'use strict';

var _ = require('lodash');
var $ = require('preconditions').singleton();
var util = require('util');
var async = require('async');
var log = require('npmlog');
var request = require('request')
var events = require('events');
log.debug = log.verbose;
var Bitcore = require('bitcore')

var Credentials = require('./credentials');
var WalletUtils = require('../walletutils');
var Verifier = require('./verifier');
var ServerCompromisedError = require('./servercompromisederror');
var ClientError = require('../clienterror');

var BASE_URL = 'http://localhost:3001/copay/api';

function _encryptMessage(message, encryptingKey) {
  if (!message) return null;
  return WalletUtils.encryptMessage(message, encryptingKey);
};

function _decryptMessage(message, encryptingKey) {
  if (!message) return '';
  try {
    return WalletUtils.decryptMessage(message, encryptingKey);
  } catch (ex) {
    return '<ECANNOTDECRYPT>';
  }
};

function _processTxps(txps, encryptingKey) {
  if (!txps) return;
  _.each([].concat(txps), function(txp) {
    txp.encryptedMessage = txp.message;
    txp.message = _decryptMessage(txp.message, encryptingKey);
    _.each(txp.actions, function(action) {
      action.comment = _decryptMessage(action.comment, encryptingKey);
    });
  });
};

function _parseError(body) {
  if (_.isString(body)) {
    try {
      body = JSON.parse(body);
    } catch (e) {
      body = {
        error: body
      };
    }
  }
  var ret;
  if (body.code) {
    ret = new ClientError(body.code, body.message);
  } else {
    ret = {
      code: 'ERROR',
      error: body.error || 'There was an unknown error processing the request',
    };
  }
  log.error(ret);
  return ret;
};

function _signRequest(method, url, args, privKey) {
  var message = method.toLowerCase() + '|' + url + '|' + JSON.stringify(args);
  return WalletUtils.signMessage(message, privKey);
};

function API(opts) {
  opts = opts || {};

  this.verbose = !!opts.verbose;
  this.request = opts.request || request;
  this.baseUrl = opts.baseUrl || BASE_URL;
  this.basePath = this.baseUrl.replace(/http.?:\/\/[a-zA-Z0-9:-]*\//, '/');
  if (this.verbose) {
    log.level = 'debug';
  } else {
    log.level = 'info';
  }
};

util.inherits(API, events.EventEmitter);

API.prototype.seedFromAirGapped = function(seed) {
  this.credentials = Credentials.fromAirGapped(seed.network, seed.xPubKey, seed.requestPrivKey);
};

API.prototype._doRequest = function(method, url, args, cb) {
  $.checkState(this.credentials);

  var reqSignature;

  if (this.credentials.requestPrivKey) {
    reqSignature = _signRequest(method, url, args, this.credentials.requestPrivKey);
  }

  var absUrl = this.baseUrl + url;
  var args = {
    // relUrl: only for testing with `supertest`
    relUrl: this.basePath + url,
    headers: {
      'x-identity': this.credentials.copayerId,
      'x-signature': reqSignature,
    },
    method: method,
    url: absUrl,
    body: args,
    json: true,
  };

  log.verbose('Request Args', util.inspect(args, {
    depth: 10
  }));
  this.request(args, function(err, res, body) {
    log.verbose(util.inspect(body, {
      depth: 10
    }));
    if (err) return cb(err);

    if (res.statusCode != 200) {
      return cb(_parseError(body));
    }

    return cb(null, body, res.header);
  });
};


API.prototype._doPostRequest = function(url, args, cb) {
  return this._doRequest('post', url, args, cb);
};

API.prototype._doGetRequest = function(url, cb) {
  return this._doRequest('get', url, {}, cb);
};


API.prototype._doJoinWallet = function(walletId, walletPrivKey, xPubKey, copayerName, cb) {
  var args = {
    walletId: walletId,
    name: copayerName,
    xPubKey: xPubKey,
    xPubKeySignature: WalletUtils.signMessage(xPubKey, walletPrivKey),
  };
  var url = '/v1/wallets/' + walletId + '/copayers';
  this._doPostRequest(url, args, function(err, body) {
    if (err) return cb(err);
    return cb(null, body.wallet);
  });
};

API.prototype.isComplete = function() {
  return this.credentials && this.credentials.isComplete();
};

