'''\
A python client for jsonserver.

This is a separate file that is not needed for jsonserver to work.

It can be used to

- test json components from the command line
- create a standalone python json-rpc client.

This file needs to import minjson.py, it uses nothing else
from the server.
'''

import urllib2
from minjson import read, write

request_content_type = 'application/json-rpc'
pythonkwmarker = 'pythonKwMaRkEr' 

class JsonRpcError(Exception):
    pass
    
class JsonserverClient(object):
    '''A Jsonserver client.
    
    On creation it is bound to an url and you
    can call up methods on it.
    
    Example::
    
        c = JsonserverClient('http://localhost:9777/xx1/edit_title_content')
        result = c.title_widget(widget_mode=1)

    '''
    
    class Opener(object):
        
        def __init__(self, baseurl, method):
            self.baseurl = baseurl
            self.method = method

        def __call__(self, *args, **kw):
            # build the data
            if kw:
                args += ({pythonkwmarker: kw}, )
            data = {
                'id': 'httpReq',
                'method': self.method,
                'params': args,
                }
            raw_data = write(data, 'utf-8', 'utf-8')
            #
            headers={'Content-Type': request_content_type}
            r = urllib2.Request(self.baseurl, raw_data, headers=headers)
            f = urllib2.urlopen(r)
            #
            raw_response = f.read()
            response = read(raw_response, 'utf-8')
            if response['error']:
                raise JsonRpcError, 'Error: %s' % (response['error'], )
            result = response['result']
            return result
     
    def __init__(self, baseurl):
        '''Create a Jsonserver client class
        
        Then you can call methods on this class
        '''
        self._baseurl = baseurl
        
    def __getattr__(self, name):
        # If a new method is called up, a descriptor is created for it
        # and it is stored in the class.
        if not name or name[0] == '_':
            raise JsonRpcError('Method names cannot start with "_". (%s)' % (name, ))
        method = self.Opener(self._baseurl, name)
        setattr(self, name, method)
        return method

if __name__ == '__main__':
    c = JsonserverClient('http://localhost:9676/xx1/edit_title_content')
    result = c.title_widget(widget_mode=1)
    print result