using System.Security.Claims;
using SeaHaven.DataServices.Interfaces;
using SeaHaven.Services.DTOs;
using SeaHaven.Services.Exceptions;
using SeaHaven.Services.Helpers;
using SeaHaven.Services.Interfaces;

namespace SeaHaven.Services.Implementation
{
    public class DashboardService : IDashboardService
    {
        private readonly IDashboardDataService _dataService;
        private readonly IWorkOrderAccountResolver _accountResolver;

        public DashboardService(
            IDashboardDataService dataService,
            IWorkOrderAccountResolver accountResolver)
        {
            _dataService = dataService;
            _accountResolver = accountResolver;
        }

        public async Task<DashboardStatsDTO> GetStatsAsync(
            ClaimsPrincipal user,
            DashboardStatsQueryDTO query,
            CancellationToken cancellationToken)
        {
            var accountId = _accountResolver.ResolveAccountFilter(user);
            var dispatcherId = user.IsInRole("Dispatcher")
                ? user.FindFirstValue(ClaimTypes.NameIdentifier)
                : null;
            if (user.IsInRole("Dispatcher") && string.IsNullOrWhiteSpace(dispatcherId))
                throw new WorkOrderBoardValidationException("Forbidden", "Dispatcher identity is required.");

            var counts = await _dataService.GetWorkOrderCountsAsync(accountId, cancellationToken);
            var workOrders = await _dataService.GetDashboardWorkOrdersAsync(
                accountId,
                dispatcherId,
                query.DateFrom,
                query.DateTo,
                cancellationToken);
            var metrics = DashboardMetrics.Calculate(workOrders, DashboardBusinessTime.Today());

            var useMetrics = query.DateFrom.HasValue && query.DateTo.HasValue || dispatcherId is not null;

            return new DashboardStatsDTO
            {
                Total = useMetrics ? metrics.Total : counts.Total,
                Open = useMetrics ? metrics.Open : counts.Open,
                NotDispatched = useMetrics ? metrics.NotDispatched : counts.NotDispatched,
                Completed = useMetrics ? metrics.Completed : counts.Completed,
                Breakdown = metrics.Breakdown,
                DueCount = metrics.DueCount,
                CompletedDueCount = metrics.CompletedDueCount,
                CompletionRate = metrics.CompletionRate,
                AverageResolutionDays = metrics.AverageResolutionDays
            };
        }

        public async Task<DashboardWorkloadResponseDTO> GetWorkloadAsync(
            ClaimsPrincipal user,
            DashboardStatsQueryDTO query,
            int page,
            CancellationToken cancellationToken)
        {
            if (page < 1)
                throw new ArgumentOutOfRangeException(nameof(page));

            var accountId = _accountResolver.ResolveAccountFilter(user);
            var dispatcherId = user.IsInRole("Dispatcher")
                ? user.FindFirstValue(ClaimTypes.NameIdentifier)
                : null;
            if (user.IsInRole("Dispatcher") && string.IsNullOrWhiteSpace(dispatcherId))
                throw new WorkOrderBoardValidationException("Forbidden", "Dispatcher identity is required.");

            var rows = await _dataService.GetDispatcherWorkloadAsync(
                accountId,
                dispatcherId,
                query.DateFrom,
                query.DateTo,
                cancellationToken);
            var orderedRows = rows
                .OrderByDescending(row => row.OpenCount)
                .ThenBy(row => row.DispatcherName, StringComparer.OrdinalIgnoreCase)
                .ThenBy(row => row.DispatcherId, StringComparer.Ordinal)
                .ToList();
            const int pageSize = 10;

            return new DashboardWorkloadResponseDTO
            {
                Items = orderedRows.Skip((page - 1) * pageSize).Take(pageSize)
                    .Select(row => new DashboardWorkloadRowDTO
                    {
                        DispatcherId = row.DispatcherId,
                        DispatcherName = row.DispatcherName,
                        Color = row.Color,
                        TotalCount = row.TotalCount,
                        OpenCount = row.OpenCount
                    }).ToList(),
                Page = page,
                PageSize = pageSize,
                TotalDispatchers = orderedRows.Count
            };
        }

        public async Task<DashboardPerformanceResponseDTO> GetPerformanceAsync(
            ClaimsPrincipal user,
            DashboardStatsQueryDTO query,
            int page,
            CancellationToken cancellationToken)
        {
            if (page < 1)
                throw new ArgumentOutOfRangeException(nameof(page));

            var accountId = _accountResolver.ResolveAccountFilter(user);
            var dispatcherId = user.IsInRole("Dispatcher")
                ? user.FindFirstValue(ClaimTypes.NameIdentifier)
                : null;
            if (user.IsInRole("Dispatcher") && string.IsNullOrWhiteSpace(dispatcherId))
                throw new WorkOrderBoardValidationException("Forbidden", "Dispatcher identity is required.");

