using System;
using System.Collections.Generic;
using Deltares.Standard;
using Deltares.Standard.Extensions;

namespace Deltares.Dam.Data.Sensors
{
    public class SensorRepository
    {
        private SensorLocation sensorLocation;
        private readonly HashSet<string> names;
        private readonly HashSet<int> ids;

        private SensorRepository()
        {
            names = new HashSet<string>();
            ids = new HashSet<int>();
        }

        public SensorRepository(Location location) : this()
        {            
            if (location.SensorLocation == null)
            {
                location.AddNewSensorLocation();
            }

            sensorLocation = location.SensorLocation;

            if (sensorLocation.Group == null)
                sensorLocation.Group = new Group();
        }

        internal Group Group
        {
            get { return sensorLocation.Group; }
        }

        public IEnumerable<Sensor> Sensors
        {
            get { return Group.Selection; }
        }

        internal int GetUniqueSensorID()
        {
            return Group.Selection.GetUniqueID(x => x.ID);
        }

        /// <summary>
        /// Adds a new sensor to the location sensor group.
        /// </summary>
        /// <returns>The created Sensor</returns>
        public Sensor AddNew()
        {
            var factory = new SensorFactory();
            Sensor sensor = factory.CreateUniqueSensor(Group.Selection);
            AddSensor(sensor);
            return sensor;
        }

        /// <summary>
        /// Adds the collection of sensors to the group.
        /// </summary>
        /// <remarks>The sensor needs to meet the business rules before it can be added</remarks>
        /// <param name="sensors">The sensor collection to add to the group of this location.</param>
        /// <exception cref="ArgumentNullException"></exception>
        /// <exception cref="ArgumentException"></exception>
        public void Add(IEnumerable<Sensor> sensors)
        {
            if (sensors == null) throw new ArgumentNullException("sensors");
            foreach (var sensor in sensors)
                Add(sensor);
        }

        /// <summary>
        /// Adds the specified sensor.
        /// </summary>
        /// <remarks>The sensor needs to meet the business rules before it can be added</remarks>
        /// <param name="sensor">The sensor to add.</param>
        /// <exception cref="ArgumentNullException"></exception>
        /// <exception cref="ArgumentException"></exception>
        public void Add(Sensor sensor)
        {
            if (sensor == null) 
                throw new ArgumentNullException("sensor");
           
            if (string.IsNullOrWhiteSpace(sensor.Name))
                throw new ArgumentException("Cant add this sensor because its name is empty");

            if (sensor.IsTransient())
                throw new ArgumentException("Cant add this sensor because its ID is not valid. The ID must be greater then -1");

            if (ids.Contains(sensor.ID))
                throw new ArgumentException("Cant add this sensor becuase its ID is already added");

            if (names.Contains(sensor.Name))
                throw new ArgumentException("Cant add this sensor because its name is already used");

            AddSensor(sensor);
        }

        /// <summary>
        /// Adds the sensor unconditionally
        /// </summary>
        /// <param name="sensor">The sensor.</param>
        private void AddSensor(Sensor sensor)
        {
            ids.Add(sensor.ID);
            names.Add(sensor.Name);
            sensorLocation.Group.Add(sensor);
        }

        /// <summary>
        /// Serializes the state of this repository to a XML string.
        /// </summary>
        /// <returns></returns>
        internal string Serialize()
        {
            return sensorLocation.Serialize();
        }

        /// <summary>
        /// Deserializes the specified XML to restore the state of this repository
        /// </summary>
        /// <param name="xml">The XML.</param>
        internal static SensorRepository Deserialize(string xml)
        {
            if (string.IsNullOrWhiteSpace(xml)) throw new ArgumentException("xml");
            return new SensorRepository() { sensorLocation = SensorLocation.Deserialize(xml) };
        }
    }
}