module AssetSync
  class Config
    include ActiveModel::Validations

    class Invalid < StandardError; end

    # AssetSync
    attr_accessor :existing_remote_files # What to do with your existing remote files? (keep or delete)
    attr_accessor :gzip_compression
    attr_accessor :manifest
    attr_accessor :fail_silently
    attr_accessor :always_upload
    attr_accessor :ignored_files
    attr_accessor :prefix
    attr_accessor :public_path
    attr_accessor :enabled

    # FOG configuration
    attr_accessor :fog_provider          # Currently Supported ['AWS', 'Rackspace']
    attr_accessor :fog_directory         # e.g. 'the-bucket-name'
    attr_accessor :fog_region            # e.g. 'eu-west-1'

    # Amazon AWS
    attr_accessor :aws_access_key_id, :aws_secret_access_key

    # Rackspace
    attr_accessor :rackspace_username, :rackspace_api_key, :rackspace_auth_url

    # Google Storage
    attr_accessor :google_storage_secret_access_key, :google_storage_access_key_id

    validates :existing_remote_files, :inclusion => { :in => %w(keep delete ignore) }

    validates :fog_provider,          :presence => true
    validates :fog_directory,         :presence => true

    validates :aws_access_key_id,     :presence => true, :if => Proc.new{|f| f.aws? && !Fog.credentials[:aws_access_key_id]}
    validates :aws_secret_access_key, :presence => true, :if => Proc.new{|f| f.aws? && !Fog.credentials[:aws_secret_access_key]}
    validates :rackspace_username,    :presence => true, :if => :rackspace?
    validates :rackspace_api_key,     :presence => true, :if => :rackspace?
    validates :google_storage_secret_access_key,  :presence => true, :if => :google?
    validates :google_storage_access_key_id,      :presence => true, :if => :google?

    def initialize
      self.fog_region = nil
      self.existing_remote_files = 'keep'
      self.gzip_compression = false
      self.manifest = false
      self.fail_silently = false
      self.always_upload = []
      self.ignored_files = []
      self.enabled = true
      load_yml! if defined?(Rails) && yml_exists?
    end

    def manifest_path
      directory =
        Rails.application.config.assets.manifest || default_manifest_directory
      File.join(directory, "manifest.yml")
    end

    def gzip?
      self.gzip_compression
    end

    def existing_remote_files?
      ['keep', 'ignore'].include?(self.existing_remote_files)
    end

    def aws?
      fog_provider == 'AWS'
    end

    def fail_silently?
      fail_silently == true
    end

    def enabled?
      enabled == true
    end

    def rackspace?
      fog_provider == 'Rackspace'
    end

    def google?
      fog_provider == 'Google'
    end

    def yml_exists?
      File.exists?(self.yml_path)
    end

    def yml
      begin
        @yml ||= YAML.load(ERB.new(IO.read(yml_path)).result)[Rails.env] rescue nil || {}
      rescue Psych::SyntaxError
        @yml = {}
      end
    end

    def yml_path
      Rails.root.join("config", "asset_sync.yml").to_s
    end

    def assets_prefix
      # Fix for Issue #38 when Rails.config.assets.prefix starts with a slash
      self.prefix || Rails.application.config.assets.prefix.sub(/^\//, '')
    end

    def public_path
      @public_path || Rails.public_path
    end

    def load_yml!
      self.enabled               = yml["enabled"] if yml.has_key?('enabled')
      self.fog_provider          = yml["fog_provider"]
      self.fog_directory         = yml["fog_directory"]
      self.fog_region            = yml["fog_region"]
      self.aws_access_key_id     = yml["aws_access_key_id"]
      self.aws_secret_access_key = yml["aws_secret_access_key"]
      self.rackspace_username    = yml["rackspace_username"]
      self.rackspace_auth_url    = yml["rackspace_auth_url"] if yml.has_key?("rackspace_auth_url")
      self.rackspace_api_key     = yml["rackspace_api_key"]
      self.google_storage_secret_access_key = yml["google_storage_secret_access_key"]
      self.google_storage_access_key_id     = yml["google_storage_access_key_id"]
      self.existing_remote_files  = yml["existing_remote_files"] if yml.has_key?("existing_remote_files")
      self.gzip_compression       = yml["gzip_compression"] if yml.has_key?("gzip_compression")
      self.manifest               = yml["manifest"] if yml.has_key?("manifest")
      self.fail_silently          = yml["fail_silently"] if yml.has_key?("fail_silently")
      self.always_upload          = yml["always_upload"] if yml.has_key?("always_upload")
      self.ignored_files          = yml["ignored_files"] if yml.has_key?("ignored_files")

      # TODO deprecate the other old style config settings. FML.
      self.aws_access_key_id      = yml["aws_access_key"] if yml.has_key?("aws_access_key")
      self.aws_secret_access_key  = yml["aws_access_secret"] if yml.has_key?("aws_access_secret")
      self.fog_directory          = yml["aws_bucket"] if yml.has_key?("aws_bucket")
      self.fog_region             = yml["aws_region"] if yml.has_key?("aws_region")

      # TODO deprecate old style config settings
      self.aws_access_key_id      = yml["access_key_id"] if yml.has_key?("access_key_id")
      self.aws_secret_access_key  = yml["secret_access_key"] if yml.has_key?("secret_access_key")
      self.fog_directory          = yml["bucket"] if yml.has_key?("bucket")
      self.fog_region             = yml["region"] if yml.has_key?("region")
    end


    def fog_options
      options = { :provider => fog_provider }
      if aws?
        options.merge!(:aws_access_key_id => aws_access_key_id) if aws_access_key_id
        options.merge!(:aws_secret_access_key => aws_access_key_id) if aws_secret_access_key
      elsif rackspace?
        options.merge!({
          :rackspace_username => rackspace_username,
          :rackspace_api_key => rackspace_api_key
        })
        options.merge!({ :rackspace_auth_url => rackspace_auth_url }) if rackspace_auth_url
      elsif google?
        options.merge!({
          :google_storage_secret_access_key => google_storage_secret_access_key,
          :google_storage_access_key_id => google_storage_access_key_id
        })
      else
        raise ArgumentError, "AssetSync Unknown provider: #{fog_provider} only AWS and Rackspace are supported currently."
      end

      options.merge!({:region => fog_region}) if fog_region
      return options
    end

  private

    def default_manifest_directory
      File.join(Rails.public_path, assets_prefix)
    end
  end
end
