using Luna.Channels.Abstractions;
using Luna.Core.Abstractions;
using Luna.Identity.Abstractions;
using Luna.Shared;

namespace Luna.Channels.Web;

public class WebChannel(string channelId, IChatHubContext hubContext, IUserIdentityService identityService) : IChannel
{
    public string ChannelId { get; } = channelId;
    public string ChannelType => Abstractions.ChannelType.Web;
    public string DisplayName { get; } = "Web Interface";
    public bool IsConnected { get; }
    
    public event ChannelMessageReceivedEventHandler? MessageReceived;
    public event ChannelConnectionChangedEventHandler? ConnectionStateChanged;

    public Task<bool> VerifyChannelLinkAsync()
        => Task.FromResult(true);
    
    public async Task SendStreamingMessageAsync(IAsyncEnumerable<ChatStreamUpdate> messageStream, CancellationToken cancellationToken = default)
    {
        await hubContext.SendStreamingResponseAsync(ChannelId, messageStream, cancellationToken);
    }

    public async Task SendMessageAsync(ChannelMessage message, CancellationToken cancellationToken = default)
    {
        await hubContext.SendResponseAsync(ChannelId, message, cancellationToken);
    }
    
    public async Task RaiseMessageReceivedAsync(object? sender, ChannelMessage message)
    {
        if (message.Content.StartsWith("/"))
        {
            await HandleCommandAsync(message.Content);
            return;
        }
        
        MessageReceived?.Invoke(sender, new ChannelMessageReceivedEventArgs
        {
            Channel = this,
            Message = message,
            IsHandled = false
        });
    }

    private async Task HandleCommandAsync(string command)
    {
        var parts = command.Split(' ', StringSplitOptions.RemoveEmptyEntries);
        var commandName = parts[0].ToLowerInvariant();

        var responseText = commandName switch
        {
            "/link" => HandleLinkCommand(parts),
            _ => $"Unknown command: {commandName}"
        };

        await SendMessageAsync(new ChannelMessage(
            MessageId: Guid.NewGuid().ToString(),
            ConversationId: Guid.NewGuid().ToString(),
            SenderId: "luna",
            SenderName: "Luna",
            Content: responseText,
            Timestamp: DateTimeOffset.UtcNow));
    }

    private string HandleLinkCommand(string[] parts)
    {
        if (parts.Length < 3)
            return "Usage: /link <channel-type> <pairing-code>";

        var channelType = parts[1].ToLowerInvariant();
        var code = parts[2].ToUpperInvariant();
        var currentUser = identityService.GetCurrentUser();

        if (identityService.IsChannelLinked(currentUser.UserId, channelType))
            return $"Channel {channelType} is already linked to your account.";

        try
        {
            identityService.CompleteChannelLink(currentUser.UserId, channelType, code);
            return $"Successfully linked {channelType} channel to your account.";
        }
        catch (InvalidOperationException ex)
        {
            return $"Failed to link channel: {ex.Message}";
        }
    }
    
    public void Dispose() { }
}