#!/usr/bin/env python
#
# Copyright 2017 Ettus Research (National Instruments)
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.
#
"""
RPC shell to debug USRP MPM capable devices
"""

import sys
import cmd
import types
from mprpc import RPCClient
from mprpc.exceptions import RPCError
from usrp_mpm import types
from importlib import import_module


class RPCShell(cmd.Cmd):
    prompt = "MPM> "
    client = None
    remote_methods = []

    def rpc_template(self, command, args=None):
        """Template function to create new RPC shell commands"""
        eval_preamble = "="
        try:
            if args:
                if isinstance(args, list):
                    parsed_args = [
                        eval(a.lstrip(eval_preamble))
                        if a.startswith(eval_preamble) else a for a in args
                    ]
                    response = self.client.call(command, parsed_args)
                else:
                    response = self.client.call(
                        command,
                        eval(args.lstrip(eval_preamble))
                        if args.startswith(eval_preamble) else args)
            else:
                response = self.client.call(command)
        except RPCError as e:
            print("RPC Command failed!")
            print("Error: {}".format(e))
            return
        if isinstance(response, bool):
            if response:
                print("Commend executed successfully!")
                return
            print("Command failed!")
            return
        print(response)

    def do_connect(self, host, port=types.MPM_RPC_PORT):
        """connect to a remote RPC serverconnect <host> (port=MPM_RPC_PORT)"""
        try:
            self.client = RPCClient(host, port)
        except:
            print("Connection refused")
            return
        methods = self.client.call('list_methods')
        for method in methods:
            self.add_command(*method)

    def do_disconnect(self, args):
        """disconnect from the RPC server"""
        if self.client:
            try:
                self.client.close()
            except RPCError as e:
                print("Error while closing the connection")
                print("Error: {}".format(e))
        for method in self.remote_methods:
            delattr(self, "do_" + method)
        self.remote_methods = []
        self.client = None

    def do_import(self, args):
        """import a python module into the global namespace"""
        globals()[args] = import_module(args)

    def do_EOF(self, args):
        exit(0)

    def add_command(self, command, docs):
        def new_command(args): self.rpc_template(str(command), args)
        new_command.__doc__ = docs
        setattr(self, "do_" + command, new_command)
        self.remote_methods.append(command)

    def run(self):
        try:
            self.cmdloop()
        except KeyboardInterrupt:
            self.do_disconnect(None)
            exit(0)

    def get_names(self):
        return dir(self)


if __name__ == "__main__":
    my_shell = RPCShell()
    exit(not (my_shell.run()))