import {EventEmitter} from 'events';

let clientId = 0;

class IpcClient extends EventEmitter {

  constructor(service) {
    super();

    this.id = clientId;

    process.send({
      type: 'connect',
      payload: {
        clientId: this.id,
        service,
      },
    });

    const messageListener = ({type, payload}) => {

      switch (type) {

        case 'connection_to':

          if (payload.clientId !== this.id) { return; }

          this.connection = payload.connection;
          this.to = payload.to;

          setTimeout(() => {
            this.emit('ready');
          }, 0);

          break;

        case 'connection_error':

          if (payload.clientId !== this.id) { return; }

          process.off('message', messageListener);

          setTimeout(() => {
            this.emit('error', {code: 'ENOTFOUND'});
          }, 0);

          break;

        case 'client_recv':

          if (payload.clientId !== this.id) { return; }

          process.off('message', messageListener);

          setTimeout(() => {
            this.emit('data', payload.data);
            this.emit('end');
          }, 0);

          break;

      }
    };

    process.on('message', messageListener);

    clientId++;
  }

  end() {}

  setEncoding() {}

  write(data) {

    process.send({
      type: 'client_send',
      payload: {
        clientId: this.id,
        data,
        to: this.to,
      },
    });
  }
}

export function client(address) {
  return new IpcClient(address);
}

class IpcSocket extends EventEmitter {

  constructor(clientId, to) {
    super();

    return {

      emit: this.emit,

      end() {
        this.emit('end');
      },

      on: this.on,

      setEncoding() {},

      write(data) {

        process.send({
          type: 'server_send',
          payload: {
            clientId,
            data,
            to,
          },
        });
      },
    };
  }
}

class IpcServer extends EventEmitter {

  constructor() {
    super();

    const connections = {};

    return {

      emit: this.emit,

      listen() {

        process.send({
          type: 'listening',
        });

        setTimeout(() => {
          this.emit('listening');
        }, 0);

        process.on('message', ({type, payload}) => {

          switch (type) {

            case 'connection_from':

              const socket = new IpcSocket(payload.clientId, payload.from);
              connections[payload.clientId] = socket;
              this.emit('connection', socket);

              socket.on('end', () => {
                delete connections[payload.clientId];
              });

              break;

            case 'server_recv':

              if (connections[payload.clientId]) {
                connections[payload.clientId].emit('data', payload.data);
              }

              break;

          }
        });
      },

      on: this.on,

      setEncoding() {},
    };
  }
}

export function server() {
  return new IpcServer();
}