#!/usr/bin/env python -tt

import base64;
import hmac;
import hashlib;
import random;
import re;
import time;
import urlparse;
import urllib2;
import pdb

class OAuthSimpleException(Exception):
    def __init__(self,value):
        self.msg = value
        
    def __str__(self):
        return repr(self.msg)
        
class OAuthSimple:
    from OAuthSimple import OAuthSimpleException
    _secrets={}
    _parameters={}
    _default_signature_method="HMAC-SHA1"
    _action="GET"
    _nonce_characters='0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz'
    sbs=""
    _path=""
    
    def __init__(self, apiKey = None, sharedSecret = None):
        if apiKey:
            self._secrets['oauth_consumer_key']=apiKey
        if sharedSecret:
            self._secrets['shared_secret']=sharedSecret
        return ;
    
    def reset (self):
        self._parameters={}
        self.path={}
        self.sbs={}
        return self
    
    def setParameters(self,parameters={}):
        if parameters:
            if type(parameters)==type(""):
                parameters = self._parseParameterString(parameters)
            if not self._parameters:
                self._parameters = parameters
            elif parameters:
                self._parameters = self._arrayMerge(self._parameters,parameters)
        if not self._parameters.get('oauth_nonce'):
            self._getNonce()
        if not self._parameters.get('oauth_timestamp'):
            self._getTimeStamp();
        if not self._parameters.get('oauth_consumer_key'):
            self._getApiKey();
        if not self._parameters.get('oauth_token'):
            self._getAccessToken();
        if not self._parameters.get('oauth_signature_method'):
            self.setSignatureMethod()
        if not self._parameters.get('oauth_version'):
            self._parameters['oauth_version']='1.0';
            
        return self;
    
    def setPath (self,path):
        if not path:
            raise OAuthSimpleException('No path specified');
        self._path = path;
        return self;
       
    def setAction(self, action):
        action = action.upper();
        if re.match('[^A-Z]',action):
            raise OAuthSimpleException('Invalid action specified for OAuthSimple.setAction');
        self._action = action;
        return self;
    
    def signatures(self,signatures):
        if signatures and (type(signatures) != type({})):
            raise OAuthSimpleException('Must pass Dict to OAuthSimple.signatures')
            
        if signatures:
            self._secrets = self._arrayMerge(signatures,self._secrets)
            
        # swap keys
        swap = (('api_key','oauth_consumer_key'),
                 ('consumer_key','oauth_consumer_key'),
                 ('access_token','oauth_token'),
                 ('access_token_secret','oauth_secret'))
        for swapable in swap:
            if (self._secrets.get(swapable[0])):
                self._secrets[swapable[1]]=self._secrets[swapable[0]]
                del self._secrets[swapable[0]]
        if not self._secrets.get('oauth_consumer_key'):
            raise OAuthSimpleException('Missing required oauth_consumer_key')
        if not self._secrets.get('shared_secret'):
            raise OAuthSimpleException('Missing required shared_secret')
        if self._secrets.get('oauth_token') and not self._secrets.get('oauth_secret'):
            raise OAuthSimpleException('Missing oauth_secret for supplied oauth_token')
            
        return self;
    
    def setSignatureMethod(self,method=None):
        if not method:
            method=self._default_signature_method
        method = method.upper()
        if method not in ('PLAINTEXT','HMAC-SHA1'):
            raise OAuthSimpleException('Invalid Signature method specified ')
        self._parameters['oauth_signature_method']=method;
        return self;
    
    def sign(self,args={}):
        if args.get('action'):
            self.setAction(args['action']);
        if args.get('path'):
            self.setPath(args['path']);
        if args.get('method'):
            self.setSignatureMethod(args['method']);
        if args.get('signatures'):
            self.signatures(args.get('signatures'));
        self.setParameters(args.get('parameters'));
        normParamString = self._normalizeParameters();
        self._parameters['oauth_signature'] = self._generateSignature(normParamString)
        return {'parameters':self._parameters,
                'signature':self._oauthEscape(self._parameters['oauth_signature']),
                'signed_url':self._path+'?'+self._normalizeParameters(),
                'header':self.getHeaderString(),
                'sbs':self.sbs
        };
        
