using Distribution.Features.Stock;
using Distribution.Features.DriverComplianceConfig;
using Distribution.Features.DriverProfile;
using Distribution.Infra.UoW;
using Distribution.Models;

namespace Distribution.Features.Ride;

public class RideService(
    IRideRepository rideRepo,
    IDriverProfileRepository driverRepo,
    IDriverComplianceConfigRepository complianceRepo,
    IRideCancelRequestRepository cancelRepo,
    Features.Vehicle.IVehicleRepository vehicleRepo,
    IStockRepository stockRepo,
    IUnitOfWork uow)
{
    public async Task<PagedResponse<RideResponse>> GetAllAsync(
        RideStatus? status,
        RideType? type,
        Guid? driverProfileId,
        Guid? vehicleId,
        int page,
        int pageSize)
    {
        var total = await rideRepo.GetCountAsync(status, type, driverProfileId, vehicleId);
        var items = await rideRepo.GetAllAsync(status, type, driverProfileId, vehicleId, page, pageSize);
        return new PagedResponse<RideResponse>(page, pageSize, total, items.Select(ToResponse).ToList());
    }

    public async Task<RideResponse?> GetByIdAsync(Guid id)
    {
        var ride = await rideRepo.GetByIdAsync(id);
        return ride is null ? null : ToResponse(ride);
    }

    public async Task<RideResponse> CreateAsync(CreateRideRequest request, CancellationToken ct = default)
    {
        var vehicle = await vehicleRepo.GetByIdAsync(request.FK_VehicleId)
            ?? throw new InvalidOperationException("Vehicle not found");

        var sourceWarehouseId = vehicle.FK_DefaultWarehouseId ?? request.FK_SourceWarehouseId;
        if (!sourceWarehouseId.HasValue)
            throw new InvalidOperationException("Source warehouse is required for this vehicle");

        var ride = new DeliveryRun
        {
            RideType = request.RideType,
            FK_VehicleId = request.FK_VehicleId,
            FK_DriverProfileId = request.FK_DriverProfileId,
            FK_RouteId = request.FK_RouteId,
            FK_SourceWarehouseId = sourceWarehouseId.Value,
            Status = RideStatus.Draft
        };

        await uow.BeginAsync(ct);
        try
        {
            await rideRepo.AddAsync(ride);
            await uow.CommitAsync(ct);
        }
        catch
        {
            await uow.RollbackAsync(ct);
            throw;
        }

        var saved = await rideRepo.GetByIdAsync(ride.Id);
        return ToResponse(saved!);
    }

    public async Task<RideResponse> OpenAsync(Guid rideId, CancellationToken ct = default)
    {
        var ride = await rideRepo.GetByIdAsync(rideId)
            ?? throw new KeyNotFoundException("Ride not found");

        if (ride.Status != RideStatus.Draft)
            throw new InvalidOperationException($"Cannot open a ride in {ride.Status} status");

        if (await rideRepo.HasOpenOrActiveRideForVehicleAsync(ride.FK_VehicleId, ride.Id))
            throw new InvalidOperationException("Vehicle already has an open or active ride");

        await CheckDriverComplianceAsync(ride.FK_DriverProfileId);

        ride.Status = RideStatus.Open;
        ride.StartedAt = DateTime.Now;

        await uow.BeginAsync(ct);
        try { rideRepo.Update(ride); await uow.CommitAsync(ct); }
        catch { await uow.RollbackAsync(ct); throw; }

        return ToResponse(ride);
    }

    public async Task<RideResponse> AssignDriverAsync(Guid rideId, Guid driverProfileId, CancellationToken ct = default)
    {
        var ride = await rideRepo.GetByIdAsync(rideId)
            ?? throw new KeyNotFoundException("Ride not found");

        if (ride.Status != RideStatus.Draft)
            throw new InvalidOperationException("Driver can only be changed while the ride is in Draft status");

        var driver = await driverRepo.GetByIdAsync(driverProfileId);
        if (driver is null || !driver.IsActive)
            throw new InvalidOperationException("Driver profile not found or inactive");

        ride.FK_DriverProfileId = driverProfileId;

        await uow.BeginAsync(ct);
        try { rideRepo.Update(ride); await uow.CommitAsync(ct); }
        catch { await uow.RollbackAsync(ct); throw; }

        var saved = await rideRepo.GetByIdAsync(rideId);
        return ToResponse(saved!);
    }

    public async Task<RideResponse> ActivateAsync(Guid rideId, ActivateRideRequest request, CancellationToken ct = default)
    {
        var ride = await rideRepo.GetByIdAsync(rideId)
            ?? throw new KeyNotFoundException("Ride not found");

        if (ride.Status != RideStatus.Open)
            throw new InvalidOperationException($"Cannot activate a ride in {ride.Status} status");

