#!/usr/bin/python
#-*- coding: utf-8 -*-

"""
SAT: a jabber client
Copyright (C) 2009, 2010, 2011  Jérôme Poisson (goffi@goffi.org)

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/>.
"""


#consts
NAME = u"bridge_constructor"
VERSION="0.1.0"
ABOUT = NAME+u""" v%s (c) Jérôme Poisson (aka Goffi) 2011

---
"""+NAME+u""" Copyright (C) 2011  Jérôme Poisson (aka Goffi)
This program comes with ABSOLUTELY NO WARRANTY;
This is free software, and you are welcome to redistribute it
under certain conditions.
---

This script construct a SàT bridge using the given protocol
"""
MANAGED_PROTOCOLES=['dbus']
DEFAULT_PROTOCOLE='dbus'

import sys
import os
from os import path
from optparse import OptionParser
from ConfigParser import RawConfigParser as Parser
from ConfigParser import NoOptionError


class ParseError(Exception):
    #Used when the signature parsing is going wrong (invalid signature ?) 
    pass

class Constructor:
    
    def __init__(self, bridge_template, options):
        self.bridge_template = bridge_template
        self.options = options

    def getValues(self, name):
        """Return values of a function in a dict
        @param name: Name of the function to get
        @return: dict, each key has the config value or None if the value is not set"""
        function={}
        for option in ['type','category','sig_in','sig_out','doc']:
            try:
                value = self.bridge_template.get(name, option)
            except NoOptionError:
                value = None
            function[option] = value
        return function

    def getArguments(self, signature):
        """Return arguments to user given a signature
        @param signature: signature in the short form (using s,a,i,b etc)
        @return: list of arguments that correspond to a signature (e.g.: "sss" return "arg1, arg2, arg3")""" 
        i=0
        idx=0
        attr_string=""
        while i<len(signature):
            if signature[i] not in ['b','y','n','i','x','q','u','t','d','s','a']:
                raise ParseError("Unmanaged attribute type [%c]" % signature[i])

            attr_string += ("" if idx==0 else ", ") + ("arg_%i" % idx)
            idx+=1

            if signature[i] == 'a':
                i+=1
                if signature[i]!='{' and signature[i]!='(': #FIXME: must manage tuples out of arrays
                    i+=1
                    continue #we have a simple type for the array
                opening_car = signature[i]
                closing_car = '}' if opening_car == '{' else ')'
                opening_count = 1
                while (True): #we have a dict or a list of tuples
                    i+=1
                    if i>=len(signature):
                        raise ParseError("missing }")
                    if signature[i] == opening_car:
                        opening_count+=1
                    if signature[i] == closing_car:
                        opening_count-=1
                        if opening_count == 0:
                            break
            i+=1
        return attr_string

    def generateCoreSide(self):
        """create the constructor in SàT core side (backend)"""
        raise NotImplementedError

class DbusConstructor(Constructor):

    def __init__(self, bridge_template, options):
        Constructor.__init__(self, bridge_template, options)
        self.core_template="dbus_core_template.py" 
        self.core_dest="DBus.py" 

    def generateCoreSide(self):
        signals_part = []
        methods_part = []
        direct_calls = []
        sections = self.bridge_template.sections()
        sections.sort()
        for section in sections:
            function = self.getValues(section)
            print ("Adding %s %s" % (section, function["type"]))
            completion = {
        'sig_in':function['sig_in'] or '',
        'sig_out':function['sig_out'] or '',
        'category':'REQ' if function['category'] == 'request' else 'COMM',
        'name':section, 
        'args':self.getArguments(function['sig_in'])
        }

            if function["type"] == "signal":
                completion['body'] = "pass" if not self.options.debug else 'debug ("%s")' % section
                signals_part.append("""\
    @dbus.service.signal(const_INT_PREFIX+const_%(category)s_SUFFIX,
                         signature='%(sig_in)s')
    def %(name)s(self, %(args)s):
        %(body)s
""" % completion)
                direct_calls.append("""\
    def %(name)s(self, %(args)s):
        self.dbus_bridge.%(name)s(%(args)s)
""" % completion)

            elif function["type"] == "method":
                completion['debug'] = "" if not self.options.debug else 'debug ("%s")\n%s' % (section,8*' ')
                methods_part.append("""\
    @dbus.service.method(const_INT_PREFIX+const_%(category)s_SUFFIX,
                         in_signature='%(sig_in)s', out_signature='%(sig_out)s')
    def %(name)s(self, %(args)s):
        %(debug)sreturn self.cb["%(name)s"](%(args)s)
""" % completion)

        #at this point, signals_part, methods_part and direct_calls should be filled,
        #we just have to place them in the right part of the template
        core_bridge = []
        try:
            with open(self.core_template) as core_template:
                for line in core_template:
                    if line.startswith('##SIGNALS_PART##'):
                        core_bridge.extend(signals_part)
                    elif line.startswith('##METHODS_PART##'):
                        core_bridge.extend(methods_part)
                    elif line.startswith('##DIRECT_CALLS##'):
                        core_bridge.extend(direct_calls)
                    else:
                        core_bridge.append(line.replace('\n',''))
        except IOError:
            print ("Can't open template file [%s]" % self.core_template)
            sys.exit(1) 

        #now we write to final file
        if os.path.exists(self.core_dest) and not self.options.force:
            print ("The destination file [%s] already exists ! Use --force to overwrite it" % self.core_dest) 
        try:
            with open(self.core_dest,'w') as dest_file:
                dest_file.write('\n'.join(core_bridge))
        except IOError:
            print ("Can't open destination file [%s]" % self.dest_file)

class ConstructorError(Exception):
    pass

class ConstructorFactory:
    def create(self, bridge_template, options):
       if options.protocole=='dbus':
           return DbusConstructor(bridge_template, options)

       raise ConstructorError('Unknown constructor type')

class BridgeConstructor:
    def __init__(self):
        self.options = None
    
    def check_options(self):
        """Check command line options"""
        _usage="""
        %prog [options]

        %prog --help for options list
        """
        parser = OptionParser(usage=_usage,version=ABOUT % VERSION)

        parser.add_option("-p", "--protocole", action="store", type="string", default=DEFAULT_PROTOCOLE,
                    help="Generate bridge using PROTOCOLE (default: %s, possible values: [%s])" % (DEFAULT_PROTOCOLE, ", ".join(MANAGED_PROTOCOLES)))
        parser.add_option("-s", "--side", action="store", type="string", default="core",
                    help="Which side of the bridge do you want to make ? (default: %default, possible values: [core, frontend])")
        parser.add_option("-t", "--template", action="store", type="string", default='bridge_template.ini',
                    help="Use TEMPLATE to generate bridge (default: %default)")
        parser.add_option("-f", "--force", action="store_true", default=False,
                    help=("Force overwritting of existing files"))
        parser.add_option("-d", "--debug", action="store_true", default=False,
                    help=("Add debug information printing"))

        (self.options, args) = parser.parse_args()
        return args

    def go(self):
        self.check_options()
        self.template = Parser()
        try:
            self.template.readfp(open(self.options.template))
        except IOError:
            print ("The template file doesn't exist or is not accessible")
            exit(1)
        constructor = ConstructorFactory().create(self.template, self.options)
        if self.options.side == "core":
            constructor.generateCoreSide()

if __name__ == "__main__":
    bc = BridgeConstructor()
    bc.go()