module RedminePublications
  # Patches Redmine's Issues dynamically. Adds a +after_save+ filter.

  module IssuePatch
    def self.included(base) # :nodoc:
      base.extend(ClassMethods)
 
      base.send(:include, InstanceMethods)
 
      # Same as typing in the class
      base.class_eval do
        unloadable # Send unloadable so it will not be unloaded in development
 
        validate :check_relations
        after_save :update_relations
      end
 
    end
    
    module ClassMethods
    end
    
    module InstanceMethods

      def publication_names	
        if not @pubnames
          self.publications.map { |pub| pub.name }
        else
          @pubnames
        end
      end

      def publication_names=(value)
        @pubnames = value.sort!
      end

      def publications
        Publication.all( 
          :joins =>
            "JOIN issue_publications ON (issue_publications.publication_id = publications.id)",
          :conditions =>
            ["issue_publications.issue_id = ? ", self.id] )
      end

      def check_relations
        current_names = self.publication_names
        non_existant = []

        pubs =  Publication.find_all_by_name(current_names).map {|i| i.name}
        missing = current_names.select {|name| not pubs.include?name }

        if not missing.empty?
          errors.add("publications", "Missing publication(s): " + missing.join(', '))
        end
      end

      def update_relations
        old = self.publications
        current_names = self.publication_names
        Rails.logger.info('[INFO] Updating relations: old= ' << old.inspect << ' current=' << current_names.inspect)

        # delete unused relations
        deleted = old.select { |v| not (current_names.include?(v.name)) }
        deleted.each do |pub|
          IssuePublication.delete_all(["issue_publications.issue_id = ? AND issue_publications.publication_id = ?", self.id, pub.id])
        end

        current_names.each do |name|
          pub = Publication.find_by_name(name)
          IssuePublication.find_or_create_by_publication_id_and_issue_id(pub.id, self.id)
        end

        return true
      end

    end
  end
end