using System;
using System.Collections.Generic;
using System.Text;
using Microsoft.Practices.ComponentModel;
using System.ComponentModel.Design;
using Microsoft.Practices.RecipeFramework.Extensions.Actions.OS;
using Microsoft.Practices.Common;
using EnvDTE;

namespace Microsoft.Practices.RecipeFramework.Extensions.ValueProviders.OS
{
    /// <summary>
    /// LocalMachineEntryProvider class
    /// </summary>
    [ServiceDependency(typeof(DTE))]
    [ServiceDependency(typeof(IDictionaryService))]
    public class LocalMachineEntryProvider : ValueProvider, IAttributesConfigurable
    {
        #region Constants & Fields
        /// <summary>
        /// Placeholder
        /// </summary>
        public const string RegistryPathAttribute = "RegistryPath";
        /// <summary>
        /// Placeholder
        /// </summary>
        public const string RegistryEntryAttribute = "RegistryEntry";
        private string registryPath;
        private string registryEntry;
        #endregion

        #region ValueProvider Implementation

        /// <summary>
        /// Contains code that will be called when recipe execution begins. This is the first method in the lifecycle.
        /// </summary>
        /// <param name="currentValue">An <see cref="T:System.Object"/> that contains the current value of the argument.</param>
        /// <param name="newValue">When this method returns, contains an <see cref="T:System.Object"/> that contains
        /// the new value of the argument, if the returned value
        /// of the method is <see langword="true"/>. Otherwise, it is ignored.</param>
        /// <returns>
        /// 	<see langword="true"/> if the argument value should be replaced with
        /// the value in <paramref name="newValue"/>; otherwise, <see langword="false"/>.
        /// </returns>
        /// <remarks>By default, always returns <see langword="false"/>, unless overriden by a derived class.</remarks>
        public override bool OnBeginRecipe(object currentValue, out object newValue)
        {
            if(string.IsNullOrEmpty(currentValue as string))
            {
                ReadLocalMachineEntryAction action = new ReadLocalMachineEntryAction();
                action.RegistryPath = this.registryPath;
                action.RegistryEntry = this.registryEntry;
                action.Execute();

                newValue = action.Value;
                return true;
            }
            else
            {
                newValue = currentValue;
                return false;
            }
        }

        #endregion

        #region IAttributesConfigurable Members

        /// <summary>
        /// Configures the component using the dictionary of attributes specified
        /// in the configuration file.
        /// </summary>
        /// <param name="attributes">The attributes in the configuration element.</param>
        public void Configure(System.Collections.Specialized.StringDictionary attributes)
        {
            if(attributes.ContainsKey(RegistryPathAttribute))
            {
                this.registryPath = attributes[RegistryPathAttribute];
            }

            if(attributes.ContainsKey(RegistryEntryAttribute))
            {
                this.registryEntry = attributes[RegistryEntryAttribute];
            }
        }

        #endregion
    }
}
