import { type Address, encodeFunctionData, erc20Abi } from 'viem';
import { type Mock, describe, expect, it, vi } from 'vitest';
import { buildSendTransaction } from './buildSendTransaction';
import { ApiErrorCode } from './constants';

vi.mock('viem', async () => {
  const actual = await vi.importActual('viem');
  return {
    ...actual,
    encodeFunctionData: vi.fn(),
  };
});

describe('buildSendTransaction', () => {
  const mockRecipient = '0x742d35Cc6634C0532925a3b844Bc454e4438f44e';
  const mockToken = '0x1234567890123456789012345678901234567890';
  const mockAmount = 1000000000000000000n; // 1 ETH/token in wei

  it('should build native ETH transfer transaction', () => {
    const result = buildSendTransaction({
      recipientAddress: mockRecipient,
      tokenAddress: undefined as unknown as Address, // type assertion okay because we're testing the case where tokenAddress is undefined
      amount: mockAmount,
    });

    expect(result).toEqual({
      to: mockRecipient,
      data: '0x',
      value: mockAmount,
    });
  });

  it('should build ERC20 token transfer transaction', () => {
    const expectedCallData = encodeFunctionData({
      abi: erc20Abi,
      functionName: 'transfer',
      args: [mockRecipient, mockAmount],
    });

    const result = buildSendTransaction({
      recipientAddress: mockRecipient,
      tokenAddress: mockToken,
      amount: mockAmount,
    });

    expect(result).toEqual({
      to: mockToken,
      data: expectedCallData,
    });
  });

  it('should handle Error objects', () => {
    (encodeFunctionData as Mock).mockImplementation(() => {
      throw new Error('Test error');
    });
    const result = buildSendTransaction({
      recipientAddress: mockRecipient,
      tokenAddress: mockToken,
      amount: mockAmount,
    });

    expect(result).toMatchObject({
      code: ApiErrorCode.AmBSeTx01,
      message: 'Could not build transfer transaction',
      error: 'Test error',
    });
  });

  it('should handle non-Error objects', () => {
    (encodeFunctionData as Mock).mockImplementation(() => {
      throw 'Some string error';
    });
    const result = buildSendTransaction({
      recipientAddress: mockRecipient,
      tokenAddress: mockToken,
      amount: mockAmount,
    });

    expect(result).toMatchObject({
      code: 'AmBSeTx01',
      message: 'Could not build transfer transaction',
      error: 'Some string error',
    });
  });
});