class AddEarthdistance

# File lib/generators/magic_addresses/templates/earthdistance_migration.rb, line 49
def self.down
  # => execute "DROP EXTENSION IF EXISTS earthdistance"
  # => execute "DROP EXTENSION IF EXISTS cube"
  # comented out in staging and production to avoid PG::InsufficientPrivilege-ERROR .. add with cap postgresql:remove_extensions
  if Rails.env.development? || Rails.env.test?
    disable_extension "earthdistance"
    disable_extension "cube"
  end
  
  
  if get_indexes_for_table('mgca_addresses').include?("mgca_addresses_earthdistance_ix")
    remove_earthdistance_index :mgca_addresses
  end
  
  ## remove from Job
  # => if get_indexes_for_table('jobs').include?("jobs_earthdistance_ix")
  # =>   remove_earthdistance_index :jobs
  # => end
  # => remove_column :jobs,      :latitude,    :float
  # => remove_column :jobs,      :longitude,   :float
  
  
end

# File lib/generators/magic_addresses/templates/earthdistance_migration.rb, line 10
def self.up
  
  # comented out to avoid PG::InsufficientPrivilege-ERROR
  # add with cap postgresql:add_extensions
  # => execute "CREATE EXTENSION IF NOT EXISTS cube"
  # => execute "CREATE EXTENSION IF NOT EXISTS earthdistance"
  
  if Rails.env.development? || Rails.env.test?
    enable_extension "cube"
    enable_extension "earthdistance"
  end
  
  unless get_indexes_for_table('mgca_addresses').include?("mgca_addresses_earthdistance_ix")
    add_earthdistance_index :mgca_addresses, lat: 'latitude', lng: 'longitude'
  end
  
  
  ## Want to add indexes to other models?
  ## -- Model needs this mehtod
  ##       acts_as_geolocated lat: 'latitude', lng: 'longitude')
  ##
  ## i.e.: Job-model:
  ##
  # => add_column :jobs,   :latitude,      :float
  # => add_column :jobs,   :longitude,     :float
  # => Job.all.each do |that|
  # =>   if that.address && that.address.latitude && that.address.longitude
  # =>     that.latitude   = that.address.latitude
  # =>     that.longitude  = that.address.longitude
  # =>     that.save(:validate => false)
  # =>   end
  # => end
  # => unless get_indexes_for_table('jobs').include?("jobs_earthdistance_ix")
  # =>   add_earthdistance_index :jobs, lat: 'latitude', lng: 'longitude'
  # => end
  
  
end

# File lib/generators/magic_addresses/templates/earthdistance_migration.rb, line 2
def get_indexes_for_table( table = 'mgca_addresses' )
  ## ActiveRecord indexes .. doesnt include earthdistance, because its build directly in postgres!
  # => ActiveRecord::Base.connection.indexes(:mgca_addresses).map{ |x| x.name }
  # => index_exists?(:mgca_addresses, :earthdistance, name: "mgca_addresses_earthdistance_ix")
  ## Postgres-Indexes .. thanks to: http://www.alberton.info/postgresql_meta_info.html#p13
  execute( "SELECT c.relname AS index_name FROM pg_class AS a JOIN pg_index AS b ON (a.oid = b.indrelid) JOIN pg_class AS c ON (c.oid = b.indexrelid) WHERE a.relname = '#{table}';").map{ |that| that["index_name"] }
end