#region License
/*
 * CookieCollection.cs
 *
 * This code is derived from CookieCollection.cs (System.Net) of Mono
 * (http://www.mono-project.com).
 *
 * The MIT License
 *
 * Copyright (c) 2004,2009 Novell, Inc. (http://www.novell.com)
 * Copyright (c) 2012-2019 sta.blockhead
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
#endregion

#region Authors
/*
 * Authors:
 * - Lawrence Pit <loz@cable.a2000.nl>
 * - Gonzalo Paniagua Javier <gonzalo@ximian.com>
 * - Sebastien Pouliot <sebastien@ximian.com>
 */
#endregion

using System;
using System.Collections;
using System.Collections.Generic;
using System.Globalization;
using System.Text;

namespace WebSocketSharp.Net
{
  /// <summary>
  /// Provides a collection of instances of the <see cref="Cookie"/> class.
  /// </summary>
  [Serializable]
  public class CookieCollection : ICollection<Cookie>
  {
    #region Private Fields

    private List<Cookie> _list;
    private bool         _readOnly;
    private object       _sync;

    #endregion

    #region Public Constructors

    /// <summary>
    /// Initializes a new instance of the <see cref="CookieCollection"/> class.
    /// </summary>
    public CookieCollection ()
    {
      _list = new List<Cookie> ();
      _sync = ((ICollection) _list).SyncRoot;
    }

    #endregion

    #region Internal Properties

    internal IList<Cookie> List {
      get {
        return _list;
      }
    }

    internal IEnumerable<Cookie> Sorted {
      get {
        var list = new List<Cookie> (_list);
        if (list.Count > 1)
          list.Sort (compareForSorted);

        return list;
      }
    }

    #endregion

    #region Public Properties

    /// <summary>
    /// Gets the number of cookies in the collection.
    /// </summary>
    /// <value>
    /// An <see cref="int"/> that represents the number of cookies in
    /// the collection.
    /// </value>
    public int Count {
      get {
        return _list.Count;
      }
    }

    /// <summary>
    /// Gets a value indicating whether the collection is read-only.
    /// </summary>
    /// <value>
    ///   <para>
    ///   <c>true</c> if the collection is read-only; otherwise, <c>false</c>.
    ///   </para>
    ///   <para>
    ///   The default value is <c>false</c>.
    ///   </para>
    /// </value>
    public bool IsReadOnly {
      get {
        return _readOnly;
      }

      internal set {
        _readOnly = value;
      }
    }

    /// <summary>
    /// Gets a value indicating whether the access to the collection is
    /// thread safe.
    /// </summary>
    /// <value>
    ///   <para>
    ///   <c>true</c> if the access to the collection is thread safe;
    ///   otherwise, <c>false</c>.
    ///   </para>
    ///   <para>
    ///   The default value is <c>false</c>.
    ///   </para>
    /// </value>
    public bool IsSynchronized {
      get {
        return false;
      }
    }

    /// <summary>
    /// Gets the cookie at the specified index from the collection.
    /// </summary>
    /// <value>
    /// A <see cref="Cookie"/> at the specified index in the collection.
    /// </value>
    /// <param name="index">
    /// An <see cref="int"/> that specifies the zero-based index of the cookie
    /// to find.
    /// </param>
    /// <exception cref="ArgumentOutOfRangeException">
    /// <paramref name="index"/> is out of allowable range for the collection.
    /// </exception>
    public Cookie this[int index] {
      get {
        if (index < 0 || index >= _list.Count)
          throw new ArgumentOutOfRangeException ("index");

        return _list[index];
      }
    }

    /// <summary>
    /// Gets the cookie with the specified name from the collection.
    /// </summary>
    /// <value>
    ///   <para>
    ///   A <see cref="Cookie"/> with the specified name in the collection.
    ///   </para>
    ///   <para>
    ///   <see langword="null"/> if not found.
    ///   </para>
    /// </value>
    /// <param name="name">
    /// A <see cref="string"/> that specifies the name of the cookie to find.
    /// </param>
    /// <exception cref="ArgumentNullException">
    /// <paramref name="name"/> is <see langword="null"/>.
    /// </exception>
    public Cookie this[string name] {
      get {
        if (name == null)
          throw new ArgumentNullException ("name");

        var caseInsensitive = StringComparison.InvariantCultureIgnoreCase;

        foreach (var cookie in Sorted) {
          if (cookie.Name.Equals (name, caseInsensitive))
            return cookie;
        }

        return null;
      }
    }

    /// <summary>
    /// Gets an object used to synchronize access to the collection.
    /// </summary>
    /// <value>
    /// An <see cref="object"/> used to synchronize access to the collection.
    /// </value>
    public object SyncRoot {
      get {
        return _sync;
      }
    }

