> ## Documentation Index
> Fetch the complete documentation index at: https://numadocs.secc.org/llms.txt
> Use this file to discover all available pages before exploring further.

# Message Service

> Handles logic related to the `Message` model.

Namespace: [Numa.Services](numaservices)<br />
Related Models: [Message.cs](../models/message)<br />
Related Interfaces: `IMessageService.cs`

## Fields

| Field Name          | Type                             | Description                                                               |
| :------------------ | :------------------------------- | :------------------------------------------------------------------------ |
| `_dbContextFactory` | `IDbContextFactory<NumaContext>` | `DbContextFactory` for instantiating instances of `NumaContext` on-demand |

## Constructor

```csharp theme={null}
public MessageService( IDbContextFactory<NumaContext> dbContextFactory )
{
    _dbContextFactory = dbContextFactory ?? throw new ArgumentNullException( nameof( dbContextFactory ) );
}
```

## Properties

`MessageService` does not have any properties.

## Methods

| Method Name                        | Description                                                                              | Parameters | Return Type           |
| :--------------------------------- | :--------------------------------------------------------------------------------------- | :--------- | :-------------------- |
| `GetMessagesByConversationIdAsync` | Gets a list of messages for a conversation in ascending order by their `CreatedDatetime` | `string`   | `Task<List<Message>>` |
| `AddMessageAsync`                  | Adds a message to the Cosmos DB                                                          | `Message`  | `Task`                |

## IMessageService.cs

```csharp theme={null}
using Numa.Models;

namespace Numa.Interfaces
{
    public interface IMessageService
    {
        Task<List<Message>> GetMessagesByConversationIdAsync( string conversationId );
        Task AddMessageAsync(Message newMessage);
    }
}
```