/* A list of sample links from the SAS Dummy blog */
/* YTD 2012 blog topics as of July */
data links;
  infile datalines dsd;
  length url $ 255;
  input url;
  datalines;
http://blogs.sas.com/content/sasdummy/2012/01/03/pitfalls-of-the-lag-function/
http://blogs.sas.com/content/sasdummy/2012/01/11/uncovering-the-hidden-parts-of-the-sas-log/
http://blogs.sas.com/content/sasdummy/2012/01/18/sasondemand-forpros/
http://blogs.sas.com/content/sasdummy/2012/01/19/sas-is-no-3/
http://blogs.sas.com/content/sasdummy/2012/01/25/export-to-excel-got-easier/
http://blogs.sas.com/content/sasdummy/2012/01/27/achieving-mediocrity/
http://blogs.sas.com/content/sasdummy/2012/02/02/profiles-via-eg-automation/
http://blogs.sas.com/content/sasdummy/2012/02/11/export-excel-methods/
http://blogs.sas.com/content/sasdummy/2012/02/22/about-sas-report-format/
http://blogs.sas.com/content/sasdummy/2012/03/01/precision-in-sas-numbers/
http://blogs.sas.com/content/sasdummy/2012/03/06/be-a-code-poet-laureate/
http://blogs.sas.com/content/sasdummy/2012/03/07/sasgf2012-closing-sessio/
http://blogs.sas.com/content/sasdummy/2012/03/12/making-up-for-lost-time-utc-dst/
http://blogs.sas.com/content/sasdummy/2012/03/15/how-many-obs-sysnobs/
http://blogs.sas.com/content/sasdummy/2012/03/20/sas-program-by-processing/
http://blogs.sas.com/content/sasdummy/2012/03/23/improving-on-a-sas-programming-pattern/
http://blogs.sas.com/content/sasdummy/2012/04/01/new-certification-program-sas-versions-professional/
http://blogs.sas.com/content/sasdummy/2012/04/03/64-bit-versus-32-bit-apps/
http://blogs.sas.com/content/sasdummy/2012/04/11/the-heme-finder-where-ill-be-during-sas-global-forum/
http://blogs.sas.com/content/sasdummy/2012/04/12/build-your-own-sas-data-set-viewer-using-powershell/
http://blogs.sas.com/content/sasdummy/2012/04/17/doing-more-with-sas-enterprise-guide-automation/
http://blogs.sas.com/content/sasdummy/2012/04/18/sas-tech-talks/
http://blogs.sas.com/content/sasdummy/2012/04/19/myths-about-64-bit-computing-on-windows/
http://blogs.sas.com/content/sasdummy/2012/04/29/the-makeup-of-sas-global-forum/
http://blogs.sas.com/content/sasdummy/2012/05/01/64-bit-gotchas/
http://blogs.sas.com/content/sasdummy/2012/05/09/powershell-read-sas-data-files/
http://blogs.sas.com/content/sasdummy/2012/05/15/how-long-will-eg-process-run/
http://blogs.sas.com/content/sasdummy/2012/05/18/using-proc-sql-to-get-the-schema-of-a-mysql-database/
http://blogs.sas.com/content/sasdummy/2012/05/22/windows-reg-query-from-sas/
http://blogs.sas.com/content/sasdummy/2012/05/23/sas-on-a-video-game-system/
http://blogs.sas.com/content/sasdummy/2012/06/04/top-gear-for-sas-professionals-knowledge/
http://blogs.sas.com/content/sasdummy/2012/06/07/egp-search-tool/
http://blogs.sas.com/content/sasdummy/2012/06/12/high-performance-analytics-it-may-be-a-show-is-no-act/
http://blogs.sas.com/content/sasdummy/2012/06/14/read-a-microsoft-date-time-value-into-a-sas-date-time-value/
run;

/* Get count of URLs in source data                */
/* Here it assumes WORK.LINKS                      */
/* and the page link to check is in the URL column */
proc sql noprint;
  select count(URL) into :urlCount from WORK.LINKS;
quit;

