class Eco::API::UseCases::DefaultCases::Samples::Sftp < Eco::API::Common::Loaders::UseCase
  name "sftp-sample"
  type :other

  attr_reader :session, :options

  def main(session, options, usecase)
    @session = session; @options = options
    options[:end_get] = false
    raise "The SFTP is not configured" unless session.sftp?
    case options.dig(:sftp, :command)
    when :list
      list_folder
    when :get
      get_files
    when :get_last
      get_last
    when :archive
      archive_files
    end
  end

  private

  def file_pattern
    raise "You should redefine the file_pattern function as a RegEx expression that matches the target remote file"
  end

  # Ex: "/IN/Personnel"
  def remote_subfolder
    raise "You should redefine remote_subfolder as the folder where the target file sits. Ex: /IN/Personnel"
  end

  def archive_subfolder
    "Archive"
  end

  def with_remote_files
    begin
      sftp.files(remote_folder, pattern: file_pattern).each do |remote_file|
        yield(remote_file) if block_given?
      end
    rescue Net::SFTP::StatusException => e
      logger.error("SFTP samplecase: There was an error trying to access the remote folder '#{remote_folder}'")
      []
    end
  end

  def list_folder
    puts "Listing remote folder: '#{remote_folder}' (host: #{sftp.host}):"
    with_remote_files {|file| puts file.longname}
  end

  def get_files
    with_remote_files.tap do |files|
      unless files.empty?
        file_names = files.map {|file| to_remote_path(file.name)}
        puts "Getting the following files into the local folder '#{local_folder}':"
        puts file_names
        sftp.download(file_names, local_folder: local_folder)
      end
    end
  end

  def get_last
    with_remote_files.last.tap do |file|
      if file
        file_name = to_remote_path(file.name)
        puts "Getting the following file: #{file_name}"
        sftp.download(file_name, local_folder: local_folder)
      end
    end
  end

  def archive_files
    with_remote_files do |file|
      source = to_remote_path(file.name) # should probably be file.longname
      dest   = to_remote_path("#{archive_subfolder}/#{file.name}")
      move_file(source, dest)
    end.tap do |files|
      puts "Moved the file(s) to the #{archive_subfolder} folder" unless files.empty?
    end
  end

  def move_file(source, dest)
    sftp.move(source, dest, 0x0001) do |response|
      if response.ok?
        puts "#{source}\n  -to-> #{dest}"
      else
        puts "Could not move file #{source}"
      end
    end
  end

  def to_remote_path(file)
    remote_folder + "/" + file
  end

  def local_folder
    options.dig(:sftp, :local_folder) || "."
  end

  def remote_folder
    @remote_folder ||= sftp_config.remote_folder + remote_subfolder
  end

  def sftp_config
    session.config.sftp
  end

  def sftp
    session.sftp
  end
end