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mapper.coffee

#
# Module dependencies
#
utils = require './utils'

#
# @api private
#
class Mapper
  constructor: (phases, riak) ->
    @phases = phases
    @riak = riak

  #
  # Add one or more *map* phases to the Map/Reduce job
  #
  # @param {Object} One (function, string, or object containing `source`, `name`, `args`, etc) or more phases (each one contained in an Array)
  # @return {Mapper} To be able to chain until `#run()` is called
  # @api public
  #
  map: (phase, args) ->
    @addPhases utils.makePhases("map", phase, args)
    this
  
  #
  # Add one or more *reduce* phases to the Map/Reduce job
  #
  # @param {Object} One (function, string, or object containing `source`, `name`, `args`, etc) or more phases (each one contained in an Array)
  # @return {Mapper} To be able to chain until `#run()` is called
  # @api public
  #
  reduce: (phase, args) ->
    @addPhases utils.makePhases("reduce", phase, args)
    this
  
  #
  # Add one or more *link* phases to the Map/Reduce job
  #
  # @param {Object} One (function, string, or object containing `source`, `name`, `args`, etc) or more phases (each one contained in an Array)
  # @return {Mapper} To be able to chain until `#run()` is called
  # @api public
  #
  link: (phase) ->
    @addPhases utils.makePhases("link", phase)
    this
  
  #
  # Run the Map/Reduce job
  #
  # @param {Array} for a list of `[bucket, key]`, or {String} for a bucket name (*warning*: it has to list the bucket's keys)
  # @return {Function} A function that takes a callback as its only input
  # @api public
  #
  run: (inputs, options) ->
    options = utils.ensure options
    options.interface = 'mapred'
    options.method = 'POST'

    @phases.forEach (phase) ->
      for p in phase # map, reduce or link
        phase[p].language ||= 'javascript';

    options.data = 
      inputs: inputs
      query: this.phases

    @riak.execute '', options
  
  #
  # @api private
  #
  addPhases: (phases) ->
    phases.forEach (phase) =>
      @phases.push phase

# exports

module.exports = Mapper

mapper.js

/**
 * Module dependencies
 */
var utils = require('./utils')

/**
 * @api private
 */
function Mapper(phases, riak) {
  this.phases = phases ;
  this.riak = riak;
}

/**
 * Add one or more *map* phases to the Map/Reduce job
 *
 * @param {Object} One (function, string, or object containing `source`, `name`, `args`, etc) or more phases (each one contained in an Array)
 * @return {Mapper} To be able to chain until `#run()` is called
 * @api public
 */
Mapper.prototype.map = function(phase, args) {
  this.addPhases(utils.makePhases("map", phase, args))
  return this;
}

/**
 * Add one or more *reduce* phases to the Map/Reduce job
 *
 * @param {Object} One (function, string, or object containing `source`, `name`, `args`, etc) or more phases (each one contained in an Array)
 * @return {Mapper} To be able to chain until `#run()` is called
 * @api public
 */
Mapper.prototype.reduce = function(phase, args) {
  this.addPhases(utils.makePhases("reduce", phase, args))
  return this;
}

/**
 * Add one or more *link* phases to the Map/Reduce job
 *
 * @param {Object} One (function, string, or object containing `source`, `name`, `args`, etc) or more phases (each one contained in an Array)
 * @return {Mapper} To be able to chain until `#run()` is called
 * @api public
 */
Mapper.prototype.link = function(phase) {
  this.addPhases(utils.makePhases("link", phase))
  return this;
}

/**
 * Run the Map/Reduce job
 *
 * @param {Array} for a list of `[bucket, key]`, or {String} for a bucket name (*warning*: it has to list the bucket's keys)
 * @return {Function} A function that takes a callback as its only input
 * @api public
 */
Mapper.prototype.run = function(inputs, options) {
  options = utils.ensure(options);
  options.interface = 'mapred';
  options.method = 'POST';

  this.phases.forEach(function(phase) {
    for (p in phase) { // map, reduce or link
      if (phase[p].language === undefined) {
        phase[p].language = 'javascript';
      };
    }
  })
  
  options.data = {
    inputs: inputs,
    query: this.phases
  }

  return this.riak.execute('', options);
}

/**
 * @api private
 */
Mapper.prototype.addPhases = function(phases) {
  var self = this;
  phases.forEach(function(phase) {
    self.phases.push(phase);
  })
}

// exports

module.exports = Mapper