import httplib2
import json
from urllib import urlencode

_credentials = None

def SetCredentials(username, password):
    global _credentials
    _credentials = (username, password)

def _SetupCredentials(h):
    global _credentials
    if _credentials != None:
        h.add_credentials(_credentials[0], _credentials[1])

def DoGet(uri, data = {}, interpretAsJson = True):
    d = ''
    if len(data.keys()) > 0:
        d = '?' + urlencode(data)

    h = httplib2.Http()
    _SetupCredentials(h)
    resp, content = h.request(uri + d, 'GET')
    if not (resp.status in [ 200 ]):
        raise Exception(resp.status)
    elif not interpretAsJson:
        return content
    else:
        try:
            return json.loads(content)
        except:
            return content


def _DoPutOrPost(uri, method, data, contentType):
    h = httplib2.Http()
    _SetupCredentials(h)

    if isinstance(data, str):
        body = data
        if len(contentType) != 0:
            headers = { 'content-type' : contentType }
        else:
            headers = { 'content-type' : 'text/plain' }
    else:
        body = json.dumps(data)
        headers = { 'content-type' : 'application/json' }
    
    resp, content = h.request(
        uri, method,
        body = body,
        headers = headers)

    if not (resp.status in [ 200, 302 ]):
        raise Exception(resp.status)
    else:
        try:
            return json.loads(content)
        except:
            return content


def DoDelete(uri):
    h = httplib2.Http()
    _SetupCredentials(h)
    resp, content = h.request(uri, 'DELETE')

    if not (resp.status in [ 200 ]):
        raise Exception(resp.status)
    else:
        try:
            return json.loads(content)
        except:
            return content


def DoPut(uri, data = {}, contentType = ''):
    return _DoPutOrPost(uri, 'PUT', data, contentType)


def DoPost(uri, data = {}, contentType = ''):
    return _DoPutOrPost(uri, 'POST', data, contentType)