/**
 * Opens a wallet and tries to complete the public key ring.
 * @param {Function} cb - Returns an error and a flag indicating that the wallet has just been completed and needs to be persisted
 */
API.prototype.openWallet = function(cb) {
  $.checkState(this.credentials);

  var self = this;

  if (self.credentials.isComplete()) return cb(null, false);

  var url = '/v1/wallets/';
  self._doGetRequest(url, function(err, ret) {
    if (err) return cb(err);
    var wallet = ret.wallet;

    if (wallet.status != 'complete')
      return cb('Wallet Incomplete');

    if (!Verifier.checkCopayers(self.credentials, wallet.copayers)) {
      return cb(new ServerCompromisedError(
        'Copayers in the wallet could not be verified to have known the wallet secret'));
    }

    self.credentials.addPublicKeyRing(_.pluck(wallet.copayers, 'xPubKey'));
    return cb(null, true);
  });
};

API.prototype.createWallet = function(walletName, copayerName, m, n, network, cb) {
  var self = this;

  network = network || 'livenet';
  if (!_.contains(['testnet', 'livenet'], network))
    return cb('Invalid network');

  if (!self.credentials) {
    self.credentials = Credentials.create(network);
  }

  $.checkState(network == self.credentials.network);

  var walletPrivKey = new Bitcore.PrivateKey();
  var args = {
    name: walletName,
    m: m,
    n: n,
    pubKey: walletPrivKey.toPublicKey().toString(),
    network: network,
  };
  var url = '/v1/wallets/';
  self._doPostRequest(url, args, function(err, body) {
    if (err) return cb(err);

    var walletId = body.walletId;

    var secret = WalletUtils.toSecret(walletId, walletPrivKey, network);
    self.credentials.addWalletInfo(walletId, walletName, m, n, walletPrivKey.toString(), copayerName);

    self._doJoinWallet(walletId, walletPrivKey, self.credentials.xPubKey, copayerName,
      function(err, wallet) {
        if (err) return cb(err);
        return cb(null, n > 1 ? secret : null);
      });
  });
};


// API.prototype.reCreateWallet = function(walletName, cb) {
//   var self = this;
//   this._loadAndCheck(function(err, wcd) {
//     if (err) return cb(err);

//     var walletPrivKey = new Bitcore.PrivateKey();
//     var args = {
//       name: walletName,
//       m: wcd.m,
//       n: wcd.n,
//       pubKey: walletPrivKey.toPublicKey().toString(),
//       network: wcd.network,
//     };
//     var url = '/v1/wallets/';
//     self._doPostRequest(url, args, function(err, body) {
//       if (err) return cb(err);

//       var walletId = body.walletId;

//       var secret = WalletUtils.toSecret(walletId, walletPrivKey, wcd.network);
//       var i = 0;
//       async.each(wcd.publicKeyRing, function(xpub, next) {
//         var copayerName = 'recovered Copayer #' + i;
//         self._doJoinWallet(walletId, walletPrivKey, wcd.publicKeyRing[i++], copayerName, next);
//       }, function(err) {
//         return cb(err);
//       });
//     });
//   });
// };


API.prototype.joinWallet = function(secret, copayerName, cb) {
  var self = this;

  try {
    var secretData = WalletUtils.fromSecret(secret);
  } catch (ex) {
    return cb(ex);
  }

  if (!self.credentials) {
    self.credentials = Credentials.create(secretData.network);
  }

  self._doJoinWallet(secretData.walletId, secretData.walletPrivKey, self.credentials.xPubKey, copayerName,
    function(err, wallet) {
      if (err) return cb(err);
      self.credentials.addWalletInfo(wallet.id, wallet.name, wallet.m, wallet.n, secretData.walletPrivKey, copayerName);
      return cb(null, wallet);
    });
};

API.prototype.getStatus = function(cb) {
  $.checkState(this.credentials && this.credentials.isComplete());
  var self = this;

  var url = '/v1/wallets/';
  self._doGetRequest(url, function(err, result) {
    _processTxps(result.pendingTxps, self.credentials.sharedEncryptingKey);
    return cb(err, result, self.credentials.copayerId);
  });
};