/* trim this for later use in constructing data set names*/
%let urlCount = %trim(&urlCount);

%macro gatherSocialStats;
  /* This loop reads each URL link from the data set */
  /* one at a time, and then uses FILENAME URL       */
  /* to invoke the Twitter and Facebook APIs for     */
  /* Tweet counts and Share counts                   */
  %do i = 1 %to &urlCount;

    /* read the next URL */
    proc sql noprint;
      select trim(url) into :url from work.links(firstobs=&i obs=&i);
    quit;

    %put Checking %str(&url.);

    /* format of the Twitter API call */
    filename twurl url "http://urls.api.twitter.com/1/urls/count.json?url=&url." 
      /* supply PROXY= option if behind a corporate firewall/gateway */
    ;

    /* format of the Facebook API call */
    filename fburl url "http://graph.facebook.com/?ids=&url." 
      /* supply PROXY= option if behind a corporate firewall/gateway */
    ;

    data twresult&i;
      /* Running in EG? SYSECHO helps convey progress in status bar */
      SYSECHO "Checking Tweet URL &i. of &urlCount.";
      length line $ 500 url $ 500;
      infile twurl;
      url = "&url.";
      input line;
    run;

    data fbresult&i;
      /* Running in EG? SYSECHO helps convey progress in status bar */
      SYSECHO "Checking FB URL &i. of &urlCount.";
      length line $ 500 url $ 500;
      infile fburl;
      input line;
      url = "&url.";
    run;

    /* Free up the filerefs */
    filename twurl clear;
    filename fburl clear;
  %end;

  /* concatenate all Twitter counts */
  data twresults;
    set twresult1-twresult&urlCount.;
  run;

  /* concatenate all Facebook share counts */
  data fbresults;
    set fbresult1-fbresult&urlCount.;
  run;

  /* clean up all of the tiny data sets */
  proc datasets lib=work nolist;
    delete twresult1-twresult&urlCount.;
    delete fbresult1-fbresult&urlCount.;
  quit;

%mend;

%gatherSocialStats;

/* Post processing to PARSE the results, which */
/* are in JSON format */

/* Example result:
{
  "http://blogs.sas.com/content/sasdummy/2012/01/25/export-to-excel-got-easier/": 
  {
     "id": "http://blogs.sas.com/content/sasdummy/2012/01/25/export-to-excel-got-easier/",
     "shares": 3
  }
}
*/
data work.fbcounts (keep=fbshares url);
  set fbresults;
  length fbshares 8;
  if _n_ = 1 then
    do;
      retain fb_regex;

      /* looking for "shares":<a number> */
      fb_regex = prxparse("/\""shares\""\:([0-9]*)/");
    end;
  position = prxmatch(fb_regex,line);
  if (position ^= 0) then
    do;
      call prxposn(fb_regex, 1, start, length);
      fbshares = substr(line,start,length);
    end;
run;

/* Post processing to PARSE the results, which */
/* are in JSON format */

/* Example result:
   {"count":8,"url":"http:\/\/blogs.sas.com\/content\/sasdummy\/2012\/01\/27\/achieving-mediocrity\/"}
*/
data work.twcounts (keep=tweets url);
  set twresults;
  length tweets 8;
  if _n_ = 1 then
    do;
      retain tw_regex;
      /* looking for "count":<a number> */
      tw_regex = prxparse("/\""count\""\:([0-9]*)/");
    end;
  position = prxmatch(tw_regex,line);
  if (position ^= 0) then
    do;
      call prxposn(tw_regex, 1, start, length);
      tweets = substr(line,start,length);
    end;
run;

/* Join it all together with the URL, tweet counts, */
/* and share counts */
proc sql;
  create table work.socialcounts as 
    select t1.url, 
      ifn(t2.fbshares eq .,0,t2.fbshares) as fbshares, 
      t3.tweets,
      /* date-stamp the value for use in history/comparisons */
      today() as as_of_date format=date9.
  from work.links t1 
    left join work.fbcounts t2 on (t1.url = t2.url) 
    left join work.twcounts t3 on (t1.url = t3.url)
  ;
quit;