"""
	jupyter-mysql-kernel
	author:rabin
"""
from ipykernel.kernelbase import Kernel
from pexpect import replwrap, EOF
import pexpect

from subprocess import check_output
from .parser import MysqlParser
import os.path

import re
import signal

__version__ = '0.0.1'

version_pat = re.compile(r'version (\d+(\.\d+)+)')


class MysqlWrapper(replwrap.REPLWrapper):
	def __init__(self, cmd_or_spawn, orig_prompt, prompt_change,
				 extra_init_cmd=None, line_output_callback=None):
		self.line_output_callback = line_output_callback
		replwrap.REPLWrapper.__init__(self, cmd_or_spawn, orig_prompt, prompt_change, extra_init_cmd=extra_init_cmd)

	def _expect_prompt(self, timeout=-1):
		if timeout == None:
			while True:
				pos = self.child.expect_exact([self.prompt, self.continuation_prompt, u'\r\n'], timeout=None)
				if pos == 2:
					self.line_output_callback(self.child.before + '\n')
				else:
					if len(self.child.before) != 0:
						self.line_output_callback(self.child.before)
					break
		else:
			pos = replwrap.REPLWrapper._expect_prompt(self, timeout=timeout)

		return pos

class MysqlKernel(Kernel):
	implementation = 'jupyter-mysql-kernel'
	implementation_version = __version__

	@property
	def language_version(self):
		m = version_pat.search(self.banner)
		return m.group(1)

	_banner = None

	@property
	def banner(self):
		if self._banner is None:
			self._banner = check_output(['mysql', '--version']).decode('utf-8')
		return self._banner

	language_info = {'name': 'mysql',
					 'mimetype': 'text/x-sh',
					 'file_extension': '.sql'}

	mysql_setting_file = os.path.join(os.path.expanduser('~'), '.local/config/mysql_config.json')
	mysql_config = {
	   'prompt'	 : u'>'
	   ,'user'	  : 'root'
	   ,'host'	  : '192.168.15.10'
	   ,'port'	  : '3309'
	   ,'charset'   : 'utf-8'
	   ,'password'  : '123456'
	}

	def __init__(self, **kwargs):
		Kernel.__init__(self, **kwargs)
		if os.path.exists(self.mysql_setting_file):
			with open(self.mysql_setting_file,"r") as f:
				self.mysql_config.update(json.load(f))
		self.prompt = self.mysql_config['prompt']
		self.start_mysql()

	def start_mysql(self):
		sig = signal.signal(signal.SIGINT, signal.SIG_DFL)
		try:
			if 'password' in self.mysql_config:
				child = pexpect.spawn('mysql -A -h {host} -P {port} -u {user} -p{password}'.format(**self.mysql_config), echo=False, encoding=self.mysql_config['charset'], codec_errors='replace')
			else:
				child = pexpect.spawn('mysql -A -h {host} -P {port} -u {user}'.format(**self.mysql_config))
			prompt_change = None
			init_cmd = None
			self.wrapper = MysqlWrapper(child, self.prompt, prompt_change=prompt_change, extra_init_cmd=init_cmd, line_output_callback=self.process_output)
		finally:
			signal.signal(signal.SIGINT, sig)

	def process_output(self, output):
		if not self.silent and '|' in output:
			output = output.decode(self.mysql_config['charset'])
			output = MysqlParser(output)
			#stream_content = {'name': 'stdout', 'text': output}
			#self.send_response(self.iopub_socket, 'stream', stream_content)
			display_content = {
				'source': 'kernel',
				'data': {
					'text/plain': output.text(),
					'text/html': output.html()
				}, 'metadata': {}
			}
			self.send_response(self.iopub_socket, 'display_data', display_content)

	def do_execute(self, code, silent, store_history=True,
				   user_expressions=None, allow_stdin=False):
		self.silent = silent
		if not code.strip():
			return {'status': 'ok', 'execution_count': self.execution_count,
					'payload': [], 'user_expressions': {}}

		interrupted = False
		try:
			self.wrapper.run_command(code.rstrip(), timeout=None)
		except KeyboardInterrupt:
			self.wrapper.child.sendintr()
			interrupted = True
			self.wrapper._expect_prompt()
			output = self.wrapper.child.before
			self.process_output(output)
		except EOF:
			output = self.wrapper.child.before + 'Restarting Mysql'
			self.start_mysql()
			self.process_output(output)

		if interrupted:
			return {'status': 'abort', 'execution_count': self.execution_count}

		return {'status': 'ok', 'execution_count': self.execution_count,
					'payload': [], 'user_expressions': {}}