using System;
using System.Collections;
using System.Collections.Generic;

namespace TINK.Model.Station
{
    public class StationDictionary : IEnumerable<IStation>
    {
        /// <summary> Holds the list of stations. </summary>
        private readonly IDictionary<string, IStation> m_oStationDictionary;

        /// <summary> Count of stations. </summary>
        public int Count { get { return m_oStationDictionary.Count; } }

        public Version CopriVersion { get;  }

        /// <summary> Constructs a station dictionary object. </summary>
        /// <param name="p_oVersion">Version of copri- service.</param>
        public StationDictionary(Version p_oVersion = null, IDictionary<string, IStation> p_oStations = null)
        {
            m_oStationDictionary = p_oStations ?? new Dictionary<string, IStation>();

            CopriVersion = p_oVersion != null
                ? new Version(p_oVersion.Major, p_oVersion.Minor, p_oVersion.Revision, p_oVersion.Build)
                : new Version(0, 0, 0, 0);
        }

        public IEnumerator<IStation> GetEnumerator()
        {
            return m_oStationDictionary.Values.GetEnumerator();
        }

        /// <summary>
        /// Deteermines whether a station by given key exists.
        /// </summary>
        /// <param name="key">Key to check.</param>
        /// <returns>True if station exists.</returns>
        public bool ContainsKey(string key)
        {
            return m_oStationDictionary.ContainsKey(key);
        }

        /// <summary>
        /// Remove a station by station id.
        /// </summary>
        /// <param name="id"></param>
        public void RemoveById(string id)
        {
            if (!m_oStationDictionary.ContainsKey(id))
            {
                // Nothing to do if there is no station with given name.
                return;
            }

            m_oStationDictionary.Remove(id);
        }

        /// <summary>
        /// Remove a station by station name.
        /// </summary>
        /// <param name="id"></param>
        public IStation GetById(string id)
        {
            if (!m_oStationDictionary.ContainsKey(id))
            {
                // Nothing to do if there is no station with given name.
                return null;
            }

            return m_oStationDictionary[id];
        }

        /// <summary>
        /// Adds a station to dictionary of stations.
        /// </summary>
        /// <param name="p_oStation"></param>
        public void Add(Station p_oStation)
        {
            if (p_oStation == null)
            {
                throw new ArgumentException("Can not add empty station to collection of stations.");
            }

            if (m_oStationDictionary.ContainsKey(p_oStation.Id))
            {
                throw new ArgumentException(string.Format("Can not add station {0} to collection of stations. A station with given name already exists.", p_oStation.Id));
            }

            m_oStationDictionary.Add(p_oStation.Id, p_oStation);
        }

        IEnumerator IEnumerable.GetEnumerator()
        {
            return m_oStationDictionary.Values.GetEnumerator();
        }
    }
}