/*
 * Greenshot - a free and open source screenshot tool
 * Copyright (C) 2007-2016 Thomas Braun, Jens Klingen, Robin Krom
 * 
 * For more information see: http://getgreenshot.org/
 * The Greenshot project is hosted on GitHub https://github.com/greenshot/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.ComponentModel;
using System.Drawing;
using System.Runtime.Serialization;

using Greenshot.Configuration;
using Greenshot.IniFile;
using log4net;
using GreenshotPlugin.Interfaces.Drawing;

namespace Greenshot.Drawing.Fields
{
	/// <summary>
	/// Basic IFieldHolder implementation, providing access to a set of fields
	/// </summary>
	[Serializable]
	public abstract class AbstractFieldHolder : IFieldHolder
	{
		private static readonly ILog LOG = LogManager.GetLogger(typeof(AbstractFieldHolder));
		private static readonly EditorConfiguration EditorConfig = IniConfig.GetIniSection<EditorConfiguration>();
		[NonSerialized]
		private readonly IDictionary<IField, PropertyChangedEventHandler> _handlers = new Dictionary<IField, PropertyChangedEventHandler>();

		/// <summary>
		/// called when a field's value has changed
		/// </summary>
		[NonSerialized]
		private FieldChangedEventHandler _fieldChanged;

		public event FieldChangedEventHandler FieldChanged
		{
			add { _fieldChanged += value; }
			remove { _fieldChanged -= value; }
		}

		// we keep two Collections of our fields, dictionary for quick access, list for serialization
		// this allows us to use default serialization
		[NonSerialized]
		private IDictionary<IFieldType, IField> _fieldsByType = new Dictionary<IFieldType, IField>();
		private readonly IList<IField> fields = new List<IField>();

		[OnDeserialized]
		private void OnDeserialized(StreamingContext context)
		{
			_fieldsByType = new Dictionary<IFieldType, IField>();
			// listen to changing properties
			foreach (var field in fields)
			{
				field.PropertyChanged += delegate {
					_fieldChanged?.Invoke(this, new FieldChangedEventArgs(field));
				};
				_fieldsByType[field.FieldType] = field;
			}
		}

		public void AddField(Type requestingType, IFieldType fieldType, object fieldValue)
		{
			AddField(EditorConfig.CreateField(requestingType, fieldType, fieldValue));
		}

		public virtual void AddField(IField field)
		{
			fields.Add(field);
			if (_fieldsByType == null)
			{
				return;
			}

			if (_fieldsByType.ContainsKey(field.FieldType))
			{
				if (LOG.IsDebugEnabled)
				{
					LOG.DebugFormat("A field with of type '{0}' already exists in this {1}, will overwrite.", field.FieldType, GetType());
				}
			}

			_fieldsByType[field.FieldType] = field;

			_handlers[field] = (sender, args) =>
			{
				_fieldChanged?.Invoke(this, new FieldChangedEventArgs(field));
			};
			field.PropertyChanged += _handlers[field];
		}

		public void RemoveField(IField field)
		{
			fields.Remove(field);
			_fieldsByType.Remove(field.FieldType);
			field.PropertyChanged -= _handlers[field];
			_handlers.Remove(field);
		}

		public IList<IField> GetFields()
		{
			return fields;
		}


		public IField GetField(IFieldType fieldType)
		{
			try
			{
				return _fieldsByType[fieldType];
			}
			catch (KeyNotFoundException e)
			{
				throw new ArgumentException("Field '" + fieldType + "' does not exist in " + GetType(), e);
			}
		}

		public object GetFieldValue(IFieldType fieldType)
		{
			return GetField(fieldType).Value;
		}

		#region convenience methods to save us some casts outside
		public string GetFieldValueAsString(IFieldType fieldType)
		{
			return Convert.ToString(GetFieldValue(fieldType));
		}

		public int GetFieldValueAsInt(IFieldType fieldType)
		{
			return Convert.ToInt32(GetFieldValue(fieldType));
		}

		public decimal GetFieldValueAsDecimal(IFieldType fieldType)
		{
			return Convert.ToDecimal(GetFieldValue(fieldType));
		}

		public double GetFieldValueAsDouble(IFieldType fieldType)
		{
			return Convert.ToDouble(GetFieldValue(fieldType));
		}

		public float GetFieldValueAsFloat(IFieldType fieldType)
		{
			return Convert.ToSingle(GetFieldValue(fieldType));
		}

		public bool GetFieldValueAsBool(IFieldType fieldType)
		{
			return Convert.ToBoolean(GetFieldValue(fieldType));
		}

		public Color GetFieldValueAsColor(IFieldType fieldType)
		{
			return (Color)GetFieldValue(fieldType);
		}
		#endregion

		public bool HasField(IFieldType fieldType)
		{
			return _fieldsByType.ContainsKey(fieldType);
		}

		public bool HasFieldValue(IFieldType fieldType)
		{
			return HasField(fieldType) && _fieldsByType[fieldType].HasValue;
		}

		public void SetFieldValue(IFieldType fieldType, object value)
		{
			try
			{
				_fieldsByType[fieldType].Value = value;
			}
			catch (KeyNotFoundException e)
			{
				throw new ArgumentException("Field '" + fieldType + "' does not exist in " + GetType(), e);
			}
		}

		protected void OnFieldChanged(object sender, FieldChangedEventArgs e)
		{
			_fieldChanged?.Invoke(sender, e);
		}
	}
}