using Indotalent.Infrastructure.Database;
using Indotalent.Data.Entities;
using Indotalent.Data.Enums;
using MediatR;
using Microsoft.EntityFrameworkCore;

namespace Indotalent.Features.Root.Home.Cqrs;

// Chart data
public class ChartDataPoint
{
    public string? Label { get; set; }
    public double SalesAmount { get; set; }
    public double PurchaseAmount { get; set; }
}

// SWM-specific DTOs
public class BookingKpiDto
{
    public string? ResourceName { get; set; }
    public int BookingCount { get; set; }
    public double WinRate { get; set; }
    public string? Color { get; set; }
}

public class BookingStatusDto
{
    public string? Source { get; set; }
    public int Count { get; set; }
    public double Percentage { get; set; }
    public string? Color { get; set; }
}

public class CustomerGroupDto
{
    public string? Name { get; set; }
    public int Count { get; set; }
    public double PctValue { get; set; }
    public string? BarColor { get; set; }
}

public class VendorGroupDto
{
    public string? Name { get; set; }
    public int Count { get; set; }
    public string? IconClass { get; set; }
}

public class TopProductDto
{
    public string? Name { get; set; }
    public double Quantity { get; set; }
    public double Share { get; set; }
}

public class PaymentMethodDto
{
    public string? Name { get; set; }
    public int Count { get; set; }
}

public class DocGridDto
{
    public string? Label { get; set; }
    public string? Value { get; set; }
    public string? Color { get; set; }
}

public class CashFlowDto
{
    public string? Label { get; set; }
    public string? Value { get; set; }
    public string? Color { get; set; }
}

public class RecentSoDto
{
    public string? Number { get; set; }
    public string? Customer { get; set; }
    public decimal Value { get; set; }
    public string? Stage { get; set; }
    public string? Status { get; set; }
    public DateTimeOffset? Date { get; set; }
}

public class ActivityFeedDto
{
    public string? Title { get; set; }
    public string? Detail { get; set; }
    public string? TimeAgo { get; set; }
    public string? ChipLabel { get; set; }
    public string? ChipColor { get; set; }
    public string? AvatarBg { get; set; }
    public string? AvatarText { get; set; }
}

public class PipelineSummaryDto
{
    public string? Label { get; set; }
    public string? Value { get; set; }
    public string? IconColorClass { get; set; }
}

public class DealStageDto
{
    public string? Stage { get; set; }
    public int Count { get; set; }
    public string? Color { get; set; }
}

public class SalesActivityDto
{
    public string? Category { get; set; }
    public int Count { get; set; }
    public string? Color { get; set; }
}

public class DashboardSwmResponse
{
    // Core KPIs
    public int TotalCustomer { get; set; }
    public int TotalVendor { get; set; }
    public int TotalBookings { get; set; }
    public int ConfirmedBookings { get; set; }
    public int DraftBookings { get; set; }
    public int CancelledBookings { get; set; }
    public int TotalResources { get; set; }
    public int TotalBookingGroups { get; set; }
    public double BookingWinRate { get; set; }
    public int PendingSO { get; set; }
    public int PendingPO { get; set; }

    // Financial
    public decimal SalesMTD { get; set; }
    public decimal PurchaseMTD { get; set; }
    public decimal TotalReceivable { get; set; }
    public decimal TotalPayable { get; set; }

    // Collections
    public List<BookingKpiDto> BookingsByResource { get; set; } = new();
    public List<BookingKpiDto> BookingsByGroup { get; set; } = new();
    public List<BookingStatusDto> BookingStatuses { get; set; } = new();
    public List<CustomerGroupDto> CustomerGroups { get; set; } = new();
    public List<VendorGroupDto> VendorGroups { get; set; } = new();
    public List<TopProductDto> TopProducts { get; set; } = new();
    public List<PaymentMethodDto> PaymentMethods { get; set; } = new();
    public List<DocGridDto> DocGrid { get; set; } = new();
    public List<CashFlowDto> CashFlowMTD { get; set; } = new();
    public List<RecentSoDto> RecentSalesOrders { get; set; } = new();
    public List<ActivityFeedDto> RecentBookingsFeed { get; set; } = new();
    public List<ChartDataPoint> RevenueTrend { get; set; } = new();
    public List<ChartDataPoint> MonthlyBookingsTrend { get; set; } = new();
    public List<PipelineSummaryDto> PipelineSummary { get; set; } = new();
    public List<DealStageDto> BookingStages { get; set; } = new();
    public List<SalesActivityDto> BookingActivity { get; set; } = new();

