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

namespace HttpServer
{
    /// <summary>
    /// Cookies that should be set.
    /// </summary>
    public sealed class ResponseCookies : IEnumerable<ResponseCookie>
    {
        private readonly IDictionary<string, ResponseCookie> _items = new Dictionary<string, ResponseCookie>();

        /// <summary>
        /// Adds a cookie in the collection.
        /// </summary>
        /// <param name="cookie">cookie to add</param>
        /// <exception cref="ArgumentNullException">cookie is null</exception>
        public void Add(ResponseCookie cookie)
        {
            // Verifies the parameter
            if (cookie == null)
                throw new ArgumentNullException("cookie");
            if (cookie.Name == null || cookie.Name.Trim() == string.Empty)
                throw new ArgumentException("Name must be specified.");
            if (cookie.Value == null || cookie.Value.Trim() == string.Empty)
                throw new ArgumentException("Content must be specified.");

            if (_items.ContainsKey(cookie.Name))
                _items[cookie.Name] = cookie;
            else _items.Add(cookie.Name, cookie);
        }

        /// <summary>
        /// Copy a request cookie
        /// </summary>
        /// <param name="cookie"></param>
        /// <param name="expires">When the cookie should expire</param>
        public void Add(RequestCookie cookie, DateTime expires)
        {
            Add(new ResponseCookie(cookie, expires));
        }

        /// <summary>
        /// Gets the count of cookies in the collection.
        /// </summary>
        public int Count
        {
            get { return _items.Count; }
        }


        /// <summary>
        /// Gets the cookie of a given identifier (null if not existing).
        /// </summary>
        public ResponseCookie this[string id]
        {
            get
            {
                if (_items.ContainsKey(id))
                    return _items[id];
                else
                    return null;
            }
            set
            {
                if (_items.ContainsKey(id))
                    _items[id] = value;
                else
                    Add(value);
            }
        }
        /// <summary>
        /// Gets a collection enumerator on the cookie list.
        /// </summary>
        /// <returns>collection enumerator</returns>
        public IEnumerator GetEnumerator()
        {
            return _items.Values.GetEnumerator();
        }


        /// <summary>
        /// Remove all cookies
        /// </summary>
        public void Clear()
        {
            _items.Clear();
        }

        #region IEnumerable<ResponseCookie> Members

        ///<summary>
        ///Returns an enumerator that iterates through the collection.
        ///</summary>
        ///
        ///<returns>
        ///A <see cref="T:System.Collections.Generic.IEnumerator`1"></see> that can be used to iterate through the collection.
        ///</returns>
        ///<filterpriority>1</filterpriority>
        IEnumerator<ResponseCookie> IEnumerable<ResponseCookie>.GetEnumerator()
        {
            return _items.Values.GetEnumerator();
        }

        #endregion
    }
}
