/*
 * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
 * 
 * Licensed under the Apache License, Version 2.0 (the "License").
 * You may not use this file except in compliance with the License.
 * A copy of the License is located at
 * 
 *  http://aws.amazon.com/apache2.0
 * 
 * or in the "license" file accompanying this file. This file is distributed
 * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
 * express or implied. See the License for the specific language governing
 * permissions and limitations under the License.
 */
using System;
using System.Collections.Generic;
using System.Xml.Serialization;
using System.Text;
using System.IO;
using Amazon.Runtime;

namespace Amazon.S3.Model {
  /// <summary>
  /// This class contains custom querystring parameters for an S3 object, which can then be signed as part of a Pre-signed URL request
  /// </summary>
  public sealed class ParameterCollection {

    IDictionary<string, string> values = new Dictionary<string, string>();

    /// <summary>
    /// Gets and sets parameters for the object. Parameter names must start with "x-". If the name passeed in as the indexer 
    /// doesn't start with "x-" then it will be prepended.
    /// </summary>
    /// <param name="name">The name of the parameter.</param>
    /// <returns>The value for the meta data</returns>
    public string this[string name] {
      get {
        if (!name.StartsWith("x-", StringComparison.OrdinalIgnoreCase))
          name = "x-" + name;

        string value;
        if (values.TryGetValue(name, out value))
          return value;

        return null;
      }
      set {
        if (!name.StartsWith("x-", StringComparison.OrdinalIgnoreCase))
          name = "x-" + name;

        values[name] = value;
      }
    }

    /// <summary>
    /// Adds the parameter to the collection, if the name already exists it will be overwritten.
    /// </summary>
    /// <param name="name">The name of the parameter</param>
    /// <param name="value">The value for the parameter</param>
    public void Add(string name, string value) {
      this[name] = value;
    }

    /// <summary>
    /// Gets the count of parameters.
    /// </summary>
    public int Count {
      get { return this.values.Count; }
    }

    /// <summary>
    /// Gets the names of the parameter elements.
    /// </summary>
    public ICollection<string> Keys {
      get { return values.Keys; }
    }
  }
}