namespace Cepis.Tests;

/// <summary>The CSV reader behind the batch endpoint.</summary>
public sealed class CsvTests
{
    [Fact]
    public void ReadsTheHeaderAndOneRecord()
    {
        var rows = Csv.Parse("a,b,c\n1,2,3\n");

        var row = Assert.Single(rows);
        Assert.Equal("1", row["a"]);
        Assert.Equal("2", row["b"]);
        Assert.Equal("3", row["c"]);
    }

    [Fact]
    public void AQuotedValueMayContainACommaAndANewline()
    {
        var rows = Csv.Parse("a,b\n\"Praça da Sé, lado ímpar\",\"two\nlines\"\n");

        var row = Assert.Single(rows);
        Assert.Equal("Praça da Sé, lado ímpar", row["a"]);
        Assert.Equal("two\nlines", row["b"]);
    }

    [Fact]
    public void DoubledQuotesAreOneQuote()
    {
        var rows = Csv.Parse("a\n\"say \"\"hi\"\"\"\n");

        Assert.Equal("say \"hi\"", Assert.Single(rows)["a"]);
    }

    [Theory]
    [InlineData("a,b\n1,2\n")]
    [InlineData("a,b\r\n1,2\r\n")]
    [InlineData("a,b\r1,2\r")]
    [InlineData("a,b\n1,2")]
    public void EveryLineEndingWorks(string text)
    {
        var rows = Csv.Parse(text);

        Assert.Equal("1", Assert.Single(rows)["a"]);
    }

    [Fact]
    public void ALeadingByteOrderMarkIsDropped()
    {
        var rows = Csv.Parse("\uFEFFa,b\n1,2\n");

        Assert.Equal("1", Assert.Single(rows)["a"]);
    }

    [Fact]
    public void AnEmptyValueStaysEmpty()
    {
        var rows = Csv.Parse("a,b,c\n1,,3\n");

        Assert.Equal("", Assert.Single(rows)["b"]);
    }

    [Fact]
    public void AShortRecordIsFilledOut()
    {
        var rows = Csv.Parse("a,b,c\n1\n");

        var row = Assert.Single(rows);
        Assert.Equal("1", row["a"]);
        Assert.Equal("", row["b"]);
        Assert.Equal("", row["c"]);
    }

    [Fact]
    public void AHeaderAloneYieldsNoRecords() => Assert.Empty(Csv.Parse("a,b,c\n"));

    [Fact]
    public void AnEmptyDocumentYieldsNoRecords() => Assert.Empty(Csv.Parse(""));
}