/*
 * Greenshot - a free and open source screenshot tool
 * Copyright (C) 2007-2015 Thomas Braun, Jens Klingen, Robin Krom
 *
 * For more information see: http://getgreenshot.org/
 * The Greenshot project is hosted on Sourceforge: http://sourceforge.net/projects/greenshot/
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 1 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

using System;
using System.Collections.Generic;
using System.Runtime.Serialization;

namespace Greenshot.Drawing.Fields
{
    /// <summary>
    /// Basic IFieldHolderWithChildren implementation. Similar to IFieldHolder,
    /// but has a List<IFieldHolder> of children.
    /// Field values are passed to and from children as well.
    /// </summary>
    [Serializable()]
    public abstract class AbstractFieldHolderWithChildren : AbstractFieldHolder
    {
        private readonly FieldChangedEventHandler fieldChangedEventHandler;

        [NonSerialized]
        private EventHandler childrenChanged;
        public event EventHandler ChildrenChanged
        {
            add { childrenChanged += value; }
            remove { childrenChanged -= value; }
        }

        public List<IFieldHolder> Children = new List<IFieldHolder>();

        public AbstractFieldHolderWithChildren()
        {
            fieldChangedEventHandler = OnFieldChanged;
        }

        [OnDeserialized()]
        private void OnDeserialized(StreamingContext context)
        {
            // listen to changing properties
            foreach (IFieldHolder fieldHolder in Children)
            {
                fieldHolder.FieldChanged += fieldChangedEventHandler;
            }
            if (childrenChanged != null) childrenChanged(this, EventArgs.Empty);
        }

        public void AddChild(IFieldHolder fieldHolder)
        {
            Children.Add(fieldHolder);
            fieldHolder.FieldChanged += fieldChangedEventHandler;
            if (childrenChanged != null) childrenChanged(this, EventArgs.Empty);
        }

        public void RemoveChild(IFieldHolder fieldHolder)
        {
            Children.Remove(fieldHolder);
            fieldHolder.FieldChanged -= fieldChangedEventHandler;
            if (childrenChanged != null) childrenChanged(this, EventArgs.Empty);
        }

        public new List<Field> GetFields()
        {
            List<Field> ret = new List<Field>();
            ret.AddRange(base.GetFields());
            foreach (IFieldHolder fh in Children)
            {
                ret.AddRange(fh.GetFields());
            }
            return ret;
        }

        public new Field GetField(FieldType fieldType)
        {
            Field ret = null;
            if (base.HasField(fieldType))
            {
                ret = base.GetField(fieldType);
            }
            else
            {
                foreach (IFieldHolder fh in Children)
                {
                    if (fh.HasField(fieldType))
                    {
                        ret = fh.GetField(fieldType);
                        break;
                    }
                }
            }
            if (ret == null)
            {
                throw new ArgumentException("Field '" + fieldType + "' does not exist in " + GetType());
            }
            return ret;
        }

        public new bool HasField(FieldType fieldType)
        {
            bool ret = base.HasField(fieldType);
            if (!ret)
            {
                foreach (IFieldHolder fh in Children)
                {
                    if (fh.HasField(fieldType))
                    {
                        ret = true;
                        break;
                    }
                }
            }
            return ret;
        }

        public new bool HasFieldValue(FieldType fieldType)
        {
            Field f = GetField(fieldType);
            return f != null && f.HasValue;
        }

        public new void SetFieldValue(FieldType fieldType, object value)
        {
            Field f = GetField(fieldType);
            if (f != null) f.Value = value;
        }
    }
}