using Opc.Ua;
using Shouldly;
using Xunit;
using ZB.MOM.WW.OtOpcUa.Client.CLI.Helpers;

namespace ZB.MOM.WW.OtOpcUa.Client.CLI.Tests;

public class NodeIdParserTests
{
    /// <summary>Verifies that Parse returns null for null input.</summary>
    [Fact]
    public void Parse_NullInput_ReturnsNull()
    {
        NodeIdParser.Parse(null).ShouldBeNull();
    }

    /// <summary>Verifies that Parse returns null for empty string input.</summary>
    [Fact]
    public void Parse_EmptyString_ReturnsNull()
    {
        NodeIdParser.Parse("").ShouldBeNull();
    }

    /// <summary>Verifies that Parse returns null for whitespace-only input.</summary>
    [Fact]
    public void Parse_WhitespaceOnly_ReturnsNull()
    {
        NodeIdParser.Parse("   ").ShouldBeNull();
    }

    /// <summary>Verifies that Parse correctly parses standard NodeId format (ns=2;s=MyNode).</summary>
    [Fact]
    public void Parse_StandardStringFormat_ReturnsNodeId()
    {
        var result = NodeIdParser.Parse("ns=2;s=MyNode");
        result.ShouldNotBeNull();
        result.Value.NamespaceIndex.ShouldBe((ushort)2);
        result.Value.IdentifierAsString.ShouldBe("MyNode");
    }

    /// <summary>Verifies that Parse correctly parses numeric NodeId format (i=85).</summary>
    [Fact]
    public void Parse_NumericFormat_ReturnsNodeId()
    {
        var result = NodeIdParser.Parse("i=85");
        result.ShouldNotBeNull();
        result.Value.IdType.ShouldBe(IdType.Numeric);
    }

    /// <summary>Verifies that Parse treats bare numeric input as namespace 0 numeric NodeId.</summary>
    [Fact]
    public void Parse_BareNumeric_ReturnsNamespace0NumericNodeId()
    {
        var result = NodeIdParser.Parse("85");
        result.ShouldNotBeNull();
        result.Value.NamespaceIndex.ShouldBe((ushort)0);
        result.Value.TryGetValue(out uint identifier).ShouldBeTrue();
        identifier.ShouldBe(85u);
    }

    /// <summary>Verifies that Parse trims whitespace padding from input.</summary>
    [Fact]
    public void Parse_WithWhitespacePadding_Trims()
    {
        var result = NodeIdParser.Parse("  ns=2;s=MyNode  ");
        result.ShouldNotBeNull();
        result.Value.IdentifierAsString.ShouldBe("MyNode");
    }

    /// <summary>Verifies that Parse throws FormatException for invalid input.</summary>
    [Fact]
    public void Parse_InvalidFormat_ThrowsFormatException()
    {
        Should.Throw<FormatException>(() => NodeIdParser.Parse("not-a-node-id"));
    }

    /// <summary>Verifies that ParseRequired throws ArgumentException for null input.</summary>
    [Fact]
    public void ParseRequired_NullInput_ThrowsArgumentException()
    {
        Should.Throw<ArgumentException>(() => NodeIdParser.ParseRequired(null));
    }

    /// <summary>Verifies that ParseRequired throws ArgumentException for empty input.</summary>
    [Fact]
    public void ParseRequired_EmptyInput_ThrowsArgumentException()
    {
        Should.Throw<ArgumentException>(() => NodeIdParser.ParseRequired(""));
    }

    /// <summary>Verifies that ParseRequired returns a NodeId for valid input.</summary>
    [Fact]
    public void ParseRequired_ValidInput_ReturnsNodeId()
    {
        var result = NodeIdParser.ParseRequired("ns=2;s=TestNode");
        result.IsNull.ShouldBeFalse();
        result.IdentifierAsString.ShouldBe("TestNode");
    }

    [Fact]
    public void Parse_OpaqueIdentifier_PreservesBytes()
    {
        var node = NodeIdParser.ParseRequired("ns=3;b=AQID");
        node.IdType.ShouldBe(IdType.Opaque);
        node.NamespaceIndex.ShouldBe((ushort)3);
        node.TryGetValue(out ByteString bytes).ShouldBeTrue();
        bytes.ToArray().ShouldBe(new byte[] { 1, 2, 3 });
    }

    [Fact]
    public void Parse_StringIdentifierContainingEncodedText_StaysLiteral()
    {
        var node = NodeIdParser.ParseRequired("ns=4;s=ns=2;b=AQID");
        node.IdType.ShouldBe(IdType.String);
        node.NamespaceIndex.ShouldBe((ushort)4);
        node.TryGetValue(out string? identifier).ShouldBeTrue();
        identifier.ShouldBe("ns=2;b=AQID");
    }

    [Theory]
    [InlineData("ns=bad;i=1")]
    [InlineData("ns=2;b=invalid!")]
    [InlineData("ns=2;i=invalid")]
    public void Parse_InvalidEncodedIdentifier_IsRejected(string input)
    {
        Should.Throw<FormatException>(() => NodeIdParser.ParseRequired(input));
    }
}