class Attachment < ActiveRecord::Base
  set_table_name 'uploads'
  attr_accessor :temp_file # this is for holding the file field reference during the creation process.
  before_create {|a| a.uploaded ||= Time.now}
  before_create :backwards_compat
  #after_create :save_file
  after_destroy :delete_file

  has_and_belongs_to_many :tags, :join_table => 'upload_tags', :foreign_key => 'upload_id', :uniq => true
  belongs_to :attachable, :polymorphic => true
  belongs_to :user

  named_scope :having_any_tags, lambda {|tags|
    {:include => [:tags],:conditions=>{:tags => {:name => tags}}}
  }

  #validates_presence_of :file, :on => :create
  validates_presence_of :name, :origin, :attachable_type, :attachable_id
  validates_associated :user

  def self.update_to_new
    att = find(:all)
    att.each do |a|
      spl = a.relation.split '_'
      a.attachable_type = spl[0]
      a.attachable_id = spl[1]
      a.save
    end
  end

  # This is a virtual field that will recieve the file info from the controller.
  def file=(file_field)
    self.file_name = sanitize_filename(file_field.original_filename)
    self.mime_type = file_field.content_type.chomp
    self.file_size = file_field.size.to_i
    # store the file field in temp_file for later processing.
    self.temp_file = file_field
  end
  def file
    self.temp_file
  end

  def full_path
    config = (AppConfig.uploads || {})
    config['dir'] + self.url_path
  end

  def get_resized_image(width,height)
    require 'RMagick'
    valid_formats = ["image/bmp", "image/gif", "image/jpeg", "image/pipeg", "image/tiff", "image/png"]
    raise "Attachment is not a valid image." unless valid_formats.include? self.mime_type
    cached_file = AppConfig.image_resizing['cache_dir'] + "#{self.id}/#{width}x#{height}/#{self.file_name}"
    unless File.exists? cached_file
      # resize image
      img = Magick::Image.read(self.full_path).first
      new_width = width || height
      new_height = height || width

      if width.blank? or height.blank?
        # make image fit the height or width
        img.resize_to_fit!(new_width.to_f,new_height.to_f)
      else
        # make image fill height and width, (that means crop if necessary.)
        img.resize_to_fill!(new_width.to_f,new_height.to_f)
      end
      FileUtils.mkdir_p File.dirname(cached_file)
      img.write(cached_file)
    end
    cached_file
  end

  # clean extraction of filename
  protected
  def sanitize_filename(file_name)
    # get only the filename, not the whole path (from IE)
    just_filename = File.basename(file_name)
    # replace all non alphanumeric, underscore or perioids with underscore
    just_filename.gsub(/[^\w\.\_]/,'_')
  end
  def backwards_compat
    self.relation = self.attachable_type + '_' + self.attachable_id.to_s
  end
  def save_file
    return false unless self.temp_file
    config = (AppConfig.uploads || {}).symbolize_keys
    self.url_path = "#{self.attachable_type}/#{self.attachable_id}/#{self.id}_#{self.file_name}"
    self.file_system_path = self.url_path.gsub(/\//,'\\') # .NET likes backslashes for file paths (Backwards compat)
    FileUtils.mkdir_p config[:dir] + File.dirname(self.url_path)
    FileUtils.copy(self.temp_file.local_path, config[:dir] + '/' + self.url_path)
    self.save!
  end
  def delete_file
    FileUtils.remove(self.full_path) if File.exists? self.full_path
  end
end