class MySQLSlowQueryParser

# File lib/mysql-slowquery-parser.rb, line 4
def self.parse(raw_slow_logs)
  split_raw_slow_logs(raw_slow_logs).map { |raw_slow_log|
    parse_slow_log(raw_slow_log)
  }
end

# File lib/mysql-slowquery-parser.rb, line 26
def self.parse_slow_log(raw_slow_log)
  result = {}
  line = raw_slow_log.shift

  while !line.start_with?('#')
    # こういうのを suppress する
    #### /usr/local/Cellar/mysql/5.6.12/bin/mysqld, Version: 5.6.12 (Source distribution). started with:
    #### Tcp port: 3306  Unix socket: /tmp/mysql.sock
    line = raw_slow_log.shift
  end

  if record = line.match(/^# Time:\s+(.+)/)
    result[:datetime] = Time.parse(record[1]).to_i
    line = raw_slow_log.shift
  end

  if record = line.match(/^# User@Host: ([^\[]+)?\[([^\]]*)\] @ ([^\[]+)\[([^\]]*)\]/)
    result[:user] = record[1].nil? || record[1].empty? ? record[2] : record[1]
    result[:host] = record[3].nil? || record[3].strip.empty? ? record[4] : record[3].strip
    line = raw_slow_log.shift
  end

  # こういうのをハッシュにする
  #### # Query_time: 4.267253  Lock_time: 0.000017  Rows_sent: 0  Rows_examined: 734266  Rows_affected: 734266  Rows_read: 734266
  while line.start_with?('#')
    line = line.sub(/^#\s+/, '')

    # '  ' で split したかったけど、' ' で区切られてる場合(MacのMySQLで確認)もあったからこうした
    record = line.split(/\s+/).map { |val|
      case val
      when /\:$/
        val.sub(/\:$/, '').downcase.to_sym
      when /^\d+$/
        val.to_i
      when /^\d+\.\d+$/
        val.to_f
      else
        val
      end
    }

    # # Thread_id: 45  Schema:   Last_errno: 0  Killed: 0
    # ↑ の Schema みたいに、値がない場合に nil を埋めて対応する
    begin
      result = result.merge(Hash[*record])
    rescue ArgumentError # odd number of arguments for Hash
      _record = []
      record.each_with_index do |val, i|
        _record << val
        if val.is_a?(Symbol) && record[i+1].is_a?(Symbol)
          _record << nil
        end
      end
      _record << nil if _record.last.is_a?(Symbol)
      result = result.merge(Hash[*_record])
    end

    line = raw_slow_log.shift
  end

  if record = line.match(/^use (\w+);$/)
    result[:db] = record[1]
    line = raw_slow_log.shift
  end

  if record = line.match(/^SET timestamp=(\d+);$/)
    result[:datetime] = record[1].to_i
    line = raw_slow_log.shift
  end

  result[:sql] = line
  raw_slow_log.each do |l|
    result[:sql] = result[:sql] + l
  end
  result[:sql] = result[:sql].sub(/;$/, '')
  result[:sql] = result[:sql].strip

  result
end

# File lib/mysql-slowquery-parser.rb, line 11
def self.split_raw_slow_logs(raw_slow_logs)
  result = []
  part = []

  raw_slow_logs.each_line do |line|
    part << line
    if line.end_with?(';', ";\n") && !line.start_with?('use ', 'SET timestamp=')
      result << part
      part = []
    end
  end

  result
end