require 'paperclip'
require 'cms/attachments/attachment_serving'

module Cms
  # Cms::Attachments::Configuration exposes an interface to setup paperclip for BrowserCMS.
  #
  # Provides defaults that are suitable for the CMS and that probably make sense for most installations.
  #
  #This module also declares Paperclip interpolations that are used
  #to construct the default url and path.
  #
  # For example, the default path:
  #
  # ":attachments_root/:id_partition/:style/:fingerprint"
  #
  # expands to something like:
  #
  #  #{Rails.root}/tmp/uploads/2011/1/30/thumb/thcu098rc87dgd
  #
  # but can be changed by using paperclip interpolations, either
  # the ones already defined by Paperlip itself, the Cms::Assets
  # module, or user defined.
  module Attachments
    mattr_accessor :configuration

    def self.configure
      configuration = self.configuration
      yield configuration if block_given?
      @@configuration = configuration
      Attachment.configure_paperclip
    end

    def self.configuration
      @@configuration || Configuration.new
    end

    # Allows each Attachment to have a customized configuration, even though there is a single Attachment class.
    # Designed to allow 'typical' Paperclip configuration to be specified per attachment.
    class Configuration
      attr_accessor :url, :path, :styles, :processors, :default_url, :default_style, :storage, :whiny
      attr_accessor :s3_credentials, :bucket
      attr_accessor :file_permissions

      attr_reader :use_timestamp

      # Set default configurations for Attachments.
      def initialize
        self.url = Rails.configuration.cms.attachments[:url] || ":attachment_file_path"
        self.path = ":attachments_root/:id_partition/:style/:fingerprint"
        self.styles = {}
        self.processors = [:thumbnail]
        self.default_url = "/:attachment/:style/missing.png"
        self.default_style = :original
        self.storage = :filesystem
        self.whiny = false

        @use_timestamp = false
      end
    end


    # This is the typical url for attachments
    # Some attachments will have a custom path (data_file_path) specified by users
    # while others will just be 'defaults'. This dynamically returns path at runtime based
    # on the instance of the specific instance.
    Paperclip.interpolates :attachment_file_path do |asset, style|
      path = asset.instance.data_file_path
      unless path
        path = "/attachments/#{asset.instance.id}/#{asset.instance.data_file_name}"
      end
      if style && style != :original
        "#{path}?style=#{style}"
      else
        path
      end
    end

    Paperclip.interpolates :attachments_root do |_, _|
      strategy = Cms::Attachments::Serving.send_attachments_with
      strategy.attachments_storage_location
    end

    Paperclip.interpolates :full_filename do |asset, _|
      "#{asset.instance.content_block_class}_#{asset.instance.data_file_name}"
    end

  end
end