    // Formatted
    public string FormattedSales => FormatNumber(SalesMTD);
    public string FormattedPurchase => FormatNumber(PurchaseMTD);
    public string FormattedReceivable => FormatNumber(TotalReceivable);
    public string FormattedPayable => FormatNumber(TotalPayable);

    private static string FormatNumber(decimal v)
    {
        if (v >= 1_000_000) return (v / 1_000_000m).ToString("F1") + "M";
        if (v >= 1_000) return (v / 1_000m).ToString("F1") + "K";
        return v.ToString("N0");
    }
}

public record GetSwmDashboardQuery() : IRequest<DashboardSwmResponse>;

public class DashboardHandler : IRequestHandler<GetSwmDashboardQuery, DashboardSwmResponse>
{
    private readonly AppDbContext _context;

    public DashboardHandler(AppDbContext context) => _context = context;

    public async Task<DashboardSwmResponse> Handle(GetSwmDashboardQuery request, CancellationToken ct)
    {
        var today = DateTime.Today;
        var monthStart = new DateTime(today.Year, today.Month, 1);

        // 1. Pull top 1000 bookings (with resource)
        var topBookings = await _context.Booking
            .AsNoTracking()
            .OrderByDescending(x => x.StartTime)
            .Take(1000)
            .Select(x => new
            {
                x.Status,
                x.StartTime,
                x.Subject,
                x.AutoNumber,
                ResourceName = x.BookingResource != null ? x.BookingResource.Name : "N/A",
                ResourceId = x.BookingResourceId ?? "0",
            })
            .ToListAsync(ct);

        // 2. Pull top 1000 sales orders (with customer)
        var topSO = await _context.SalesOrder
            .AsNoTracking()
            .Where(x => x.OrderDate != null)
            .OrderByDescending(x => x.OrderDate)
            .Take(1000)
            .Select(x => new
            {
                x.AutoNumber,
                x.OrderDate,
                x.AfterTaxAmount,
                x.OrderStatus,
                CustomerName = x.Customer != null ? x.Customer.Name : "N/A",
            })
            .ToListAsync(ct);

        // 3. Pull top 1000 sales order items (with product)
        var topSOItems = await _context.SalesOrderItem
            .AsNoTracking()
            .Where(x => x.Quantity != null)
            .OrderByDescending(x => x.SalesOrder!.OrderDate)
            .Take(1000)
            .Select(x => new
            {
                ProductName = x.Product != null ? x.Product.Name : "N/A",
                x.Quantity,
            })
            .ToListAsync(ct);

        // 4. Pull all booking resources & groups (small tables, pull all)
        var allResources = await _context.BookingResource
            .AsNoTracking()
            .Select(x => new { x.Name, GroupName = x.BookingGroup != null ? x.BookingGroup.Name : "General" })
            .ToListAsync(ct);

        // 5. Pull all customers & vendors (with groups)
        var allCustomers = await _context.Customer
            .AsNoTracking()
            .Select(x => new { GroupName = x.CustomerGroup != null ? x.CustomerGroup.Name : "General" })
            .ToListAsync(ct);

        var allVendors = await _context.Vendor
            .AsNoTracking()
            .Select(x => new { GroupName = x.VendorGroup != null ? x.VendorGroup.Name : "General" })
            .ToListAsync(ct);

        // 6. Pull payment methods
        var allPayMethods = await _context.PaymentReceive
            .AsNoTracking()
            .Select(x => new { MethodName = x.PaymentMethod != null ? x.PaymentMethod.Name : "Cash" })
            .ToListAsync(ct);

        // === AGGREGATE IN MEMORY ===

        // Core counts from bookings
        var totalBookings = topBookings.Count;
        var confirmedBookings = topBookings.Count(x => x.Status == BookingStatus.Confirmed);
        var draftBookings = topBookings.Count(x => x.Status == BookingStatus.Draft);
        var cancelledBookings = topBookings.Count(x => x.Status == BookingStatus.Cancelled);
        var bookingWinRate = totalBookings > 0 ? Math.Round((double)confirmedBookings / totalBookings * 100, 1) : 0;
        var totalResources = allResources.Select(x => x.Name).Distinct().Count();
        var totalGroups = allResources.Select(x => x.GroupName).Distinct().Count();
        var totalCustomer = allCustomers.Count;
        var totalVendor = allVendors.Count;

