const BaseFinancialRepository = require('./BaseFinancialRepository');

/**
 * Transaction Line Repository
 * 
 * Manages transaction lines for double-entry bookkeeping.
 * Each transaction should have balanced debit and credit lines.
 */
class TransactionLineRepository extends BaseFinancialRepository {
  constructor() {
    super('pg_fn_transaction_lines');
  }

  /**
   * Find lines for a transaction
   * @param {string} transactionId - Transaction ID
   * @returns {Promise<Array>} Array of transaction lines
   */
  async findByTransactionId(transactionId) {
    try {
      return await this.findAll({ transaction_id: transactionId }, { orderBy: 'created_at' });
    } catch (error) {
      throw error;
    }
  }

  /**
   * Find lines for an account
   * @param {string} accountId - Account ID
   * @returns {Promise<Array>} Array of transaction lines
   */
  async findByAccountId(accountId) {
    try {
      return await this.findAll({ account_id: accountId }, { 
        orderBy: 'created_at',
        orderDirection: 'desc'
      });
    } catch (error) {
      throw error;
    }
  }

  /**
   * Create transaction lines in batch
   * @param {Array<Object>} lines - Array of transaction lines
   * @returns {Promise<Array>} Created lines
   */
  async createLines(lines) {
    try {
      const createdLines = [];
      for (const line of lines) {
        const created = await this.create(line);
        createdLines.push(created);
      }
      return createdLines;
    } catch (error) {
      throw error;
    }
  }

  /**
   * Validate double-entry balance
   * @param {Array<Object>} lines - Transaction lines
   * @returns {boolean} True if debits equal credits
   */
  validateBalance(lines) {
    const totalDebits = lines.reduce((sum, line) => sum + parseFloat(line.debit_amount || 0), 0);
    const totalCredits = lines.reduce((sum, line) => sum + parseFloat(line.credit_amount || 0), 0);
    return totalDebits === totalCredits;
  }
}

module.exports = TransactionLineRepository;