paystack/index.js

Paystack API wrapper

/*
Paystack API wrapper
@author Obembe Opeyemi <@kehers>
*/

'use strict';

var
    request = require('request'),
    root = 'https://api.paystack.co',
    Promise = require('promise')
;

var resources = {
  customer: require('./resources/customer'),
  plan: require('./resources/plan'),
  transaction: require('./resources/transaction'),
  page: require('./resources/page'),
  subscription: require('./resources/subscription'),
  subaccount: require('./resources/subaccount'),
  settlements: require('./resources/settlements'),
  misc: require('./resources/misc')
}

function Paystack(key) {
  if (!(this instanceof Paystack)) {
    return new Paystack(key);
  }

  this.key = key;
  this.importResources();
}

Paystack.prototype = {

  extend:  function(params) {
  	// This looks more sane.
    var self = this;
    return function(){
      // Convert argument to array
      var args = new Array(arguments.length);
      var l = args.length;
      for(var i = 0; i < l; ++i) {
        args[i] = arguments[i];
      }

      // Check for callback & Pull it out from the array
      var callback = l > 0 && typeof args.slice(l-1)[0] === "function" ? args.splice(l-1)[0] : undefined;

      var body, qs;

      // quick fix - method checking
      var method = params.method in {"get":'', "post":'', "put":''}
                 ? params.method
                 : (function () { throw new Error("Method not Allowed! - Resource declaration error") })()
      var endpoint = [root, params.endpoint].join('');
      // Checking for required params;
      if(params.params) {
        var paramList = params.params;

        // Pull body passed
        var body = args.length === 2 ? args[1] : args[0];
        paramList.filter(function(item, index, array) {
          if(item.indexOf("*") === -1) {
            // Not required
            return;
          }
          item = item.replace("*", "");

          if(!(item in body)) {
            throw new Error("Required Parameters Ommited - " + item);
          }
          return;

        });
      }

      // Get arguments in endpoint e.g {id} in customer/{id} and pull
      // out from array
      var argsInEndpoint = endpoint.match(/{[^}]+}/g);
      if (argsInEndpoint) {
        l = argsInEndpoint.length;

        // Do we have one or more?
        if (l > 0) {
          // Confirm resource declaration good
          if (!Array.isArray(params.args)) {
            // error
            throw new Error('Resource declaration error');
          }

          // Confirm user passed the argument to method
          // and replace in endpoint

          var match, index;
          for (var i=0;i<l;i++) {
            match = argsInEndpoint[i].replace(/\W/g, '');
            index = params.args.indexOf(match);
            if (index != -1) {
              if (!args[index]) {
                // error
                throw new Error('Resource declaration error');
              }

              // todo: args[index] must be string or int
              endpoint = endpoint.replace(new RegExp(argsInEndpoint[i]), args[index]);
              args.splice(index, 1);
            }
          }
        }
      }

      // Add post/put/[delete?] body
      if (args[0]) {
        if (method == 'post' || method == 'put') {
          // Body
          body = args[0];
        }
        else if (method == 'get') {
          qs = args[0];
        }
      }

      // Make request
      var options = {
        url: endpoint,
        json: true,
        method: method.toUpperCase(),
        headers: {
          'Authorization': ['Bearer ', self.key].join('')
        }
      }

      if (body)
        options.body = body;

      if (qs)
        options.qs = qs;

      return new Promise(function (fulfill, reject){
        request(options, function(error, response, body) {
          // return body
          if (error){
            reject(error);
          }
          else if(!body.status){
          
            // Error from API??
            error = body;
            body = null;
            reject(error);
          }
          else{
            fulfill(body);
          }
        });
      }).then(function(value) {
      	if(callback) {
      		return callback(null, value);
      	}
      	return value;
      }).catch(function(reason) {
      	if(callback) {
      		return callback(reason, null);
      	}
      	return reason;
      });
    }
  },

  importResources: function() {
    var anon;
    // Looping over all resources
    for (var j in resources) {
      // Creating a surrogate function
      anon = function(){};
      // Looping over the properties of each resource
      for(var i in resources[j]) {
        anon.prototype[i] = this.extend(resources[j][i]);
      }
      Paystack.prototype[j] = new anon();
    }
  }
};


module.exports = Paystack;