        ride.Status = RideStatus.Active;
        ride.ActivatedAt = DateTime.Now;
        ride.Meterstart = request.Meterstart;

        await uow.BeginAsync(ct);
        try { rideRepo.Update(ride); await uow.CommitAsync(ct); }
        catch { await uow.RollbackAsync(ct); throw; }

        return ToResponse(ride);
    }

    public async Task<RideResponse> CloseAsync(Guid rideId, CloseRideRequest request, CancellationToken ct = default)
    {
        var ride = await rideRepo.GetByIdAsync(rideId)
            ?? throw new KeyNotFoundException("Ride not found");

        if (ride.Status != RideStatus.Active)
            throw new InvalidOperationException($"Cannot close a ride in {ride.Status} status");

        await EnsureVehicleStockClearedAsync(ride.FK_VehicleId);

        ride.Status = RideStatus.Closed;
        ride.ClosedAt = DateTime.Now;
        ride.Meterend = request.Meterend;

        await uow.BeginAsync(ct);
        try { rideRepo.Update(ride); await uow.CommitAsync(ct); }
        catch { await uow.RollbackAsync(ct); throw; }

        return ToResponse(ride);
    }

    public async Task<RideCancelRequestResponse> RaiseCancelRequestAsync(Guid rideId, RaiseCancelRequest request, Guid requestedBy, CancellationToken ct = default)
    {
        var ride = await rideRepo.GetByIdAsync(rideId)
            ?? throw new KeyNotFoundException("Ride not found");

        if (ride.Status != RideStatus.Active)
            throw new InvalidOperationException($"Cannot raise a cancel request for a ride in {ride.Status} status");

        var existing = await cancelRepo.GetPendingByRideIdAsync(rideId);
        if (existing is not null)
            throw new InvalidOperationException("There is already a pending cancel request for this ride");

        var cancelRequest = new RideCancelRequest
        {
            FK_RideId = rideId,
            TypeCode = request.TypeCode,
            Reason = request.Reason,
            RequestedBy = requestedBy,
            RequestedAt = DateTime.Now,
            Status = CancelRequestStatus.Pending
        };

        ride.Status = RideStatus.CancelRequested;

        await uow.BeginAsync(ct);
        try
        {
            await cancelRepo.AddAsync(cancelRequest);
            rideRepo.Update(ride);
            await uow.CommitAsync(ct);
        }
        catch { await uow.RollbackAsync(ct); throw; }

        return ToCancelResponse(cancelRequest);
    }

    public async Task<PagedResponse<RideCancelRequestResponse>> GetCancelRequestsAsync(CancelRequestStatus? status, int page, int pageSize)
    {
        var total = await cancelRepo.GetCountAsync(status);
        var items = await cancelRepo.GetAllAsync(status, page, pageSize);
        return new PagedResponse<RideCancelRequestResponse>(page, pageSize, total, items.Select(ToCancelResponse).ToList());
    }

    public async Task<RideCancelRequestResponse> ApproveCancelAsync(Guid cancelRequestId, Guid approvedBy, CancellationToken ct = default)
    {
        var cancelRequest = await cancelRepo.GetByIdAsync(cancelRequestId)
            ?? throw new KeyNotFoundException("Cancel request not found");

        if (cancelRequest.Status != CancelRequestStatus.Pending)
            throw new InvalidOperationException("Cancel request is not pending");

        var ride = await rideRepo.GetByIdAsync(cancelRequest.FK_RideId)
            ?? throw new KeyNotFoundException("Ride not found");

        if (ride.Status != RideStatus.CancelRequested)
            throw new InvalidOperationException("Ride is not in CancelRequested status");

        await EnsureVehicleStockClearedAsync(ride.FK_VehicleId);

        cancelRequest.Status = CancelRequestStatus.Approved;
        cancelRequest.ApprovedBy = approvedBy;
        cancelRequest.ApprovedAt = DateTime.Now;

        ride.Status = RideStatus.Cancelled;

        await uow.BeginAsync(ct);
        try
        {
            cancelRepo.Update(cancelRequest);
            rideRepo.Update(ride);
            await uow.CommitAsync(ct);
        }
        catch { await uow.RollbackAsync(ct); throw; }

        return ToCancelResponse(cancelRequest);
    }

    public async Task<RideCancelRequestResponse> RejectCancelAsync(Guid cancelRequestId, Guid rejectedBy, CancellationToken ct = default)
    {
        var cancelRequest = await cancelRepo.GetByIdAsync(cancelRequestId)
            ?? throw new KeyNotFoundException("Cancel request not found");

        if (cancelRequest.Status != CancelRequestStatus.Pending)
            throw new InvalidOperationException("Cancel request is not pending");

        var ride = await rideRepo.GetByIdAsync(cancelRequest.FK_RideId)
            ?? throw new KeyNotFoundException("Ride not found");

        if (ride.Status != RideStatus.CancelRequested)
            throw new InvalidOperationException("Ride is not in CancelRequested status");

        cancelRequest.Status = CancelRequestStatus.Rejected;
        cancelRequest.ApprovedBy = rejectedBy;
        cancelRequest.ApprovedAt = DateTime.Now;

