global class SocialPresence {
    static SessionInfo__c sessionInfo;
    @InvocableMethod(label='Get Social Presence' description='Goes through records and computes the social presence score.')
    global static void getSocialPresence(List<SessionInfo__c> sessionInfos) {
        System.debug('inside getSocialPresence');
        sessionInfo = sessionInfos[0];
        SessionInfo__c sessionInfoCopy  = new SessionInfo__c(Id = sessionInfo.Id);
        //sessionInfoCopy.name = 'lol';
        //upsert sessionInfoCopy;
        submittotwitter();
        //return null;
    }

    global static String getBearerToken() {
        //Encode them
        String keyencoded = EncodingUtil.urlEncode('KEY', 'UTF-8');
        String secretkeyencoded = EncodingUtil.urlEncode('SECRET', 'UTF-8');

        //Create Final Key String
        String sFinal = keyencoded + ':' + secretkeyencoded;
        //Convert to Blob
        Blob headerValue = Blob.valueOf(sFinal);

        //Build Request
        HttpRequest req = new HttpRequest();
        req.setEndpoint('https://api.twitter.com/oauth2/token');
        req.setMethod('POST');

        //Add Auth Header
        String authorizationHeader = 'Basic ' + EncodingUtil.base64Encode(headerValue);
        req.setHeader('Authorization', authorizationHeader);

        //You need to add this to the request - proved easy to miss in instructions...
        req.setBody('grant_type=client_credentials');

        //Make request
        Http http = new Http();
        HTTPResponse res = http.send(req);
        String stoken;
        //Parse JSON for Bearer Token
        JSONParser parser = JSON.createParser(res.getBody());
        while (parser.nextToken() != null) {
        if (parser.getCurrentToken() == JSONToken.FIELD_NAME && parser.getText() == 'access_token'){
        parser.nextToken();
        stoken = parser.getText();
        }
        }
        //Return Token so it can be used in next call
        return stoken;
    }

   @future(callout=true) webservice static void submittotwitter () {
        System.debug('calling twitter');
        HttpRequest req2 = new HttpRequest();
        //I actually store the endpoint in the same custom setting and build dynamically, but for purposes of demo:
        req2.setEndpoint('https://api.twitter.com/1.1/users/lookup.json?screen_name=britishboyindc,salesforce');
        req2.setMethod('GET');

        //Call Bearer token Method
        //Note - unless invalidated, I believe you can store this and keep using it indefinitely, but again, to demo concept
        String authorizationHeader = 'Bearer ' + getBearerToken();
        req2.setHeader('Authorization', authorizationHeader);

        Http http = new Http();
        HTTPResponse res = http.send(req2);
        String sBody = res.getBody();

        System.debug(sBody);
        //saveNewRecord(sBody);
        SessionInfo__c sessionInfoCopy  = new SessionInfo__c(Id = sessionInfo.Id);
        sessionInfoCopy.name = 'lol2';
        //sessionInfoCopy.abstract__c = sBody;
        upsert sessionInfoCopy;


    }

    @future(callout=true) global  static void saveNewRecord(String sBody)
    {
        SessionInfo__c sessionInfoCopy  = new SessionInfo__c(Id = sessionInfo.Id);
        sessionInfoCopy.name__c = sBody;
        Update sessionInfoCopy;
    }
}