using System.Text.Json;
using Microsoft.AspNetCore.SignalR;
using Microsoft.EntityFrameworkCore;
using LittleShop.Data;
using LittleShop.DTOs;
using LittleShop.Hubs;
using LittleShop.Models;

namespace LittleShop.Services;

public class BotActivityService : IBotActivityService
{
    private readonly LittleShopContext _context;
    private readonly IHubContext<ActivityHub> _hubContext;
    private readonly ILogger<BotActivityService> _logger;

    public BotActivityService(
        LittleShopContext context,
        IHubContext<ActivityHub> hubContext,
        ILogger<BotActivityService> logger)
    {
        _context = context;
        _hubContext = hubContext;
        _logger = logger;
    }

    public async Task<BotActivity> LogActivityAsync(CreateBotActivityDto dto)
    {
        var activity = new BotActivity
        {
            Id = Guid.NewGuid(),
            BotId = dto.BotId,
            SessionIdentifier = dto.SessionIdentifier,
            UserDisplayName = dto.UserDisplayName,
            ActivityType = dto.ActivityType,
            ActivityDescription = dto.ActivityDescription,
            ProductId = dto.ProductId,
            ProductName = dto.ProductName,
            OrderId = dto.OrderId,
            CategoryName = dto.CategoryName,
            Value = dto.Value,
            Quantity = dto.Quantity,
            Platform = dto.Platform,
            DeviceType = dto.DeviceType,
            Location = dto.Location,
            Timestamp = DateTime.UtcNow,
            Metadata = dto.Metadata
        };

        _context.BotActivities.Add(activity);
        await _context.SaveChangesAsync();

        // Broadcast the activity to connected clients
        await BroadcastActivityAsync(activity);

        _logger.LogInformation("Activity logged: {User} - {Type} - {Description}",
            activity.UserDisplayName, activity.ActivityType, activity.ActivityDescription);

        return activity;
    }

    public async Task<List<BotActivityDto>> GetRecentActivitiesAsync(int minutesBack = 5)
    {
        var cutoffTime = DateTime.UtcNow.AddMinutes(-minutesBack);

        var activities = await _context.BotActivities
            .Include(a => a.Bot)
            .Where(a => a.Timestamp >= cutoffTime)
            .OrderByDescending(a => a.Timestamp)
            .Take(100)
            .Select(a => MapToDto(a))
            .ToListAsync();

        return activities;
    }

    public async Task<List<BotActivityDto>> GetActivitiesBySessionAsync(string sessionIdentifier)
    {
        var activities = await _context.BotActivities
            .Include(a => a.Bot)
            .Where(a => a.SessionIdentifier == sessionIdentifier)
            .OrderByDescending(a => a.Timestamp)
            .Take(200)
            .Select(a => MapToDto(a))
            .ToListAsync();

        return activities;
    }

    public async Task<List<BotActivityDto>> GetActivitiesByBotAsync(Guid botId, int limit = 100)
    {
        var activities = await _context.BotActivities
            .Include(a => a.Bot)
            .Where(a => a.BotId == botId)
            .OrderByDescending(a => a.Timestamp)
            .Take(limit)
            .Select(a => MapToDto(a))
            .ToListAsync();

        return activities;
    }

    public async Task<LiveActivitySummaryDto> GetLiveActivitySummaryAsync()
    {
        var fiveMinutesAgo = DateTime.UtcNow.AddMinutes(-5);
        var oneMinuteAgo = DateTime.UtcNow.AddMinutes(-1);

        var recentActivities = await _context.BotActivities
            .Include(a => a.Bot)
            .Where(a => a.Timestamp >= fiveMinutesAgo)
            .ToListAsync();

        var activeUsers = recentActivities
            .Where(a => a.Timestamp >= oneMinuteAgo)
            .Select(a => a.SessionIdentifier)
            .Distinct()
            .Count();

        var activeUserNames = recentActivities
            .Where(a => a.Timestamp >= oneMinuteAgo)
            .Select(a => a.UserDisplayName)
            .Distinct()
            .Take(10)
            .ToList();

        var productViews = recentActivities
            .Where(a => a.ActivityType == "ViewProduct")
            .Count();

        var cartsActive = recentActivities
            .Where(a => a.ActivityType == "AddToCart" || a.ActivityType == "UpdateCart")
            .Select(a => a.SessionIdentifier)
            .Distinct()
            .Count();

        var totalCartValue = recentActivities
            .Where(a => a.ActivityType == "AddToCart" && a.Value.HasValue)
            .Sum(a => a.Value ?? 0);

        var summary = new LiveActivitySummaryDto
        {
            ActiveUsers = activeUsers,
            TotalActivitiesLast5Min = recentActivities.Count,
            ProductViewsLast5Min = productViews,
            CartsActiveNow = cartsActive,
            TotalValueInCartsNow = totalCartValue,
            ActiveUserNames = activeUserNames,
            RecentActivities = recentActivities
                .OrderByDescending(a => a.Timestamp)
                .Take(20)
                .Select(a => MapToDto(a))
                .ToList()
        };

        return summary;
    }

    public async Task<List<BotActivityDto>> GetProductActivitiesAsync(Guid productId, int limit = 50)
    {
        var activities = await _context.BotActivities
            .Include(a => a.Bot)
            .Where(a => a.ProductId == productId)
            .OrderByDescending(a => a.Timestamp)
            .Take(limit)
            .Select(a => MapToDto(a))
            .ToListAsync();

        return activities;
    }

    public async Task<Dictionary<string, int>> GetActivityTypeStatsAsync(int hoursBack = 24)
    {
        var cutoffTime = DateTime.UtcNow.AddHours(-hoursBack);

        var stats = await _context.BotActivities
            .Where(a => a.Timestamp >= cutoffTime)
            .GroupBy(a => a.ActivityType)
            .Select(g => new { Type = g.Key, Count = g.Count() })
            .ToDictionaryAsync(x => x.Type, x => x.Count);

        return stats;
    }

    public async Task BroadcastActivityAsync(BotActivity activity)
    {
        try
        {
            var dto = MapToDto(activity);
            await _hubContext.Clients.All.SendAsync("NewActivity", dto);

            // Also send summary update
            var summary = await GetLiveActivitySummaryAsync();
            await _hubContext.Clients.All.SendAsync("SummaryUpdate", summary);
        }
        catch (Exception ex)
        {
            _logger.LogError(ex, "Error broadcasting activity");
        }
    }

    private static BotActivityDto MapToDto(BotActivity activity)
    {
        return new BotActivityDto
        {
            Id = activity.Id,
            BotId = activity.BotId,
            BotName = activity.Bot?.Name ?? "Unknown Bot",
            SessionIdentifier = activity.SessionIdentifier,
            UserDisplayName = activity.UserDisplayName,
            ActivityType = activity.ActivityType,
            ActivityDescription = activity.ActivityDescription,
            ProductId = activity.ProductId,
            ProductName = activity.ProductName,
            OrderId = activity.OrderId,
            CategoryName = activity.CategoryName,
            Value = activity.Value,
            Quantity = activity.Quantity,
            Platform = activity.Platform,
            DeviceType = activity.DeviceType,
            Location = activity.Location,
            Timestamp = activity.Timestamp,
            Metadata = activity.Metadata
        };
    }
}