module PostSets
  class Post < Base
    class Error < Exception ; end
  
    attr_accessor :tags, :errors, :count
    attr_accessor :wiki_page, :artist, :suggestions
  
    def initialize(tags, options = {})
      super(options)
      @tags = Tag.normalize(tags)
      @errors = []
      load_associations
      load_suggestions
      validate
    end
    
    def has_wiki?
      is_single_tag?
    end
    
    def has_errors?
      errors.any?
    end
  
    def offset
      x = (page - 1) * limit
      if x < 0
        x = 0
      end
      x
    end
  
    def limit
      Danbooru.config.posts_per_page
    end
  
    def is_single_tag?
      tag_array.size == 1
    end
  
    def date_tag
      tag_array.grep(/date:/).first
    end
  
    def load_associations
      if is_single_tag?
        @wiki_page = WikiPage.find_by_title(tags)
        @artist = Artist.find_by_name(tags)
      end
    end
  
    def load_posts
      @count = Post.fast_count(tags)
      @posts = Post.find_by_tags(tags, :before_id => before_id).all(:order => "posts.id desc", :limit => limit, :offset => offset)
    end
  
    def load_suggestions
      if count < limit && is_single_tag?
        @suggestions = Tag.find_suggestions(tags)
      else
        @suggestions = []
      end
    end
  
    def tag_array
      @tag_array ||= Tag.scan_query(tags)
    end
  
    def validate
      validate_page
      validate_query_count
    rescue Error => x
      @errors << x.to_s
    end
  
    def validate_page
      if page > 1_000
        raise Error.new("You cannot explicitly specify the page after page 1000")
      end
    end
  
    def validate_query_count
      if !CurrentUser.is_privileged? && tag_array.size > 2
        raise Error.new("You can only search up to two tags at once with a basic account")
      end
    
      if tag_array.size > 6
        raise Error.new("You can only search up to six tags at once")
      end
    end
  end
end