# /*#########################################################################
#
# The PyMca X-Ray Fluorescence Toolkit
#
# Copyright (c) 2004-2019 European Synchrotron Radiation Facility
#
# This file is part of the PyMca X-ray Fluorescence Toolkit developed at
# the ESRF by the Software group.
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
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# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
# THE SOFTWARE.
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# ###########################################################################*/
__author__ = "T. Vincent - ESRF Data Analysis"
__contact__ = "thomas.vincent@esrf.fr"
__license__ = "MIT"
__copyright__ = "European Synchrotron Radiation Facility, Grenoble, France"
__doc__ = """
This module provides a PyMca plugin allowing to either download or receive
`JSON-RPC 2.0 <http://www.jsonrpc.org/specification>`_ requests that are
interpreted as commands for the 1D plot window.

Two modes are supported:

- *A client mode*, where the plugin downloads JSON-RPC files.
  In this mode, it is possible to download files from a given URL
  either on demand or at regular intervals (i.e., polling).
- *A server mode*, where the plugin is a TCP server that parses incoming data
  as JSON-RPC files.

As is, only :meth:`Plugin1DBase.addCurve` is available through RPC, but
more methods can be supported by populating the ``_handlers`` attribute of
:class:`PyMcaJsonRpc1DPlugin`.

Remote code in either server or client mode can use the
:func:`addCurveToJsonRpc` that has the same signature as
:meth:`Plugin1DBase.addCurve` and returns the corresponding JSON-RPC string
that can be interpreted by the plugin.
"""


# import ######################################################################

import json
import numpy as np

import sys
if sys.version_info.major == 2:
    from urllib2 import urlopen
    from BaseHTTPServer import BaseHTTPRequestHandler, HTTPServer
    from SocketServer import StreamRequestHandler, TCPServer
else:
    from urllib.request import urlopen
    from http.server import BaseHTTPRequestHandler, HTTPServer
    from socketserver import StreamRequestHandler, TCPServer

from PyMca5.PyMcaCore import Plugin1DBase
from PyMca5.PyMcaGui import PyMcaQt as qt


# JSON-RPC ####################################################################
# Light implementation of JSON-RPC 2.0 : http://www.jsonrpc.org/specification

_PARSE_ERROR = -32700
_INVALID_REQUEST = -32600
_METHOD_NOT_FOUND = -32601
_INVALID_PARAMS = -32602
_INTERNAL_ERROR = -32603
_SERVER_ERROR = -32000

_ERRORS = {
    _PARSE_ERROR: 'Parse Error',
    _INVALID_REQUEST: 'Invalid Request',
    _METHOD_NOT_FOUND: 'Method Not Found',
    _INVALID_PARAMS: 'Invalid Parameters',
    _INTERNAL_ERROR: 'Internal Error',
    _SERVER_ERROR: 'Server Error',
}


def _jsonRpcError(code, data=None):
    assert code in _ERRORS
    return {'code': code, 'message': _ERRORS[code], 'data': data}


def jsonRpcProcessRequest(requestFileObj, handlers):
    """Parse a single JSON-RPC request and call the associated handler function

    Limitations: Do not support batch, not checking parameters

    :param requestFileObj: JSON-RPC request document
    :type requestFileObj: A .read()-supporting file-like object
    :param dict handlers: RPC method handlers: {method name: handler function}
    :returns: The JSON-RPC reply or None if request was a notification
    :rtype: str
    """
    try:
        request = json.load(requestFileObj)
    except ValueError:
        return {'jsonrpc': '2.0',
                'id': None,
                'error': _jsonRpcError(_PARSE_ERROR)}

    try:
        reply = {'jsonrpc': '2.0', 'id': request['id']}
    except KeyError:
        reply = None

    try:
        methodName = request['method']
    except KeyError:
        if reply is not None:
            reply['error'] = _jsonRpcError(_INVALID_REQUEST,
                                           'Request has no method name')
        return reply

    try:
        method = handlers[methodName]
    except KeyError:
        if reply is not None:
            data = 'Unknown method: {}'.format(methodName)
            reply['error'] = _jsonRpcError(_METHOD_NOT_FOUND, data)
        return reply

    params = request.get('params', {})

