'use strict';

var should = require('chai').should();
var bitcore = require('..');
var ScriptInterpreter = bitcore.ScriptInterpreter;
var Transaction = bitcore.Transaction;
var Script = bitcore.Script;
var BN = bitcore.crypto.BN;
var Sig = bitcore.crypto.Signature;
var BufferReader = bitcore.encoding.BufferReader;

var script_valid = require('./data/bitcoind/script_valid');
var script_invalid = require('./data/bitcoind/script_invalid');
var tx_valid = require('./transaction/tx_valid');
var tx_invalid = require('./transaction/tx_invalid');

describe('ScriptInterpreter', function() {

  it('should make a new interp', function() {
    var interp = new ScriptInterpreter();
    (interp instanceof ScriptInterpreter).should.equal(true);
    interp.stack.length.should.equal(0);
    interp.altstack.length.should.equal(0);
    interp.pc.should.equal(0);
    interp.pbegincodehash.should.equal(0);
    interp.nOpCount.should.equal(0);
    interp.vfExec.length.should.equal(0);
    interp.errstr.should.equal('');
    interp.flags.should.equal(0);
  });

  describe('@castToBool', function() {

    it('should cast these bufs to bool correctly', function() {
      ScriptInterpreter.castToBool(BN(0).toSM({
        endian: 'little'
      })).should.equal(false);
      ScriptInterpreter.castToBool(new Buffer('0080', 'hex')).should.equal(false); //negative 0
      ScriptInterpreter.castToBool(BN(1).toSM({
        endian: 'little'
      })).should.equal(true);
      ScriptInterpreter.castToBool(BN(-1).toSM({
        endian: 'little'
      })).should.equal(true);

      var buf = new Buffer('00', 'hex');
      var bool = BN().fromSM(buf, {
        endian: 'little'
      }).cmp(0) !== 0;
      ScriptInterpreter.castToBool(buf).should.equal(bool);
    });

  });

  describe('#verify', function() {

    it('should verify these trivial scripts', function() {
      var verified;
      var si = ScriptInterpreter();
      verified = si.verify(Script('OP_1'), Script('OP_1'));
      verified.should.equal(true);
      verified = ScriptInterpreter().verify(Script('OP_1'), Script('OP_0'));
      verified.should.equal(false);
      verified = ScriptInterpreter().verify(Script('OP_0'), Script('OP_1'));
      verified.should.equal(true);
      verified = ScriptInterpreter().verify(Script('OP_CODESEPARATOR'), Script('OP_1'));
      verified.should.equal(true);
      verified = ScriptInterpreter().verify(Script(''), Script('OP_DEPTH OP_0 OP_EQUAL'));
      verified.should.equal(true);
      verified = ScriptInterpreter().verify(Script('OP_1 OP_2'), Script('OP_2 OP_EQUALVERIFY OP_1 OP_EQUAL'));
      verified.should.equal(true);
      verified = ScriptInterpreter().verify(Script('9 0x000000000000000010'), Script(''));
      verified.should.equal(true);
      verified = ScriptInterpreter().verify(Script('OP_1'), Script('OP_15 OP_ADD OP_16 OP_EQUAL'));
      verified.should.equal(true);
      verified = ScriptInterpreter().verify(Script('OP_0'), Script('OP_IF OP_VER OP_ELSE OP_1 OP_ENDIF'));
      verified.should.equal(true);
    });

    it('should verify this new pay-to-pubkey script', function() {
      var keypair = Keypair().fromRandom();
      var scriptPubkey = Script().writeBuffer(keypair.pubkey.toDER(true)).writeOp('OP_CHECKSIG');

      var hashbuf = new Buffer(32);
      hashbuf.fill(0);
      var credtx = Transaction();
      credtx.addTxin(hashbuf, 0xffffffff, Script('OP_0 OP_0'), 0xffffffff);
      credtx.addTxout(BN(0), scriptPubkey);

      var idbuf = credtx.hash();
      var spendtx = Transaction();
      spendtx.addTxin(idbuf, 0, Script(), 0xffffffff);
      spendtx.addTxout(BN(0), Script());

