module Zafu
  module Calendar

    def r_calendar
      if @context[:block] == self
        # called from self (storing template / rendering)
        if role = @params[:assign_as]
          assign_calendar(role)
        else
          display_calendar
        end
      else
        # This is called first to prepare calendar
        if @params[:assign_as]
          fld = 'date'
          table_name = 'links'
        else
          fld = @params[:date] || 'event_at'
          if ['log_at', 'created_at', 'updated_at', 'event_at'].include?(fld) # TODO: use rubyless to learn type
            table_name = 'nodes'
          elsif fld == 'l_date'
            fld = 'date'
            table_name = 'links'
          else
            return parser_error("Invalid 'date' value for calendar (#{fld.inspect}).")
          end
        end

        @date_scope = "TABLE_NAME[#{table_name}].#{fld} >= '\#{start_date.strftime('%Y-%m-%d')}' AND TABLE_NAME[#{table_name}].#{fld} <= '\#{end_date.strftime('%Y-%m-%d')}'"

        new_dom_scope

        # SAVED TEMPLATE
        template = expand_block(self, :block => self, :saved_template => true)
        out helper.save_erb_to_url(template, template_url)

        # INLINE
        out expand_block(self, :block => self, :saved_template => false)
      end
    end

    private
      def display_calendar
        size     = (params[:size]  || 'large').to_sym
        finder   = params[:select] || 'notes in project'

        if @blocks == []
          # add a default <r:link/> block
          if size == :tiny
            @blocks = [make(:void, :method=>'void', :text=>"<em do='link' date='current_date' do='[current_date]' format='%d'/><r:else do='[current_date]' format='%d'/>")]
          else
            @blocks = [make(:void, :method=>'void', :text=>"<span do='show' date='current_date' format='%d'/><ul><li do='each' do='link' attr='name'/></ul><r:else do='[current_date]' format='%d'/>")]
          end
          remove_instance_variable(:@all_descendants)
        elsif !descendant('else')
          @blocks += [make(:void, :method=>'void', :text=>"<r:else do='[current_date]' format='%d'/>")]
          remove_instance_variable(:@all_descendants)
        end

        @html_tag_done = false
        @html_tag_params[:id] = erb_dom_id
        @html_tag_params[:class] ||= "#{size}cal"
        @html_tag ||= 'div'

        finder, klass = build_finder_for(:all, finder, @params, [@date_scope])
        return unless finder
        return parser_error("invalid class (#{klass})") unless klass.ancestors.include?(Node)

        cell_code = "<% if #{list_var} = nodes_#{list_var}[cal_#{list_var}.strftime('%Y-%m-%d %H')] -%>#{expand_with(:in_if => true, :list => list_var, :date => "cal_#{list_var}", :saved_template => nil, :dom_prefix => nil, :in_calendar => true)}<% end -%>"

        render_html_tag(calendar_code(finder, "", cell_code, "", params))
      end

      # manage links from @node ---- reference ----> ...
      # <div do='calendar' assign='reference' to='main' split_hours='12' />
      def assign_calendar(as_role)
        size = (params[:size]  || 'large').to_sym
        @html_tag_done = false
        @html_tag_params[:id] = erb_dom_id
        @html_tag_params[:class] ||= "#{size}cal"
        @html_tag ||= 'div'
        if rel = RelationProxy.find_by_role(as_role.singularize)
          role = rel.this_role
        else
          return parser_error("Invalid role #{as_role.inspect}.")
        end
        finder, klass = build_finder_for(:all, role, @params, [@date_scope])
        return unless finder
        return parser_error("invalid class (#{klass})") unless klass.ancestors.include?(Node)

        # SAVED TEMPLATE ========
        template_url  = self.template_url + 'cell'
        template      = "<%= cal_assign_cell(@node, #{role.inspect}, #{@params[:used].inspect}) %>"
        out helper.save_erb_to_url(template, template_url)