    # Convert list to np.array
    if isinstance(params, dict):
        for key in params:
            value = params[key]
            if isinstance(value, list):
                params[key] = np.array(value)
    else:
        params = [np.array(v) if isinstance(v, list) else v for v in params]

    try:
        if isinstance(params, dict):
            result = method(**params)
        else:
            result = method(*params)
    except Exception as exception:
        if reply is not None:
            if isinstance(exception, TypeError):
                reply['error'] = _jsonRpcError(_INVALID_PARAMS,
                                               params)
            else:
                reply['error'] = _jsonRpcError(_SERVER_ERROR,
                                               (exception.errno,
                                                exception.strerror))
        return reply

    if reply is not None:
        reply['result'] = result
        reply = json.dumps(reply)

    return reply


# dialog box ##################################################################

class _DialogBox(qt.QDialog):
    LOAD = "Load"
    START_POLL = "Start Polling"
    STOP_POLL = "Stop Polling"
    START_SERVER = "Start Server"
    STOP_SERVER = "Stop Server"

    def __init__(self, parent, plugin):
        self._plugin = plugin

        qt.QDialog.__init__(self, parent)
        self.setWindowTitle('JSON-RPC Plugin')

        # Poll GUI
        pollLayout = qt.QFormLayout()
        pollGroup = qt.QGroupBox()
        pollGroup.setTitle('Client mode (Polling)')
        pollGroup.setLayout(pollLayout)

        pollUrlLabel = qt.QLabel("URL:")
        pollUrlLabel.setToolTip(
            "The URL to download JSON-RPC file from\n" +
            "Supported protocols: http:, ftp: file:")
        self.pollUrlLineEdit = qt.QLineEdit(self._plugin.pollUrl)
        pollLayout.addRow(pollUrlLabel, self.pollUrlLineEdit)

        pollTimeoutLabel = qt.QLabel("Timeout (s):")
        pollTimeoutLabel.setToolTip(
            "The interval in seconds at which the plugin is polling the URL")
        self.pollTimeoutLineEdit = qt.QLineEdit(str(self._plugin.pollTimeout))
        # Bounds timeout to avoid to small timeout
        self.pollTimeoutLineEdit.setValidator(
            qt.CLocaleQDoubleValidator(0.02, 1000.0, 2))
        pollLayout.addRow(pollTimeoutLabel, self.pollTimeoutLineEdit)

        self.pollLoadBtn = qt.QPushButton(self.LOAD)
        pollLayout.addRow(self.pollLoadBtn)

        if self._plugin.isPollRunning():
            pollBtnText = self.STOP_POLL
        else:
            pollBtnText = self.START_POLL
        self.pollBtn = qt.QPushButton(pollBtnText)
        pollLayout.addRow(self.pollBtn)

        # Server GUI
        serverLayout = qt.QFormLayout()
        serverGroup = qt.QGroupBox()
        serverGroup.setTitle('TCP Server mode')
        serverGroup.setLayout(serverLayout)

        serverPortLabel = qt.QLabel("TCP Port:")
        serverPortLabel.setToolTip(
            "The TCP port the server is listening to.\n" +
            "Ranging in [1024-65535]")
        self.serverPortLineEdit = qt.QLineEdit(str(self._plugin.serverPort))
        # Bounds port to 'user' ports
        self.serverPortLineEdit.setValidator(qt.QIntValidator(1024, 65535))
        serverLayout.addRow(serverPortLabel, self.serverPortLineEdit)

        if self._plugin.isServerRunning():
            serverBtnText = self.STOP_SERVER
        else:
            serverBtnText = self.START_SERVER
        self.serverBtn = qt.QPushButton(serverBtnText)
        serverLayout.addRow(self.serverBtn)

        # Main layout
        closeBtn = qt.QPushButton('Close')

        mainLayout = qt.QVBoxLayout()
        mainLayout.addWidget(pollGroup)
        mainLayout.addWidget(serverGroup)
        mainLayout.addWidget(closeBtn)

        self.setLayout(mainLayout)

        # Signals
        self.pollTimeoutLineEdit.editingFinished.connect(self.pollTimeoutCB)
        self.pollUrlLineEdit.editingFinished.connect(self.pollUrlCB)
        self.serverPortLineEdit.editingFinished.connect(self.serverPortCB)

        self.pollLoadBtn.clicked.connect(self.pollLoadBtnCB)
        self.pollBtn.clicked.connect(self.pollBtnCB)
        self.serverBtn.clicked.connect(self.serverBtnCB)
        closeBtn.clicked.connect(self.accept)

    def pollTimeoutCB(self):
        self._plugin.pollTimeout = float(self.pollTimeoutLineEdit.text())

    def pollUrlCB(self):
        self._plugin.pollUrl = self.pollUrlLineEdit.text()

    def serverPortCB(self):
        self._plugin.serverPort = int(self.serverPortLineEdit.text())

