using System.Runtime.CompilerServices;
using Luna.Agents.Abstractions;
using Luna.Configuration;
using Luna.Providers.Abstractions;
using Microsoft.Extensions.AI;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Options;

namespace Luna.Agents.Librarian;

public class LibrarianAgent(
    [FromKeyedServices("Mistral")] IProvider provider,
    IOptionsMonitor<AgentOptions> options)
    : IAgent
{
    private readonly IChatClient chatClient = provider.GetChatClient(options.Get(Name).ModelId);

    public static string Name => "Librarian";
    
    public string DisplayName => Options.DisplayName ?? Name;
    public string Description => Options.Description ?? string.Empty;
    public AgentOptions Options { get; init; } = options.Get(Name);
    
    public async Task<IEnumerable<ChatMessage>> ProcessAsync(
        IReadOnlyList<ChatMessage> messages,
        CancellationToken ct)
    {
        var chatOptions = new ChatOptions
        {
            Instructions = Options.Instructions
        };

        var messagesWithoutSystemPrompt = messages
            .Where(m => m.Role != ChatRole.System)
            .ToList();
        
        var response = await chatClient.GetResponseAsync(messagesWithoutSystemPrompt, chatOptions, ct);
        return response.Messages
            .Where(m => m.Role != ChatRole.System);
    }

    public async IAsyncEnumerable<ChatResponseUpdate> ProcessStreamingAsync(
        IReadOnlyList<ChatMessage> messages,
        [EnumeratorCancellation] CancellationToken ct = default)
    {
        var chatOptions = new ChatOptions
        {
            Instructions = Options.Instructions
        };

        var messagesWithoutSystemPrompt = messages
            .Where(m => m.Role != ChatRole.System)
            .ToList();

        await foreach (var update in chatClient.GetStreamingResponseAsync(messagesWithoutSystemPrompt, chatOptions, ct))
        {
            if (update.Role != ChatRole.System)
            {
                yield return update;
            }
        }
    }
}