      var sig = spendtx.sign(keypair, Sig.SIGHASH_ALL, 0, scriptPubkey);
      var scriptSig = Script().writeBuffer(sig.toTxFormat());
      spendtx.txins[0].setScript(scriptSig);

      var interp = ScriptInterpreter();
      var verified = interp.verify(scriptSig, scriptPubkey, spendtx, 0);
      verified.should.equal(true);
    });

    it('should verify this pay-to-pubkey script from script_valid.json', function() {
      var scriptSig = Script().fromBitcoindString('0x47 0x3044022007415aa37ce7eaa6146001ac8bdefca0ddcba0e37c5dc08c4ac99392124ebac802207d382307fd53f65778b07b9c63b6e196edeadf0be719130c5db21ff1e700d67501');
      var scriptPubkey = Script().fromBitcoindString('0x41 0x0479be667ef9dcbbac55a06295ce870b07029bfcdb2dce28d959f2815b16f81798483ada7726a3c4655da4fbfc0e1108a8fd17b448a68554199c47d08ffb10d4b8 CHECKSIG');

      var hashbuf = new Buffer(32);
      hashbuf.fill(0);
      var credtx = Transaction();
      credtx.addTxin(hashbuf, 0xffffffff, Script('OP_0 OP_0'), 0xffffffff);
      credtx.addTxout(BN(0), scriptPubkey);

      var idbuf = credtx.hash();
      var spendtx = Transaction();
      spendtx.addTxin(idbuf, 0, scriptSig, 0xffffffff);
      spendtx.addTxout(BN(0), Script());

      var interp = ScriptInterpreter();
      var verified = interp.verify(scriptSig, scriptPubkey, spendtx, 0, 0);
      verified.should.equal(true);
    });

  });

  describe('vectors', function() {

    var getFlags = function getFlags(flagstr) {
      var flags = 0;
      if (flagstr.indexOf('NONE') !== -1) {
        flags = flags | ScriptInterpreter.SCRIPT_VERIFY_NONE;
      }
      if (flagstr.indexOf('P2SH') !== -1) {
        flags = flags | ScriptInterpreter.SCRIPT_VERIFY_P2SH;
      }
      if (flagstr.indexOf('STRICTENC') !== -1) {
        flags = flags | ScriptInterpreter.SCRIPT_VERIFY_STRICTENC;
      }
      if (flagstr.indexOf('DERSIG') !== -1) {
        flags = flags | ScriptInterpreter.SCRIPT_VERIFY_DERSIG;
      }
      if (flagstr.indexOf('LOW_S') !== -1) {
        flags = flags | ScriptInterpreter.SCRIPT_VERIFY_LOW_S;
      }
      if (flagstr.indexOf('NULLDUMMY') !== -1) {
        flags = flags | ScriptInterpreter.SCRIPT_VERIFY_NULLDUMMY;
      }
      if (flagstr.indexOf('SIGPUSHONLY') !== -1) {
        flags = flags | ScriptInterpreter.SCRIPT_VERIFY_SIGPUSHONLY;
      }
      if (flagstr.indexOf('MINIMALDATA') !== -1) {
        flags = flags | ScriptInterpreter.SCRIPT_VERIFY_MINIMALDATA;
      }
      if (flagstr.indexOf('DISCOURAGE_UPGRADABLE_NOPS') !== -1) {
        flags = flags | ScriptInterpreter.SCRIPT_VERIFY_DISCOURAGE_UPGRADABLE_NOPS;
      }
      return flags;
    };

    var c = 0;
    script_valid.forEach(function(vector) {
      if (vector.length === 1) {
        return;
      }
      c++;
      var descstr = vector[3];
      it('should pass script_valid vector ' + c + '(' + descstr + ')', function() {
        var scriptSig = Script().fromBitcoindString(vector[0]);
        var scriptPubkey = Script().fromBitcoindString(vector[1]);
        var flags = getFlags(vector[2]);

        var hashbuf = new Buffer(32);
        hashbuf.fill(0);
        var credtx = Transaction();
        credtx.addTxin(hashbuf, 0xffffffff, Script('OP_0 OP_0'), 0xffffffff);
        credtx.addTxout(BN(0), scriptPubkey);

