require 'rest_client'
require 'yajl'
require 'erb'

class CouchdbException < RuntimeError
   attr :error
   def initialize(error)
    @error = error.values[0]
  end
end

module Couchdb

def self.salt
 o =  [('a'..'z'),('A'..'Z')].map{|i| i.to_a}.flatten;  
 salt  =  (0..50).map{ o[rand(o.length)]  }.join; 
end

#change non-admin user password
def self.change_password(username, new_password,auth_session = "")
 salty = salt()
 password_sha = Digest::SHA1.hexdigest(new_password + salty) 
 user_id = 'org.couchdb.user:' + username
 data = {"salt" => salty,"password_sha" => password_sha}
 doc = { :database => '_users', :doc_id => user_id, :data => data}   
 update_doc doc,auth_session
end

#add a new user 
def self.add_user(user, auth_session="")
  o =  [('a'..'z'),('A'..'Z')].map{|i| i.to_a}.flatten;  
  salt  =  (0..50).map{ o[rand(o.length)]  }.join; 
  new_user = {:username => user[:username], :password => user[:password], :roles => user[:roles], :salt => salt}
  create_user(new_user,auth_session)
end

#create a new user 
def self.create_user(user,auth_session= "")
  password_sha = Digest::SHA1.hexdigest(user[:password] + user[:salt])              
  
  user_hash = { :type => "user",
                   :name => user[:username],
                   :password_sha => password_sha,
                   :salt => user[:salt],
                   :roles => user[:roles]
                  }
   
   str = Yajl::Encoder.encode(user_hash)
   set_address
   begin
    response = RestClient.put 'http://' + @address + ':' + @port + '/_users/org.couchdb.user:' + URI.escape(user[:username]), str,{:cookies => {"AuthSession" => auth_session}}
    hash = Yajl::Parser.parse(response.to_str)
  rescue => e
    hash = Yajl::Parser.parse(e.response.to_s)
    raise CouchdbException.new(hash), "CouchDB: Error - " + hash.values[0] + ". Reason - "  + hash.values[1]
  end 

end

#add security object
def self.set_security(db_name, data,auth_session="")
  security_data = Yajl::Encoder.encode(data)
  set_address
  begin
  response = RestClient.put 'http://' + @address + ':' + @port + '/' + URI.escape(db_name) + '/_security/',security_data, {:cookies => {"AuthSession" => auth_session}}
  hash = Yajl::Parser.parse(response.to_str)
  rescue => e
   hash = Yajl::Parser.parse(e.response.to_s)
   raise CouchdbException.new(hash), "CouchDB: Error - " + hash.values[0] + ". Reason - "  + hash.values[1]
  end 
end
#get security object
def self.get_security(db_name, auth_session="")
 set_address
 begin
  response = RestClient.get 'http://' + @address + ':' + @port + '/' + URI.escape(db_name) + '/_security/', {:cookies => {"AuthSession" => auth_session}}
  hash = Yajl::Parser.parse(response.to_str)
  rescue => e
  hash = Yajl::Parser.parse(e.response.to_s)
  raise CouchdbException.new(hash), "CouchDB: Error - " + hash.values[0] + ". Reason - "  + hash.values[1]
 end 
end


#login to couchdb
def self.login(username, password)
  set_address
  data = 'name=' + username + '&password=' + password
  begin
   response = RestClient.post 'http://' + @address + ':' + @port + '/_session/', data, {:content_type => 'application/x-www-form-urlencoded'}
   response.cookies
  rescue => e
   hash = Yajl::Parser.parse(e.response.to_s)
   raise CouchdbException.new(hash), "CouchDB: Error - " + hash.values[0] + ". Reason - "  + hash.values[1]
 end
end

