using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Collections.ObjectModel;

using Microsoft.ResourceManagement.ObjectModel;



namespace Quest.FIMPowerShellSnapin

{

    /// <summary>

    /// The FIMPSCmdletResource class represents a FIM resource object as a PowerShell object. It contains a reference to the RmResource object

    /// as well as a reference to the FIMPSCmdletSession that the RmResource object is associate with.

    /// </summary>

    public class FIMPSResource

    {

        private readonly RmResource _resource;

        private readonly FIMPSSession _session;

        private RmResourceChanges _changes;



        public FIMPSResource(FIMPSSession session)

            : this(new RmResource(), session)

        {

        }



        internal FIMPSResource(RmResource obj, FIMPSSession session)

        {

            if (session == null)

            {

                throw new ArgumentNullException();

            }



            _resource = obj;

            _session = session;

            _changes = new RmResourceChanges(_resource);



            _changes.BeginChanges(); // Copies current attribute values so we can calculate changeset later

        }



        /// <summary>

        /// Determines if two FIM PS cmdlet resource objects are equal. To be equal, they must be from the same FIM server, the

        /// credentials used to obtain the object must be the same, and the property values must all be the same.

        /// </summary>

        /// <param name="obj">The PS object to compare</param>

        /// <returns>true if the two objects are equal, false if they are not equal</returns>

        public override bool Equals(object obj)

        {

            if (obj == this)

            {

                return true;

            }



            FIMPSResource other = obj as FIMPSResource;

            if (other == null)

            {

                return false;

            }



            if (Session.Server.ToLowerInvariant() != other.Session.Server.ToLowerInvariant())

            {

                return false;

            }



            if (Session.Credential.UserName.Trim().ToLowerInvariant() != other.Session.Credential.UserName.Trim().ToLowerInvariant())

            {

                return false;

            }



            return Resource.Equals(other.Resource);

        }



        public override int GetHashCode()

        {

            return _resource.GetHashCode();

        }





        public RmResource Resource

        {

            get

            {

                return _resource;

            }

        }



        public FIMPSSession Session

        {

            get

            {

                return _session;

            }

        }



        /// <summary>

        /// Indexer. Allows PoSh to retrieve attributes from the object using indexed array notation. Attribute values are 

        /// returned as strings, except for attributes defined in the schema as dates, which are returned as DateTime.

        /// Multi-valued attributes are returned as a List of either strings or DateTimes.

        /// </summary>

        /// <param name="attributeName">The name of the attribute to retrieve.</param>

        /// <returns></returns>

        public object this[string attributeName]

        {

            get

            {

                object pSValue;



                try // or else PoSh suppresses exceptions 

                {

                    RmAttributeName resourceAttributeName = new RmAttributeName(attributeName);

                    RmAttributeValue resourceValue = _resource[resourceAttributeName];



                    bool isDateTime = (_session.Client.Schema.GetAttributeType(attributeName) == SchemaCache.AttributeType.DateTime);



                    if (_session.Client.Schema.IsMultiValued(resourceAttributeName))

                    {

                        List<object> listOfValues = new List<object>(resourceValue.Values.Count);

                        foreach (RmAttributeValue rmValue in resourceValue.Values)

                        {

                            listOfValues.Add(isDateTime ? ConvertValueToDateTime(rmValue) : rmValue);

                        }

                        pSValue = new ReadOnlyCollection<object>(listOfValues);

                    }

                    else

                    {

                        pSValue = isDateTime ? ConvertValueToDateTime(resourceValue) : resourceValue;

                    }

                }

                catch

                {

                    throw;

                }

                return pSValue;

            }

        }



        private object ConvertValueToDateTime(RmAttributeValue rmValue)

        {

            if (rmValue.IsNullValue())

            {

                return new DateTime();

            }

            else

            {

                return DateTime.Parse(rmValue.ToString());

            }

        }



#if false

        public ICollection<ILMAttributeInfo> Attributes

        {

            get

            {

                List<retList = new List<ILMAttributeInfo>();



                foreach (String key in RmObject.AttributeNames)

