# To run this script, you need to install ruby, rubygems, the httparty gem,
# and any of the json gems.
require 'rubygems'
require 'httparty'
require 'json'
require 'pp'
 
class CouchDb
  include HTTParty
  format :json
  base_uri 'http://localhost:5984/'
 
  class << self
    # Add some logging
    [:post, :get, :delete, :put].each do |method|
      define_method method do |*args|
        puts "", "#{method}(#{args.inspect})"
        result = super
        pp result.delegate
        #puts result.inspect
        result
      end
    end
 
    def temp_view(db, view_definition)
      post(db + '/_temp_view', :body => view_definition.to_json, :headers => { 'Content-type' => 'application/json' })
    end
  end
end
 
def urlencode(str)
  str.gsub(/[^a-zA-Z0-9_\.\-]/n) {|s| sprintf('%%%02x', s[0]) }
end
 
EmployeeDb = '/employees_example'
BlogDb     = '/blog_example'
 
CouchDb.get("/_all_dbs", :format => :txt)
 
CouchDb.delete(EmployeeDb)
CouchDb.put(EmployeeDb)
resp = CouchDb.put(EmployeeDb + '/gwashington', :body => {}.to_json)
CouchDb.post(EmployeeDb + '/gwashington', :body =>
  {:name => "George Washington", :rev => resp['rev'], :titles => [
    {"begin" => 1773, "end" => 1785, "title" => "Commander of the Continental Army"},
    {"begin" => 1789, "end" => 1797, "title" => "President of the United States"},
    {"begin" => 1798, "end" => 1799, "title" => "United States Army Senior Officer"}
]}.to_json)
CouchDb.put(EmployeeDb + '/jadams', :body => {:name => "John Adams", :titles => [
  {"begin" => 1789, "end" => 1797, "title" => "Vice President of the United States"},
  {"begin" => 1797, "end" => 1801, "title" => "President of the United States"}
]}.to_json)
 
puts "", "Default View"
CouchDb.temp_view(EmployeeDb, {:map => <<END_MAP})
function(doc) { emit(null, doc); }
END_MAP
 
puts "", "Titles, by year"
by_year_map = <<END_MAP
function(doc) {
  var i, title, year;
  if(doc.titles && doc.name)
  {
    for(i = 0; i < doc.titles.length; i++)
    {
       title = doc.titles[i];
       for (year = title.begin; year <= title.end; year++)
       {
          emit(year, {"name":doc.name, "begin":title.begin, "end": title.end, "title": title.title});
       }
    }
  }
}
END_MAP
CouchDb.temp_view(EmployeeDb, {:map => by_year_map})
 
puts "", "Permanent Views"
CouchDb.put(EmployeeDb + '/_design/titles', :body => {
  :language => 'javascript',
  :views => {
     :by_year => {
       :map => by_year_map
     }
  }
}.to_json)
CouchDb.get(EmployeeDb + '/_design/titles/_view/by_year')
CouchDb.get(EmployeeDb + '/_design/titles/_view/by_year?key=1796')
 
 
CouchDb.delete(BlogDb)
CouchDb.put(BlogDb)
 
CouchDb.put(BlogDb + '/post1', :body => {
  :type => 'post',
  :title => 'My First Post!',
  :content => 'Welcome to my blog! I\'ll tell you all about the stuff I do, day to day.'
}.to_json)
CouchDb.put(BlogDb + '/post2', :body => {
  :type => 'post',
  :title => 'Report',
  :content => 'Today, I typed a bunch of TPS reports.'
}.to_json)
CouchDb.post(BlogDb + '/', :body => {
  :type => 'comment',
  :post_id => 'post1',
  :title => 'Awesome!',
  :content => 'I\'m totally looking forward to reading this blog!',
}.to_json)
CouchDb.post(BlogDb + '/', :body => {
  :type => 'comment',
  :post_id => 'post2',
  :content => 'You had to do that too??!?!?! No freakin\' way!'
}.to_json)
CouchDb.post(BlogDb + '/', :body => {
  :type => 'comment',
  :post_id => 'post2',
  :title => 'Good work!',
  :content => 'I read your reports, and they are really top notch!'
}.to_json)
 
all_posts_map = <<END_MAP
function(doc)
{
  if(doc.type && doc.type == 'post')
  {
    emit(doc._id, doc);
  }
}
END_MAP
with_comments_map = <<END_MAP
function(doc)
{
  if(doc.type)
  {
    if(doc.type == 'post')    emit([doc._id,     0], doc);
    if(doc.type == 'comment') emit([doc.post_id, 1], doc);
  }
}
END_MAP
comments_per_post_map = <<END_MAP
function(doc)
{
  if(doc.type && doc.type == 'comment')
  {
    emit(doc.post_id, 1);
  }
}
END_MAP
comments_per_post_reduce = <<END_REDUCE
function(key, values, rereduce)
{
  return sum(values);
}
END_REDUCE
CouchDb.put(BlogDb + '/_design/posts', :body => {
  :language => 'javascript',
  :views => {
     :all => {
       :map => all_posts_map
     },
     :with_comments => {
       :map => with_comments_map
     },
     :comments_per_post => {
       :map => comments_per_post_map,
       :reduce => comments_per_post_reduce
     },
  }
}.to_json)
CouchDb.get(BlogDb + '/_design/posts/_view/all')
CouchDb.get(BlogDb + '/_design/posts/_view/with_comments?startkey=' + urlencode(['post2', 0].to_json) + '&endkey=' + urlencode(['post2', 1].to_json))
CouchDb.get(BlogDb + '/_design/posts/_view/comments_per_post?group=true')