using FluentAssertions;
using Purrse.Core.Helpers;

namespace Purrse.Tests.Helpers;

public class TransactionFingerprintTests
{
    [Fact]
    public void Generate_SameInputs_ReturnsSameHash()
    {
        var accountId = Guid.NewGuid();
        var date = new DateTime(2024, 1, 15);
        var amount = -42.50m;
        var fitId = "FIT123";

        var hash1 = TransactionFingerprint.Generate(accountId, date, amount, fitId);
        var hash2 = TransactionFingerprint.Generate(accountId, date, amount, fitId);

        hash1.Should().Be(hash2);
    }

    [Fact]
    public void Generate_DifferentAmounts_ReturnsDifferentHash()
    {
        var accountId = Guid.NewGuid();
        var date = new DateTime(2024, 1, 15);

        var hash1 = TransactionFingerprint.Generate(accountId, date, -42.50m, "FIT123");
        var hash2 = TransactionFingerprint.Generate(accountId, date, -42.51m, "FIT123");

        hash1.Should().NotBe(hash2);
    }

    [Fact]
    public void Generate_NullFitId_StillWorks()
    {
        var accountId = Guid.NewGuid();
        var date = new DateTime(2024, 1, 15);

        var hash = TransactionFingerprint.Generate(accountId, date, -42.50m, null);

        hash.Should().NotBeNullOrEmpty();
        hash.Should().HaveLength(64); // SHA256 hex = 64 chars
    }

    [Fact]
    public void Generate_DifferentAccounts_ReturnsDifferentHash()
    {
        var date = new DateTime(2024, 1, 15);

        var hash1 = TransactionFingerprint.Generate(Guid.NewGuid(), date, -42.50m, null);
        var hash2 = TransactionFingerprint.Generate(Guid.NewGuid(), date, -42.50m, null);

        hash1.Should().NotBe(hash2);
    }
}