class Web < ActiveRecord::Base
  has_many :pages, :dependent => :destroy
  has_many :wiki_files, :dependent => :destroy

  def wiki
    Wiki.new
  end
  
  def settings_changed?(markup, safe_mode, brackets_only)
    self.markup != markup || 
    self.safe_mode != safe_mode || 
    self.brackets_only != brackets_only
  end
  
  def add_page(name, content, time, author, renderer)
    page = page(name) || Page.new(:web => self, :name => name)
    page.revise(content, name, time, author, renderer)
  end
  
  def authors
    connection.select_all(
        'SELECT DISTINCT r.author AS author ' + 
        'FROM revisions r ' +
        'JOIN pages p ON p.id = r.page_id ' +
        'WHERE p.web_id = ' + self.id.to_s +
        ' ORDER by 1 '
        ).collect { |row| row['author'] }        
  end

  def categories
    select.map { |page| page.categories }.flatten.uniq.sort
  end

  def page(name)
    pages.first(:conditions => ['name = ?', name])
  end
  
  def last_page
    return Page.first(:order => 'id desc', :conditions => ['web_id = ?', self.id])
  end

  def has_page?(name)
    Page.count(:conditions => ['web_id = ? AND name = ?', id, name]) > 0
  end
  
  def has_redirect_for?(name)
     WikiReference.page_that_redirects_for(self, name) 
  end

  def page_that_redirects_for(name)
     page(WikiReference.page_that_redirects_for(self, name))
  end

  def has_file?(file_name)
    WikiFile.find_by_file_name(file_name) != nil
  end
  
  def file_list(sort_order = 'file_name')
    WikiFile.all(:order => sort_order, :conditions => ['web_id = ?', id])
  end

  def pages_that_link_to(page_name)
    WikiReference.pages_that_link_to(self, page_name)
  end

  def pages_that_link_to_file(file_name)
    WikiReference.pages_that_link_to_file(self, file_name)
  end

  def description(file_name)
    file = WikiFile.find_by_file_name(file_name)
    file.description if file
  end

  def markup
    read_attribute('markup').to_sym
  end

  def page_names_by_author
    connection.select_all(
        'SELECT DISTINCT r.author AS author, p.name AS page_name ' +
        'FROM revisions r ' +
        'JOIN pages p ON r.page_id = p.id ' +
        "WHERE p.web_id = #{self.id} " +
        'ORDER by p.name'
    ).inject({}) { |result, row|
        author, page_name = row['author'], row['page_name']
        result[author] = [] unless result.has_key?(author)
        result[author] << page_name
        result
    }
  end

  def remove_pages(pages_to_be_removed)
    pages_to_be_removed.each { |p| p.destroy }
  end
  
  def revised_at
    select.most_recent_revision
  end
    
  def select(&condition)
    PageSet.new(self, pages, condition)
  end
  
  def select_all
    PageSet.new(self, pages, nil)
  end
  
  def to_param
    address
  end
  
  def create_files_directory
    return unless allow_uploads == 1
    dummy_file = self.wiki_files.build(:file_name => '0', :description => '0', :content => '0')
    File.umask(0002)
    dir = File.dirname(dummy_file.content_path)
    begin
      require 'fileutils'
      FileUtils.mkdir_p dir
      dummy_file.save
      dummy_file.destroy
    rescue => e
      logger.error("Failed create files directory for #{self.address}: #{e}")
      raise "Instiki could not create directory to store uploaded files. " +
            "Please make sure that Instiki is allowed to create directory " +
            "#{File.expand_path(dir)} and add files to it."
    end
  end
  
  def files_path
    if default_web?
      "#{RAILS_ROOT}/webs/files"
    else
      "#{RAILS_ROOT}/webs/#{self.address}/files"
    end
  end

  def blahtex_pngs_path
    if default_web?
      "#{RAILS_ROOT}/webs/files/pngs"
    else
      "#{RAILS_ROOT}/webs/#{self.address}/files/pngs"
    end
  end

  private

    # Returns an array of all the wiki words in any current revision
    def wiki_words
      pages.inject([]) { |wiki_words, page| wiki_words << page.wiki_words }.flatten.uniq
    end
    
    # Returns an array of all the page names on this web
    def page_names
      pages.map { |p| p.name }
    end
    
  protected
    before_save :sanitize_markup
    after_save :create_files_directory
    before_validation :validate_address
    validates_uniqueness_of :address
    validates_length_of :color, :in => 3..6
  
    def sanitize_markup
      self.markup = markup.to_s
    end
    
    def validate_address
      unless address == CGI.escape(address)
        self.errors.add(:address, 'should contain only valid URI characters')
        raise Instiki::ValidationError.new("#{self.class.human_attribute_name('address')} #{errors.on(:address)}")
      end
    end
    
    def default_web?
      defined? DEFAULT_WEB and self.address == DEFAULT_WEB
    end
end