using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using RealTimeGraphX.EventArguments;

namespace RealTimeGraphX
{
    /// <summary>
    /// Represents a <see cref="IGraphOutputComponent{TOut}"/> and <see cref="IGraphInputComponent{TIn}"/> base class.
    /// </summary>
    /// <typeparam name="TIn">The type of the in.</typeparam>
    /// <typeparam name="TOut">The type of the out.</typeparam>
    /// <seealso cref="RealTimeGraphX.GraphObject" />
    /// <seealso cref="RealTimeGraphX.IGraphInputComponent{TIn}" />
    /// <seealso cref="RealTimeGraphX.IGraphOutputComponent{TOut}" />
    public abstract class GraphInputOutputComponentBase<TIn, TOut> : GraphObject, IGraphInputComponent<TIn>, IGraphOutputComponent<TOut> where TIn : IGraphComponent where TOut : IGraphComponent
    {
        /// <summary>
        /// Occurs when the <see cref="P:RealTimeGraphX.IGraphInputComponent`1.Input" /> property has changed.
        /// </summary>
        public event EventHandler<InputChangedEventArgs<TIn>> InputChanged;

        /// <summary>
        /// Occurs when the <see cref="P:RealTimeGraphX.IGraphOutputComponent`1.Output" /> property has changed.
        /// </summary>
        public event EventHandler<OutputChangedEventArgs<TOut>> OutputChanged;

        private TIn _input;
        /// <summary>
        /// Gets the connected input <see cref="T:RealTimeGraphX.IGraphComponent" />.
        /// </summary>
        public TIn Input
        {
            get { return _input; }
            protected set
            {
                _input = value;
                RaisePropertyChangedAuto();
                OnInputChanged(_input);
            }
        }

        private TOut _output;
        /// <summary>
        /// Gets the connected output <see cref="T:RealTimeGraphX.IGraphComponent" />.
        /// </summary>
        public TOut Output
        {
            get { return _output; }
            protected set
            {
                _output = value;
                RaisePropertyChangedAuto();
                OnOutputChanged(_output);
            }
        }

        /// <summary>
        /// Raises the <see cref="InputChanged"/> event.
        /// </summary>
        /// <param name="input">The input.</param>
        protected virtual void OnInputChanged(TIn input)
        {
            InputChanged?.Invoke(this, new InputChangedEventArgs<TIn>(input));
        }

        /// <summary>
        /// Raises the <see cref="OutputChanged"/> event.
        /// </summary>
        /// <param name="output">The output.</param>
        protected virtual void OnOutputChanged(TOut output)
        {
            OutputChanged?.Invoke(this, new OutputChangedEventArgs<TOut>(output));
        }

        /// <summary>
        /// Connects the specified component output to this component input.
        /// </summary>
        /// <param name="component">The component.</param>
        /// <param name="fromInput">Specifies whether this call was made from a <see cref="TIn" /> component.</param>
        public abstract void ConnectInput(TIn component, bool fromInput = false);

        /// <summary>
        /// Disconnects this component input from the current connected <see cref="P:RealTimeGraphX.IGraphInputComponent`1.Input" /><see cref="T:RealTimeGraphX.IGraphComponent" />.
        /// </summary>
        /// <param name="fromInput">Specifies whether this call was made from a <see cref="TIn" /> component.</param>
        public abstract void DisconnectInput(bool fromInput = false);

        /// <summary>
        /// Connects this component to another <see cref="T:RealTimeGraphX.IGraphComponent" />.
        /// </summary>
        /// <param name="output">The output component.</param>
        /// <param name="fromOutput">Specifies whether this call was made from a <see cref="TOut" /> component.</param>
        public abstract void ConnectOutput(TOut output, bool fromOutput = false);

        /// <summary>
        /// Disconnects this component from the connected <see cref="P:RealTimeGraphX.IGraphOutputComponent`1.Output" /><see cref="T:RealTimeGraphX.IGraphComponent" />.
        /// </summary>
        /// <param name="fromOutput">Specifies whether this call was made from a <see cref="TOut" /> component.</param>
        public abstract void DisconnectOutput(bool fromOutput = false);
    }
}