using Microsoft.Extensions.Logging;
using SatelliteProvider.Common.DTO;
using SatelliteProvider.Common.Interfaces;
using SatelliteProvider.Common.Utils;
using SatelliteProvider.DataAccess.Models;
using SatelliteProvider.DataAccess.Repositories;

namespace SatelliteProvider.Services;

public class RouteService : IRouteService
{
    private readonly IRouteRepository _routeRepository;
    private readonly ILogger<RouteService> _logger;
    private const double MAX_POINT_SPACING_METERS = 200.0;

    public RouteService(
        IRouteRepository routeRepository,
        ILogger<RouteService> logger)
    {
        _routeRepository = routeRepository;
        _logger = logger;
    }

    public async Task<RouteResponse> CreateRouteAsync(CreateRouteRequest request)
    {
        if (request.Points.Count < 2)
        {
            throw new ArgumentException("Route must have at least 2 points");
        }

        if (request.RegionSizeMeters < 100 || request.RegionSizeMeters > 10000)
        {
            throw new ArgumentException("Region size must be between 100 and 10000 meters");
        }

        if (string.IsNullOrWhiteSpace(request.Name))
        {
            throw new ArgumentException("Route name is required");
        }

        _logger.LogInformation("Creating route {RouteId} with {PointCount} original points", 
            request.Id, request.Points.Count);

        var allPoints = new List<RoutePointDto>();
        var totalDistance = 0.0;
        var sequenceNumber = 0;

        for (int segmentIndex = 0; segmentIndex < request.Points.Count; segmentIndex++)
        {
            var currentPoint = request.Points[segmentIndex];
            var isStart = segmentIndex == 0;
            var isEnd = segmentIndex == request.Points.Count - 1;

            var geoPoint = new GeoPoint(currentPoint.Latitude, currentPoint.Longitude);
            
            double? distanceFromPrevious = null;
            if (segmentIndex > 0)
            {
                var prevPoint = request.Points[segmentIndex - 1];
                var prevGeoPoint = new GeoPoint(prevPoint.Latitude, prevPoint.Longitude);
                distanceFromPrevious = GeoUtils.CalculateDistance(prevGeoPoint, geoPoint);
                totalDistance += distanceFromPrevious.Value;
            }

            var pointType = isStart ? "start" : (isEnd ? "end" : "waypoint");
            
            allPoints.Add(new RoutePointDto
            {
                Latitude = currentPoint.Latitude,
                Longitude = currentPoint.Longitude,
                PointType = pointType,
                SequenceNumber = sequenceNumber++,
                SegmentIndex = segmentIndex,
                DistanceFromPrevious = distanceFromPrevious
            });

            if (!isEnd)
            {
                var nextPoint = request.Points[segmentIndex + 1];
                var startGeo = new GeoPoint(currentPoint.Latitude, currentPoint.Longitude);
                var endGeo = new GeoPoint(nextPoint.Latitude, nextPoint.Longitude);
                
                var intermediatePoints = GeoUtils.CalculateIntermediatePoints(startGeo, endGeo, MAX_POINT_SPACING_METERS);
                
                _logger.LogInformation("Segment {SegmentIndex}: Adding {Count} intermediate points", 
                    segmentIndex, intermediatePoints.Count);

                foreach (var intermediateGeo in intermediatePoints)
                {
                    var prevGeo = sequenceNumber == 1 ? startGeo : new GeoPoint(
                        allPoints[sequenceNumber - 1].Latitude, 
                        allPoints[sequenceNumber - 1].Longitude);
                    
                    var distFromPrev = GeoUtils.CalculateDistance(prevGeo, intermediateGeo);
                    totalDistance += distFromPrev;

                    allPoints.Add(new RoutePointDto
                    {
                        Latitude = intermediateGeo.Lat,
                        Longitude = intermediateGeo.Lon,
                        PointType = "intermediate",
                        SequenceNumber = sequenceNumber++,
                        SegmentIndex = segmentIndex,
                        DistanceFromPrevious = distFromPrev
                    });
                }
            }
        }

        _logger.LogInformation("Route {RouteId}: Total {TotalPoints} points (original + intermediate), distance {Distance:F2}m",
            request.Id, allPoints.Count, totalDistance);

        var now = DateTime.UtcNow;
        var routeEntity = new RouteEntity
        {
            Id = request.Id,
            Name = request.Name,
            Description = request.Description,
            RegionSizeMeters = request.RegionSizeMeters,
            ZoomLevel = request.ZoomLevel,
            TotalDistanceMeters = totalDistance,
            TotalPoints = allPoints.Count,
            CreatedAt = now,
            UpdatedAt = now
        };

        await _routeRepository.InsertRouteAsync(routeEntity);

        var pointEntities = allPoints.Select(p => new RoutePointEntity
        {
            Id = Guid.NewGuid(),
            RouteId = request.Id,
            SequenceNumber = p.SequenceNumber,
            Latitude = p.Latitude,
            Longitude = p.Longitude,
            PointType = p.PointType,
            SegmentIndex = p.SegmentIndex,
            DistanceFromPrevious = p.DistanceFromPrevious,
            CreatedAt = now
        }).ToList();

        await _routeRepository.InsertRoutePointsAsync(pointEntities);

        _logger.LogInformation("Route {RouteId} created successfully", request.Id);

        return new RouteResponse
        {
            Id = routeEntity.Id,
            Name = routeEntity.Name,
            Description = routeEntity.Description,
            RegionSizeMeters = routeEntity.RegionSizeMeters,
            ZoomLevel = routeEntity.ZoomLevel,
            TotalDistanceMeters = routeEntity.TotalDistanceMeters,
            TotalPoints = routeEntity.TotalPoints,
            Points = allPoints,
            CreatedAt = routeEntity.CreatedAt,
            UpdatedAt = routeEntity.UpdatedAt
        };
    }

    public async Task<RouteResponse?> GetRouteAsync(Guid id)
    {
        var route = await _routeRepository.GetByIdAsync(id);
        if (route == null)
        {
            return null;
        }

        var points = await _routeRepository.GetRoutePointsAsync(id);
        
        return new RouteResponse
        {
            Id = route.Id,
            Name = route.Name,
            Description = route.Description,
            RegionSizeMeters = route.RegionSizeMeters,
            ZoomLevel = route.ZoomLevel,
            TotalDistanceMeters = route.TotalDistanceMeters,
            TotalPoints = route.TotalPoints,
            Points = points.Select(p => new RoutePointDto
            {
                Latitude = p.Latitude,
                Longitude = p.Longitude,
                PointType = p.PointType,
                SequenceNumber = p.SequenceNumber,
                SegmentIndex = p.SegmentIndex,
                DistanceFromPrevious = p.DistanceFromPrevious
            }).ToList(),
            CreatedAt = route.CreatedAt,
            UpdatedAt = route.UpdatedAt
        };
    }
}