import * as plugins from './plugins.js';
import { getDbSync } from './skr.database.js';
import { Account } from './skr.classes.account.js';
import type {
  TSKRType,
  TTransactionStatus,
  ITransactionData,
} from './skr.types.js';

const { SmartDataDbDoc, svDb, unI, index, searchable } = plugins.smartdata;

@plugins.smartdata.Collection(() => getDbSync())
export class Transaction extends SmartDataDbDoc<Transaction, Transaction> {
  @unI()
  public id: string;

  @svDb()
  @index()
  public transactionNumber: string;

  @svDb()
  @index()
  public date: Date;

  @svDb()
  @index()
  public debitAccount: string;

  @svDb()
  @index()
  public creditAccount: string;

  @svDb()
  public amount: number;

  @svDb()
  @searchable()
  public description: string;

  @svDb()
  @index()
  public reference: string;

  @svDb()
  @index()
  public skrType: TSKRType;

  @svDb()
  public vatAmount: number;

  @svDb()
  public costCenter: string;

  @svDb()
  @index()
  public status: TTransactionStatus;

  @svDb()
  public reversalOf: string;

  @svDb()
  public reversedBy: string;

  @svDb()
  @index()
  public period: string; // Format: YYYY-MM

  @svDb()
  public fiscalYear: number;

  @svDb()
  public createdAt: Date;

  @svDb()
  public postedAt: Date;

  @svDb()
  public createdBy: string;

  constructor(data?: Partial<ITransactionData>) {
    super();

    if (data) {
      this.id = plugins.smartunique.shortId();
      this.transactionNumber = this.generateTransactionNumber();
      this.date = data.date || new Date();
      this.debitAccount = data.debitAccount || '';
      this.creditAccount = data.creditAccount || '';
      this.amount = data.amount || 0;
      this.description = data.description || '';
      this.reference = data.reference || '';
      this.skrType = data.skrType || 'SKR03';
      this.vatAmount = data.vatAmount || 0;
      this.costCenter = data.costCenter || '';
      this.status = 'pending';
      this.reversalOf = '';
      this.reversedBy = '';

      // Set period and fiscal year
      const transDate = new Date(this.date);
      this.period = `${transDate.getFullYear()}-${String(transDate.getMonth() + 1).padStart(2, '0')}`;
      this.fiscalYear = transDate.getFullYear();

      this.createdAt = new Date();
      this.postedAt = null;
      this.createdBy = 'system';
    }
  }

  private generateTransactionNumber(): string {
    const timestamp = Date.now();
    const random = Math.floor(Math.random() * 1000);
    return `TXN-${timestamp}-${random}`;
  }

  public static async createTransaction(
    data: ITransactionData,
  ): Promise<Transaction> {
    const transaction = new Transaction(data);
    await transaction.validateAndPost();
    return transaction;
  }

  public static async getTransactionById(
    id: string,
  ): Promise<Transaction | null> {
    const transaction = await Transaction.getInstance({ id });
    return transaction;
  }

  public static async getTransactionsByAccount(
    accountNumber: string,
    skrType: TSKRType,
  ): Promise<Transaction[]> {
    const transactionsDebit = await Transaction.getInstances({
      debitAccount: accountNumber,
      skrType,
      status: 'posted',
    });
    const transactionsCredit = await Transaction.getInstances({
      creditAccount: accountNumber,
      skrType,
      status: 'posted',
    });
    const transactions = [...transactionsDebit, ...transactionsCredit];
    return transactions;
  }

  public static async getTransactionsByPeriod(
    period: string,
    skrType: TSKRType,
  ): Promise<Transaction[]> {
    const transactions = await Transaction.getInstances({
      period,
      skrType,
      status: 'posted',
    });
    return transactions;
  }

  public static async getTransactionsByDateRange(
    dateFrom: Date,
    dateTo: Date,
    skrType: TSKRType,
  ): Promise<Transaction[]> {
    const allTransactions = await Transaction.getInstances({
      skrType,
      status: 'posted',
    });
    const transactions = allTransactions.filter(
      (t) => t.date >= dateFrom && t.date <= dateTo,
    );
    return transactions;
  }

  public async validateAndPost(): Promise<void> {
    // Validate transaction
    await this.validateTransaction();

    // Update account balances
    await this.updateAccountBalances();

    // Mark as posted
    this.status = 'posted';
    this.postedAt = new Date();

    await this.save();
  }

  private async validateTransaction(): Promise<void> {
    // Check if accounts exist
    const debitAccount = await Account.getAccountByNumber(
      this.debitAccount,
      this.skrType,
    );
    const creditAccount = await Account.getAccountByNumber(
      this.creditAccount,
      this.skrType,
    );

    if (!debitAccount) {
      throw new Error(
        `Debit account ${this.debitAccount} not found for ${this.skrType}`,
      );
    }

    if (!creditAccount) {
      throw new Error(
        `Credit account ${this.creditAccount} not found for ${this.skrType}`,
      );
    }

    // Check if accounts are active
    if (!debitAccount.isActive) {
      throw new Error(`Debit account ${this.debitAccount} is not active`);
    }

    if (!creditAccount.isActive) {
      throw new Error(`Credit account ${this.creditAccount} is not active`);
    }

    // Validate amount
    if (this.amount <= 0) {
      throw new Error('Transaction amount must be greater than zero');
    }

    // Check for same account
    if (this.debitAccount === this.creditAccount) {
      throw new Error('Debit and credit accounts cannot be the same');
    }
  }

  private async updateAccountBalances(): Promise<void> {
    const debitAccount = await Account.getAccountByNumber(
      this.debitAccount,
      this.skrType,
    );
    const creditAccount = await Account.getAccountByNumber(
      this.creditAccount,
      this.skrType,
    );

    if (debitAccount) {
      await debitAccount.updateBalance(this.amount, 0);
    }

    if (creditAccount) {
      await creditAccount.updateBalance(0, this.amount);
    }
  }

  public async reverseTransaction(): Promise<Transaction> {
    if (this.status !== 'posted') {
      throw new Error('Can only reverse posted transactions');
    }

    if (this.reversedBy) {
      throw new Error('Transaction has already been reversed');
    }

    // Create reversal transaction
    const reversalData: ITransactionData = {
      date: new Date(),
      debitAccount: this.creditAccount, // Swap accounts
      creditAccount: this.debitAccount, // Swap accounts
      amount: this.amount,
      description: `Reversal of ${this.transactionNumber}: ${this.description}`,
      reference: `REV-${this.transactionNumber}`,
      skrType: this.skrType,
      vatAmount: this.vatAmount,
      costCenter: this.costCenter,
    };

    const reversalTransaction = new Transaction(reversalData);
    reversalTransaction.reversalOf = this.id;
    await reversalTransaction.validateAndPost();

    // Update original transaction
    this.reversedBy = reversalTransaction.id;
    this.status = 'reversed';
    await this.save();

    return reversalTransaction;
  }

  public async beforeSave(): Promise<void> {
    // Additional validation before saving
    if (!this.debitAccount || !this.creditAccount) {
      throw new Error('Both debit and credit accounts are required');
    }

    if (!this.date) {
      throw new Error('Transaction date is required');
    }

    if (!this.description) {
      throw new Error('Transaction description is required');
    }
  }
}