        // Financial from topSO (already has dates and amounts)
        var salesMTD = topSO.Where(x => x.OrderDate >= monthStart).Sum(x => x.AfterTaxAmount ?? 0);
        var purchaseMTD = await _context.PurchaseOrder.AsNoTracking()
            .Where(x => x.OrderDate >= monthStart)
            .SumAsync(x => x.AfterTaxAmount ?? 0, ct);
        var totalReceivable = await _context.Invoice.AsNoTracking()
            .Where(x => x.InvoiceStatus == InvoiceStatus.Confirmed)
            .SumAsync(x => (x.SalesOrder != null ? x.SalesOrder.AfterTaxAmount : 0) ?? 0, ct);
        var totalPayable = await _context.Bill.AsNoTracking()
            .Where(x => x.BillStatus == BillStatus.Confirmed)
            .SumAsync(x => (x.PurchaseOrder != null ? x.PurchaseOrder.AfterTaxAmount : 0) ?? 0, ct);
        var pendingSO = topSO.Count(x => x.OrderStatus == SalesOrderStatus.Draft);
        var pendingPO = await _context.PurchaseOrder.AsNoTracking().CountAsync(x => x.OrderStatus == PurchaseOrderStatus.Draft, ct);

        // Bookings by Resource (from topBookings)
        var whColors = new[] { "#2563eb", "#10b981", "#f59e0b", "#8b5cf6", "#ec4899", "#06b6d4", "#f97316", "#6366f1" };
        var bookingsByResource = topBookings
            .GroupBy(x => x.ResourceName)
            .Select((g, i) => new BookingKpiDto
            {
                ResourceName = g.Key,
                BookingCount = g.Count(),
                WinRate = g.Count() > 0 ? Math.Round((double)g.Count(x => x.Status == BookingStatus.Confirmed) / g.Count() * 100, 1) : 0,
                Color = whColors[i % whColors.Length]
            })
            .OrderByDescending(x => x.BookingCount)
            .Take(8)
            .ToList();

        // Bookings by Group (from allResources)
        var bookingsByGroup = allResources
            .GroupBy(x => x.GroupName)
            .Select((g, i) => new BookingKpiDto
            {
                ResourceName = g.Key,
                BookingCount = g.Count(),
                WinRate = 0,
                Color = "#8b5cf6"
            })
            .ToList();

        // Booking Statuses (for doughnut chart)
        var statusColors = new[] { "#10b981", "#f59e0b", "#e11d48" };
        var statusLabels = new[] { "Confirmed", "Draft", "Cancelled" };
        var statusCounts = new[] { confirmedBookings, draftBookings, cancelledBookings };
        var totalStatus = statusCounts.Sum();
        var bookingStatuses = statusLabels.Select((l, i) => new BookingStatusDto
        {
            Source = l,
            Count = statusCounts[i],
            Percentage = totalStatus > 0 ? Math.Round((double)statusCounts[i] / totalStatus * 100, 1) : 0,
            Color = i < statusColors.Length ? statusColors[i] : "#94a3b8"
        }).ToList();

        // Customer Groups (with progress bars)
        var customerGroups = allCustomers
            .GroupBy(x => x.GroupName)
            .Select(g => new CustomerGroupDto
            {
                Name = g.Key,
                Count = g.Count(),
                PctValue = totalCustomer > 0 ? Math.Min(Math.Round((double)g.Count() / totalCustomer * 100, 1), 100) : 0,
                BarColor = "#2563eb"
            })
            .OrderByDescending(x => x.Count)
            .Take(6)
            .ToList();

        // Vendor Groups
        var vendorGroups = allVendors
            .GroupBy(x => x.GroupName)
            .Select(g => new VendorGroupDto
            {
                Name = g.Key,
                Count = g.Count(),
                IconClass = "gc7"
            })
            .ToList();

        // Top Products (from topSOItems)
        var totalQty = topSOItems.Sum(x => x.Quantity ?? 0);
        var topProducts = topSOItems
            .GroupBy(x => x.ProductName)
            .Select(g => new { Name = g.Key, Qty = g.Sum(x => (double)(x.Quantity ?? 0)) })
            .OrderByDescending(x => x.Qty)
            .Take(4)
            .Select(x => new TopProductDto
            {
                Name = x.Name,
                Quantity = x.Qty,
                Share = totalQty > 0 ? Math.Round(x.Qty / totalQty * 100, 1) : 0
            })
            .ToList();

        // Payment Methods
        var paymentMethods = allPayMethods
            .GroupBy(x => x.MethodName)
            .Select(g => new PaymentMethodDto { Name = g.Key, Count = g.Count() })
            .ToList();

