using BotSharp.Abstraction.Routing;
using Newtonsoft.Json.Serialization;
using Newtonsoft.Json;

namespace BotSharp.OpenAPI.Controllers;

[Authorize]
[ApiController]
public class ConversationController : ControllerBase
{
    private readonly IServiceProvider _services;
    private readonly IUserIdentity _user;

    public ConversationController(IServiceProvider services,
        IUserIdentity user)
    {
        _services = services;
        _user = user;
    }

    [HttpPost("/conversation/{agentId}")]
    public async Task<ConversationViewModel> NewConversation([FromRoute] string agentId, [FromBody] MessageConfig config)
    {
        var service = _services.GetRequiredService<IConversationService>();
        var conv = new Conversation
        {
            AgentId = agentId,
            Channel = ConversationChannel.OpenAPI,
            UserId = _user.Id,
            TaskId = config.TaskId
        };
        conv = await service.NewConversation(conv);
        service.SetConversationId(conv.Id, config.States);

        return ConversationViewModel.FromSession(conv);
    }

    [HttpPost("/conversations")]
    public async Task<PagedItems<ConversationViewModel>> GetConversations([FromBody] ConversationFilter filter)
    {
        var service = _services.GetRequiredService<IConversationService>();
        var conversations = await service.GetConversations(filter);

        var userService = _services.GetRequiredService<IUserService>();
        var agentService = _services.GetRequiredService<IAgentService>();
        var list = conversations.Items
            .Select(x => ConversationViewModel.FromSession(x))
            .ToList();

        foreach (var item in list)
        {
            var user = await userService.GetUser(item.User.Id);
            item.User = UserViewModel.FromUser(user);

            var agent = await agentService.GetAgent(item.AgentId);
            item.AgentName = agent?.Name;
        }

        return new PagedItems<ConversationViewModel>
        {
            Count = conversations.Count,
            Items = list
        };
    }

    [HttpGet("/conversation/{conversationId}/dialogs")]
    public async Task<IEnumerable<ChatResponseModel>> GetDialogs([FromRoute] string conversationId)
    {
        var conv = _services.GetRequiredService<IConversationService>();
        conv.SetConversationId(conversationId, new List<MessageState>());
        var history = conv.GetDialogHistory(fromBreakpoint: false);

        var userService = _services.GetRequiredService<IUserService>();
        var agentService = _services.GetRequiredService<IAgentService>();

        var dialogs = new List<ChatResponseModel>();
        foreach (var message in history)
        {
            if (message.Role == AgentRole.User)
            {
                var user = await userService.GetUser(message.SenderId);

                dialogs.Add(new ChatResponseModel
                {
                    ConversationId = conversationId,
                    MessageId = message.MessageId,
                    CreatedAt = message.CreatedAt,
                    Text = !string.IsNullOrEmpty(message.SecondaryContent) ? message.SecondaryContent : message.Content,
                    Data = message.Data,
                    Sender = UserViewModel.FromUser(user),
                    Payload = message.Payload
                });
            }
            else if (message.Role == AgentRole.Assistant)
            {
                var agent = await agentService.GetAgent(message.CurrentAgentId);
                dialogs.Add(new ChatResponseModel
                {
                    ConversationId = conversationId,
                    MessageId = message.MessageId,
                    CreatedAt = message.CreatedAt,
                    Text = !string.IsNullOrEmpty(message.SecondaryContent) ? message.SecondaryContent : message.Content,
                    Function = message.FunctionName,
                    Data = message.Data,
                    Sender = new UserViewModel
                    {
                        FirstName = agent.Name,
                        Role = message.Role,
                    },
                    RichContent = message.SecondaryRichContent ?? message.RichContent
                });
            }
        }

        return dialogs;
    }

    [HttpGet("/conversation/{conversationId}")]
    public async Task<ConversationViewModel> GetConversation([FromRoute] string conversationId)
    {
        var service = _services.GetRequiredService<IConversationService>();
        var conversations = await service.GetConversations(new ConversationFilter
        {
            Id = conversationId
        });

        var userService = _services.GetRequiredService<IUserService>();
        var result = ConversationViewModel.FromSession(conversations.Items.First());

        var state = _services.GetRequiredService<IConversationStateService>();
        result.States = state.Load(conversationId, isReadOnly: true);

        var user = await userService.GetUser(result.User.Id);
        result.User = UserViewModel.FromUser(user);

        return result;
    }

    [HttpGet("/conversation/{conversationId}/user")]
    public async Task<UserViewModel> GetConversationUser([FromRoute] string conversationId)
    {
        var service = _services.GetRequiredService<IConversationService>();
        var conversations = await service.GetConversations(new ConversationFilter
        {
            Id = conversationId
        });

        var userService = _services.GetRequiredService<IUserService>();
        var conversation = conversations?.Items?.FirstOrDefault();
        var userId = conversation == null ? _user.Id : conversation.UserId;
        var user = await userService.GetUser(userId);
        if (user == null)
        {
            return new UserViewModel
            {
                Id = _user.Id,
                UserName = _user.UserName,
                FirstName = _user.FirstName,
                LastName = _user.LastName,
                Email = _user.Email,
                Source = "Unknown"
            };
        }

        return UserViewModel.FromUser(user);
    }

    [HttpDelete("/conversation/{conversationId}")]
    public async Task<bool> DeleteConversation([FromRoute] string conversationId)
    {
        var conversationService = _services.GetRequiredService<IConversationService>();
        var response = await conversationService.DeleteConversations(new List<string> { conversationId });
        return response;
    }

