import * as plugins from './plugins.js';
import * as path from 'path';
import type { IAccountBalance } from './skr.types.js';

// Extended interface for export with additional fields
export interface IAccountBalanceExport extends IAccountBalance {
  openingBalance?: number;
  transactionCount?: number;
}

export interface IBalanceExportRow {
  account_code: string;
  account_name: string;
  fiscal_year: number;
  period?: string;
  opening_balance: string;
  closing_balance: string;
  debit_sum: string;
  credit_sum: string;
  balance: string;
  transaction_count: number;
}

export class BalancesExporter {
  private exportPath: string;
  private balances: IBalanceExportRow[] = [];
  private fiscalYear: number;
  
  constructor(exportPath: string, fiscalYear: number) {
    this.exportPath = exportPath;
    this.fiscalYear = fiscalYear;
  }

  /**
   * Adds a balance entry to the export
   */
  public addBalance(
    accountCode: string,
    accountName: string,
    balance: IAccountBalanceExport,
    period?: string
  ): void {
    const exportRow: IBalanceExportRow = {
      account_code: accountCode,
      account_name: accountName,
      fiscal_year: this.fiscalYear,
      period: period,
      opening_balance: (balance.openingBalance || 0).toFixed(2),
      closing_balance: balance.balance.toFixed(2),
      debit_sum: balance.debitTotal.toFixed(2),
      credit_sum: balance.creditTotal.toFixed(2),
      balance: balance.balance.toFixed(2),
      transaction_count: balance.transactionCount || 0
    };
    
    this.balances.push(exportRow);
  }

  /**
   * Exports balances to CSV format
   */
  public async exportToCSV(): Promise<void> {
    const csvPath = path.join(this.exportPath, 'data', 'accounting', 'balances.csv');
    await plugins.smartfile.fs.ensureDir(path.dirname(csvPath));
    
    // Create CSV header
    const headers = [
      'account_code',
      'account_name',
      'fiscal_year',
      'period',
      'opening_balance',
      'closing_balance',
      'debit_sum',
      'credit_sum',
      'balance',
      'transaction_count'
    ];
    
    let csvContent = headers.join(',') + '\n';
    
    // Sort balances by account code
    this.balances.sort((a, b) => a.account_code.localeCompare(b.account_code));
    
    // Add balance rows
    for (const balance of this.balances) {
      const row = [
        this.escapeCSV(balance.account_code),
        this.escapeCSV(balance.account_name),
        balance.fiscal_year.toString(),
        this.escapeCSV(balance.period || ''),
        balance.opening_balance,
        balance.closing_balance,
        balance.debit_sum,
        balance.credit_sum,
        balance.balance,
        balance.transaction_count.toString()
      ];
      
      csvContent += row.join(',') + '\n';
    }
    
    await plugins.smartfile.memory.toFs(csvContent, csvPath);
  }

  /**
   * Exports trial balance (Summen- und Saldenliste)
   */
  public async exportTrialBalance(): Promise<void> {
    const csvPath = path.join(this.exportPath, 'data', 'accounting', 'trial_balance.csv');
    await plugins.smartfile.fs.ensureDir(path.dirname(csvPath));
    
    // Create CSV header for trial balance
    const headers = [
      'Konto',
      'Bezeichnung',
      'Anfangssaldo',
      'Soll',
      'Haben',
      'Saldo',
      'Endsaldo'
    ];
    
    let csvContent = headers.join(',') + '\n';
    
    // Add rows with German formatting
    for (const balance of this.balances) {
      const row = [
        this.escapeCSV(balance.account_code),
        this.escapeCSV(balance.account_name),
        this.formatGermanNumber(parseFloat(balance.opening_balance)),
        this.formatGermanNumber(parseFloat(balance.debit_sum)),
        this.formatGermanNumber(parseFloat(balance.credit_sum)),
        this.formatGermanNumber(parseFloat(balance.debit_sum) - parseFloat(balance.credit_sum)),
        this.formatGermanNumber(parseFloat(balance.closing_balance))
      ];
      