    #endregion

    #region Private Methods

    private void add (Cookie cookie)
    {
      var idx = search (cookie);
      if (idx == -1) {
        _list.Add (cookie);
        return;
      }

      _list[idx] = cookie;
    }

    private static int compareForSort (Cookie x, Cookie y)
    {
      return (x.Name.Length + x.Value.Length)
             - (y.Name.Length + y.Value.Length);
    }

    private static int compareForSorted (Cookie x, Cookie y)
    {
      var ret = x.Version - y.Version;
      return ret != 0
             ? ret
             : (ret = x.Name.CompareTo (y.Name)) != 0
               ? ret
               : y.Path.Length - x.Path.Length;
    }

    private static CookieCollection parseRequest (string value)
    {
      var ret = new CookieCollection ();

      Cookie cookie = null;
      var ver = 0;

      var caseInsensitive = StringComparison.InvariantCultureIgnoreCase;
      var pairs = value.SplitHeaderValue (',', ';').ToList ();

      for (var i = 0; i < pairs.Count; i++) {
        var pair = pairs[i].Trim ();
        if (pair.Length == 0)
          continue;

        var idx = pair.IndexOf ('=');
        if (idx == -1) {
          if (cookie == null)
            continue;

          if (pair.Equals ("$port", caseInsensitive)) {
            cookie.Port = "\"\"";
            continue;
          }

          continue;
        }

        if (idx == 0) {
          if (cookie != null) {
            ret.add (cookie);
            cookie = null;
          }

          continue;
        }

        var name = pair.Substring (0, idx).TrimEnd (' ');
        var val = idx < pair.Length - 1
                  ? pair.Substring (idx + 1).TrimStart (' ')
                  : String.Empty;

        if (name.Equals ("$version", caseInsensitive)) {
          if (val.Length == 0)
            continue;

          int num;
          if (!Int32.TryParse (val.Unquote (), out num))
            continue;

          ver = num;
          continue;
        }

        if (name.Equals ("$path", caseInsensitive)) {
          if (cookie == null)
            continue;

          if (val.Length == 0)
            continue;

          cookie.Path = val;
          continue;
        }

        if (name.Equals ("$domain", caseInsensitive)) {
          if (cookie == null)
            continue;

          if (val.Length == 0)
            continue;

          cookie.Domain = val;
          continue;
        }

        if (name.Equals ("$port", caseInsensitive)) {
          if (cookie == null)
            continue;

          if (val.Length == 0)
            continue;

          cookie.Port = val;
          continue;
        }

        if (cookie != null)
          ret.add (cookie);

        if (!Cookie.TryCreate (name, val, out cookie))
          continue;

        if (ver != 0)
          cookie.Version = ver;
      }

      if (cookie != null)
        ret.add (cookie);

      return ret;
    }

    private static CookieCollection parseResponse (string value)
    {
      var ret = new CookieCollection ();

      Cookie cookie = null;

      var caseInsensitive = StringComparison.InvariantCultureIgnoreCase;
      var pairs = value.SplitHeaderValue (',', ';').ToList ();

      for (var i = 0; i < pairs.Count; i++) {
        var pair = pairs[i].Trim ();
        if (pair.Length == 0)
          continue;

        var idx = pair.IndexOf ('=');
        if (idx == -1) {
          if (cookie == null)
            continue;

          if (pair.Equals ("port", caseInsensitive)) {
            cookie.Port = "\"\"";
            continue;
          }

          if (pair.Equals ("discard", caseInsensitive)) {
            cookie.Discard = true;
            continue;
          }

          if (pair.Equals ("secure", caseInsensitive)) {
            cookie.Secure = true;
            continue;
          }

          if (pair.Equals ("httponly", caseInsensitive)) {
            cookie.HttpOnly = true;
            continue;
          }

          continue;
        }

        if (idx == 0) {
          if (cookie != null) {
            ret.add (cookie);
            cookie = null;
          }

          continue;
        }

        var name = pair.Substring (0, idx).TrimEnd (' ');
        var val = idx < pair.Length - 1
                  ? pair.Substring (idx + 1).TrimStart (' ')
                  : String.Empty;

        if (name.Equals ("version", caseInsensitive)) {
          if (cookie == null)
            continue;

          if (val.Length == 0)
            continue;

          int num;
          if (!Int32.TryParse (val.Unquote (), out num))
            continue;

          cookie.Version = num;
          continue;
        }

        if (name.Equals ("expires", caseInsensitive)) {
          if (val.Length == 0)
            continue;

          if (i == pairs.Count - 1)
            break;

          i++;

          if (cookie == null)
            continue;

          if (cookie.Expires != DateTime.MinValue)
            continue;

          var buff = new StringBuilder (val, 32);
          buff.AppendFormat (", {0}", pairs[i].Trim ());

