import BlockchainTimeModel from '../../lib/core/models/BlockchainTimeModel';
import IBlockchain from '../../lib/core/interfaces/IBlockchain';
import TransactionModel from '../../lib/common/models/TransactionModel';

/**
 * Mock Blockchain class for testing.
 */
export default class MockBlockchain implements IBlockchain {
  /** Stores each hash given in write() method. */
  hashes: string[] = [];

  public async write (anchorString: string): Promise<void> {
    this.hashes.push(anchorString);
  }

  public async read (sinceTransactionNumber?: number, _transactionTimeHash?: string): Promise<{ moreTransactions: boolean, transactions: TransactionModel[] }> {
    if (sinceTransactionNumber === undefined) {
      sinceTransactionNumber = -1;
    }

    let moreTransactions = false;
    if (this.hashes.length > 0 &&
      sinceTransactionNumber < this.hashes.length - 2) {
      moreTransactions = true;
    }

    const transactions: TransactionModel[] = [];
    if (this.hashes.length > 0 &&
      sinceTransactionNumber < this.hashes.length - 1) {
      const hashIndex = sinceTransactionNumber + 1;
      const transaction = {
        transactionNumber: hashIndex,
        transactionTime: hashIndex,
        transactionTimeHash: this.hashes[hashIndex],
        anchorString: this.hashes[hashIndex]
      };
      transactions.push(transaction);
    }

    return {
      moreTransactions: moreTransactions,
      transactions: transactions
    };
  }

  public async getFirstValidTransaction (_transactions: TransactionModel[]): Promise<TransactionModel | undefined> {
    return undefined;
  }

  private latestTime?: BlockchainTimeModel = { time: 500000, hash: 'dummyHash' };

  public get approximateTime (): BlockchainTimeModel {
    return this.latestTime!;
  }
  /**
   * Hardcodes the latest time to be returned.
   */
  public setLatestTime (time: BlockchainTimeModel) {
    this.latestTime = time;
  }
}