using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading;
using System.Threading.Tasks;
using FinlyticCore.Dtos;
using FinlyticCore.Dtos.News;
using FinlyticCore.Dtos.Sentiment;
using FinlyticCore.Dtos.Settings;
using FinlyticCore.Models;
using FinlyticCore.Services;
using FinlyticCore.Util;
using FinlyticNews.Entities;
using FinlyticNews.Services;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;
using Microsoft.Extensions.Logging;

namespace FinlyticNews.Util;

/// <summary>
/// Managed MQTT client for broadcasting completed news articles and handling typed RPC requests for FinlyticNews.
/// </summary>
public class NewsMqttClient : ManagedMqttClient, IHostedService
{
    private readonly IServiceScopeFactory _scopeFactory;
    private readonly ILogger<NewsMqttClient> _logger;
    private readonly IConfiguration _configuration;

    public NewsMqttClient(
        ILogger<NewsMqttClient> logger,
        IServiceScopeFactory scopeFactory,
        IConfiguration configuration) : base(logger)
    {
        _scopeFactory = scopeFactory;
        _logger = logger;
        _configuration = configuration;
    }

    /// <inheritdoc />
    public async Task StartAsync(CancellationToken cancellationToken)
    {
        var config = MqttConfiguration.FromConfiguration(_configuration, "FinlyticNews");

        _logger.LogInformation("Starting News MQTT client. Host: {Host}, ClientId: {ClientId}", config.Host, config.ClientId);
        await ConnectAsync(config);
    }

    /// <inheritdoc />
    public async Task StopAsync(CancellationToken cancellationToken)
    {
        _logger.LogInformation("Stopping News MQTT client and disconnecting.");
        await DisconnectAsync();
    }

    /// <inheritdoc />
    protected override async Task OnConnectedAsync()
    {
        _logger.LogInformation("News MQTT client connected. Registering RPC topic subscriptions...");

        await SubscribeAsync(MqttTopics.ResponseWildcard);
        await SubscribeRpcAsync<DailyNewsRequest, List<NewsArticleDto>>(MqttTopics.RequestFilter(MqttTopics.Channels.NewsGet), HandleNewsGetRpcAsync);
        await SubscribeRpcAsync<ArticleRequest, NewsArticleDto?>(MqttTopics.RequestFilter(MqttTopics.Channels.NewsGetById), HandleNewsGetByIdRpcAsync);
        await SubscribeRpcAsync<object, List<NewsArticleDto>>(MqttTopics.RequestFilter(MqttTopics.Channels.NewsGetPending), HandleNewsGetPendingRpcAsync);
        await SubscribeRpcAsync<UpdateNewsStatusRequest, UpdateNewsStatusResponse>(MqttTopics.RequestFilter(MqttTopics.Channels.NewsUpdateStatus), HandleNewsUpdateStatusRpcAsync);
        await SubscribeRpcAsync<object, List<DynamicSettingDto>>(MqttTopics.RequestFilter(MqttTopics.Channels.NewsSettingsGetAll), HandleSettingsGetAllRpcAsync);
        await SubscribeRpcAsync<Dictionary<string, object?>, List<DynamicSettingDto>>(MqttTopics.RequestFilter(MqttTopics.Channels.NewsSettingsUpdate), HandleSettingsUpdateRpcAsync);
        await SubscribeAsync<object>(MqttTopics.RequestFilter(MqttTopics.Channels.HealthPing), HandleHealthPingRpcAsync);

        FinlyticLogBroadcaster.OnLogPublished = async (logDto) =>
        {
            if (IsConnected && string.Equals(logDto.ServiceName, "FinlyticNews", StringComparison.OrdinalIgnoreCase))
            {
                await PublishAsync(MqttTopics.Logs("FinlyticNews"), logDto);
            }
        };
    }