        # we call update on node 'B'
        # A (main)
        # ... B (other node)
        #     calendar (in B context) ---- role --->

        cell_prefix_code = "<span><%= day_#{list_var}.strftime('%d').to_i -%></span><ul>"
        cell_code = "<%= #{list_var} = nodes_#{list_var}[cal_#{list_var}.strftime('%Y-%m-%d %H')]; #{node}.linked_node = #{list_var} ? #{list_var}.first : nil; cal_assign_cell(#{node}, #{role.inspect}, #{@params[:used].inspect}, params[:s] || @node.zip, cal_#{list_var}, #{template_url.inspect}) %>"
        cell_postfix_code = "</ul>"
        render_html_tag(calendar_code(finder, cell_prefix_code, cell_code, cell_postfix_code, params))
      end

      def calendar_code(finder, cell_prefix_code, cell_code, cell_postfix_code, params)
        type = params[:type] ? params[:type].to_sym : :month
        size = (params[:size] || 'large').to_sym
        ref_date = params[:assign_as] ? 'l_date' : (params[:date] || 'event_at')

        case type
        when :month
          title = "\"\#{_(Date::MONTHNAMES[main_date.mon])} \#{main_date.year}\""
          prev_date = "\#{main_date.advance(:months => -1).strftime(\"%Y-%m-%d\")}"
          next_date = "\#{main_date.advance(:months =>  1).strftime(\"%Y-%m-%d\")}"
        when :week
          title = "\"\#{_(Date::MONTHNAMES[main_date.mon])} \#{main_date.year}\""
          prev_date = "\#{main_date.advance(:days => -7).strftime(\"%Y-%m-%d\")}"
          next_date = "\#{main_date.advance(:days => +7).strftime(\"%Y-%m-%d\")}"
        else
          return parser_error("invalid type (should be 'month' or 'week')")
        end

        if hours = @params[:split_hours]
          hours = hours.split(',').map{|l| l.to_i}
          hours << 0
          hours = hours.uniq.sort
          # I feel all this would be much better if we could use "each_group" but then how do we access hours ?
          week_code = "<% week.step(week+6,1) do |day_#{list_var}| -%>
          <td<%= cal_class(day_#{list_var},#{current_date}) %>>#{cell_prefix_code}<% #{hours.inspect}.each do |set_hour|; cal_#{list_var} = Time.utc(day_#{list_var}.year,day_#{list_var}.month,day_#{list_var}.day,set_hour) -%>#{cell_code}<% end -%>#{cell_postfix_code}</td>
          <% end -%>"
          (@context[:vars] ||= []) << "hour"
        else
          hours = nil
          week_code = "<% week.step(week+6,1) do |day_#{list_var}| -%>
          <td<%= cal_class(day_#{list_var},#{current_date}) %>><% cal_#{list_var} = Time.utc(day_#{list_var}.year,day_#{list_var}.month,day_#{list_var}.day) -%>#{cell_prefix_code}#{cell_code}#{cell_postfix_code}</td>
          <% end -%>"
        end

        res = <<-END_TXT
<h3 class='title'>
<span><%= link_to_remote(#{_('img_prev_page').inspect}, :url => #{base_class.to_s.underscore}_path(#{node_id}) + \"/zafu?t_url=#{CGI.escape(template_url)}&dom_id=#{dom_id}&date=#{prev_date}&#{start_node_s_param(:string)}\", :method => :get) %></span>
<span class='date'><%= link_to_remote(#{title}, :url => #{base_class.to_s.underscore}_path(#{node_id}) + \"/zafu?t_url=#{CGI.escape(template_url)}&dom_id=#{dom_id}&#{start_node_s_param(:string)}\", :method => :get) %></span>
<span><%= link_to_remote(#{_('img_next_page').inspect}, :url => #{base_class.to_s.underscore}_path(#{node_id}) + \"/zafu?t_url=#{CGI.escape(template_url)}&dom_id=#{dom_id}&date=#{next_date}&#{start_node_s_param(:string)}\", :method => :get) %></span>
</h3>
<table cellspacing='0' class='#{size}cal#{@params[:assign_as] ? " assign" : ''}'>
<tr class='head'><%= cal_day_names(#{size.inspect}) %></tr>
<% start_date, end_date = cal_start_end(#{current_date}, #{type.inspect}) -%>
<% cal_weeks(#{ref_date.to_sym.inspect}, #{finder}, start_date, end_date, #{hours.inspect}) do |week, nodes_#{list_var}| -%>
<tr class='body'>
#{week_code}
</tr>
<% end -%>
</table>
        END_TXT
      end
  end # Calendar
end # Zafu