          DateTime expires;
          if (
            !DateTime.TryParseExact (
              buff.ToString (),
              new[] { "ddd, dd'-'MMM'-'yyyy HH':'mm':'ss 'GMT'", "r" },
              CultureInfo.CreateSpecificCulture ("en-US"),
              DateTimeStyles.AdjustToUniversal
              | DateTimeStyles.AssumeUniversal,
              out expires
            )
          )
            continue;

          cookie.Expires = expires.ToLocalTime ();
          continue;
        }

        if (name.Equals ("max-age", caseInsensitive)) {
          if (cookie == null)
            continue;

          if (val.Length == 0)
            continue;

          int num;
          if (!Int32.TryParse (val.Unquote (), out num))
            continue;

          cookie.MaxAge = num;
          continue;
        }

        if (name.Equals ("path", caseInsensitive)) {
          if (cookie == null)
            continue;

          if (val.Length == 0)
            continue;

          cookie.Path = val;
          continue;
        }

        if (name.Equals ("domain", caseInsensitive)) {
          if (cookie == null)
            continue;

          if (val.Length == 0)
            continue;

          cookie.Domain = val;
          continue;
        }

        if (name.Equals ("port", caseInsensitive)) {
          if (cookie == null)
            continue;

          if (val.Length == 0)
            continue;

          cookie.Port = val;
          continue;
        }

        if (name.Equals ("comment", caseInsensitive)) {
          if (cookie == null)
            continue;

          if (val.Length == 0)
            continue;

          cookie.Comment = urlDecode (val, Encoding.UTF8);
          continue;
        }

        if (name.Equals ("commenturl", caseInsensitive)) {
          if (cookie == null)
            continue;

          if (val.Length == 0)
            continue;

          cookie.CommentUri = val.Unquote ().ToUri ();
          continue;
        }

        if (name.Equals ("samesite", caseInsensitive)) {
          if (cookie == null)
            continue;

          if (val.Length == 0)
            continue;

          cookie.SameSite = val.Unquote ();
          continue;
        }

        if (cookie != null)
          ret.add (cookie);

        Cookie.TryCreate (name, val, out cookie);
      }

      if (cookie != null)
        ret.add (cookie);

      return ret;
    }

    private int search (Cookie cookie)
    {
      for (var i = _list.Count - 1; i >= 0; i--) {
        if (_list[i].EqualsWithoutValue (cookie))
          return i;
      }

      return -1;
    }

    private static string urlDecode (string s, Encoding encoding)
    {
      if (s.IndexOfAny (new[] { '%', '+' }) == -1)
        return s;

      try {
        return HttpUtility.UrlDecode (s, encoding);
      }
      catch {
        return null;
      }
    }

    #endregion

    #region Internal Methods

    internal static CookieCollection Parse (string value, bool response)
    {
      try {
        return response
               ? parseResponse (value)
               : parseRequest (value);
      }
      catch (Exception ex) {
        throw new CookieException ("It could not be parsed.", ex);
      }
    }

    internal void SetOrRemove (Cookie cookie)
    {
      var idx = search (cookie);
      if (idx == -1) {
        if (cookie.Expired)
          return;

        _list.Add (cookie);
        return;
      }

      if (cookie.Expired) {
        _list.RemoveAt (idx);
        return;
      }

      _list[idx] = cookie;
    }

    internal void SetOrRemove (CookieCollection cookies)
    {
      foreach (var cookie in cookies._list)
        SetOrRemove (cookie);
    }

    internal void Sort ()
    {
      if (_list.Count > 1)
        _list.Sort (compareForSort);
    }

    #endregion

    #region Public Methods

    /// <summary>
    /// Adds the specified cookie to the collection.
    /// </summary>
    /// <param name="cookie">
    /// A <see cref="Cookie"/> to add.
    /// </param>
    /// <exception cref="InvalidOperationException">
    /// The collection is read-only.
    /// </exception>
    /// <exception cref="ArgumentNullException">
    /// <paramref name="cookie"/> is <see langword="null"/>.
    /// </exception>
    public void Add (Cookie cookie)
    {
      if (_readOnly) {
        var msg = "The collection is read-only.";
        throw new InvalidOperationException (msg);
      }

      if (cookie == null)
        throw new ArgumentNullException ("cookie");

