{
 "cells": [
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": [
    "\"\"\"\n",
    "The module optimizer_server implements the connection to Optimizer server. \n",
    "\n",
    "\"\"\"\n",
    "\n",
    "import asyncio\n",
    "import nest_asyncio\n",
    "nest_asyncio.apply()\n",
    "\n",
    "class Optimizer():\n",
    "    \"\"\"\n",
    "    This class contains attributes and methods for connecting to a running Optimizer server, \n",
    "    optimizing commands and queries, returning the result queries to be executed by Secondo.\n",
    "    \n",
    "    \"\"\"\n",
    "    \n",
    "    def __init__(self, server, port):\n",
    "        \"\"\"\n",
    "        The constructor of the calss Optimizer.\n",
    "        \n",
    "        :param server: The IP-address of Optimizer server.\n",
    "        :param port: The port number of the socket.\n",
    "        :return: None.\n",
    "    \n",
    "        \"\"\"\n",
    "         \n",
    "        self.server = server\n",
    "        self.port = port\n",
    "        self.initialized = False\n",
    "        self.conn = None\n",
    "        self.optreader = None\n",
    "        self.optwriter = None\n",
    "        loop = asyncio.get_event_loop()\n",
    "        loop.run_until_complete(self.connect())\n",
    "        \n",
    "    \n",
    "    async def connect(self):\n",
    "        \"\"\"\n",
    "        This method connects to Optimizer server using asyncio methods and sets the connection, \n",
    "        stream- reader and writer attributes of the Optimizer class. \n",
    "        \n",
    "        \"\"\"\n",
    "        \n",
    "        if self.initialized == True:\n",
    "            raise SecondoAPI_Error('Optimizer already initialised.')\n",
    "            \n",
    "        elif self.initialized == False:\n",
    "            \n",
    "            try:\n",
    "                self.conn = asyncio.open_connection(self.server, int(self.port))\n",
    "            except ConnectionRefusedError as e:\n",
    "                raise SecondoAPI_Error(e.args[1] + ' - Connection to Optimizer server refused.')\n",
    "            except OSError as e:\n",
    "                raise SecondoAPI_Error(e.args[1] + ' - Connection to Optimizer couldnt be stablished.')\n",
    "            \n",
    "            \n",
    "            try:\n",
    "                self.optreader, self.optwriter = await asyncio.wait_for(self.conn, timeout = 10)\n",
    "            except ConnectionRefusedError as e:\n",
    "                raise SecondoAPI_Error(e.args[1] + ' - Connection to Optimizer server refused.')\n",
    "            except OSError as e:\n",
    "                raise SecondoAPI_Error(e.args[1] + ' - Connection to Optimizer couldnt be stablished.')    \n",
    "            \n",
    "            \n",
    "            message = \"<who>\\n\"\n",
    "            while True:\n",
    "                self.optwriter.write(message.encode(\"utf-8\"))\n",
    "                await self.optwriter.drain()\n",
    "        \n",
    "                \n",
    "                line = await self.optreader.readline()\n",
    "                \n",
    "                line = line.decode(\"utf-8\")\n",
    "           \n",
    "                if not line:\n",
    "                    break\n",
    "            \n",
    "                if line != \"<optimizer>\\n\":\n",
    "                    break\n",
    "            \n",
    "                if line == \"<optimizer>\\n\":\n",
    "                    self.initialized = True\n",
    "                    print(\"Connection to Optimizer stablished...\")\n",
    "                    break\n",
    "                \n",
    "     \n",
    "    def close(self):\n",
    "        \"\"\"\n",
    "        This method closes the connections to Optimizer server.\n",
    "\n",
    "        \"\"\"\n",
    "        if not self.initialized:\n",
    "              raise SecondoAPI_Error('The connection to Optimizer has not been initialised.')\n",
    "        self.initialized = False\n",
    "        if self.optwriter is not None:\n",
    "            self.optwriter.close()\n",
    "        if self.conn is not None:\n",
    "            self.conn.close()\n",
    "    \n",
    "    \n",
    "    \n",
    "    def get_opt_conn(self):\n",
    "        \"\"\"\n",
    "        This method returns the connection attribute of Optimizer object.\n",
    "\n",
    "        :return: The connection attribute of Optimizer object.\n",
    "        \"\"\"\n",
    "        if self.conn is not None:\n",
    "            return self.conn\n",
    "        else:\n",
    "            raise SecondoAPI_Error('The connection to Optimizer is reset.')\n",
    "        \n",
    "        \n",
    "    def get_opt_initialized(self):\n",
    "        if self.initialized:\n",
    "            return True\n",
    "        else:\n",
    "            raise SecondoAPI_Error('Optimizer is already initialised.')\n",
    "        \n",
    "            \n",
    "    def get_opt_streams(self):\n",
    "        \"\"\"\n",
    "        This method returns the stream reader/ writer attributes of Optimizer object.\n",
    "        \n",
    "        :return: The stream reader/ writer attributes of Optimizer object.\n",
    "        \"\"\"\n",
    "        if self.optreader is not None and self.optwriter is not None:\n",
    "            return self.optreader, self.optwriter\n",
    "        else:\n",
    "            raise SecondoAPI_Error('Connection Error, Streams not connected.')\n",
    "            #return None\n",
    "    \n",
    "    def get_server(self):\n",
    "        \"\"\"\n",
    "        This method returns the server attributes of Optimizer object.\n",
    "        \n",
    "        :return: The server attributes of Optimizer object, which consists of an IP-address eg. 127.0.0.0.\n",
    "        \"\"\"\n",
    "        return self.server\n",
    "    \n",
    "    \n",
    "    def get_port(self):\n",
    "        \n",
    "        \"\"\"\n",
    "        This method returns the port attributes of Optimizer object.\n",
    "        :return: The port attributes of Optimizer object, which consists of an integer number as port eg. 5678.\n",
    "        \"\"\"\n",
    "        return self.port\n",
    "    \n",
    "    \n",
    "    def set_opt_initialized(self, val):\n",
    "        \"\"\"\n",
    "        This method sets an attribute of Optimizer object that shows if the Optimizer is initialised and running.\n",
    "        :param initialized: A boolean value, when True means the Optimizer is initialised and running.\n",
    "        \"\"\"\n",
    "        self.initialized = val\n",
    "        \n",
    "    "
   ]
  }
 ],
 "metadata": {
  "kernelspec": {
   "display_name": "Python 3",
   "language": "python",
   "name": "python3"
  },
  "language_info": {
   "codemirror_mode": {
    "name": "ipython",
    "version": 3
   },
   "file_extension": ".py",
   "mimetype": "text/x-python",
   "name": "python",
   "nbconvert_exporter": "python",
   "pygments_lexer": "ipython3",
   "version": "3.7.4"
  }
 },
 "nbformat": 4,
 "nbformat_minor": 2
}