    /// <summary>
    /// Broadcasts a newly processed news article to downstream subscribers.
    /// </summary>
    public async Task BroadcastArticleAsync(NewsArticleDto article)
    {
        const string topic = MqttTopics.NewsCompleted;
        _logger.LogInformation("Broadcasting completed article to MQTT topic: {Topic}. ID: {Id}", topic, article.Id);
        await PublishAsync(topic, article);

        var firstIsin = article.MatchedAssets.FirstOrDefault()?.Isin;
        if (!string.IsNullOrWhiteSpace(firstIsin))
        {
            string isinTopic = MqttTopics.NewsStream(firstIsin);
            await PublishAsync(isinTopic, article);
        }
    }

    private async Task<List<NewsArticleDto>> HandleNewsGetRpcAsync(DailyNewsRequest? req, string correlationId)
    {
        using var scope = _scopeFactory.CreateScope();
        var finlyticLogger = scope.ServiceProvider.GetRequiredService<IFinlyticLogger<NewsMqttClient>>();

        await finlyticLogger.LogInfoAsync(SettingKeys.NewsChannel, "Received RPC news_Get request [CorrelationId: {CorrelationId}]", correlationId);

        int limit = req?.Limit > 0 ? req.Limit : 20;
        int offset = req?.Offset >= 0 ? req.Offset : 0;
        string? isin = !string.IsNullOrWhiteSpace(req?.Isin) ? req.Isin : null;
        string? status = req?.Status;
        string? searchQuery = req?.Query;
        DateTime? date = req?.Date;

        if (req?.HasSentiment == true && string.IsNullOrEmpty(status))
        {
            status = "Analyzed";
        }

        try
        {
            var dbService = scope.ServiceProvider.GetRequiredService<INewsDbService>();
            var articles = await dbService.GetFilteredNewsAsync(limit, offset, isin, date, status, searchQuery);
            return (await Task.WhenAll(articles.Select(a => MapToDtoAsync(a)))).ToList();
        }
        catch (Exception ex)
        {
            await finlyticLogger.LogErrorAsync(SettingKeys.NewsChannel, ex, "Failed to compile RPC response for news_Get");
            return [];
        }
    }

    private async Task<NewsArticleDto?> HandleNewsGetByIdRpcAsync(ArticleRequest? req, string correlationId)
    {
        var targetIdStr = req?.ArticleId ?? req?.Id;
        if (Guid.TryParse(targetIdStr, out var articleId))
        {
            using var scope = _scopeFactory.CreateScope();
            var dbService = scope.ServiceProvider.GetRequiredService<INewsDbService>();
            var article = await dbService.GetArticleByIdAsync(articleId);

            if (article != null)
            {
                return await MapToDtoAsync(article);
            }
        }
        return null;
    }

    private async Task<List<NewsArticleDto>> HandleNewsGetPendingRpcAsync(object? _, string correlationId)
    {
        try
        {
            using var scope = _scopeFactory.CreateScope();
            var dbService = scope.ServiceProvider.GetRequiredService<INewsDbService>();
            var pendingArticles = await dbService.GetArticlesByStatusAsync("Completed");
            return (await Task.WhenAll(pendingArticles.Take(10).Select(a => MapToDtoAsync(a)))).ToList();
        }
        catch
        {
            return [];
        }
    }

    private async Task<UpdateNewsStatusResponse> HandleNewsUpdateStatusRpcAsync(UpdateNewsStatusRequest? req, string correlationId)
    {
        if (req != null && req.Id != Guid.Empty)
        {
            using var scope = _scopeFactory.CreateScope();
            var dbService = scope.ServiceProvider.GetRequiredService<INewsDbService>();
            await dbService.UpdateArticleStatusAsync(req.Id, req.Status);
            return new UpdateNewsStatusResponse(true, "Status updated successfully.");
        }
        return new UpdateNewsStatusResponse(false, "Invalid payload.");
    }

    private async Task<List<DynamicSettingDto>> HandleSettingsGetAllRpcAsync(object? _, string correlationId)
    {
        using var scope = _scopeFactory.CreateScope();
        var finlyticLogger = scope.ServiceProvider.GetRequiredService<IFinlyticLogger<NewsMqttClient>>();
        var settingsService = scope.ServiceProvider.GetRequiredService<ISettingsService>();

        await finlyticLogger.LogInfoAsync(SettingKeys.MqttChannel, "[FinlyticNews] [Settings_GetAll] Retrieving service dynamic settings [CorrelationId: {CorrelationId}]", correlationId);
        return await settingsService.GetAllRegisteredSettingsAsync(new[] { typeof(SettingKeys) });
    }

