echonest.rb

#!/usr/bin/env ruby
# -*- coding: utf-8 -*-
require 'rubygems'
require 'uri'
require 'net/http'
require 'digest/md5'
require 'rexml/document'
require 'extlib'
require 'yaml'

class WebService; end
class WebService::EchoNest
  def initialize(apikey)
    @api_key = apikey
    @base_url = 'http://developer.echonest.com'
    @host = 'developer.echonest.com'
  end

  def upload(file)
    file_data = File.read(file)
    boundary = '----BOUNDARYBOUNDARY----'
    data = <<EOF
--#{boundary}\r
Content-Disposition: form-data; name="api_key"\r
\r
#{@api_key}\r
--#{boundary}\r
Content-Disposition: form-data; name="version"\r
\r
3\r
--#{boundary}\r
Content-Disposition: form-data; name="wait"\r
\r
Y\r
--#{boundary}\r
Content-Disposition: form-data; name="file"; filename="#{file}"\r
Content-Type: application/octet-stream\r
\r
#{file_data}\r
--#{boundary}--\r
EOF

    header ={
      'Content-Length' => data.length.to_s,
      'Content-Type' => "multipart/form-data; boundary=#{boundary}"
    }
    url = @base_url + '/api/upload'
    uri = URI.parse(url)
    response = Net::HTTP.start(uri.host, 80) {|http|
      http.post(uri.path, data, header)
    }
    doc = REXML::Document.new response.body
    result = {
      'status' => {},
      'query' => {},
      'track' => {},
    }
    %w[code message].each do |m|
      result['status'][m] = doc.elements['response'].elements['status'].elements[m].text
    end
    %w[api_key url file wait].each do |m|
      elm = REXML::XPath.first(doc, "//parameter[@name=\"#{m}\"]")
      result['query'][m] = elm.text if elm
    end
    %w[id md5].each do |m|
      result['track'][m] = doc.elements['response'].elements['track'].attributes[m]
    end
    result
  end

  def get_beats(args)
    p args
    url = @base_url + '/api/get_beats?' + 
      ['api_key=' + @api_key,
       'version=3'].join('&')
    if args[:id]
      url += "&id=#{args[:id]}"
    else
      if args[:file]
        md5 = Digest::MD5.hexdigest(File.open(args[:file], 'rb').read)
      else
        md5 = args[:md5]
      end
      url += "&md5=#{md5}"
    end
    response = Net::HTTP::get_response(URI.parse(url));
    doc = REXML::Document.new response.body
    result = Mash.new({
                        :status => Mash.new({}),
                        :query => Mash.new({}),
                        :beats => [],
    })
    %w[code message].each do |m|
      result[:status][m] = doc.elements['response'].elements['status'].elements[m].text
    end
    # unknown md5
    if result[:status][:code] == '5'
      puts "unknown md5. uploading..."
      upload args[:file]
      get_beats :md5 => md5
    else
      %w[api_key id md5].each do |m|
        elm = REXML::XPath.first(doc, "//parameter[@name=\"#{m}\"]")
        result[:query][m] = elm.text if elm
      end
      doc.elements.each('response/analysis/beat') {|elm|
        result[:beats].push(Mash.new({
                                       :confidence => elm.attributes['confidence'],
                                       :value => elm.text
                                     }))
      }
      result
    end
  end

  def get_tatums(args)
  end

  def get_bars(args)
  end

  def get_sections(args)
    url = @base_url + '/api/get_sections?' + 
      ['api_key=' + @api_key,
       'version=3'].join('&')
    if args[:id]
      url += "&id=#{args[:id]}"
    else
      if args[:file]
        md5 = Digest::MD5.hexdigest(File.open(args[:file], 'rb').read)
      else
        md5 = args[:md5]
      end
      url += "&md5=#{md5}"
    end
    response = Net::HTTP::get_response(URI.parse(url));
    doc = REXML::Document.new response.body
    result = Mash.new({
      :status => Mash.new({}),
      :query => Mash.new({}),
      :sections => [],
    })
    %w[code message].each do |m|
      result[:status][m] = doc.elements['response'].elements['status'].elements[m].text
    end
    # unknown md5
    if result[:status][:code] == '5'
      puts "unknown md5. uploading..."
      upload args[:file]
      get_sections :md5 => md5
    else
      %w[api_key id md5].each do |m|
        elm = REXML::XPath.first(doc, "//parameter[@name=\"#{m}\"]")
        result[:query][m] = elm.text if elm
      end
      doc.elements.each('response/analysis/section') {|elm|
        result[:sections].push(Mash.new({
                                          :start => elm.attributes['start'],
                                          :duration => elm.attributes['duration'],
                                        }))
      }
      result
    end
  end

  def get_segments(args)
    url = @base_url + '/api/get_segments?' + 
      ['api_key=' + @api_key,
       'version=3'].join('&')
    if args[:id]
      url += "&id=#{args[:id]}"
    else
      if args[:file]
        md5 = Digest::MD5.hexdigest(File.open(args[:file], 'rb').read)
      else
        md5 = args[:md5]
      end
      url += "&md5=#{md5}"
    end
    response = Net::HTTP::get_response(URI.parse(url));
    doc = REXML::Document.new response.body
    result = Mash.new({
      :status => Mash.new({}),
      :query => Mash.new({}),
      :segments => [],
    })
    %w[code message].each do |m|
      result[:status][m] = doc.elements['response'].elements['status'].elements[m].text
    end
    # unknown md5
    if result[:status][:code] == '5'
      puts "unknown md5. uploading..."
      upload args[:file]
      get_segments :md5 => md5
    else
      %w[api_key id md5].each do |m|
        elm = REXML::XPath.first(doc, "//parameter[@name=\"#{m}\"]")
        result[:query][m] = elm.text if elm
      end
      doc.elements.each('response/analysis/segment') {|elm|
        loudness = []
        elm.elements.each('loudness/dB') {|e|
          loudness.push({
                          :time => e.attributes['time'] || 0,
                          :value => e.text
                        })
        }
        pitches = []
        elm.elements.each('pitches/pitch') {|e|
          pitches.push e.text
        }
        timbre = []
        elm.elements.each('timbre/coeff') {|e|
          timbre.push e.text
        }
        result[:segments].push(Mash.new({
                                          :start => elm.attributes['start'],
                                          :duration => elm.attributes['duration'],
                                          :loudness => {
                                            :min => {
                                              :time => loudness[0][:time],
                                              :value => loudness[0][:value],
                                            },
                                            :max => {
                                              :time => loudness[1][:time],
                                              :value => loudness[1][:value],
                                            },
                                          },
                                          :pitches => pitches,
                                          :timbre => timbre,
                                          
                                        }))
      }
      result
    end
  end


  def search_tracks(query)
    p 'search_tracks'
    query = query.gsub(' ', '+')
    url = @base_url + '/api/search_tracks?' + 
      ['api_key=' + @api_key,
       'version=3',
       'query=' + query].join('&')
    response = Net::HTTP::get_response(URI.parse(url));
    REXML::Document.new response.body
  end

end