        // Doc Grid
        var docGrid = new List<DocGridDto> {
            new() { Label = "Sales Order", Value = await _context.SalesOrder.CountAsync(ct).ContinueWith(t => t.Result.ToString()), Color = "#10b981" },
            new() { Label = "Purchase Order", Value = await _context.PurchaseOrder.CountAsync(ct).ContinueWith(t => t.Result.ToString()), Color = "#ef4444" },
            new() { Label = "Invoice", Value = await _context.Invoice.CountAsync(ct).ContinueWith(t => t.Result.ToString()), Color = "#14b8a6" },
            new() { Label = "Bill", Value = await _context.Bill.CountAsync(ct).ContinueWith(t => t.Result.ToString()), Color = "#f97316" },
            new() { Label = "Bookings", Value = totalBookings.ToString(), Color = "#8b5cf6" },
            new() { Label = "Resources", Value = totalResources.ToString(), Color = "#6366f1" }
        };

        // Cash Flow MTD
        var cashFlowMTD = new List<CashFlowDto> {
            new() { Label = "Inflow (Receive)", Value = await _context.PaymentReceive.Where(x => x.PaymentDate >= monthStart).SumAsync(x => x.PaymentAmount ?? 0, ct).ContinueWith(t => t.Result.ToString("N0")), Color = "#10b981" },
            new() { Label = "Outflow (Disburse)", Value = await _context.PaymentDisburse.Where(x => x.PaymentDate >= monthStart).SumAsync(x => x.PaymentAmount ?? 0, ct).ContinueWith(t => t.Result.ToString("N0")), Color = "#ef4444" }
        };

        // Recent Sales Orders (from topSO)
        var recentSalesOrders = topSO
            .OrderByDescending(x => x.OrderDate)
            .Take(6)
            .Select(x => new RecentSoDto
            {
                Number = x.AutoNumber,
                Customer = x.CustomerName,
                Value = x.AfterTaxAmount ?? 0,
                Stage = x.OrderStatus.ToString(),
                Status = x.OrderStatus == SalesOrderStatus.Confirmed ? "Posted" : "Pending",
                Date = x.OrderDate.HasValue ? new DateTimeOffset(x.OrderDate.Value, TimeSpan.Zero) : null
            })
            .ToList();

        // Recent Bookings activity feed
        var recentBookingsFeed = topBookings
            .OrderByDescending(x => x.StartTime)
            .Take(3)
            .Select((b, i) =>
            {
                var statusClass = b.Status == BookingStatus.Confirmed ? "chip-green" : b.Status == BookingStatus.Draft ? "chip-amber" : "chip-red";
                var avatarBg = b.Status == BookingStatus.Confirmed ? "#10b981" : b.Status == BookingStatus.Draft ? "#f59e0b" : "#e11d48";
                var timeAgo = b.StartTime.HasValue
                    ? (DateTime.Now - b.StartTime.Value).TotalMinutes < 60
                        ? $"{(int)(DateTime.Now - b.StartTime.Value).TotalMinutes}m ago"
                        : (DateTime.Now - b.StartTime.Value).TotalHours < 24
                            ? $"{(int)(DateTime.Now - b.StartTime.Value).TotalHours}h ago"
                            : $"{(int)(DateTime.Now - b.StartTime.Value).TotalDays}d ago"
                    : "";
                var initials = b.ResourceName.Length > 0 ? b.ResourceName[..Math.Min(2, b.ResourceName.Length)].ToUpper() : "BK";
                return new ActivityFeedDto
                {
                    Title = $"{b.Subject} — {b.AutoNumber}",
                    Detail = $"📍 {b.ResourceName} · {b.StartTime:MMM dd, yyyy}",
                    TimeAgo = timeAgo,
                    ChipLabel = b.Status.ToString(),
                    ChipColor = statusClass,
                    AvatarBg = avatarBg,
                    AvatarText = initials
                };
            }).ToList();

        // Revenue Trend (from topSO + PurchaseOrder)
        var monthNames = new[] { "Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec" };
        var last6Months = Enumerable.Range(0, 6)
            .Select(i => today.AddMonths(-5 + i))
            .Select(d => new { d.Year, d.Month })
            .ToList();

        var poMonthsRaw = await _context.PurchaseOrder.AsNoTracking()
            .Where(x => x.OrderDate != null)
            .Select(x => x.OrderDate!.Value)
            .ToListAsync(ct);

        var revenueTrend = last6Months.Select(m =>
        {
            var salesAmount = topSO
                .Where(x => x.OrderDate.HasValue
                            && x.OrderDate.Value.Year == m.Year
                            && x.OrderDate.Value.Month == m.Month)
                .Sum(x => (double)(x.AfterTaxAmount ?? 0));
            var purchaseAmount = poMonthsRaw
                .Where(d => d.Year == m.Year && d.Month == m.Month)
                .Sum(d => (double)0); // Purchase amounts computed below
            // Actually compute PO amounts from DB for each month
            return new { Label = monthNames[m.Month - 1], SalesAmount = Math.Round(salesAmount / 1000.0, 1), m.Year, m.Month };
        }).ToList();

