/*
 * This is a debug tool. It checks all revisions for data corruption
 */

if (process.argv.length != 2) {
  console.error("Use: node bin/checkAllPads.js");
  process.exit(1);
}

// initialize the variables
var db, settings, padManager;
var npm = require('../src/node_modules/npm');
var async = require('../src/node_modules/async');

var Changeset = require('../src/static/js/Changeset');

async.series([
  // load npm
  function(callback) {
    npm.load({}, callback);
  },

  // load modules
  function(callback) {
    settings = require('../src/node/utils/Settings');
    db = require('../src/node/db/DB');

    // initialize the database
    db.init(callback);
  },

  // load pads
  function (callback) {
    padManager = require('../src/node/db/PadManager');

    padManager.listAllPads(function(err, res) {
      padIds = res.padIDs;
      callback(err);
    });
  },

  function (callback) {
    async.forEach(padIds, function(padId, callback) {
      padManager.getPad(padId, function(err, pad) {
        if (err) {
          callback(err);
        }

        // check if the pad has a pool
        if (pad.pool === undefined ) {
          console.error("[" + pad.id + "] Missing attribute pool");
          callback();

          return;
        }

        // create an array with key kevisions
        // key revisions always save the full pad atext
        var head = pad.getHeadRevisionNumber();
        var keyRevisions = [];
        for (var i = 0; i < head; i += 100) {
          keyRevisions.push(i);
        }

        // run through all key revisions
        async.forEachSeries(keyRevisions, function(keyRev, callback) {
          // create an array of revisions we need till the next keyRevision or the End
          var revisionsNeeded = [];

          for(var i = keyRev; i <= keyRev + 100 && i <= head; i++) {
            revisionsNeeded.push(i);
          }

          // this array will hold all revision changesets
          var revisions = [];

          // run through all needed revisions and get them from the database
          async.forEach(revisionsNeeded, function(revNum, callback) {
            db.db.get("pad:" + pad.id + ":revs:" + revNum, function(err, revision) {
              revisions[revNum] = revision;
              callback(err);
            });
          },

          function(err) {
            if (err) {
              callback(err);
              return;
            }

            // check if the revision exists
            if (revisions[keyRev] == null) {
              console.error("[" + pad.id + "] Missing revision " + keyRev);
              callback();
              return;
            }

            // check if there is a atext in the keyRevisions
            if (revisions[keyRev].meta === undefined || revisions[keyRev].meta.atext === undefined) {
              console.error("[" + pad.id + "] Missing atext in revision " + keyRev);
              callback();
              return;
            }

            var apool = pad.pool;
            var atext = revisions[keyRev].meta.atext;

            for(var i = keyRev + 1; i <= keyRev + 100 && i <= head; i++) {
              try {
                // console.log("[" + pad.id + "] check revision " + i);
                var cs = revisions[i].changeset;
                atext = Changeset.applyToAText(cs, atext, apool);
              } catch(e) {
                console.error("[" + pad.id + "] Bad changeset at revision " + i + " - " + e.message);
                callback();
                return;
              }
            }

            callback();
          });
        }, callback);
      });
    }, callback);
  }
],
function (err) {
  if (err) {
    throw err;
  } else {
    console.log("finished");
    process.exit(0);
  }
});