// -----------------------------------------------------------------------
// <copyright file="OsmNode.cs" company="">
// TODO: Update copyright text.
// </copyright>
// -----------------------------------------------------------------------

namespace OsmReader.OsmData.Elements
{
    using System;
    using System.Collections.Generic;
    using System.Linq;
    using System.Text;
    using System.Globalization;
    using System.Xml.Serialization;

    /// <summary>
    /// TODO: Update summary.
    /// </summary>
    public class OsmNode : AbstractTaggedOsmElement
    {
        private const double EARTH_RADIUS = 6371000.0;
        private const double HALFCIRCLE = 180.0;

        [XmlAttribute(AttributeName = "id")]
        public long id { get; set; }

        [XmlAttribute(AttributeName = "lat")]
        public double lat { get; set; }

        [XmlAttribute(AttributeName = "lon")]
        public double lon { get; set; }

        [XmlAttribute(AttributeName = "user")]
        public string user { get; set; }

        [XmlAttribute(AttributeName = "uid")]
        public int uid { get; set; }

        [XmlAttribute(AttributeName = "visible")]
        public bool visible { get; set; }

        [XmlAttribute(AttributeName = "version")]
        public int version { get; set; }

        [XmlAttribute(AttributeName = "changeset")]
        public long changeset { get; set; }

        [XmlAttribute(AttributeName = "timestamp")]
        public string timestamp { get; set; }

        [XmlIgnore]
        public int links { get; set; }

        [XmlIgnore]
        public int inLinks { get; set; }

        [XmlIgnore]
        public int outLinks { get; set; }

        [XmlIgnore]
        public string NodeType
        {
            get
            {
                return getTagValue("highway");
            }
        }

        [XmlIgnore]
        public string Ref
        {
            get
            {
                return getTagValue("ref");
            }
        }

        /// <summary>
        /// Get the distance in meters between two nodes.
        /// </summary>
        /// <param name="node1">Node 1</param>
        /// <param name="node2">Node 2</param>
        /// <returns>Distance in meters.</returns>
        public static double calcDistance(OsmNode node1, OsmNode node2)
        {
            double d = 0;

            if (node1 != null && node2 != null)
            {
                double dLat = (node2.lat - node1.lat) / HALFCIRCLE * Math.PI;
                double dLon = (node2.lon - node1.lon) / HALFCIRCLE * Math.PI;
                double lat1 = node1.lat / HALFCIRCLE * Math.PI;
                double lat2 = node2.lat / HALFCIRCLE * Math.PI;

                double a = Math.Sin(dLat / 2) * Math.Sin(dLat / 2) +
                        Math.Sin(dLon / 2) * Math.Sin(dLon / 2) * Math.Cos(lat1) * Math.Cos(lat2);

                double c = 2 * Math.Atan2(Math.Sqrt(a), Math.Sqrt(1 - a));
                d = EARTH_RADIUS * c;
            }

            return d;
        }

        public override string ToString()
        {
            return id.ToString() + " [" + this.lat.ToString(CultureInfo.InvariantCulture) + "," + this.lon.ToString(CultureInfo.InvariantCulture) + "]";
        }

        public override int GetHashCode()
        {
            uint hash = (uint)this.lat.GetHashCode() ^ (((uint)this.lon.GetHashCode() & 0xffff) << 16 | ((uint)this.lon.GetHashCode() & 0xffff0000) >> 16);

            return (int)hash;
        }

        public override bool Equals(object obj)
        {
            bool match = false;
            if (obj is OsmNode)
            {
                OsmNode node1 = (OsmNode)obj;

                match = (this.lat == node1.lat) && (this.lon == node1.lon);
            }

            return match;
        }

        /// <summary>
        /// Check if the position is close to the given position.
        /// </summary>
        /// <param name="obj">Object to compare with.</param>
        /// <param name="radius">Distance to cover from position.</param>
        /// <returns></returns>
        public bool CloseTo(OsmNode obj, double radius)
        {
            bool match = calcDistance(this, obj) <= radius;

            return match;
        }
    }
}