    private async Task<List<DynamicSettingDto>> HandleSettingsUpdateRpcAsync(Dictionary<string, object?>? updates, string correlationId)
    {
        using var scope = _scopeFactory.CreateScope();
        var finlyticLogger = scope.ServiceProvider.GetRequiredService<IFinlyticLogger<NewsMqttClient>>();
        var settingsService = scope.ServiceProvider.GetRequiredService<ISettingsService>();

        await finlyticLogger.LogInfoAsync(SettingKeys.MqttChannel, "[FinlyticNews] [Settings_Update] Processing settings update RPC [CorrelationId: {CorrelationId}]", correlationId);
        if (updates != null && updates.Count > 0)
        {
            await settingsService.UpdateSettingsAsync(updates);
            await finlyticLogger.LogInfoAsync(SettingKeys.MqttChannel, "[FinlyticNews] [Settings_Update] Successfully updated {Count} settings in database and cache.", updates.Count);
        }
        return await settingsService.GetAllRegisteredSettingsAsync(new[] { typeof(SettingKeys) });
    }

    private async Task HandleHealthPingRpcAsync(object? _, string topic, string correlationId)
    {
        if (topic.Contains("FinlyticNews", StringComparison.OrdinalIgnoreCase))
        {
            string respTopic = MqttTopics.ResponseTopic(MqttTopics.Channels.HealthPing, correlationId);
            await PublishAsync(respTopic, new ServiceHealthResponse("FinlyticNews", "Online", DateTime.UtcNow, "Connected"));

            using var scope = _scopeFactory.CreateScope();
            var finlyticLogger = scope.ServiceProvider.GetRequiredService<IFinlyticLogger<NewsMqttClient>>();
            await finlyticLogger.LogInfoAsync(SettingKeys.HealthPingChannel, "Responded to live health_Ping RPC request [CorrelationId: {CorrelationId}].", correlationId);
        }
    }

    /// <summary>
    /// Maps a NewsArticleEntity to a NewsArticleDto, enriching it with the FinBERT sentiment result for the
    /// article by querying FinlyticSentiment over the <see cref="MqttTopics.Channels.SentimentGetArticle"/> RPC
    /// channel. This previously read a legacy on-disk cache at <c>data/summaries/articles/*.json</c> and
    /// <c>data/summaries/isin/*.json</c>, but nothing in this repository writes those files anymore (FinlyticSentiment
    /// persists results to its own database) - the disk lookup was silently degrading Sentiment to always-null.
    /// </summary>
    private async Task<NewsArticleDto> MapToDtoAsync(NewsArticleEntity a)
    {
        string? sentimentLabel = null;
        double? sentimentScore = null;
        double? confidence = null;
        FinBertResultDto? finbertResult = null;

        try
        {
            if (IsConnected)
            {
                var targetId = a.Id.ToString();
                var sentimentEntry = await SendRpcRequestAsync<IsinAnalysisEntry, ArticleRequest>(
                    MqttTopics.Channels.SentimentGetArticle,
                    new ArticleRequest(targetId, targetId),
                    TimeSpan.FromSeconds(3));

                if (sentimentEntry?.FinbertResult != null)
                {
                    finbertResult = sentimentEntry.FinbertResult;
                    sentimentLabel = finbertResult.Label;
                    sentimentScore = finbertResult.CompoundScore;
                    confidence = finbertResult.Confidence;
                }
            }
        }
        catch (Exception ex)
        {
            _logger.LogWarning(ex, "[NewsMqttClient] Failed to fetch sentiment for article {ArticleId} via '{Channel}' RPC.", a.Id, MqttTopics.Channels.SentimentGetArticle);
        }

        return new NewsArticleDto
        {
            Id = a.Id,
            Title = a.Title,
            Author = a.Author,
            Summary = a.Summary,
            ContentRaw = a.ContentRaw,
            Language = a.Language,
            SourceUrl = a.SourceUrl,
            ScrapedAt = a.ScrapedAt,
            PublishedAt = a.PublishedAt,
            Status = a.Status,
            Sentiment = sentimentLabel,
            SentimentScore = sentimentScore,
            Confidence = confidence,
            FinbertResult = finbertResult,
            MatchedAssets = (a.MatchedAssets ?? []).Select(m => new MatchedAssetDto
            {
                Name = m.Name,
                Isin = m.Isin
            }).ToList()
        };
    }
}