module PgHeroLogs

# File lib/pghero_logs.rb, line 9
def run(args)
  command = args[0]
  case command
  when nil
    parse
  when "download"
    download args[1]
  else
    abort "Unknown command: #{command}"
  end
end

# File lib/pghero_logs.rb, line 23
def download(db_instance_identifier)
  db_instance_identifier ||= ENV["AWS_DB_INSTANCE_IDENTIFIER"]
  rds = AWS::RDS.new
  resp = rds.client.describe_db_log_files(db_instance_identifier: db_instance_identifier)
  files = resp[:describe_db_log_files].map{|f| f[:log_file_name] }
  files.each do |log_file_name|
    local_file_name = log_file_name.sub("error/", "")
    if File.exists?(local_file_name)
      puts "EXISTS #{local_file_name}"
    else
      data = ""
      marker = nil
      begin
        options = {
          db_instance_identifier: db_instance_identifier,
          log_file_name: log_file_name
        }
        options.merge!(marker: marker) if marker
        resp = rds.client.download_db_log_file_portion(options)
        data << resp[:log_file_data].to_s
      end while resp[:additional_data_pending] && (marker = resp[:marker])
      File.open(local_file_name, "w") { |file| file.write(data) }
      puts "DOWNLOADED #{local_file_name}"
    end
  end
end

# File lib/pghero_logs.rb, line 50
def parse
  active_entry = ""
  $stdin.each_line do |line|
    if line.include?(":  ")
      if active_entry
        parse_entry(active_entry)
      end
      active_entry = ""
    end
    active_entry << line
  end
  parse_entry(active_entry)

  queries = self.queries.sort_by{|q, i| -i[:total_time] }[0...20]

  puts "Slowest Queries\n\n"
  puts "Total    Avg  Count  Query"
  puts "(min)   (ms)"
  queries.each do |query, info|
    puts "%5d  %5d  %5d  %s" % [info[:total_time] / 60000, info[:total_time] / info[:count], info[:count], query[0...60]]
  end

  puts "\nFull Queries\n\n"
  queries.each_with_index do |(query, info), i|
    puts "#{i + 1}. #{info[:sample]}"
    puts
  end
end

# File lib/pghero_logs.rb, line 79
def parse_entry(active_entry)
  if (matches = active_entry.match(REGEX))
    begin
      query = PgQuery.normalize(squish(matches[2].gsub(/\/\*.+/, ""))).gsub(/\?(, \?)+/, "?")
      queries[query][:count] += 1
      queries[query][:total_time] += matches[1].to_f
      queries[query][:sample] = squish(matches[2])
    rescue PgQuery::ParseError
      # do nothing
    end
  end
end

# File lib/pghero_logs.rb, line 92
def queries
  @queries ||= Hash.new {|hash, key| hash[key] = {count: 0, total_time: 0} }
end

# File lib/pghero_logs.rb, line 96
def squish(str)
  str.gsub(/\A[[:space:]]+/, '').gsub(/[[:space:]]+\z/, '').gsub(/[[:space:]]+/, ' ')
end