#couchdb configuration api
def self.set_config(data,auth_session = "") 
  section = data[:section]
  key = data[:key] 
  value = data[:value]
  json_data = Yajl::Encoder.encode(value)
  set_address
  begin
   response = RestClient.put 'http://' + @address + ':' + @port + '/_config/' + URI.escape(section) + '/' + URI.escape(key),json_data, {:cookies => {"AuthSession" => auth_session}}
   hash = Yajl::Parser.parse(response.to_str)
  rescue => e
   hash = Yajl::Parser.parse(e.response.to_s)
   raise CouchdbException.new(hash), "CouchDB: Error - " + hash.values[0] + ". Reason - "  + hash.values[1]
 end
end

def self.delete_config(data,auth_session = "") 
  section = data[:section]
  key = data[:key] 
  set_address
  begin
   response = RestClient.delete 'http://' + @address + ':' + @port + '/_config/' + URI.escape(section) + '/' + URI.escape(key), {:cookies => {"AuthSession" => auth_session}}
   hash = Yajl::Parser.parse(response.to_str)
  rescue => e
   hash = Yajl::Parser.parse(e.response.to_s)
   raise CouchdbException.new(hash), "CouchDB: Error - " + hash.values[0] + ". Reason - "  + hash.values[1]
 end
end


def self.get_config(data,auth_session = "") 
  section = data[:section]
  key = data[:key] 
  set_address
  begin
   response = RestClient.get 'http://' + @address + ':' + @port + '/_config/' + URI.escape(section) + '/' + URI.escape(key), {:cookies => {"AuthSession" => auth_session}}
   hash = Yajl::Parser.parse(response.to_str)
  rescue => e
   hash = Yajl::Parser.parse(e.response.to_s)
   raise CouchdbException.new(hash), "CouchDB: Error - " + hash.values[0] + ". Reason - "  + hash.values[1]
 end
end

#create a document 
  def self.create_doc( doc,auth_session = "")  
      db_name =  doc[:database]
      doc_id = doc[:doc_id]
      data = doc[:data]
      json_data = Yajl::Encoder.encode(data)
      set_address
      begin
         response = RestClient.put 'http://' + @address + ':' + @port + '/' + URI.escape(db_name) + '/' + URI.escape(doc_id),json_data, {:cookies => {"AuthSession" => auth_session}}
         hash = Yajl::Parser.parse(response.to_str)
       rescue => e
         hash = Yajl::Parser.parse(e.response.to_s)
         raise CouchdbException.new(hash), "CouchDB: Error - " + hash.values[0] + ". Reason - "  + hash.values[1]
       end
  end

  #edit a document
  def self.edit_doc(doc,auth_session = "")
      db_name = doc[:database]
      doc_id = doc[:doc_id]
      data = doc[:data]
      json_data = Yajl::Encoder.encode(data)
      set_address
      begin
        response = RestClient.put 'http://' + @address + ':' + @port + '/' + URI.escape(db_name) + '/' + URI.escape(doc_id), json_data, {:cookies => {"AuthSession" => auth_session}}
         hash = Yajl::Parser.parse(response.to_str)
       rescue => e
         hash = Yajl::Parser.parse(e.response.to_s)
         raise CouchdbException.new(hash), "CouchDB: Error - " + hash.values[0] + ". Reason - "  + hash.values[1]
      end
  end

 #update a doc
 def self.update_doc(doc,auth_session = "")
      db_name = doc[:database]
      doc_id = doc[:doc_id]
      data = doc[:data]
      doc = {:database => db_name, :doc_id => doc_id}
      options = Couchdb.view doc,auth_session 
      options = options.merge(data)
      doc = {:database => db_name, :doc_id => doc_id, :data => options}
      edit_doc doc,auth_session
 end

#delete document
 def self.delete_doc(doc,auth_session = "")  
   db_name = doc[:database]
   doc_id = doc[:doc_id]
   doc = {:database => db_name, :doc_id => doc_id}
   hash = Couchdb.view doc,auth_session
   doc = {:database => db_name, :doc_id => doc_id, :rev => hash["_rev"]}
   delete_rev(doc,auth_session)
 end


 #delete a doc by rev#
 def self.delete_rev(doc,auth_session = "")
   db_name = doc[:database]
   doc_id = doc[:doc_id]
   rev = doc[:rev]
   set_address
   begin 
    response = RestClient.delete 'http://' + @address + ':' + @port + '/' + URI.escape(db_name)  + '/' + URI.escape(doc_id) + '?rev=' + rev, {:cookies => {"AuthSession" => auth_session}}
      hash = Yajl::Parser.parse(response.to_str)
    rescue => e
     hash = Yajl::Parser.parse(e.response.to_s)
     raise CouchdbException.new(hash), "CouchDB: Error - " + hash.values[0] + ". Reason - "  + hash.values[1]
    end
 end


