection works correctly
   */
  static assertFormatDetection(
    detectedFormat: InvoiceFormat,
    expectedFormat: InvoiceFormat,
    filePath: string
  ): void {
    if (detectedFormat !== expectedFormat) {
      throw new Error(
        `Format detection failed for ${filePath}: expected ${expectedFormat}, got ${detectedFormat}`
      );
    }
  }

  /**
   * Asserts validation results
   */
  static assertValidationResult(
    result: { valid: boolean; errors: any[] },
    expectedValid: boolean,
    filePath: string
  ): void {
    if (result.valid !== expectedValid) {
      const errorMessages = result.errors.map(e => e.message).join(', ');
      throw new Error(
        `Validation result mismatch for ${filePath}: expected ${expectedValid}, got ${result.valid}. Errors: ${errorMessages}`
      );
    }
  }
}

/**
 * Performance testing utilities
 */
export class PerformanceUtils {
  private static measurements = new Map<string, number[]>();

  /**
   * Measures execution time of an async function
   */
  static async measure<T>(
    name: string,
    fn: () => Promise<T>
  ): Promise<{ result: T; duration: number }> {
    const start = performance.now();
    const result = await fn();
    const duration = performance.now() - start;
    
    // Store measurement
    if (!this.measurements.has(name)) {
      this.measurements.set(name, []);
    }
    this.measurements.get(name)!.push(duration);
    
    return { result, duration };
  }

  /**
   * Gets performance statistics
   */
  static getStats(name: string): {
    count: number;
    min: number;
    max: number;
    avg: number;
    median: number;
  } | null {
    const measurements = this.measurements.get(name);
    if (!measurements || measurements.length === 0) {
      return null;
    }
    
    const sorted = [...measurements].sort((a, b) => a - b);
    const sum = sorted.reduce((a, b) => a + b, 0);
    
    return {
      count: sorted.length,
      min: sorted[0],
      max: sorted[sorted.length - 1],
      avg: sum / sorted.length,
      median: sorted[Math.floor(sorted.length / 2)]
    };
  }

  /**
   * Clears all measurements
   */
  static clear(): void {
    this.measurements.clear();
  }

  /**
   * Generates a performance report
   */
  static generateReport(): string {
    let report = 'Performance Report\n==================\n\n';
    
    for (const [name] of this.measurements) {
      const stats = this.getStats(name);
      if (stats) {
        report += `${name}:\n`;
        report += `  Executions: ${stats.count}\n`;
        report += `  Min: ${stats.min.toFixed(2)}ms\n`;
        report += `  Max: ${stats.max.toFixed(2)}ms\n`;
        report += `  Avg: ${stats.avg.toFixed(2)}ms\n`;
        report += `  Median: ${stats.median.toFixed(2)}ms\n\n`;
      }
    }
    
    return report;
  }
}