require('classtool');


/* We dont sync any contents from TXs, only their IDs are stored */

var isSyncTxEnabled = 0;

function spec(b) {
  var mongoose  = require('mongoose');
  var util      = require('util');

  var RpcClient = require('bitcore/RpcClient').class();
  var networks  = require('bitcore/networks');
  var async     = require('async');

  var config    = require('../config/config');
  var Block     = require('../app/models/Block');
  var Transaction=require('../app/models/Transaction');

  function Sync(config) {
    this.network = config.networkName == 'testnet' ? networks.testnet : networks.livenet;
  }

  var progress_bar = function(string, current, total) {
      console.log( util.format("\t%s %d/%d [%d%%]", 
        string, current, total, parseInt(100 * current/total))
      );
  }

  Sync.prototype.getNextBlock = function (blockHash,cb) {
    var that = this;

    if ( !blockHash ) {
      return cb();
    }

    this.rpc.getBlock(blockHash, function(err, blockInfo) {
      if (err) return cb(err); 

      if ( ! ( blockInfo.result.height % 1000) ) {
        var h = blockInfo.result.height,
            d = blockInfo.result.confirmations;
        progress_bar('height', h, h + d);    
      }

      Block.create( blockInfo.result, function(err, inBlock) {

        // E11000 => already exists
        if (err && ! err.toString().match(/E11000/)) {
          return cb(err);
        }

        if (inBlock) {
          Transaction.createFromArray( blockInfo.result.tx,function (err) {
            return that.getNextBlock(blockInfo.result.nextblockhash, cb);
          });
        }
        else  
          return that.getNextBlock(blockInfo.result.nextblockhash, cb);
      });
    });
  }

  Sync.prototype.syncBlocks = function (reindex, cb)  {

    var that        = this;
    var genesisHash = this.network.genesisBlock.hash.reverse().toString('hex');

    console.log("Syncing Blocks...");
    if (reindex) 
      return this.getNextBlock(genesisHash, cb);


    Block.findOne({}, {}, { sort: { 'confirmations' : 1 } }, function(err, block) {
      if (err) return cb(err);

      var nextHash = 
        block && block.hash 
        ? block.hash
        : genesisHash
        ;

      
      console.log('\tStarting at hash: ' + nextHash);
      return that.getNextBlock(nextHash, cb);
    });
  }


  // This is not currently used. Transactions are represented by txid only
  // in mongodb
  Sync.prototype.syncTXs = function (reindex, cb)  {

    var that        = this;

    console.log("Syncing TXs...");
    if (reindex) {
      // TODO?
    }
      

    Transaction.find({blockhash: null}, function(err, txs) {
      if (err) return cb(err);

      var read = 0;
      var pull = 0;
      var write = 0;
      var total = txs.length;
      console.log("\tneed to pull %d txs", total);

      if (!total) return cb();

      async.each(txs, 
        function(tx, next){
          if (! tx.txid) {
            console.log("NO TXID skipping...", tx);
            return next();
          }

          if ( ! ( read++ % 1000) ) 
            progress_bar('read', read, total);


          that.rpc.getRawTransaction(tx.txid, 1,  function(err, txInfo) {

            if ( ! ( pull++ % 1000) ) 
              progress_bar('\tpull', pull, total);

            if (!err && txInfo) {
              Transaction.update({txid: tx.txid}, txInfo.result, function(err) {
                if (err) return next(err); 

                if ( ! ( write++ % 1000) ) 
                  progress_bar('\t\twrite', write, total);

                return next(); 
              });
            }
            else return next(); 
          });
        },
        function(err){
          if (err) return cb(err);
          return cb(err);
        }
      );
    });
  }

  Sync.prototype.start = function (opts, next)  {


    mongoose.connect(config.db);
    var db    = mongoose.connection;
    this.rpc  = new RpcClient(config.bitcoind);
    var that  = this;


    db.on('error', console.error.bind(console, 'connection error:'));

    db.once('open', function (){

      async.series([ 
        function(cb){
          if (opts.destroy) {
            console.log("Deleting Blocks...");
            return db.collections['blocks'].drop(cb);
          }
          return cb();
        },
        function(cb){
          if (opts.destroy) {
            console.log("Deleting TXs...");
            return db.collections['transactions'].drop(cb);
          }
          return cb();
        },
        function(cb) {

          if (! opts.skip_blocks) {
            that.syncBlocks(opts.reindex, function(err) {
              if (err) {
                return cb(err);

              }
              console.log("\tBlocks done.");

              return cb();
            });
          }
          else {
            return cb();
          }
        },
        function(cb) {
          if ( isSyncTxEnabled && ! opts.skip_txs) {
            that.syncTXs(opts.reindex, function(err) {
              if (err) {
                return cb(err);

              }
              return cb();
            });
          }
          else {
            return cb();
          }
        },
        function(cb) {
          db.close();
          return cb();
        },
      ],
      function(err) {
        if (err) {
          db.close();
          return next(err);
        }
        return next();
      });
    });
  }
  return Sync;
};
module.defineClass(spec);