  #create a database if one with the same name doesn't already exist
  def self.create(database_name,auth_session = "")
       set_address
       begin
         response = RestClient.put 'http://' + @address + ':' + @port + '/' + URI.escape(database_name), {:content_type => :json},{:cookies => {"AuthSession" => auth_session}}
         hash = Yajl::Parser.parse(response.to_str)
       rescue => e
         hash = Yajl::Parser.parse(e.response.to_s)
         raise CouchdbException.new(hash), "CouchDB: Error - " + hash.values[0] + ". Reason - "  + hash.values[1]
       end
  end

 #delete a database
 def self.delete(database_name,auth_session = "")
      set_address
       begin
         response = RestClient.delete 'http://' + @address + ':' + @port + '/' + URI.escape(database_name), {:cookies => {"AuthSession" => auth_session}}
         hash = Yajl::Parser.parse(response.to_str)
       rescue => e
         hash = Yajl::Parser.parse(e.response.to_s)
         raise CouchdbException.new(hash), "CouchDB: Error - " + hash.values[0] + ". Reason - "  + hash.values[1]
       end 
 end

 #return a list of all databases
 def self.all(auth_session = "")
      set_address
       begin
         response = RestClient.get 'http://' + @address + ':' + @port + '/_all_dbs', {:cookies => {"AuthSession" => auth_session}}
         hash = Yajl::Parser.parse(response.to_str)
       rescue => e
           raise e
       end
 end

##view a document 
def self.view(doc,auth_session = "")
 set_address
 db_name = doc[:database]
 doc_id = doc[:doc_id]
  begin
   response = RestClient.get 'http://' + @address + ':' + @port + '/' + db_name + '/' + doc_id,{:cookies => {"AuthSession" => auth_session}}
   hash = Yajl::Parser.parse(response.to_str)
  rescue => e
   hash = Yajl::Parser.parse(e.response.to_s)
   raise CouchdbException.new(hash), "CouchDB: Error - " + hash.values[0] + ". Reason - "  + hash.values[1]
 end 
end

#query a permanent view
def self.find(doc,auth_session = "",key=nil)
 set_address
 db_name = doc[:database]
 design_doc_name = doc[:design_doc]
 view_name = doc[:view]
   begin
    if key == nil
     response = RestClient.get 'http://' + @address + ':' + @port + '/' + db_name + '/_design/' + design_doc_name + '/_view/' + view_name,{:cookies => {"AuthSession" => auth_session}}
    else
     response = RestClient.get 'http://' + @address + ':' + @port + '/' + db_name + '/_design/' + design_doc_name + '/_view/' + view_name + URI.escape('?key="' + key + '"'),{:cookies => {"AuthSession" => auth_session}}
    end
     hash = Yajl::Parser.parse(response.to_str)
     rows = hash["rows"]
     count = 0
     rows.each do |row|
      rows[count] = row["value"]
      count += 1  
     end
     return rows
   rescue => e
    #puts e.inspect
    hash = Yajl::Parser.parse(e.response.to_s)
    raise CouchdbException.new(hash), "CouchDB: Error - " + hash.values[0] + ". Reason - "  + hash.values[1]
   end
end

#create a design document with views
def self.create_design(doc,auth_session = "")
 set_address
 db_name = doc[:database]
 design_doc_name = doc[:design_doc]
 json_doc_name = doc[:json_doc]

 begin
  #bind json doc to string
  message_template = ERB.new File.new(json_doc_name).read
  str = message_template.result(binding)
 rescue => e
   raise e
 end

  begin
   
   response = RestClient.put 'http://' + @address + ':' + @port + '/' + db_name + '/_design/' + design_doc_name, str, {:cookies => {"AuthSession" => auth_session}}
    hash = Yajl::Parser.parse(response.to_str)
  rescue => e
    hash = Yajl::Parser.parse(e.response.to_s)
    raise CouchdbException.new(hash), "CouchDB: Error - " + hash.values[0] + ". Reason - "  + hash.values[1]
  end
end

#Query view, create view on fly if it dosen't already exist
def self.find_on_fly(doc,auth_session = "",key = nil)  
   db_name = doc[:database]
   design_doc = doc[:design_doc]
   view = doc[:view]
   json_doc = doc[:json_doc]
 
   begin 
      if( key == nil)
       docs = find({:database => db_name, :design_doc => design_doc, :view => view},auth_session) 
      else
       docs = find({:database => db_name, :design_doc => design_doc, :view => view},auth_session,key) 
      end
     rescue CouchdbException => e
        document = { :database => db_name, :design_doc => design_doc, :json_doc => json_doc}
        create_design document,auth_session
        if( key == nil)
          docs = find({:database => db_name, :design_doc => design_doc, :view => view},auth_session) 
        else
          docs = find({:database => db_name, :design_doc => design_doc, :view => view},auth_session,key) 
        end
      end
    return docs
 end


