# vim: expandtab ft=python ts=4 sw=4 sts=4:
import os
import sys
import subprocess
import time
from threading import Thread

from .import prints 

__STATUSSTRINGS__ = {
    0: "Not running",
    1: "Starting",
    2: "Running",
    3: "Stopping",
    }

__INPUTPIPE__ = 'input_pipe'
__STATUSFILE__ = 'status'
__PLAYERSFILE__ = 'players'
__PIDFILE__ = 'server.pid'


class MCWrapper:
    "Minecraft server wrapper class"
    def __init__(self, command, statusfile=False, playersfile=False):
        self.players = set()
        self.status = 0
        self.process = None
        self.command = command
        self.statusfile = statusfile
        self.plaersfile = playersfile
        prints.info("Server wrapper initializing")
        if os.path.isfile(__PIDFILE__):
            with open(__PIDFILE__) as file:
                lpid = int(file.readline())
            try:
                os.kill(lpid, 0)
            except OSError:
                prints.warning("Detected forced termination of previous server "
                        "wrapper instance.")
            else:
                prints.error("Another wrapper is running with given identifier.",
                      -1, 1)
        try:
            os.mkfifo(__INPUTPIPE__, 0o640)
        except FileExistsError:
            pass
        if statusfile:
            with open(__STATUSFILE__, 'w') as file:
                file.write(__STATUSSTRINGS__[0] + '\n')
        if playersfile:
            open(__PLAYERSFILE__, 'w')
        self.inputthread = Thread(target=self.__input_thread__,
                                  daemon=True)
        self.outputhread = Thread(target=self.__output_thread__,
                                  daemon=True)

    def clean(self):
        "Cleans files generated by wrapper"
        prints.info("Server wrapper clean.")
        try:
            os.remove(__INPUTPIPE__)
        except FileNotFoundError:
            pass
        try:
            os.remove(__PIDFILE__)
        except FileNotFoundError:
            pass
        try:
            os.remove(__STATUSFILE__)
        except FileNotFoundError:
            pass
        try:
            os.remove(__STATUSFILE__)
        except FileNotFoundError:
            pass

    def execstart(self):
        "Start execution of Minecraft server and hold until its exits"
        self.start()
        self.process.wait()

    def start(self):
        "Start Minecraft server"
        self.process = subprocess.Popen(
            self.command, stdin=subprocess.PIPE,
            stdout=subprocess.PIPE, stderr=subprocess.STDOUT,
            start_new_session=False)
        with open(__PIDFILE__, "w") as file:
            file.write(str(self.process.pid))
        self.status = 1
        if self.statusfile:
            with open(__STATUSFILE__, 'w') as file:
                file.write(__STATUSSTRINGS__[1] + '\n')
        if not self.inputthread.is_alive():
            self.inputthread.start()
        if not self.outputhread.is_alive():
            self.outputhread.start()

    def stop(self):
        "Sends /stop command to Minecraft server"
        if self.running():
            self.process.stdin.write(bytes(
                "/stop\n", sys.getdefaultencoding()))
            self.process.stdin.flush()

    def running(self):
        "Returns True if mc server is running. Othervise False."
        return bool(self.status)

    def write_to_terminal(self, text):
        "Write to server terminal. If server not running it does nothing"
        if self.status == 2:
            prints.info("Input: " + text, 1)
            self.process.stdin.write(bytes(text, sys.getdefaultencoding()))
            self.process.stdin.flush()
            return True
        else:
            return False

    def __user_join__(self, username):
        prints.info("User '" + username + "' joined server.")
        self.players.add(username)
        if self.plaersfile:
            with open(__PLAYERSFILE__, 'a') as file:
                file.write(username + '\n')

    def __user_leave__(self, username):
        prints.info("User '" + username + "' left server.")
        self.players.remove(username)
        if self.plaersfile:
            with open(__PLAYERSFILE__, 'w') as file:
                file.writelines(self.players)
                if self.players:
                    file.write('\n')

    def __parse_line__(self, line):
        if ': Done' in line:
            prints.info("Server start.")
            self.status = 2
            if self.statusfile:
                with open(__STATUSFILE__, 'w') as file:
                    file.write(__STATUSSTRINGS__[2] + '\n')
        elif ': Stopping the server' in line:
            prints.info("Server stop.")
            self.status = 3
            if self.statusfile:
                with open(__STATUSFILE__, 'w') as file:
                    file.write(__STATUSSTRINGS__[3] + '\n')
        elif 'logged in with entity id' in line:
            name = line[len('[00:00:00] [Server thread/INFO]: '):]
            name = name[:name.index('[')]
            self.__user_join__(name)
        elif 'left the game' in line:
            name = line[len('[00:00:00] [Server thread/INFO]: '):]
            name = name[:name.index(' ')]
            self.__user_leave__(name)

    def __output_thread__(self):
        for linen in self.process.stdout:
            line = linen.decode(sys.getdefaultencoding())
            prints.info(line.rstrip(), 2, notime=True)
            self.__parse_line__(line.rstrip())
        if self.statusfile:
            with open(__STATUSFILE__, 'w') as file:
                file.write(__STATUSSTRINGS__[0] + '\n')

    def __input_thread__(self):
        with open(__INPUTPIPE__, 'r') as pipe:
            while True:
                line = pipe.readline().rstrip()
                if line:
                    self.write_to_terminal(line + "\n")
                else:
                    time.sleep(3)