require 'open3'
require 'opener/core'

require_relative 'polarity_tagger/version'
require_relative 'polarity_tagger/cli'

module Opener
  ##
  # Ruby wrapper around the Python based polarity tagger.
  #
  # @!attribute [r] options
  #  @return [Hash]
  #
  class PolarityTagger
    attr_reader :options, :args

    ##
    # @param [Hash] options
    #
    # @option options [Array] :args Collection of arbitrary arguments to pass
    #  to the underlying kernel.
    #
    def initialize(options = {})
      @args    = options.delete(:args) || []
      @options = options
    end

    ##
    # Returns a String containing the command to use for executing the kernel.
    #
    # @return [String]
    #
    def command
      return "#{adjust_python_path} python -E -OO #{kernel} #{lexicon_path} #{args.join(" ")}"
    end

    def lexicon_path
      if path = options[:resource_path]
        return "--lexicon-path #{path}"
      elsif path = ENV['POLARITY_LEXICON_PATH']
        return "--lexicon-path #{path}"
      else
        return nil
      end
    end

    ##
    # Processes the input and returns an Array containing the output of STDOUT,
    # STDERR and an object containing process information.
    #
    # @param [String] input The text of which to detect the language.
    # @return [Array]
    #
    def run(input)
      begin
        stdout, stderr, process = capture(input)
        raise stderr unless process.success?
        return stdout
      rescue Exception => error
        return Opener::Core::ErrorLayer.new(input, error.message, self.class).add
      end
    end

    protected
    ##
    # @return [String]
    #
    def adjust_python_path
      site_packages =  File.join(core_dir, 'site-packages')
      "env PYTHONPATH=#{site_packages}:$PYTHONPATH"
    end

    ##
    # capture3 method doesn't work properly with Jruby, so
    # this is a workaround
    #
    def capture(input)
      Open3.popen3(*command.split(" ")) {|i, o, e, t|
        out_reader = Thread.new { o.read }
        err_reader = Thread.new { e.read }
        i.write input
        i.close
        [out_reader.value, err_reader.value, t.value]
      }
    end

    ##
    # @return [String]
    #
    def core_dir
      return File.expand_path('../../../core', __FILE__)
    end

    ##
    # @return [String]
    #
    def kernel
      return File.join(core_dir, 'poltagger-basic-multi.py')
    end
  end # PolarityTagger
end # Opener