#
# A basic function to retrieve data in couchdb
#


module Puppet::Parser::Functions
  newfunction(:couchdblookup, :type => :rvalue) do |args|
    require 'json'
    require 'open-uri'

    url = args[0]
    key = args[1]

    raise Puppet::ParseError, ("couchdblookup(): wrong number of arguments (#{args.length}; must be == 2)") if args.length != 2

    begin
      json = JSON.parse(open(URI.parse(url)).read)
    rescue OpenURI::HTTPError => error
      raise Puppet::ParseError, "couchdblookup(): fetching URL #{url} failed with status #{error.message}"
    end

    result = nil

    if json.has_key?("rows")

      if json['rows'].length > 1
        arr = json['rows'].collect do |x|
          x[key] if x.is_a?(Hash) and x.has_key?(key)
        end
        arr.compact!
        result = arr unless arr.empty?

      elsif json['rows'].length == 1
        hash = json['rows'].pop
        result = hash[key] if hash.is_a?(Hash)
      end

    elsif json.has_key?(key)
      result = json[key]
    end

    result or raise Puppet::ParseError, "couchdblookup(): key '#{key}' not found in JSON object !"

  end
end