## Amazon SimpleDB library
 ## Author: Michal Ludvig <michal@logix.cz>
 ##         http://www.logix.cz/michal
 ## License: GPL Version 2
 
 """
 Low-level class for working with Amazon SimpleDB
 """
 
 import time
 import urllib
 import base64
 import hmac
 import sha
 import httplib
 from logging import debug, info, warning, error
 
 from Utils import convertTupleListToDict
 from SortedDict import SortedDict
 from Exceptions import *
 
 class SimpleDB(object):
 	# API Version
 	# See http://docs.amazonwebservices.com/AmazonSimpleDB/2007-11-07/DeveloperGuide/
 	Version = "2007-11-07"
 	SignatureVersion = 1
 
 	def __init__(self, config):
 		self.config = config
 
 	def ListDomains(self, MaxNumberOfDomains = 100):
 		'''
 		Lists all domains associated with our Access Key. Returns 
 		domain names up to the limit set by MaxNumberOfDomains.
 		'''
 		parameters = SortedDict()
 		parameters['MaxNumberOfDomains'] = MaxNumberOfDomains
 		response = self.send_request("ListDomains", domain = None, parameters = parameters)
 		return response
 	
 	def send_request(self, *args, **kwargs):
 		request = self.create_request(*args, **kwargs)
 		debug("Request: %s" % repr(request))
 		conn = self.get_connection()
 		conn.request("GET", self.format_uri(request['uri_params']))
 		http_response = conn.getresponse()
 		response = {}
 		response["status"] = http_response.status
 		response["reason"] = http_response.reason
 		response["headers"] = convertTupleListToDict(http_response.getheaders())
 		response["data"] =  http_response.read()
 		debug("Response: " + str(response))
 		conn.close()
 
 		if response["status"] < 200 or response["status"] > 299:
 			raise S3Error(response)
 
 		return response
 
 	def create_request(self, action, domain, parameters = None):
 		if not parameters:
 			parameters = SortedDict()
 		parameters['AWSAccessKeyId'] = self.config.access_key
 		parameters['Version'] = self.Version
 		parameters['SignatureVersion'] = self.SignatureVersion
 		parameters['Action'] = action
 		parameters['Timestamp'] = time.strftime("%Y-%m-%dT%H:%M:%SZ", time.gmtime())
 		if domain:
 			parameters['DomainName'] = domain
 		parameters['Signature'] = self.sign_request(parameters)
 		parameters.keys_return_lowercase = False
 		uri_params = urllib.urlencode(parameters)
 		request = {}
 		request['uri_params'] = uri_params
 		request['parameters'] = parameters
 		return request
 
 	def sign_request(self, parameters):
 		h = ""
 		parameters.keys_sort_lowercase = True
 		parameters.keys_return_lowercase = False
 		for key in parameters:
 			h += "%s%s" % (key, parameters[key])
 		debug("SignRequest: %s" % h)
 		return base64.encodestring(hmac.new(self.config.secret_key, h, sha).digest()).strip()
 
 	def get_connection(self):
 		if self.config.proxy_host != "":
 			return httplib.HTTPConnection(self.config.proxy_host, self.config.proxy_port)
 		else:
 			if self.config.use_https:
 				return httplib.HTTPSConnection(self.config.simpledb_host)
 			else:
 				return httplib.HTTPConnection(self.config.simpledb_host)
 
 	def format_uri(self, uri_params):
 		if self.config.proxy_host != "":
 			uri = "http://%s/?%s" % (self.config.simpledb_host, uri_params)
 		else:
 			uri = "/?%s" % uri_params
 		debug('format_uri(): ' + uri)
 		return uri