    def getHeaderString(self,args={}):
        result = [];
        
        if not self._parameters.get('oauth_signature'):
            self.sign(args);
                
        for pName in self._parameters:
            if not pName.startswith('oauth_'):
                continue;
            pValue = self._parameters.get(pName);
            if type(pValue) == type([]):
                for val in pValue:
                    result.append(pName + '="' + self._oauthEscape(val) + '"')
            else:
                result.append(pName + '="' + self._oauthEscape(str(pValue)) + '"');
        return 'OAuth '+', '.join(result);
    
    def _arrayMerge(self,target,source):
        for skey in source.keys():
            target[skey]=source.get(skey);
        return target;
    
    def _parseParameterString(self,paramString):
        return urlparse.parse_qs(paramString,True);
        
    def _oauthEscape (self,string):
        if not string:
            return '';
        
        string = urllib2.quote(string);
        return string.replace('/','%2F').replace('+','%20').replace('!','%21').replace('*','%2A').replace('\\','%27').replace('(','%28').replace(')','%29')
        
    def _getApiKey(self):
        if not self._parameters.has_key('oauth_consumer_key'):
            if not self._secrets.get('oauth_consumer_key'):
                raise OAuthSimpleException('No oauth_consumer_key set')
            self._parameters['oauth_consumer_key']=self._secrets.get('oauth_consumer_key')
        return self._parameters.get('oauth_consumer_key');
        
    def _getAccessToken(self):
        if not self._secrets.has_key('oauth_secret'):
            return ''
        if not self._parameters.has_key('oauth_access_token'):
            if not self._secrets.get('oauth_access_token'):
                raise OAuthSimpleException('No oauth_access_token set')
            self._parameters['oauth_access_token'] = self._secrets.get('oauth_access_token')
        return self._parameters.get('oauth_access_token')
    
    def _getNonce(self,length=5):
        result = [];
        cLength = len(self._nonce_characters);
        
        for i in range(0,length):
            rnd = random.randint(0,cLength-1)
            result.append(self._nonce_characters[rnd])
        self._parameters['oauth_nonce']=''.join(result);
        return self._parameters['oauth_nonce']
        
    def _getTimeStamp(self):
        """ return the top UTC time integer as a string """
        self._parameters['oauth_timestamp']=int(time.time());
        return self._parameters['oauth_timestamp']
        
    def _normalizeParameters(self):
        elements=[]
        if not self._parameters:
            return '';
        pKeys = self._parameters.keys();
        pKeys.sort();
        for paramName in pKeys:
            if paramName.find('_secret') > 0:
                continue;
            paramValue = self._parameters.get(paramName)
            if type(paramValue) == type([]):
                paramValue.sort();
                for value in paramValue:
                    elements.append(self._oauthEscape(paramName)+'='+self._oauthEscape(value))
                next
            else:
                elements.append(self._oauthEscape(paramName)+'='+self._oauthEscape(str(paramValue)))
        return '&'.join(elements)
        
    def _generateSignature(self,normParamString):
        secretKey='';
        
        if self._secrets.get('shared_secret'):
            secretKey = self._oauthEscape(self._secrets['shared_secret']);
        
        secretKey += '&';
        
        if self._secrets.get('oauth_secret'):
            secretKey += self._oauthEscape(self._secrets['oauth_secret']);
            
        if (self._parameters['oauth_signature_method'] == 'PLAINTEXT'):
            return secretKey;
        elif (self._parameters['oauth_signature_method'] == 'HMAC-SHA1'):
            self.sbs = '&'.join([self._oauthEscape(self._action),
                                self._oauthEscape(self._path),
                                self._oauthEscape(normParamString)]    
                                )
        return base64.b64encode(hmac.new(secretKey,self.sbs,hashlib.sha1).digest());