module ActiveGrid
  class Grid
    attr_reader :columns, :name, :options, :partial, :scope, :view
    attr_accessor :block

    def initialize(view, name, scope, partial, options = {})
      @columns = []
      @view, @name, @scope, @partial, @options = view, name, scope, partial, options

      self.view._activegrid = self
      self.view.render(partial)
    end

    def header
      mode :header do
        view.content_tag(:tr, view.capture(self, nil, &block))
      end
    end

    def filters
      mode :filter do
        view.content_tag(:tr, view.capture(self, nil, &block))
      end
    end

    def body
      mode :body do
        models.map do |model|
          view.content_tag(:tr, view.capture(self, model, &block))
        end.reduce(:<<)
      end
    end

    def column(name, options = {}, &block)
      column = Column.new(view, name, options, &block)

      case mode
      when :header
        columns << column
        view.content_tag(:th, column.header, column.tag_options)
      when :filter
        view.content_tag(:th, column.filter)
      when :body
        view.content_tag(:td, column.value)
      end
    end

    def mode(value = nil, &block)
      if value
        begin
          old_mode, @mode = @mode, value
          yield
        ensure
          @mode = old_mode
        end
      else
        @mode
      end
    end

    def models
      if paginate = options[:paginate]
        scope.limit(paginate)
      else
        scope
      end
    end

    def tag_options
      tag_options = {}
      tag_options["id"] = "#{name}_grid"
      tag_options["class"] = "activegrid"
      tag_options["data-activegrid"] = true
      tag_options["data-activegrid-name"] = name

      if options[:paginate]
        tag_options["data-activegrid-pages"] = (scope.count / options[:paginate].to_f).ceil
        tag_options["data-activegrid-paginate"] = options[:paginate]
      end

      tag_options
    end

    def to_html
      view.content_tag(:table, tag_options) do
        view.content_tag(:thead, header << filters) << view.content_tag(:tbody, body)
      end
    end
  end
end