    def pollLoadBtnCB(self):
        self._plugin.load()

    def pollBtnCB(self):
        if self.pollBtn.text() == self.START_POLL:
            self._plugin.startPoll()
        else:
            self._plugin.stopPoll()

        if self._plugin.isPollRunning():
            pollBtnText = self.STOP_POLL
        else:
            pollBtnText = self.START_POLL
        self.pollBtn.setText(pollBtnText)

    def serverBtnCB(self):
        if self.serverBtn.text() == self.START_SERVER:
            self._plugin.startTcpServer()
        else:
            self._plugin.stopTcpServer()

        if self._plugin.isServerRunning():
            serverBtnText = self.STOP_SERVER
        else:
            serverBtnText = self.START_SERVER
        self.serverBtn.setText(serverBtnText)


# plugin ######################################################################

class PyMcaJsonRpc1DPlugin(Plugin1DBase.Plugin1DBase):
    def __init__(self, *args, **kwargs):
        super(PyMcaJsonRpc1DPlugin, self).__init__(*args, **kwargs)
        self._handlers = {
            'addCurve': self.addCurve,
        }

        # Parameters used by poll and server
        self.pollTimeout = 1.
        self.pollUrl = ''
        self.serverPort = 8000
        self._serverTimeout = 0.1

    def __del__(self):
        self.stopPoll()
        self.stopTcpServer()

    def getMethods(self, plottype=None):
        return ("JSON-RPC",)

    def getMethodToolTip(self, methodName):
        return "Allow to control the plot through JSON-RPC"

    def applyMethod(self, methodName):
        dialogBox = _DialogBox(None, self)
        dialogBox.exec_()

    def load(self):
        try:
            fileObj = urlopen(self.pollUrl)
        except ValueError:
            print('PyMcaJsonRpc1DPlugin.load: Bad URL:', self.pollUrl)
            return False
        else:
            jsonRpcProcessRequest(fileObj, self._handlers)
            fileObj.close()
            return True

    def startPoll(self):
        self.stopPoll()

        # Load file once to check if URL is correct
        if not self.load():
            return False
        else:
            self._pollTimer = qt.QTimer()
            self._pollTimer.timeout.connect(self.load)
            self._pollTimer.start(1000. * self.pollTimeout)
            return True

    def stopPoll(self):
        if hasattr(self, '_pollTimer'):
            self._pollTimer.stop()
            del self._pollTimer

    def isPollRunning(self):
        return hasattr(self, '_pollTimer')

    def startTcpServer(self):
        self.stopTcpServer()

        handlers = self._handlers

        class RequestHandler(StreamRequestHandler):
            def handle(self):
                reply = jsonRpcProcessRequest(self.rfile, handlers)
                if reply is not None:
                    self.wfile.write(reply)

        self._server = TCPServer(('', self.serverPort), RequestHandler,
                                 bind_and_activate=False)
        self._server.allow_reuse_address = True
        self._server.timeout = 0.01
        self._server.server_bind()
        self._server.server_activate()

        # Should do it differently
        self._serverTimer = qt.QTimer()
        self._serverTimer.timeout.connect(self._server.handle_request)
        self._serverTimer.start(1000. * self._serverTimeout)

    def stopTcpServer(self):
        if hasattr(self, '_serverTimer'):
            self._serverTimer.stop()
            del self._serverTimer
        if hasattr(self, '_server'):
            del self._server

    def isServerRunning(self):
        return hasattr(self, '_server')


MENU_TEXT = "JSON-RPC"


def getPlugin1DInstance(plotWindow, **kwargs):
    return PyMcaJsonRpc1DPlugin(plotWindow)


# helper ######################################################################

def addCurveToJsonRpc(x, y, legend=None, info=None,
                      replace=False, replot=True, **kw):
    """Generate a JSON-RPC request for calling :meth:`Plugin1DBase.addCurve`
    on a :class:`PyMcaJsonRpc1DPlugin` plugin.

    See :class:`Plugin1DBase` for details.

