using System;
using System.Buffers.Binary;
using AcDream.Core.Net.Messages;
using Xunit;

namespace AcDream.Core.Net.Tests.Messages;

public sealed class CastSpellTests
{
    [Fact]
    public void BuildUntargeted_EmitsCorrectWireBytes()
    {
        byte[] body = CastSpellRequest.BuildUntargeted(gameActionSequence: 5, spellId: 0x3E1);

        Assert.Equal(16, body.Length);
        Assert.Equal(CastSpellRequest.GameActionEnvelope,
            BinaryPrimitives.ReadUInt32LittleEndian(body));
        Assert.Equal(5u,
            BinaryPrimitives.ReadUInt32LittleEndian(body.AsSpan(4)));
        Assert.Equal(CastSpellRequest.UntargetedSubOpcode,
            BinaryPrimitives.ReadUInt32LittleEndian(body.AsSpan(8)));
        Assert.Equal(0x3E1u,
            BinaryPrimitives.ReadUInt32LittleEndian(body.AsSpan(12)));
    }

    [Fact]
    public void BuildTargeted_EmitsCorrectWireBytes()
    {
        byte[] body = CastSpellRequest.BuildTargeted(
            gameActionSequence: 7, targetGuid: 0xAAAAu, spellId: 0x3E1);

        Assert.Equal(20, body.Length);
        Assert.Equal(CastSpellRequest.TargetedSubOpcode,
            BinaryPrimitives.ReadUInt32LittleEndian(body.AsSpan(8)));
        Assert.Equal(0xAAAAu,
            BinaryPrimitives.ReadUInt32LittleEndian(body.AsSpan(12)));
        Assert.Equal(0x3E1u,
            BinaryPrimitives.ReadUInt32LittleEndian(body.AsSpan(16)));
    }

    [Fact]
    public void ParseMagicUpdateSpell_RoundTrip()
    {
        byte[] payload = new byte[4];
        BinaryPrimitives.WriteUInt32LittleEndian(payload, 0x3E1u);
        Assert.Equal(0x3E1u, GameEvents.ParseMagicUpdateSpell(payload));
    }

    [Fact]
    public void ParseMagicUpdateEnchantment_RoundTrip()
    {
        byte[] payload = new byte[16];
        BinaryPrimitives.WriteUInt32LittleEndian(payload,             42u);       // spellId
        BinaryPrimitives.WriteUInt32LittleEndian(payload.AsSpan(4),   7u);        // layerId
        BinaryPrimitives.WriteSingleLittleEndian(payload.AsSpan(8),   300.0f);    // duration
        BinaryPrimitives.WriteUInt32LittleEndian(payload.AsSpan(12),  0xBEEFu);   // caster

        var parsed = GameEvents.ParseMagicUpdateEnchantment(payload);
        Assert.NotNull(parsed);
        Assert.Equal(42u, parsed!.Value.SpellId);
        Assert.Equal(7u, parsed.Value.LayerId);
        Assert.Equal(300f, parsed.Value.Duration, 4);
        Assert.Equal(0xBEEFu, parsed.Value.CasterGuid);
    }

    [Fact]
    public void ParseMagicRemoveEnchantment_RoundTrip()
    {
        byte[] payload = new byte[8];
        BinaryPrimitives.WriteUInt32LittleEndian(payload,           7u);       // layerId
        BinaryPrimitives.WriteUInt32LittleEndian(payload.AsSpan(4), 42u);      // spellId

        var parsed = GameEvents.ParseMagicRemoveEnchantment(payload);
        Assert.NotNull(parsed);
        Assert.Equal(7u, parsed!.Value.LayerId);
        Assert.Equal(42u, parsed.Value.SpellId);
    }
}