// Generated from executable documentation examples. Edit the source region, then regenerate.
using System;
using System.IO;
using System.IO.Pipelines;
using System.Linq;
using System.Buffers;
using System.Collections.Generic;
using System.Dynamic;
using System.Globalization;
using System.Numerics;
using System.Runtime.CompilerServices;
using System.Threading;
using System.Threading.Tasks;
using CStructSharp;
using CStructSharp.Codecs;
using CStructSharp.Diagnostics;
using CStructSharp.Introspection;
using CStructSharp.Values;

internal static partial class Program
{
    public static void Main()
    {
        GeneratedViews();
        Console.WriteLine("PASS generated-views");
    }

    private static void GeneratedViews()
    {
        byte[] bytes = [0x02, 0x00, 0x06, 0x00, 0x00, 0x00];

        // A view decodes each member straight from the span when it is read; nothing is allocated for the header.
        var view = new Wire.HeaderView(bytes);
        Equal((ushort)2, view.Kind);
        Equal(6u, view.Length);
        Equal(6, view.Bytes.Length);

        // A view can become an object when one is wanted after all.
        Wire.Header header = view.ToObject();
        Equal(6u, header.Length);

        // Too few bytes fail the way the runtime fails: the same message, offset 0, path 'header'.
        try
        {
            _ = new Wire.HeaderView(bytes.AsSpan(0, 4));
            True(false, "a short source must fail");
        }
        catch (CStructReadException error)
        {
            Equal("Not enough bytes: needed 6, available 4 (path 'header', offset 0).", error.Message);
        }
    }

    private static void Equal<T>(T expected, T actual)
    {
        if (!EqualityComparer<T>.Default.Equals(expected, actual))
        {
            throw new InvalidOperationException($"Expected '{expected}', received '{actual}'.");
        }
    }

    private static void True(bool condition, string message)
    {
        if (!condition)
        {
            throw new InvalidOperationException(message);
        }
    }

    // The layout text lives in the attribute; the generator adds the members of this partial class at build time.
    [CStructLayout("struct header { uint16 kind; uint32 length; };")]
    public static partial class Wire
    {
    }
}