        // Compute PO amounts for each of last 6 months
        var revenueTrendFinal = new List<ChartDataPoint>();
        foreach (var m in last6Months)
        {
            var ms = new DateTime(m.Year, m.Month, 1);
            var me = ms.AddMonths(1);
            var sa = topSO
                .Where(x => x.OrderDate.HasValue && x.OrderDate.Value.Year == m.Year && x.OrderDate.Value.Month == m.Month)
                .Sum(x => (double)(x.AfterTaxAmount ?? 0));
            var pa = await _context.PurchaseOrder.AsNoTracking()
                .Where(x => x.OrderDate >= ms && x.OrderDate < me)
                .SumAsync(x => (double?)x.AfterTaxAmount ?? 0, ct);
            revenueTrendFinal.Add(new ChartDataPoint
            {
                Label = monthNames[m.Month - 1],
                SalesAmount = Math.Round(sa / 1000.0, 1),
                PurchaseAmount = Math.Round(pa / 1000.0, 1)
            });
        }

        // Monthly Bookings Trend
        var monthlyBookingsTrend = last6Months.Select(m =>
        {
            var count = topBookings
                .Where(x => x.StartTime.HasValue
                            && x.StartTime.Value.Year == m.Year
                            && x.StartTime.Value.Month == m.Month)
                .Count();
            return new ChartDataPoint
            {
                Label = monthNames[m.Month - 1],
                SalesAmount = count,
                PurchaseAmount = 0
            };
        }).ToList();

        // Pipeline Summary
        var pipelineSummary = new List<PipelineSummaryDto>
        {
            new() { Label = "Total Bookings", Value = totalBookings.ToString("N0"), IconColorClass = "gc1" },
            new() { Label = "Confirmed", Value = confirmedBookings.ToString("N0"), IconColorClass = "gc4" },
            new() { Label = "Cancelled", Value = cancelledBookings.ToString("N0"), IconColorClass = "gc10" }
        };

        // Booking Stages
        var bookingStages = new List<DealStageDto>
        {
            new() { Stage = "Confirmed", Count = confirmedBookings, Color = "#10b981" },
            new() { Stage = "Draft", Count = draftBookings, Color = "#f59e0b" },
            new() { Stage = "Cancelled", Count = cancelledBookings, Color = "#e11d48" }
        };

        // Booking Activity
        var bookingActivity = new List<SalesActivityDto>
        {
            new() { Category = "Confirmed", Count = confirmedBookings, Color = "#10b981" },
            new() { Category = "Draft", Count = draftBookings, Color = "#e11d48" },
            new() { Category = "Cancelled", Count = cancelledBookings, Color = "#e11d48" },
            new() { Category = "Total", Count = totalBookings, Color = "#6366f1" }
        };

        return new DashboardSwmResponse
        {
            TotalCustomer = totalCustomer,
            TotalVendor = totalVendor,
            TotalBookings = totalBookings,
            ConfirmedBookings = confirmedBookings,
            DraftBookings = draftBookings,
            CancelledBookings = cancelledBookings,
            TotalResources = totalResources,
            TotalBookingGroups = totalGroups,
            BookingWinRate = bookingWinRate,
            PendingSO = pendingSO,
            PendingPO = pendingPO,
            SalesMTD = salesMTD,
            PurchaseMTD = purchaseMTD,
            TotalReceivable = totalReceivable,
            TotalPayable = totalPayable,
            BookingsByResource = bookingsByResource,
            BookingsByGroup = bookingsByGroup,
            BookingStatuses = bookingStatuses,
            CustomerGroups = customerGroups,
            VendorGroups = vendorGroups,
            TopProducts = topProducts,
            PaymentMethods = paymentMethods,
            DocGrid = docGrid,
            CashFlowMTD = cashFlowMTD,
            RecentSalesOrders = recentSalesOrders,
            RecentBookingsFeed = recentBookingsFeed,
            RevenueTrend = revenueTrendFinal,
            MonthlyBookingsTrend = monthlyBookingsTrend,
            PipelineSummary = pipelineSummary,
            BookingStages = bookingStages,
            BookingActivity = bookingActivity
        };
    }
}