extension/WebJobs.Extensions.RabbitMQ/Trigger/BasicDeliverEventArgsValueProvider.cs

// Copyright (c) .NET Foundation. All rights reserved.
// Licensed under the MIT License. See License.txt in the project root for license information.

using System;
using System.Text;
using System.Threading.Tasks;
using Microsoft.Azure.WebJobs.Host.Bindings;
using Newtonsoft.Json;
using RabbitMQ.Client.Events;

namespace Microsoft.Azure.WebJobs.Extensions.RabbitMQ;

public class BasicDeliverEventArgsValueProvider(BasicDeliverEventArgs input, Type destinationType) : IValueProvider
{
    private readonly BasicDeliverEventArgs input = input;

    public Type Type { get; } = destinationType;

    public Task<object> GetValueAsync()
    {
        if (this.Type.Equals(typeof(BasicDeliverEventArgs)))
        {
            return Task.FromResult<object>(this.input);
        }
        else if (this.Type.Equals(typeof(ReadOnlyMemory<byte>)))
        {
            return Task.FromResult<object>(this.input.Body);
        }
        else if (this.Type.Equals(typeof(byte[])))
        {
            return Task.FromResult<object>(this.input.Body.ToArray());
        }

        string inputValue = this.ToInvokeString();
        if (this.Type.Equals(typeof(string)))
        {
            return Task.FromResult<object>(inputValue);
        }
        else
        {
            try
            {
                return Task.FromResult(JsonConvert.DeserializeObject(inputValue, this.Type));
            }
            catch (JsonException e)
            {
                // Give useful error if object in queue is not deserialized properly.
                string msg = $@"Binding parameters to complex objects (such as '{this.Type.Name}') uses Json.NET serialization. The JSON parser failed: {e.Message}";
                throw new InvalidOperationException(msg, e);
            }
        }
    }

    public string ToInvokeString()
    {
        return Encoding.UTF8.GetString(this.input.Body.ToArray());
    }
}