require 'pathname'
require 'dandelion/utils'

module Dandelion
  module Adapter
    class SFTP < Adapter::Base
      include ::Dandelion::Utils

      adapter 'sftp'
      requires_gems 'net-sftp'

      def initialize(config)
        require 'net/sftp'

        @config = config
        @config.defaults(preserve_permissions: true)

        @sftp = sftp_client
      end

      def read(file)
        begin
          @sftp.file.open(path(file), 'r') do |f|
            f.gets
          end
        rescue Net::SFTP::StatusException => e
          raise unless e.code == 2
          nil
        end
      end

      def write(file, data)
        temp(file, data) do |temp|
          begin
            @sftp.upload!(temp, path(file))
          rescue Net::SFTP::StatusException => e
            raise unless e.code == 2
            mkdir_p(File.dirname(path(file)))
            @sftp.upload!(temp, path(file))
          end
        end

        if @config[:preserve_permissions]
          mode = get_mode(file)
          @sftp.setstat!(path(file), permissions: mode) if mode
        end
      end

      def delete(file)
        begin
          @sftp.remove!(path(file))
          cleanup(File.dirname(path(file)))
        rescue Net::SFTP::StatusException => e
          raise unless e.code == 2
        end
      end

      def to_s
        "sftp://#{@config['username']}@#{@config['host']}/#{@config['path']}"
      end

    private

      def sftp_client
        options = {
          password: @config['password'],
          port: @config['port'] || Net::SSH::Transport::Session::DEFAULT_PORT,
        }

        Net::SFTP.start(@config['host'], @config['username'], options)
      end

      def get_mode(file)
        stat = File.stat(file) if File.exists?(file)
        stat.mode if stat
      end

      def cleanpath(path)
        Pathname.new(path).cleanpath.to_s if path
      end

      def cleanup(dir)
        unless cleanpath(dir) == cleanpath(@config['path']) or dir == File.dirname(dir)
          if empty?(dir)
            @sftp.rmdir!(dir)
            cleanup(File.dirname(dir))
          end
        end
      end

      def empty?(dir)
        @sftp.dir.entries(dir).delete_if do |file|
          file.name == '.' or file.name == '..'
        end.empty?
      end

      def mkdir_p(dir)
        begin
          @sftp.mkdir!(dir)
        rescue Net::SFTP::StatusException => e
          raise unless e.code == 2
          mkdir_p(File.dirname(dir))
          @sftp.mkdir!(dir)
        end
      end

      def path(file)
        if @config['path'] and !@config['path'].empty?
          File.join(@config['path'], file)
        else
          file
        end
      end
    end
  end
end