      csvContent += row.join(',') + '\n';
    }
    
    // Add totals row
    const totalDebit = this.balances.reduce((sum, b) => sum + parseFloat(b.debit_sum), 0);
    const totalCredit = this.balances.reduce((sum, b) => sum + parseFloat(b.credit_sum), 0);
    
    csvContent += '\n';
    csvContent += [
      'SUMME',
      '',
      '',
      this.formatGermanNumber(totalDebit),
      this.formatGermanNumber(totalCredit),
      this.formatGermanNumber(totalDebit - totalCredit),
      ''
    ].join(',') + '\n';
    
    await plugins.smartfile.memory.toFs(csvContent, csvPath);
  }

  /**
   * Exports balances to JSON format
   */
  public async exportToJSON(): Promise<void> {
    const jsonPath = path.join(this.exportPath, 'data', 'accounting', 'balances.json');
    await plugins.smartfile.fs.ensureDir(path.dirname(jsonPath));
    
    const jsonData = {
      schema_version: '1.0',
      export_date: new Date().toISOString(),
      fiscal_year: this.fiscalYear,
      balances: this.balances,
      totals: {
        total_debit: this.balances.reduce((sum, b) => sum + parseFloat(b.debit_sum), 0).toFixed(2),
        total_credit: this.balances.reduce((sum, b) => sum + parseFloat(b.credit_sum), 0).toFixed(2),
        account_count: this.balances.length
      }
    };
    
    await plugins.smartfile.memory.toFs(
      JSON.stringify(jsonData, null, 2),
      jsonPath
    );
  }

  /**
   * Generates balance summary for specific account classes
   */
  public async exportClassSummary(): Promise<void> {
    const csvPath = path.join(this.exportPath, 'data', 'accounting', 'class_summary.csv');
    await plugins.smartfile.fs.ensureDir(path.dirname(csvPath));
    
    // Group balances by account class (first digit of account code)
    const classSummary: { [key: string]: { debit: number; credit: number; balance: number } } = {};
    
    for (const balance of this.balances) {
      const accountClass = balance.account_code.charAt(0);
      
      if (!classSummary[accountClass]) {
        classSummary[accountClass] = { debit: 0, credit: 0, balance: 0 };
      }
      
      classSummary[accountClass].debit += parseFloat(balance.debit_sum);
      classSummary[accountClass].credit += parseFloat(balance.credit_sum);
      classSummary[accountClass].balance += parseFloat(balance.balance);
    }
    
    // Create CSV
    let csvContent = 'Kontenklasse,Bezeichnung,Soll,Haben,Saldo\n';
    
    const classNames: { [key: string]: string } = {
      '0': 'Anlagevermögen',
      '1': 'Umlaufvermögen',
      '2': 'Eigenkapital',
      '3': 'Fremdkapital',
      '4': 'Betriebliche Erträge',
      '5': 'Materialaufwand',
      '6': 'Betriebsaufwand',
      '7': 'Weitere Aufwendungen',
      '8': 'Erträge',
      '9': 'Abschlusskonten'
    };
    
    for (const [classNum, summary] of Object.entries(classSummary)) {
      const row = [
        classNum,
        this.escapeCSV(classNames[classNum] || `Klasse ${classNum}`),
        this.formatGermanNumber(summary.debit),
        this.formatGermanNumber(summary.credit),
        this.formatGermanNumber(summary.balance)
      ];
      
      csvContent += row.join(',') + '\n';
    }
    
    await plugins.smartfile.memory.toFs(csvContent, csvPath);
  }

  /**
   * Escapes CSV values
   */
  private escapeCSV(value: string): string {
    if (value.includes(',') || value.includes('"') || value.includes('\n')) {
      return `"${value.replace(/"/g, '""')}"`;
    }
    return value;
  }

  /**
   * Formats number in German format (1.234,56)
   */
  private formatGermanNumber(value: number): string {
    return value.toLocaleString('de-DE', {
      minimumFractionDigits: 2,
      maximumFractionDigits: 2
    });
  }

  /**
   * Gets the number of balance entries
   */
  public getBalanceCount(): number {
    return this.balances.length;
  }

  /**
   * Clears the balances list
   */
  public clear(): void {
    this.balances = [];
  }
}