/**
 * send
 *
 * @param opts
 * @param opts.toAddress
 * @param opts.amount
 * @param opts.message
 */
API.prototype.sendTxProposal = function(opts, cb) {
  $.checkState(this.credentials && this.credentials.isComplete());
  $.checkArgument(opts);
  $.shouldBeNumber(opts.amount);

  var self = this;

  var args = {
    toAddress: opts.toAddress,
    amount: opts.amount,
    message: _encryptMessage(opts.message, self.credentials.sharedEncryptingKey),
  };
  var hash = WalletUtils.getProposalHash(args.toAddress, args.amount, args.message);
  args.proposalSignature = WalletUtils.signMessage(hash, self.credentials.requestPrivKey);
  log.debug('Generating & signing tx proposal hash -> Hash: ', hash, ' Signature: ', args.proposalSignature);

  var url = '/v1/txproposals/';
  self._doPostRequest(url, args, function(err, txp) {
    if (err) return cb(err);
    return cb(null, txp);
  });
};

API.prototype.createAddress = function(cb) {
  $.checkState(this.credentials && this.credentials.isComplete());

  var self = this;

  var url = '/v1/addresses/';
  self._doPostRequest(url, {}, function(err, address) {
    if (err) return cb(err);
    if (!Verifier.checkAddress(self.credentials, address)) {
      return cb(new ServerCompromisedError('Server sent fake address'));
    }

    return cb(null, address);
  });
};

/*
 * opts.doNotVerify
 */

API.prototype.getMainAddresses = function(opts, cb) {
  $.checkState(this.credentials && this.credentials.isComplete());

  var self = this;

  var url = '/v1/addresses/';
  self._doGetRequest(url, function(err, addresses) {
    if (err) return cb(err);

    if (!opts.doNotVerify) {
      var fake = _.any(addresses, function(address) {
        return !Verifier.checkAddress(self.credentials, address);
      });
      if (fake)
        return cb(new ServerCompromisedError('Server sent fake address'));
    }
    return cb(null, addresses);
  });
};

API.prototype.getBalance = function(cb) {
  $.checkState(this.credentials && this.credentials.isComplete());
  var self = this;

  var url = '/v1/balance/';
  self._doGetRequest(url, cb);
};

/**
 * Export does not try to complete the wallet from the server. Exports the
 * wallet as it is now.
 *
 * @param opts.access =['full', 'readonly', 'readwrite']
 */
// API.prototype.export = function(opts, cb) {
//   $.checkState(this.credentials);
//   $.shouldBeFunction(cb);

//   var self = this;

//   opts = opts || {};
//   var access = opts.access || 'full';

//   this._load(function(err, wcd) {
//     if (err) return cb(err);
//     var v = [];

//     var myXPubKey = wcd.xPrivKey ? (new Bitcore.HDPublicKey(wcd.xPrivKey)).toString() : '';

//     _.each(WALLET_CRITICAL_DATA, function(k) {
//       var d;

//       if (access != 'full' && k === 'xPrivKey') {
//         v.push(null);
//         return;
//       }

//       // Skips own pub key IF priv key is exported
//       if (access == 'full' && k === 'publicKeyRing') {
//         d = _.without(wcd[k], myXPubKey);
//       } else {
//         d = wcd[k];
//       }
//       v.push(d);
//     });

//     if (access != 'full') {
//       v.push(wcd.copayerId);
//       v.push(wcd.roPrivKey);
//       if (access == 'readwrite') {
//         v.push(wcd.requestPrivKey);
//       }
//     }

//     return cb(null, JSON.stringify(v));
//   });
// }


// API.prototype.import = function(str, cb) {
//   var self = this;

//   this.storage.load(function(err, wcd) {
//     if (wcd)
//       return cb('Storage already contains a wallet');

//     wcd = {};

//     var inData = JSON.parse(str);
//     var i = 0;

//     _.each(WALLET_CRITICAL_DATA.concat(WALLET_EXTRA_DATA), function(k) {
//       wcd[k] = inData[i++];
//     });

//     if (wcd.xPrivKey) {
//       var xpriv = new Bitcore.HDPrivateKey(wcd.xPrivKey);
//       var xPubKey = new Bitcore.HDPublicKey(xpriv).toString();
//       wcd.publicKeyRing.unshift(xPubKey);
//       wcd.copayerId = WalletUtils.xPubToCopayerId(xPubKey);
//       wcd.roPrivKey = xpriv.derive('m/1/0').privateKey.toWIF();
//       wcd.requestPrivKey = xpriv.derive('m/1/1').privateKey.toWIF();
//     }

//     if (!wcd.publicKeyRing)
//       return cb('Invalid source wallet');

//     wcd.network = wcd.publicKeyRing[0].substr(0, 4) == 'tpub' ? 'testnet' : 'livenet';