    :returns: A JSON-RPC request corresponding to the addCurve call
    :rtype: str
    """
    if not isinstance(x, (list, tuple)):
        x = tuple(x)
    if not isinstance(y, (list, tuple)):
        y = tuple(y)

    params = {
        "info": info,
        "x": x,
        "y": y,
        "legend": legend,
        "replace": replace,
        "replot": replot
    }
    params.update(kw)

    request = {
        "jsonrpc": "2.0",
        "method": "addCurve",
        "params": params
    }
    return json.dumps(request)


# demo polling ################################################################

def _testServer(address):
    # Create a test http server
    class TestRequestHandler(BaseHTTPRequestHandler):
        def do_GET(self):
            self.send_response(200)
            self.send_header("Content-type", "application/json")
            self.end_headers()
            request = addCurveToJsonRpc(
                np.arange(100.),
                np.random.random(100) * 10,
                legend="test {:.2f}".format(time.time()),
                replace=True,
                replot=True)
            self.wfile.write(request)

    return HTTPServer(address, TestRequestHandler)


class _DemoClientModeAuto(object):
    def __init__(self, plugin, onFinish):
        self._plugin = plugin
        self._onFinish = onFinish

    def start(self):
        import threading

        # Start server in a thread
        self._httpdServer = _testServer(('localhost', 8000))
        self._httpdThread = threading.Thread(
            target=self._httpdServer.serve_forever)
        self._httpdThread.start()

        # Set-up URL to download
        self._plugin.pollUrl = 'http://localhost:8000'

        print("Load JSON from server once")
        self._plugin.load()

        qt.QTimer.singleShot(2000., self._startPoll)

    def _startPoll(self):
        print("Start polling JSON from server")
        self._plugin.startPoll()
        qt.QTimer.singleShot(5000., self._stopPoll)

    def _stopPoll(self):
        print("Stop polling JSON from server")
        self._plugin.stopPoll()
        self._httpdServer.shutdown()
        self._httpdServer.socket.close()

        self._onFinish()


# demo server mode ############################################################

def _sendJsonRpcAddCurve(address):
    import socket

    request = addCurveToJsonRpc(
        np.arange(100.),
        np.random.random(100) * 10,
        legend="test {:.2f}".format(time.time()),
        replace=True,
        replot=True
    )

    sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    sock.connect(address)
    sock.send(request)
    sock.close()


class _DemoServerModeAuto(object):
    def __init__(self, plugin, onFinish):
        self._plugin = plugin
        self._onFinish = onFinish

    def start(self):
        import threading

        print("Start TCP server")
        self._plugin.startTcpServer()

        print("Start sending JSON-RPC through TCP")
        self._isSending = True
        self._senderThread = threading.Thread(target=self._sender)
        self._senderThread.start()

        qt.QTimer.singleShot(5000., self._stop)

    def _sender(self):
        while self._isSending:
            _sendJsonRpcAddCurve(('localhost', 8000))
            time.sleep(1)
        print("Stop sending JSON-RPC through TCP")

    def _stop(self):
        self._isSending = False
        self._senderThread.join()

        print('Stop server')
        self._plugin.stopTcpServer()

        self._onFinish()


# main ########################################################################

if __name__ == "__main__":
    import time
    import sys
    import os.path
    from PyMca5.PyMcaGui.plotting.PlotWindow import PlotWindow

    if len(sys.argv) == 1 or \
       sys.argv[1] not in ('plugin', 'demoServer', 'demoClient', 'auto'):
        print("""
Options: plugin, demoServer demoClient, auto

- plugin: Start a 1D plot window with JSPON-RPC plugin available
- demoServer: HTTP server, to load JSON-RPC from URL: http://localhost:8000
- demoClient: TCP client that sends JSPN-RPC to localhost:8000
- auto: Starts demo of polling and server that runs alone

""")
        sys.exit()

    if sys.argv[1] in ('plugin', 'auto'):
        # Create Qt main application
        app = qt.QApplication([])

        # Create plot window
        plot = PlotWindow(roi=True)
        plot.show()

        # Load plugin
        pluginDir = os.path.dirname(os.path.abspath(__file__))
        pluginName = os.path.splitext(os.path.basename(__file__))[0]

        plot.setPluginDirectoryList([pluginDir])
        nbPlugins = plot.getPlugins()  # Update plug-in list
        assert nbPlugins >= 1
        plugin = plot.pluginInstanceDict[pluginName]

        if sys.argv[1] == 'auto':
            # Run automated demos
            serverDemo = _DemoServerModeAuto(plugin, onFinish=app.quit)
            clientDemo = _DemoClientModeAuto(plugin, onFinish=serverDemo.start)
            clientDemo.start()

        app.exec_()

    elif sys.argv[1] == 'demoServer':
        httpdServer = _testServer(('localhost', 8000))
        httpdServer.serve_forever()

    elif sys.argv[1] == 'demoClient':
        while True:
            _sendJsonRpcAddCurve(('localhost', 8000))
            time.sleep(1)
