Elep

var timespan = require('./lib/timespan');
var PS_SUPPORTED = require('./lib/psSupported');
var jws = require('jws');
var includes = require('lodash.includes');
var isBoolean = require('lodash.isboolean');
var isInteger = require('lodash.isinteger');
var isNumber = require('lodash.isnumber');
var isPlainObject = require('lodash.isplainobject');
var isString = require('lodash.isstring');
var once = require('lodash.once');

var SUPPORTED_ALGS = ['RS256', 'RS384', 'RS512', 'ES256', 'ES384', 'ES512', 'HS256', 'HS384', 'HS512', 'none']
if (PS_SUPPORTED) {
  SUPPORTED_ALGS.splice(3, 0, 'PS256', 'PS384', 'PS512');
}

var registered_claims_schema = {
  iat: { isValid: isNumber, message: '"iat" should be a number of seconds' },
  exp: { isValid: isNumber, message: '"exp" should be a number of seconds' },
  nbf: { isValid: isNumber, message: '"nbf" should be a number of seconds' }
};

function validateOptions(options) {
  return validate(sign_options_schema, false, options, 'options');
}

function validatePayload(payload) {
  return validate(registered_claims_schema, true, payload, 'payload');
}

var options_to_payload = {
  'audience': 'aud',
  'issuer': 'iss',
  'subject': 'sub',
  'jwtid': 'jti'
};

var options_for_objects = [
  'expiresIn',
  'notBefore',
  'noTimestamp',
  'audience',
  'issuer',
  'subject',
  'jwtid',
];

module.exports = function (payload, secretOrPrivateKey, options, callback) {
  if (typeof options === 'function') {
    callback = options;
    options = {};
  } else {
    options = options || {};
  }

var isObjectPayload = typeof payload === 'object' &&
                        !Buffer.isBuffer(payload);

var header = Object.assign({
    alg: options.algorithm || 'HS256',
    typ: isObjectPayload ? 'JWT' : undefined,
    kid: options.keyid
  }, options.header);

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

if (!secretOrPrivateKey && options.algorithm !== 'none') {
    return failure(new Error('secretOrPrivateKey must have a value'));
  }

if (typeof payload === 'undefined') {
    return failure(new Error('payload is required'));
  } else if (isObjectPayload) {
    try {
      validatePayload(payload);
    }
    catch (error) {
      return failure(error);
    }
    if (!options.mutatePayload) {
      payload = Object.assign({},payload);
    }
  } else {
    var invalid_options = options_for_objects.filter(function (opt) {
      return typeof options[opt] !== 'undefined';
    });

if (invalid_options.length > 0) {
      return failure(new Error('invalid ' + invalid_options.join(',') + ' option for ' + (typeof payload ) + ' payload'));
    }
  }

if (typeof payload.exp !== 'undefined' && typeof options.expiresIn !== 'undefined') {
    return failure(new Error('Bad "options.expiresIn" option the payload already has an "exp" property.'));
  }

if (typeof payload.nbf !== 'undefined' && typeof options.notBefore !== 'undefined') {
    return failure(new Error('Bad "options.notBefore" option the payload already has an "nbf" property.'));
  }

try {
    validateOptions(options);
  }
  catch (error) {
    return failure(error);
  }

var timestamp = payload.iat || Math.floor(Date.now() / 1000);

if (options.noTimestamp) {
    delete payload.iat;
  } else if (isObjectPayload) {
    payload.iat = timestamp;
  }

if (typeof options.notBefore !== 'undefined') {
    try {
      payload.nbf = timespan(options.notBefore, timestamp);
    }
    catch (err) {
      return failure(err);
    }
    if (typeof payload.nbf === 'undefined') {
      return failure(new Error('"notBefore" should be a number of seconds or string representing a timespan eg: "1d", "20h", 60'));
    }
  }

if (typeof options.expiresIn !== 'undefined' && typeof payload === 'object') {
    try {
      payload.exp = timespan(options.expiresIn, timestamp);
    }
    catch (err) {
      return failure(err);
    }
    if (typeof payload.exp === 'undefined') {
      return failure(new Error('"expiresIn" should be a number of seconds or string representing a timespan eg: "1d", "20h", 60'));
    }
  }

Object.keys(options_to_payload).forEach(function (key) {
    var claim = options_to_payload[key];
    if (typeof options[key] !== 'undefined') {
      if (typeof payload[claim] !== 'undefined') {
        return failure(new Error('Bad "options.' + key + '" option. The payload already has an "' + claim + '" property.'));
      }
      payload[claim] = options[key];
    }
  });

var encoding = options.encoding || 'utf8';

if (typeof callback === 'function') {
    callback = callback && once(callback);

jws.createSign({
      header: header,
      privateKey: secretOrPrivateKey,
      payload: payload,
      encoding: encoding
    }).once('error', callback)
      .once('done', function (signature) {
        callback(null, signature);
      });
  } else {
    return jws.sign({header: header, payload: payload, secret: secretOrPrivateKey, encoding: encoding});
  }
};