# encoding: utf-8
require 'java'
java_import java.io.InputStream
java_import java.io.InputStreamReader
java_import java.io.FileInputStream
java_import java.io.BufferedReader
java_import java.util.zip.GZIPInputStream
java_import java.util.zip.ZipException

module FileWatch module ReadMode module Handlers
  class ReadZipFile < Base
    def handle_specifically(watched_file)
      add_or_update_sincedb_collection(watched_file) unless sincedb_collection.member?(watched_file.sincedb_key)
      # can't really stripe read a zip file, its all or nothing.
      watched_file.listener.opened
      # what do we do about quit when we have just begun reading the zipped file (e.g. pipeline reloading)
      # should we track lines read in the sincedb and
      # fast forward through the lines until we reach unseen content?
      # meaning that we can quit in the middle of a zip file
      begin
        file_stream = FileInputStream.new(watched_file.path)
        gzip_stream = GZIPInputStream.new(file_stream)
        decoder = InputStreamReader.new(gzip_stream, "UTF-8")
        buffered = BufferedReader.new(decoder)
        while (line = buffered.readLine(false))
          watched_file.listener.accept(line)
        end
        watched_file.listener.eof
      rescue ZipException => e
        logger.error("Cannot decompress the gzip file at path: #{watched_file.path}")
        watched_file.listener.error
      else
        sincedb_collection.store_last_read(watched_file.sincedb_key, watched_file.last_stat_size)
        sincedb_collection.request_disk_flush
        watched_file.listener.deleted
        watched_file.unwatch
      ensure
        # rescue each close individually so all close attempts are tried
        close_and_ignore_ioexception(buffered) unless buffered.nil?
        close_and_ignore_ioexception(decoder) unless decoder.nil?
        close_and_ignore_ioexception(gzip_stream) unless gzip_stream.nil?
        close_and_ignore_ioexception(file_stream) unless file_stream.nil?
      end
      sincedb_collection.unset_watched_file(watched_file)
    end

    private

    def close_and_ignore_ioexception(closeable)
      begin
        closeable.close
      rescue Exception => e # IOException can be thrown by any of the Java classes that implement the Closable interface.
        logger.warn("Ignoring an IOException when closing an instance of #{closeable.class.name}", "exception" => e)
      end
    end
  end
end end end