module AsProject
  #######################################
  # TemplateResolver
  class TemplateResolver < Hash
    attr_accessor :replace_all, :ignore_all
    @@ASPROJECT_FILE_NAME = 'AsProject'
    @@RENDER_IGNORE_FILES = ['asclass_config.rb']
    
    def initialize
      @replace_all = false
      @ignore_all = false
    end
    
    def copy_files(from, to, render=false)
      created_files = Array.new
      if(!File.exists? from)
        raise ProjectError.new('AsProject attempted to copy files from (' + from + ') but it does not exist...')
      end
      if(File.directory? from)
        Dir.open(from).each do |filename|
          if(!AsProject.ignore_file? filename)
            fullname = File.join(from, filename)
            new_fullname = File.join(to, filename)
            cleaned_filename = clean_file_name(filename)
            cleaned_fullname = File.join(to, cleaned_filename)
            if(File.directory? fullname)
              Dir.mkdir(new_fullname) unless File.exists? new_fullname
              copy_files(fullname, new_fullname, render).each do |file|
                created_files << file
              end
            else
              file = copy_file(fullname, cleaned_fullname, render)
              if(file)
                created_files << file
              end
            end
          end
        end
      else
        raise ProjectError.new("copy_files called with a file (" + from + ") instead of a directory!")
      end
      return created_files
    end
    
    def copy_file(from, to, render=false)
      if(write_file?(to))
        content = File.open(from, 'r').read
        parts = to.split(File::SEPARATOR)
        parts.pop
        File.makedirs(parts.join(File::SEPARATOR))
        target = File.open(to, 'w')
        if(render && should_render?(from))
          begin
            content = ERB.new(content, nil, '>').result(binding)
          rescue NameError => e
            puts '>> Template ' + from + ' references a value that is not defined'
            raise e
          end
        end
        target.write(content)
        target.close
        return to
      end
      return nil
    end
    
    def should_render?(file)
      if(@@RENDER_IGNORE_FILES.index(File.basename(file)))
        return false
      end
      return true
    end
    
    def write_file?(file)
      if(!File.exists?(file))
        return true
      elsif(@replace_all)
        File.delete(file)
        return true
      elsif(@ignore_all)
        return false
      end

      relative = file.gsub(Dir.pwd, '')
      msg = <<EOF

AsProject Encountered an existing file at [#{relative}], what would you like to do?
(r)eplace, (i)gnore, (R)eplace all or (I)gnore all?

EOF
      puts msg
      answer = gets.chomp!
      if(answer == 'r')
        return true
      elsif(answer == 'i')
        return false
      elsif(answer == 'R')
        msg = <<EOF
        
Are you sure you want to replace ALL duplicate files?
(y)es or (n)o

EOF
        puts msg
        answer = gets.chomp!
        if(answer == 'y')
          @replace_all = true
        else
          write_file?(file)
        end
      elsif(answer == 'I')
        @ignore_all = true
        return false
      else
        puts "I didn't understand that response... Please choose from the following choices:\n\n"
        write_file?(file)
      end
    end
    
    def render_file filename
      file = File.open(filename, 'r')
      resolved = ERB.new(file.read, nil, '>').result(binding)
      file.close
      file = File.open(filename, 'w')
      file.write(resolved)
      file.close
    end
    
    def clean_file_name name
      return name.gsub(@@ASPROJECT_FILE_NAME, project_name)
    end
    
    # Override in subclasses!
    def project_name
      return @@ASPROJECT_FILE_NAME
    end
    
    #TODO: Figure out if the file is plain text or not... Possible?
    def file_is_binary? file
      return false
    end
  end
end