                {

                    retList.Add(new ILMAttributeInfo(RmObject[key]));

                }



                return new ReadOnlyCollection<ILMAttributeInfo>(retList);

            }

        }

#endif

        /// <summary>

        /// Adds a value to the specified attribute. If the attribute doesn't exist, it will be created. If the

        /// attribute is single-valued, it throws an exception. If the attribute is multi-valued the specified value 

        /// will be added to the attribute. Note that this code does not check for the prior existence of the

        /// value, so it will be possible to create a multi-valued attribute with multiple identical values, which

        /// would be rejected by the FIM service.

        /// </summary>

        /// <param name="attributeName">The name of the attribute to modify</param>

        /// <param name="attributeValue">The value to set or add to the attribute</param>

        public void AddValue(string attributeName, IComparable attributeValue)

        {

            RmAttributeName rmAttrName = new RmAttributeName(attributeName);



            bool isMultivalued = _session.Client.Schema.IsMultiValued(rmAttrName);

            if(!isMultivalued)

            {

                throw new ArgumentException(string.Format(Constants.Messages.Error_IllegalOpForSVA, attributeName));

            }



            RmAttributeValue rmAttrValue = null;

            if(_resource.TryGetValue(rmAttrName, out rmAttrValue))

            {

                rmAttrValue.Values.Add(attributeValue);

            }

            else

            {

                rmAttrValue.Value = attributeValue;

            }

            _resource[rmAttrName] = rmAttrValue;

        }



        /// <summary>

        /// Removes a value from the specified multi-valued attribute. If the attribute does not exist, or if the 

        /// attribute is defined as single-valued, or if the value does not exist in the multi-value, throws an exception.

        /// </summary>

        /// <param name="attributeName">The name of the attribute to remove or modify</param>

        /// <param name="attributeValue">The value to remove from the attribute</param>

        public void RemoveValue(string attributeName, IComparable attributeValue)

        {

            RmAttributeName rmAttrName = new RmAttributeName(attributeName);



            bool isMultivalued = _session.Client.Schema.IsMultiValued(rmAttrName);

            if(!isMultivalued)

            {

                throw new ArgumentException(string.Format(Constants.Messages.Error_IllegalOpForSVA, attributeName));

            }



            //!! Debateable as to whether this should throw an exception if the attr doesn't exist. Could just ignore it.

            RmAttributeValue rmAttrValue = null;

            if(!_resource.TryGetValue(rmAttrName, out rmAttrValue))

            {

                throw new ArgumentException(string.Format(Constants.Messages.Error_AttributeMissing, attributeName));

            }



            rmAttrValue.Values.Remove(attributeValue);

            _resource[rmAttrName] = rmAttrValue;

        }

        

        /// <summary>

        /// Sets the value of the specified attribute to the specified value. If the attribute value does not exist, it

        /// will be added. If the attribute is single valued, any existing value will be replaced. If the attribute

        /// is multi-valued, the value will be replaced with the specified value. Null is a valid value.

        /// </summary>

        /// <param name="attributeName">The name of the attribute to remove or modify</param>

        /// <param name="attributeValue">The value to remove from the attribute</param>

        public void SetValue(string attributeName, object attributeValue)

        {



            RmAttributeName rmAttrName = new RmAttributeName(attributeName);

            RmAttributeValue rmAttrValue = new RmAttributeValue(attributeValue as IComparable);



            _resource[rmAttrName] = rmAttrValue;

        }



        /// <summary>

        /// Retrieves the RmResourceChanges object associated with this object. The RmResourceChanges object contains

        /// the original value of the objects attributes so that a delta can be computed to update the FIM web service.

        /// </summary>

        /// <returns></returns>

        public RmResourceChanges GetTransactionChanges()

        {

            return _changes;

        }



        public void AcceptChanges()

        {

            _changes.AcceptChanges();

        }

    }

}