using System.Collections.Generic;

namespace MapControl.Projections
{
    public class ProjNetMapProjectionFactory : MapProjectionFactory
    {
        public Dictionary<int, string> CoordinateSystemWkts { get; } = new Dictionary<int, string>
        {
            { 2056, WktConstants.ProjCsCh1903Lv95 },
            { 2100, WktConstants.ProjCsGgrs87 },
            { 2180, WktConstants.ProjCsEtrf2000Pl },
            { 3034, WktConstants.ProjCsEtrs89LccEurope },
            { 3035, WktConstants.ProjCsEtrs89LaeaEurope },
            { 4087, WktConstants.ProjCsWgs84 },
            { 4647, WktConstants.ProjCsEtrs89Utm32NzEN },
            { 4839, WktConstants.ProjCsEtrs89LccGermanyNE },
            { 5243, WktConstants.ProjCsEtrs89LccGermanyEN },
            { 21781, WktConstants.ProjCsCh1903Lv03 },
            { 29187, WktConstants.ProjCsSad69Utm17S },
            { 29188, WktConstants.ProjCsSad69Utm18S },
            { 29189, WktConstants.ProjCsSad69Utm19S },
            { 29190, WktConstants.ProjCsSad69Utm20S },
            { 29191, WktConstants.ProjCsSad69Utm21S },
            { 29192, WktConstants.ProjCsSad69Utm22S },
            { 29193, WktConstants.ProjCsSad69Utm23S },
        };

        public override MapProjection GetProjection(string crsId)
        {
            return crsId switch
            {
                MapControl.WebMercatorProjection.DefaultCrsId => new WebMercatorProjection(),
                MapControl.WorldMercatorProjection.DefaultCrsId => new WorldMercatorProjection(),
                MapControl.Wgs84UpsNorthProjection.DefaultCrsId => new Wgs84UpsNorthProjection(),
                MapControl.Wgs84UpsSouthProjection.DefaultCrsId => new Wgs84UpsSouthProjection(),
                MapControl.Wgs84AutoUtmProjection.DefaultCrsId => new Wgs84AutoUtmProjection(),
                MapControl.OrthographicProjection.DefaultCrsId => new Wgs84OrthographicProjection(),
                MapControl.StereographicProjection.DefaultCrsId => new Wgs84StereographicProjection(),
                _ => GetProjectionFromEpsgCode(crsId) ?? base.GetProjection(crsId)
            };
        }

        public override MapProjection GetProjection(int epsgCode)
        {
            if (CoordinateSystemWkts.TryGetValue(epsgCode, out string wkt))
            {
                return new ProjNetMapProjection(wkt);
            }

            return epsgCode switch
            {
                var c when c is >= Ed50UtmProjection.FirstZoneEpsgCode
                            and <= Ed50UtmProjection.LastZoneEpsgCode => new Ed50UtmProjection(c % 100),
                var c when c is >= Etrs89UtmProjection.FirstZoneEpsgCode
                            and <= Etrs89UtmProjection.LastZoneEpsgCode => new Etrs89UtmProjection(c % 100),
                var c when c is >= Nad27UtmProjection.FirstZoneEpsgCode
                            and <= Nad27UtmProjection.LastZoneEpsgCode => new Nad27UtmProjection(c % 100),
                var c when c is >= Nad83UtmProjection.FirstZoneEpsgCode
                            and <= Nad83UtmProjection.LastZoneEpsgCode => new Nad83UtmProjection(c % 100),
                var c when c is >= Wgs84UtmProjection.FirstZoneNorthEpsgCode
                            and <= Wgs84UtmProjection.LastZoneNorthEpsgCode => new Wgs84UtmProjection(c % 100, Hemisphere.North),
                var c when c is >= Wgs84UtmProjection.FirstZoneSouthEpsgCode
                            and <= Wgs84UtmProjection.LastZoneSouthEpsgCode => new Wgs84UtmProjection(c % 100, Hemisphere.South),
                _ => base.GetProjection(epsgCode)
            };
        }
    }
}