module Xmvc
  module Generator
    
    class EnvironmentError < Xmvc::Error; status_code(11) ; end
    
    class Base
      
      TEMPLATE_PATH = "#{File.dirname(__FILE__)}/templates"
                              
      def initialize *args
        @gsubs ||= {}
        @gsubs['namespace']  = Xmvc.environment['namespace']
      end

      protected
      def ensure_directories_present! *args
        args.each do |a|
          Dir.mkdir(a) unless File.exists?(a)
        end
      end

      def ensure_no_overwrite! *args
        args.each do |a|
          if File.exists?(a) && !ARGV.include?("--force")
            raise Xmvc::FileExists.new("File already exists: #{a}")
          end
        end
      end

      def template(template_filename, destination_filename)
        #write the file
        File.open(destination_filename, 'w') {|f| f.puts(render_template(template_filename))}

        Xmvc.ui.confirm(" Created #{destination_filename}")
      end

      def render_template(template_filename, gsubs = @gsubs)
        #grab the template file text
        template_text = IO.read("#{TEMPLATE_PATH}/#{template_filename}")

        #translate the template file text
        gsubs.each_pair do |key, value|
          template_text.gsub!(Regexp.new("<%= @#{key} %>"), value)
        end

        template_text
      end

      def include_script html_filename, script_filename, dom_id

      end
      
    private
    
      ##
      # write a newly generated controller, model or view to environment.json
      # Unfortunately, we cannot JSON.parse the entire config/environment.json, since it contains comments
      # and such.  Have to RegExp, pick-out the requested key, and JSON.parse the returned chunk.
      # Is this Regexp satisfactory??  Could probably be made better.
      #
      def to_environment(key, item)
        re      = Regexp.new("\"#{key}\"\s*\:\s*(\\[.*?\\](?!\}))", Regexp::MULTILINE)
        content = File.read('config/environment.json')  
        m = content.match(re)
        if m
          begin
            items = JSON.parse("#{m[1].strip}")
          rescue StandardError => e
            raise EnvironmentError.new("A JSON parsing error occured parsing config/environment.json.  Failed to add #{key} to environment.json.")
          end
          
          if item.kind_of?(Hash)  # <-- it's a view              
            view = items.find {|i| i[item[:package]] }
            if view
              view[item[:package]] << item[:filename]
            else 
              items << { item[:package] => [item[:filename]]}
            end
          else
            items << item unless items.include?(item)
          end
          File.open('config/environment.json', "w") do |file|
            file << content.gsub(re, "\"#{key}\": #{items.to_json}")
          end
        end
      end
      
    end
  end
end