#add a finder method to the database
#this creates a find by key method
def self.add_finder(options,auth_session = "")
 set_address 
 db_name = options[:database]
 key = options[:key] 
 design_doc_name = key + '_finder'
 
 view ='{
 "language" : "javascript",
 "views" :{
    "find_by_'+key+'" : {
      "map" : "function(doc){ if(doc.'+key+') emit(doc.'+key+',doc);}"
    }
 }
}'

 begin  
  response = RestClient.put 'http://' + @address + ':' + @port + '/' + db_name + '/_design/' + design_doc_name, view, {:cookies => {"AuthSession" => auth_session}}
 rescue => e
    hash = Yajl::Parser.parse(e.response.to_s)
    raise CouchdbException.new(hash), "CouchDB: Error - " + hash.values[0] + ". Reason - "  + hash.values[1]
 end
end

#add a counter method to the database
#this creates a count method that counts documents by key
def self.add_counter(options,auth_session = "")
 set_address 
 db_name = options[:database]
 key = options[:key] 
 design_doc_name = key + '_counter'
 
 view ='{
 "language" : "javascript",
 "views" :{
    "count_'+key+'" : {
      "map" : "function(doc){ if(doc.'+key+') emit(doc.'+key+',null);}", "reduce": "_count"   
    }
 }
}'

 begin  
  response = RestClient.put 'http://' + @address + ':' + @port + '/' + db_name + '/_design/' + design_doc_name, view, {:cookies => {"AuthSession" => auth_session}}
 rescue => e
    hash = Yajl::Parser.parse(e.response.to_s)
    raise CouchdbException.new(hash), "CouchDB: Error - " + hash.values[0] + ". Reason - "  + hash.values[1]
 end
end

#count by key 
def self.count(options,auth_session = "")
 set_address 
 db_name = options[:database]
 index =  options.keys[1].to_s
 search_term = options.values[1]
 design_doc_name = index + '_counter'
 view_name = 'count_' + index
 
 begin 
  view = { :database => db_name, :design_doc => design_doc_name, :view => view_name}
  docs = find view,auth_session,search_term
 rescue CouchdbException => e
    #add a counter index if one doesn't already exist in the database
    #then count_by_key
    add_counter({:database => db_name, :key => index},auth_session)
    docs = find view,auth_session,search_term
 end
  count = docs[0]
 return count.to_i
end

#find by key 
def self.find_by(options,auth_session = "")
 set_address 
 db_name = options[:database]
 index =  options.keys[1].to_s
 search_term = options.values[1]
 design_doc_name = index + '_finder'
 view_name = 'find_by_' + index
 
 begin 
  view = { :database => db_name, :design_doc => design_doc_name, :view => view_name}
  docs = find view,auth_session,search_term
 rescue CouchdbException => e
    #add a finder/index if one doesn't already exist in the database
    #then find_by_key
    add_finder({:database => db_name, :key => index},auth_session)
    docs = find view,auth_session,search_term
 end
 return docs
end

 #return a list of all docs in the database
def self.docs_from(database_name,auth_session = "")
  set_address
  begin
         response = RestClient.get 'http://' + @address + ':' + @port + '/' + URI.escape(database_name) + '/_all_docs?include_docs=true',{:cookies => {"AuthSession" => auth_session}}
         hash = Yajl::Parser.parse(response.to_str)
         rows = hash["rows"]
         count = 0 
         rows.each do |row|
            rows[count] = row["doc"]
            count += 1
          end
        return rows
  rescue => e
     hash = Yajl::Parser.parse(e.response.to_s)
     raise CouchdbException.new(hash), "CouchDB: Error - " + hash.values[0] + ". Reason - "  + hash.values[1]
  end  
end


 class << self
       attr_accessor :address 
       attr_accessor :port 

     def set_address()
      if @address == nil 
         @address = '127.0.0.1'
      end
      if @port == nil
         @port = '5984'
      end 
     end
  end
end