        var idbuf = credtx.hash();
        var spendtx = Transaction();
        spendtx.addTxin(idbuf, 0, scriptSig, 0xffffffff);
        spendtx.addTxout(BN(0), Script());

        var interp = ScriptInterpreter();
        var verified = interp.verify(scriptSig, scriptPubkey, spendtx, 0, flags);
        verified.should.equal(true);
      });
    });

    c = 0;
    script_invalid.forEach(function(vector) {
      if (vector.length === 1) {
        return;
      }
      c++;
      var descstr = vector[3];
      it('should pass script_invalid vector ' + c + '(' + descstr + ')', function() {
        var scriptSig = Script().fromBitcoindString(vector[0]);
        var scriptPubkey = Script().fromBitcoindString(vector[1]);
        var flags = getFlags(vector[2]);

        var hashbuf = new Buffer(32);
        hashbuf.fill(0);
        var credtx = Transaction();
        credtx.addTxin(hashbuf, 0xffffffff, Script('OP_0 OP_0'), 0xffffffff);
        credtx.addTxout(BN(0), scriptPubkey);

        var idbuf = credtx.hash();
        var spendtx = Transaction();
        spendtx.addTxin(idbuf, 0, scriptSig, 0xffffffff);
        spendtx.addTxout(BN(0), Script());

        var interp = ScriptInterpreter();
        var verified = interp.verify(scriptSig, scriptPubkey, spendtx, 0, flags);
        verified.should.equal(false);
      });
    });

    c = 0;
    tx_valid.forEach(function(vector) {
      if (vector.length === 1) {
        return;
      }
      c++;
      it('should pass tx_valid vector ' + c, function() {
        var inputs = vector[0];
        var txhex = vector[1];
        var flags = getFlags(vector[2]);

        var map = {};
        inputs.forEach(function(input) {
          var txoutnum = input[1];
          if (txoutnum === -1) {
            txoutnum = 0xffffffff; //bitcoind casts -1 to an unsigned int
          }
          map[input[0] + ':' + txoutnum] = Script().fromBitcoindString(input[2]);
        });

        var tx = Transaction().fromBuffer(new Buffer(txhex, 'hex'));
        tx.txins.forEach(function(txin, j) {
          var scriptSig = txin.script;
          var txidhex = BufR(txin.txidbuf).readReverse().toString('hex');
          var txoutnum = txin.txoutnum;
          var scriptPubkey = map[txidhex + ':' + txoutnum];
          should.exist(scriptPubkey);
          var interp = ScriptInterpreter();
          var verified = interp.verify(scriptSig, scriptPubkey, tx, j, flags);
          verified.should.equal(true);
        });
      });
    });

    c = 0;
    tx_invalid.forEach(function(vector) {
      if (vector.length === 1) {
        return;
      }
      c++;

      // tests intentionally not performed by the script interpreter:
      // TODO: check this?
      /*
      if (c === 7 || // tests if valuebn is negative
        c === 8 || // tests if valuebn is greater than MAX_MONEY
        c === 10 || // tests if two inputs are equal
        c === 11 || // coinbase
        c === 12 || // coinbase
        c === 13 // null input
      ) {
        return;
      }
      */

      it('should pass tx_invalid vector ' + c, function() {
        var inputs = vector[0];
        var txhex = vector[1];
        var flags = getFlags(vector[2]);

        var map = {};
        inputs.forEach(function(input) {
          var txoutnum = input[1];
          if (txoutnum === -1) {
            txoutnum = 0xffffffff; //bitcoind casts -1 to an unsigned int
          }
          map[input[0] + ':' + txoutnum] = Script().fromBitcoindString(input[2]);
        });

        var tx = Transaction().fromBuffer(new Buffer(txhex, 'hex'));
        if (tx.txins.length > 0) {
          tx.txins.some(function(txin, j) {
            var scriptSig = txin.script;
            var txidhex = BufR(txin.txidbuf).readReverse().toString('hex');
            var txoutnum = txin.txoutnum;
            var scriptPubkey = map[txidhex + ':' + txoutnum];
            should.exist(scriptPubkey);
            var interp = ScriptInterpreter();
            var verified = interp.verify(scriptSig, scriptPubkey, tx, j, flags);
            return verified === false;
          }).should.equal(true);
        }
      });
    });

  });

});