#!/usr/bin/env ruby
# -*- coding: utf-8 -*-
#
# Copyright (C) 2011  Kouhei Sutou <kou@clear-code.com>
#
# This library is free software; you can redistribute it and/or
# modify it under the terms of the GNU Lesser General Public
# License version 2.1 as published by the Free Software Foundation.
#
# This library is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
# Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public
# License along with this library; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

require "ostruct"
require "optparse"
require "pathname"

require "groonga/grntest-log"

options = OpenStruct.new
options.format = "tsv"
options.resolution = 1
options.output_items = ["qps"]
options.output_path = nil
option_parser = OptionParser.new do |parser|
  parser.version = Groonga::BINDINGS_VERSION
  parser.banner += " LOG1 ..."

  available_formats = ["tsv", "csv"]
  parser.on("--format=FORMAT",
            available_formats,
            "Output as FORMAT format.",
            "(#{available_formats.join(', ')})",
            "[#{options.format}]") do |format|
    options.format = format
  end

  parser.on("--resolution=RESOLUTION",
            Integer,
            "Data resolution in seconds.",
            "[#{options.resolution}]") do |resolution|
    options.resolution = resolution
  end

  available_items = ["qps"]
  parser.on("--output-item=ITEM",
            available_items,
            "Output ITEM.",
            "To output multiple items, specify this option n times.",
            "(#{available_items.join(', ')})",
            "[#{options.output_items.join(', ')}]") do |item|
    options.output_items << item
  end

  parser.on("--output=PATH",
            "Output to PATH.",
            "[standard output]") do |path|
    options.output_path = path
  end
end
args = option_parser.parse!(ARGV)

if args.empty?
  puts(option_parser)
  exit(false)
end

def analyze(output, options)
  parser = Groonga::GrntestLog::Parser.new
  previous_second = 0
  current_second = 0
  n_queries = 0
  min_elapsed = nil
  max_elapsed = nil
  parser.parse(ARGF) do |event|
    next unless event.is_a?(Groonga::GrntestLog::TaskEvent)
    case options.format
    when "tsv"
      new_second = event.relative_end_time / 1_000_000
      if current_second < new_second
        if (current_second % options.resolution).zero? or
            ((current_second - previous_second) >= options.resolution)
          qps = n_queries / options.resolution.to_f
          data = [current_second, qps, min_elapsed || 0, max_elapsed || 0]
          output.puts(data.join("\t"))
          n_queries = 0
          min_elapsed = nil
          max_elapsed = nil
          previous_second = current_second
        end
        current_second = new_second
      end
      n_queries += 1
      elapsed_time_in_millisecond = event.elapsed_time / 1_000.0
      min_elapsed ||= elapsed_time_in_millisecond
      max_elapsed ||= elapsed_time_in_millisecond
      min_elapsed = [min_elapsed, elapsed_time_in_millisecond].min
      max_elapsed = [max_elapsed, elapsed_time_in_millisecond].max
    end
  end
  if n_queries > 0
    last_resolution = current_second % options.resolution
    if last_resolution.zero?
      qps = n_queries / options.resolution.to_f
    else
      qps = n_queries / last_resolution.to_f
    end
    data = [current_second, qps, min_elapsed || 0, max_elapsed || 0]
    output.puts(data.join("\t"))
  end
end

if options.output_path
  File.open(options.output_path, "w") do |output|
    analyze(output, options)
  end
else
  analyze($stdout, options)
end