        // Restore to previous status: Active if ActivatedAt is set, else Open
        ride.Status = ride.ActivatedAt.HasValue ? RideStatus.Active : RideStatus.Open;

        await uow.BeginAsync(ct);
        try
        {
            cancelRepo.Update(cancelRequest);
            rideRepo.Update(ride);
            await uow.CommitAsync(ct);
        }
        catch { await uow.RollbackAsync(ct); throw; }

        return ToCancelResponse(cancelRequest);
    }

    public async Task<RideCancelRequestResponse?> GetCancelRequestAsync(Guid rideId)
    {
        var cancelRequest = await cancelRepo.GetByRideIdAsync(rideId);
        return cancelRequest is null ? null : ToCancelResponse(cancelRequest);
    }

    public async Task<BreakdownAssistResponse> GetBreakdownAssistAsync(Guid rideId)
    {
        var strandedRide = await rideRepo.GetByIdAsync(rideId)
            ?? throw new KeyNotFoundException("Ride not found");

        var activeRides = await rideRepo.GetActiveRidesAsync(rideId);
        var activeRideResponses = new List<BreakdownAssistRideResponse>();

        foreach (var ride in activeRides)
        {
            var stockLevels = await stockRepo.GetBalancesByLocationAsync(ride.FK_VehicleId, LocationType.Vehicle);
            activeRideResponses.Add(new BreakdownAssistRideResponse(
                ride.Id,
                ride.FK_VehicleId,
                ride.Vehicle?.NumberPlate ?? string.Empty,
                ride.FK_DriverProfileId,
                ride.DriverProfile?.User?.FullName ?? string.Empty,
                ride.FK_RouteId,
                ride.Route?.RouteName ?? string.Empty,
                stockLevels.Select(b => new StockBalanceResponse(
                    b.FK_ItemId,
                    b.Item.Name,
                    b.LocationId,
                    b.LocationType,
                    b.Quantity,
                    b.UpdatedAt)).ToList()));
        }

        var openOrders = await rideRepo.GetActiveOrdersByRouteIdAsync(strandedRide.FK_RouteId);

        return new BreakdownAssistResponse(
            strandedRide.Id,
            activeRideResponses,
            openOrders.Select(o => new BreakdownAssistOrderResponse(
                o.Id,
                o.StoreId,
                o.StoreName,
                o.OrderDate,
                o.TotalAmount)).ToList());
    }

    private async Task CheckDriverComplianceAsync(Guid driverProfileId)
    {
        var driver = await driverRepo.GetByIdAsync(driverProfileId)
            ?? throw new InvalidOperationException("Driver profile not found");

        if (!driver.IsActive)
            throw new InvalidOperationException("Driver profile is inactive");

        var config = await complianceRepo.GetAsync();
        if (config is null) return;

        var today = DateTime.Now.Date;

        if (config.EnforceLicenseExpiry && driver.LicenseExpiry.Date <= today)
            throw new InvalidOperationException("Driver license has expired");

        if (config.EnforceMedicalClearance && driver.MedicalClearanceExpiry.Date <= today)
            throw new InvalidOperationException("Driver medical clearance has expired");
    }

    private async Task EnsureVehicleStockClearedAsync(Guid vehicleId)
    {
        var balances = await stockRepo.GetBalancesByLocationAsync(vehicleId, LocationType.Vehicle);
        if (balances.Any(b => b.Quantity > 0))
            throw new InvalidOperationException("All vehicle stock must be returned before this ride can be completed");
    }

    private static RideResponse ToResponse(DeliveryRun r) =>
        new(r.Id, r.RideType, r.Status,
            r.FK_VehicleId, r.Vehicle?.NumberPlate ?? string.Empty,
            r.FK_DriverProfileId, r.DriverProfile?.User?.FullName ?? string.Empty,
            r.FK_RouteId, r.Route?.RouteName ?? string.Empty,
            r.FK_SourceWarehouseId, r.SourceWarehouse?.Name ?? string.Empty,
            r.Meterstart, r.Meterend,
            r.StartedAt, r.ActivatedAt, r.ClosedAt, r.CreatedAt);

    private static RideCancelRequestResponse ToCancelResponse(RideCancelRequest c) =>
        new(c.Id, c.FK_RideId, c.TypeCode, c.Reason, c.RequestedBy, c.RequestedAt,
            c.Status, c.ApprovedBy, c.ApprovedAt);
}