using ZB.MOM.WW.ScadaBridge.Commons.Types;

namespace ZB.MOM.WW.ScadaBridge.CLI.Tests;

/// <summary>
/// Verifies the CSV parsing behaviour that backs <c>instance import-overrides</c>:
/// parse errors block the apply step; valid CSV produces the expected
/// <c>attributeName → value</c> dictionary that <see cref="SetInstanceOverridesCommand"/>
/// consumes.
/// </summary>
public class ImportOverridesTests
{
    // ── error path ───────────────────────────────────────────────────────────

    /// <summary>Verifies that a CSV with a missing header produces errors.</summary>
    [Fact]
    public void CsvWithMissingHeader_ProducesErrors()
    {
        var result = OverrideCsvParser.Parse("Speed,100");

        Assert.NotEmpty(result.Errors);
        Assert.Empty(result.Rows);
    }

    /// <summary>Verifies that a CSV row with a blank attribute name produces an error.</summary>
    [Fact]
    public void CsvWithBlankAttributeName_ProducesError()
    {
        const string csv = "AttributeName,Value\n,100";
        var result = OverrideCsvParser.Parse(csv);

        Assert.NotEmpty(result.Errors);
        // The bad row is excluded; no rows flow through.
        Assert.Empty(result.Rows);
    }

    /// <summary>Verifies that a CSV row with the wrong column count produces an error.</summary>
    [Fact]
    public void CsvWithWrongColumnCount_ProducesError()
    {
        const string csv = "AttributeName,Value\nSpeed,100,extra";
        var result = OverrideCsvParser.Parse(csv);

        Assert.NotEmpty(result.Errors);
        Assert.Empty(result.Rows);
    }

    // ── happy path ───────────────────────────────────────────────────────────

    /// <summary>Verifies that a valid CSV produces the expected overrides dictionary.</summary>
    [Fact]
    public void ValidCsv_ProducesCorrectOverridesDictionary()
    {
        const string csv = """
            AttributeName,Value
            Speed,100
            Mode,
            Label,Hello
            """;

        var parseResult = OverrideCsvParser.Parse(csv);

        Assert.Empty(parseResult.Errors);
        Assert.Equal(3, parseResult.Rows.Count);

        // Build the same dictionary that BuildImportOverrides produces.
        var overrides = parseResult.Rows.ToDictionary(r => r.AttributeName, r => r.Value);

        Assert.Equal("100", overrides["Speed"]);
        Assert.Null(overrides["Mode"]);      // empty Value → null → clear the override
        Assert.Equal("Hello", overrides["Label"]);
    }

    /// <summary>Verifies that the element type column of a valid CSV is ignored when building the overrides dictionary.</summary>
    [Fact]
    public void ValidCsvWithElementTypeColumn_OverridesDictIgnoresElementType()
    {
        const string csv = """
            AttributeName,Value,ElementType
            Speed,100,Float
            Mode,,
            """;

        var parseResult = OverrideCsvParser.Parse(csv);

        Assert.Empty(parseResult.Errors);
        Assert.Equal(2, parseResult.Rows.Count);

        // ElementType is carried on the row but SetInstanceOverridesCommand only
        // takes attributeName → value; confirm the dict shape matches.
        var overrides = parseResult.Rows.ToDictionary(r => r.AttributeName, r => r.Value);

        Assert.Equal("100", overrides["Speed"]);
        Assert.Null(overrides["Mode"]);
    }
}