import { beforeEach, describe, expect, it, vi } from 'vitest';
import { PoolErrorException } from '../../error/pool.error';
import { getUtxosFromTxInputs } from '../fee';

const testAncestorsResult = {
  totalAncestorsSize: 100,
  totalAncestorsFee: 200n,
};

vi.mock('@saturnbtcio/psbt', () => ({
  getTotalSizeAndFeesFromAncestors: vi.fn((txStatuses: any[]) => {
    return txStatuses.length === 0
      ? { totalAncestorsSize: 0, totalAncestorsFee: 0n }
      : testAncestorsResult;
  }),
}));

interface TestUtxo {
  txid: string;
  vout: number;
  value: bigint;
  collectionStatuses?: any[];
  hasInscription?: boolean;
  status: {
    confirmed: boolean;
  };
}

const createTestUtxo = (
  txid: string,
  vout: number,
  value: bigint,
  confirmed = true,
): TestUtxo => ({
  txid,
  vout,
  value,
  collectionStatuses: [],
  hasInscription: false,
  status: {
    confirmed,
  },
});

class TestTransaction {
  inputsLength: number;
  id: string;
  private inputs: any[];

  constructor(inputs: any[], id: string) {
    this.inputs = inputs;
    this.inputsLength = inputs.length;
    this.id = id;
  }

  getInput(i: number) {
    return this.inputs[i];
  }
}

const createTestInput = (txidStr: string, index: number) => ({
  txid: Buffer.from(txidStr),
  index,
});

describe('getUtxosFromTxInputs', () => {
  let testTx: TestTransaction;
  let walletUtxos: TestUtxo[];

  beforeEach(() => {
    walletUtxos = [
      createTestUtxo('747841', 0, 1000n, true), // 747841 encoded txA
      createTestUtxo('747842', 1, 2000n, true), // 747842 encoded txB
    ];
  });

  it('Returns empty array for a transaction with no inputs', () => {
    testTx = new TestTransaction([], 'dummyTxId'); // tx with no inputs

    const result = getUtxosFromTxInputs(testTx as any, walletUtxos as any);

    expect(result).toStrictEqual([]);
  });

  it('Processes each input and returns correct totals when inputs are valid', () => {
    const input0 = createTestInput('txA', 0);
    const input1 = createTestInput('txB', 1);
    testTx = new TestTransaction([input0, input1], 'dummyTxId');

    const result = getUtxosFromTxInputs(testTx as any, walletUtxos as any);

    expect(result[0].txid).toBe('747841');
    expect(result[1].txid).toBe('747842');
  });

  it('Throws an error if an input has txid but no matching wallet utxo', () => {
    const input0 = createTestInput('txC', 0);
    testTx = new TestTransaction([input0], 'dummyTxId');

    expect(() => {
      getUtxosFromTxInputs(testTx as any, walletUtxos as any);
    }).toThrow(PoolErrorException);
  });
});