using Newtonsoft.Json;
using Newtonsoft.Json.Linq;
using Newtonsoft.Json.Serialization;
using System;

namespace ElectronNET.API
{
    /// <summary>
    /// Communicate asynchronously from the main process to renderer processes.
    /// </summary>
    public sealed class IpcMain
    {
        private static IpcMain _ipcMain;

        internal IpcMain() { }

        internal static IpcMain Instance
        {
            get
            {
                if(_ipcMain == null)
                {
                    _ipcMain = new IpcMain();
                }

                return _ipcMain;
            }
        }

        /// <summary>
        ///  Listens to channel, when a new message arrives listener would be called with 
        ///  listener(event, args...).
        /// </summary>
        /// <param name="channel">Channelname.</param>
        /// <param name="listener">Callback Method.</param>
        public void On(string channel, Action<object> listener)
        {
            BridgeConnector.Socket.Emit("registerIpcMainChannel", channel);
            BridgeConnector.Socket.On(channel, listener);
        }

        /// <summary>
        /// Send a message to the renderer process synchronously via channel, 
        /// you can also send arbitrary arguments.
        /// 
        /// Note: Sending a synchronous message will block the whole renderer process,
        /// unless you know what you are doing you should never use it.
        /// </summary>
        /// <param name="channel"></param>
        /// <param name="listener"></param>
        public void OnSync(string channel, Func<object, object> listener)
        {
            BridgeConnector.Socket.Emit("registerSyncIpcMainChannel", channel);
            BridgeConnector.Socket.On(channel, (args) => {
                var result = listener(args);

                BridgeConnector.Socket.Emit(channel + "Sync", result);
            });
        }

        /// <summary>
        /// Adds a one time listener method for the event. This listener is invoked only
        ///  the next time a message is sent to channel, after which it is removed.
        /// </summary>
        /// <param name="channel">Channelname.</param>
        /// <param name="listener">Callback Method.</param>
        public void Once(string channel, Action<object> listener)
        {
            BridgeConnector.Socket.Emit("registerOnceIpcMainChannel", channel);
            BridgeConnector.Socket.On(channel, listener);
        }

        /// <summary>
        /// Removes listeners of the specified channel.
        /// </summary>
        /// <param name="channel">Channelname.</param>
        public void RemoveAllListeners(string channel)
        {
            BridgeConnector.Socket.Emit("removeAllListenersIpcMainChannel", channel);
        }

        /// <summary>
        /// Send a message to the renderer process asynchronously via channel, you can also send
        /// arbitrary arguments. Arguments will be serialized in JSON internally and hence
        /// no functions or prototype chain will be included. The renderer process handles it by
        /// listening for channel with ipcRenderer module.
        /// </summary>
        /// <param name="browserWindow">BrowserWindow with channel.</param>
        /// <param name="channel">Channelname.</param>
        /// <param name="data">Arguments data.</param>
        public void Send(BrowserWindow browserWindow, string channel, params object[] data)
        {
            BridgeConnector.Socket.Emit("sendToIpcRenderer", JObject.FromObject(browserWindow, _jsonSerializer), channel, data);
        }

        private JsonSerializer _jsonSerializer = new JsonSerializer()
        {
            ContractResolver = new CamelCasePropertyNamesContractResolver(),
            NullValueHandling = NullValueHandling.Ignore,
            DefaultValueHandling = DefaultValueHandling.Ignore
        };
    }
}