    [HttpDelete("/conversation/{conversationId}/message/{messageId}")]
    public async Task<bool> DeleteConversationMessage([FromRoute] string conversationId, [FromRoute] string messageId)
    {
        var conversationService = _services.GetRequiredService<IConversationService>();
        var response = await conversationService.TruncateConversation(conversationId, messageId);
        return response;
    }

    private void SetStates(IConversationService conv, NewMessageModel input)
    {
        conv.States.SetState("channel", input.Channel, source: StateSource.External)
           .SetState("provider", input.Provider, source: StateSource.External)
           .SetState("model", input.Model, source: StateSource.External)
           .SetState("temperature", input.Temperature, source: StateSource.External)
           .SetState("sampling_factor", input.SamplingFactor, source: StateSource.External);
    }

    [HttpPost("/conversation/{agentId}/{conversationId}")]
    public async Task<ChatResponseModel> SendMessage([FromRoute] string agentId,
        [FromRoute] string conversationId,
        [FromBody] NewMessageModel input)
    {
        var conv = _services.GetRequiredService<IConversationService>();
        var inputMsg = new RoleDialogModel(AgentRole.User, input.Text)
        {
            Files = input.Files,
            CreatedAt = DateTime.UtcNow
        };

        if (!string.IsNullOrEmpty(input.TruncateMessageId))
        {
            await conv.TruncateConversation(conversationId, input.TruncateMessageId, inputMsg.MessageId);
        }

        var routing = _services.GetRequiredService<IRoutingService>();
        routing.Context.SetMessageId(conversationId, inputMsg.MessageId);

        conv.SetConversationId(conversationId, input.States);
        SetStates(conv, input);

        var response = new ChatResponseModel();
        
        await conv.SendMessage(agentId, inputMsg,
            replyMessage: input.Postback,
            async msg =>
            {
                response.Text = !string.IsNullOrEmpty(msg.SecondaryContent) ? msg.SecondaryContent : msg.Content;
                response.Function = msg.FunctionName;
                response.RichContent = msg.SecondaryRichContent ?? msg.RichContent;
                response.Instruction = msg.Instruction;
                response.Data = msg.Data;
            },
            _ => Task.CompletedTask,
            _ => Task.CompletedTask);

        var state = _services.GetRequiredService<IConversationStateService>();
        response.States = state.GetStates();
        response.MessageId = inputMsg.MessageId;
        response.ConversationId = conversationId;

        return response;
    }

    [HttpPost("/conversation/{agentId}/{conversationId}/sse")]
    public async Task SendMessageSse([FromRoute] string agentId,
        [FromRoute] string conversationId,
        [FromBody] NewMessageModel input)
    {
        var conv = _services.GetRequiredService<IConversationService>();
        var inputMsg = new RoleDialogModel(AgentRole.User, input.Text)
        {
            Files = input.Files,
            CreatedAt = DateTime.UtcNow
        };

        if (!string.IsNullOrEmpty(input.TruncateMessageId))
        {
            await conv.TruncateConversation(conversationId, input.TruncateMessageId, inputMsg.MessageId);
        }

        var routing = _services.GetRequiredService<IRoutingService>();
        routing.Context.SetMessageId(conversationId, inputMsg.MessageId);

        conv.SetConversationId(conversationId, input.States);
        SetStates(conv, input);

        var response = new ChatResponseModel();

        Response.StatusCode = 200;
        Response.Headers.Append(Microsoft.Net.Http.Headers.HeaderNames.ContentType, "text/event-stream");
        Response.Headers.Append(Microsoft.Net.Http.Headers.HeaderNames.CacheControl, "no-cache");
        Response.Headers.Append(Microsoft.Net.Http.Headers.HeaderNames.Connection, "keep-alive");

        await conv.SendMessage(agentId, inputMsg,
            replyMessage: input.Postback,
            async msg =>
            {
                response.Text = !string.IsNullOrEmpty(msg.SecondaryContent) ? msg.SecondaryContent : msg.Content;
                response.Function = msg.FunctionName;
                response.RichContent = msg.SecondaryRichContent ?? msg.RichContent;
                response.Instruction = msg.Instruction;
                response.Data = msg.Data;

                await OnChunkReceived(Response, msg);
            },
            async msg =>
            {
                var message = new RoleDialogModel(AgentRole.Function, msg.Content)
                {
                    FunctionArgs = msg.FunctionArgs,
                    FunctionName = msg.FunctionName,
                    Indication = msg.Indication
                };
                await OnChunkReceived(Response, message);
            },
            async msg =>
            {

            });

        var state = _services.GetRequiredService<IConversationStateService>();
        response.States = state.GetStates();
        response.MessageId = inputMsg.MessageId;
        response.ConversationId = conversationId;

        // await OnEventCompleted(Response);
    }

    private async Task OnChunkReceived(HttpResponse response, RoleDialogModel message)
    {
        var json = JsonConvert.SerializeObject(message, new JsonSerializerSettings
        {
            Formatting = Formatting.None,
            ContractResolver = new CamelCasePropertyNamesContractResolver(),
            NullValueHandling = NullValueHandling.Ignore,
        });

        var buffer = Encoding.UTF8.GetBytes($"data:{json}\n");
        await response.Body.WriteAsync(buffer, 0, buffer.Length);
        await Task.Delay(10);

        buffer = Encoding.UTF8.GetBytes("\n");
        await response.Body.WriteAsync(buffer, 0, buffer.Length);
    }

    private async Task OnEventCompleted(HttpResponse response)
    {
        var buffer = Encoding.UTF8.GetBytes("data:[DONE]\n");
        await response.Body.WriteAsync(buffer, 0, buffer.Length);

        buffer = Encoding.UTF8.GetBytes("\n");
        await response.Body.WriteAsync(buffer, 0, buffer.Length);
    }
}