//     self.save(wcd, function(err) {
//       return cb(err, WalletUtils.accessFromData(wcd));
//     });
//   });
// };

/**
 *
 */

API.prototype.parseTxProposals = function(txData, cb) {
  $.checkState(this.credentials && this.credentials.isComplete());

  var self = this;

  var txps = txData.txps;
  _processTxps(txps, self.credentials.sharedEncryptingKey);

  var fake = _.any(txps, function(txp) {
    return (!Verifier.checkTxProposal(self.credentials, txp));
  });

  if (fake)
    return cb(new ServerCompromisedError('Server sent fake transaction proposal'));

  return cb(null, txps);
};



/**
 *
 * opts.doNotVerify
 * opts.getRawTxps
 * @return {undefined}
 */

API.prototype.getTxProposals = function(opts, cb) {
  $.checkState(this.credentials && this.credentials.isComplete());

  var self = this;

  var url = '/v1/txproposals/';
  self._doGetRequest(url, function(err, txps) {
    if (err) return cb(err);

    var rawTxps;
    if (opts.getRawTxps) {
      rawTxps = JSON.parse(JSON.stringify(txps));
    }

    _processTxps(txps, self.credentials.sharedEncryptingKey);

    var fake = _.any(txps, function(txp) {
      return (!opts.doNotVerify && !Verifier.checkTxProposal(self.credentials, txp));
    });

    if (fake)
      return cb(new ServerCompromisedError('Server sent fake transaction proposal'));

    // TODO: return a single arg
    return cb(null, txps, rawTxps);
  });
};

API.prototype.getSignatures = function(txp, cb) {
  $.checkState(this.credentials && this.credentials.isComplete());
  $.checkArgument(txp.creatorId);

  var self = this;

  if (!self.credentials.canSign())
    return cb('You do not have the required keys to sign transactions');

  if (!Verifier.checkTxProposal(self.credentials, txp)) {
    return cb(new ServerCompromisedError('Transaction proposal is invalid'));
  }

  return cb(null, WalletUtils.signTxp(txp, self.credentials.xPrivKey));
};

API.prototype.signTxProposal = function(txp, cb) {
  $.checkState(this.credentials && this.credentials.isComplete());
  $.checkArgument(txp.creatorId);

  var self = this;

  if (!self.credentials.canSign() && !txp.signatures)
    return cb(new Error('You do not have the required keys to sign transactions'));

  if (!Verifier.checkTxProposal(self.credentials, txp)) {
    return cb(new ServerCompromisedError('Server sent fake transaction proposal'));
  }

  var signatures = txp.signatures || WalletUtils.signTxp(txp, self.credentials.xPrivKey);

  var url = '/v1/txproposals/' + txp.id + '/signatures/';
  var args = {
    signatures: signatures
  };

  self._doPostRequest(url, args, function(err, txp) {
    if (err) return cb(err);
    return cb(null, txp);
  });
};

API.prototype.rejectTxProposal = function(txp, reason, cb) {
  $.checkState(this.credentials && this.credentials.isComplete());
  $.checkArgument(cb);

  var self = this;

  var url = '/v1/txproposals/' + txp.id + '/rejections/';
  var args = {
    reason: _encryptMessage(reason, self.credentials.sharedEncryptingKey) || '',
  };
  self._doPostRequest(url, args, function(err, txp) {
    if (err) return cb(err);
    return cb(null, txp);
  });
};

API.prototype.broadcastTxProposal = function(txp, cb) {
  $.checkState(this.credentials && this.credentials.isComplete());

  var self = this;

  var url = '/v1/txproposals/' + txp.id + '/broadcast/';
  self._doPostRequest(url, {}, function(err, txp) {
    if (err) return cb(err);
    return cb(null, txp);
  });
};



API.prototype.removeTxProposal = function(txp, cb) {
  $.checkState(this.credentials && this.credentials.isComplete());

  var self = this;

  var url = '/v1/txproposals/' + txp.id;
  self._doRequest('delete', url, {}, function(err) {
    if (err) return cb(err);
    return cb();
  });
};

API.prototype.getTxHistory = function(opts, cb) {
  $.checkState(this.credentials && this.credentials.isComplete());

  var self = this;

  var url = '/v1/txhistory/';
  self._doGetRequest(url, function(err, txs) {
    if (err) return cb(err);

    _processTxps(txs, self.credentials.sharedEncryptingKey);

    return cb(null, txs);
  });
};

module.exports = API;