            var directory = await _dataService.GetDispatcherWorkloadAsync(
                accountId, dispatcherId, query.DateFrom, query.DateTo, cancellationToken);
            var workOrders = await _dataService.GetDashboardWorkOrdersAsync(
                accountId, dispatcherId, query.DateFrom, query.DateTo, cancellationToken);
            var today = DashboardBusinessTime.Today();
            var rows = directory.Select(dispatcher =>
            {
                var metrics = DashboardMetrics.Calculate(
                    workOrders.Where(workOrder => workOrder.AssignTo == dispatcher.DispatcherId).ToList(),
                    today);
                return new DashboardPerformanceRowDTO
                {
                    DispatcherId = dispatcher.DispatcherId,
                    DispatcherName = dispatcher.DispatcherName,
                    Color = dispatcher.Color,
                    CompletionRate = metrics.CompletionRate,
                    AverageResolutionDays = metrics.AverageResolutionDays
                };
            })
                .OrderByDescending(row => row.CompletionRate)
                .ThenBy(row => row.DispatcherName, StringComparer.OrdinalIgnoreCase)
                .ThenBy(row => row.DispatcherId, StringComparer.Ordinal)
                .ToList();
            const int pageSize = 10;

            return new DashboardPerformanceResponseDTO
            {
                Items = rows.Skip((page - 1) * pageSize).Take(pageSize).ToList(),
                Page = page,
                PageSize = pageSize,
                TotalDispatchers = rows.Count
            };
        }

        public async Task<DashboardRegionResponseDTO> GetRegionsAsync(
            ClaimsPrincipal user,
            DashboardStatsQueryDTO query,
            CancellationToken cancellationToken)
        {
            var accountId = _accountResolver.ResolveAccountFilter(user);
            var dispatcherId = user.IsInRole("Dispatcher")
                ? user.FindFirstValue(ClaimTypes.NameIdentifier)
                : null;
            if (user.IsInRole("Dispatcher") && string.IsNullOrWhiteSpace(dispatcherId))
                throw new WorkOrderBoardValidationException("Forbidden", "Dispatcher identity is required.");

            var workOrders = await _dataService.GetDashboardWorkOrdersAsync(
                accountId, dispatcherId, query.DateFrom, query.DateTo, cancellationToken);
            var counts = DashboardRegions.Count(workOrders);
            return new DashboardRegionResponseDTO
            {
                Items = DashboardRegions.Names
                    .Select(region => new DashboardRegionRowDTO
                    {
                        Region = region,
                        WorkOrderCount = counts[region]
                    })
                    .ToList()
            };
        }

        public async Task<DashboardVendorInsightsResponseDTO> GetVendorInsightsAsync(
            ClaimsPrincipal user,
            CancellationToken cancellationToken)
        {
            var accountId = _accountResolver.ResolveAccountFilter(user);
            var workOrders = await _dataService.GetDashboardWorkOrdersAsync(
                accountId, null, null, null, cancellationToken);
            var activeVendorOrders = workOrders
                .Where(workOrder => workOrder.VendorCompanyId.HasValue
                    && workOrder.VendorIsActive
                    && !workOrder.VendorCompanyIsDeleted)
                .ToList();
            var today = DashboardBusinessTime.Today();
            var rows = activeVendorOrders
                .GroupBy(workOrder => new
                {
                    Id = workOrder.VendorCompanyId!.Value,
                    Name = workOrder.VendorCompanyName ?? string.Empty
                })
                .Select(group =>
                {
                    var orders = group.ToList();
                    var metrics = DashboardMetrics.Calculate(orders, today);
                    var rescheduled = orders.Count(order => order.RescheduleCount >= 1);
                    return new DashboardVendorInsightsRowDTO
                    {
                        VendorCompanyId = group.Key.Id,
                        VendorCompanyName = group.Key.Name,
                        CompletionRate = metrics.CompletionRate,
                        RescheduleRate = Math.Round((decimal)rescheduled / orders.Count * 100, 2),
                        AverageResolutionDays = metrics.AverageResolutionDays,
                        TotalJobs = orders.Count
                    };
                })
                .OrderByDescending(row => row.CompletionRate)
                .ThenBy(row => row.VendorCompanyName, StringComparer.OrdinalIgnoreCase)
                .ThenBy(row => row.VendorCompanyId)
                .ToList();
            const int pageSize = 10;

            return new DashboardVendorInsightsResponseDTO
            {
                Items = rows.Take(pageSize).ToList(),
                Page = 1,
                PageSize = pageSize,
                TotalVendors = rows.Count
            };
        }
    }
}