      add (cookie);
    }

    /// <summary>
    /// Adds the specified cookies to the collection.
    /// </summary>
    /// <param name="cookies">
    /// A <see cref="CookieCollection"/> that contains the cookies to add.
    /// </param>
    /// <exception cref="InvalidOperationException">
    /// The collection is read-only.
    /// </exception>
    /// <exception cref="ArgumentNullException">
    /// <paramref name="cookies"/> is <see langword="null"/>.
    /// </exception>
    public void Add (CookieCollection cookies)
    {
      if (_readOnly) {
        var msg = "The collection is read-only.";
        throw new InvalidOperationException (msg);
      }

      if (cookies == null)
        throw new ArgumentNullException ("cookies");

      foreach (var cookie in cookies._list)
        add (cookie);
    }

    /// <summary>
    /// Removes all cookies from the collection.
    /// </summary>
    /// <exception cref="InvalidOperationException">
    /// The collection is read-only.
    /// </exception>
    public void Clear ()
    {
      if (_readOnly) {
        var msg = "The collection is read-only.";
        throw new InvalidOperationException (msg);
      }

      _list.Clear ();
    }

    /// <summary>
    /// Determines whether the collection contains the specified cookie.
    /// </summary>
    /// <returns>
    /// <c>true</c> if the cookie is found in the collection; otherwise,
    /// <c>false</c>.
    /// </returns>
    /// <param name="cookie">
    /// A <see cref="Cookie"/> to find.
    /// </param>
    /// <exception cref="ArgumentNullException">
    /// <paramref name="cookie"/> is <see langword="null"/>.
    /// </exception>
    public bool Contains (Cookie cookie)
    {
      if (cookie == null)
        throw new ArgumentNullException ("cookie");

      return search (cookie) > -1;
    }

    /// <summary>
    /// Copies the elements of the collection to the specified array,
    /// starting at the specified index.
    /// </summary>
    /// <param name="array">
    /// An array of <see cref="Cookie"/> that specifies the destination of
    /// the elements copied from the collection.
    /// </param>
    /// <param name="index">
    /// An <see cref="int"/> that specifies the zero-based index in
    /// the array at which copying starts.
    /// </param>
    /// <exception cref="ArgumentNullException">
    /// <paramref name="array"/> is <see langword="null"/>.
    /// </exception>
    /// <exception cref="ArgumentOutOfRangeException">
    /// <paramref name="index"/> is less than zero.
    /// </exception>
    /// <exception cref="ArgumentException">
    /// The space from <paramref name="index"/> to the end of
    /// <paramref name="array"/> is not enough to copy to.
    /// </exception>
    public void CopyTo (Cookie[] array, int index)
    {
      if (array == null)
        throw new ArgumentNullException ("array");

      if (index < 0)
        throw new ArgumentOutOfRangeException ("index", "Less than zero.");

      if (array.Length - index < _list.Count) {
        var msg = "The available space of the array is not enough to copy to.";
        throw new ArgumentException (msg);
      }

      _list.CopyTo (array, index);
    }

    /// <summary>
    /// Gets the enumerator that iterates through the collection.
    /// </summary>
    /// <returns>
    /// An <see cref="T:System.Collections.Generic.IEnumerator{Cookie}"/>
    /// instance that can be used to iterate through the collection.
    /// </returns>
    public IEnumerator<Cookie> GetEnumerator ()
    {
      return _list.GetEnumerator ();
    }

    /// <summary>
    /// Removes the specified cookie from the collection.
    /// </summary>
    /// <returns>
    ///   <para>
    ///   <c>true</c> if the cookie is successfully removed; otherwise,
    ///   <c>false</c>.
    ///   </para>
    ///   <para>
    ///   <c>false</c> if the cookie is not found in the collection.
    ///   </para>
    /// </returns>
    /// <param name="cookie">
    /// A <see cref="Cookie"/> to remove.
    /// </param>
    /// <exception cref="InvalidOperationException">
    /// The collection is read-only.
    /// </exception>
    /// <exception cref="ArgumentNullException">
    /// <paramref name="cookie"/> is <see langword="null"/>.
    /// </exception>
    public bool Remove (Cookie cookie)
    {
      if (_readOnly) {
        var msg = "The collection is read-only.";
        throw new InvalidOperationException (msg);
      }

      if (cookie == null)
        throw new ArgumentNullException ("cookie");

      var idx = search (cookie);
      if (idx == -1)
        return false;

      _list.RemoveAt (idx);
      return true;
    }

    #endregion

    #region Explicit Interface Implementations

    /// <summary>
    /// Gets the enumerator that iterates through the collection.
    /// </summary>
    /// <returns>
    /// An <see cref="IEnumerator"/> instance that can be used to iterate
    /// through the collection.
    /// </returns>
    IEnumerator IEnumerable.GetEnumerator ()
    {
      return _list.GetEnumerator ();
    }

    #endregion
  }
}