#!/usr/bin/ruby
# encoding: utf-8

#Arunas Junevicius
#2012-05-15
#Version : 1
#Kolmisoft


require 'rubygems'
require 'active_record'
require 'optparse'
require 'digest/sha1'

options = {}
optparse = OptionParser.new do|opts|

  # Define the options, and what they do
  options[:name] = nil
  opts.on( '-n', '--name NAME', "Database name, default 'mor'" ) do|n|
    options[:name] = n
  end

  options[:user] = nil
  opts.on( '-u', '--user USER', "Database user, default 'mor'" ) do|u|
    options[:user] = u
  end

  options[:pasw] = nil
  opts.on( '-p', '--password PASSWORD', "Database password, default 'mor'" ) do|p|
    options[:pasw] = p
  end

  options[:host] = nil
  opts.on( '-s', '--server HOST', "Database host, default 'localhost'" ) do|h|
    options[:host] = h
  end
  
  options[:start] = nil
  opts.on( '-S', '--start DATETIME', "DATETIME from when to delete calls, optional" ) do|s|
    options[:start] = s
  end

  options[:start] = nil
  opts.on( '-E', '--end DATETIME', "DATETIME until when to delete calls" ) do|e|
    options[:end] = e
  end

  options[:limit] = nil
  opts.on( '-l', '--limit LIMIT', "LIMIT how much calls to delete in one go, if not specified calls in specified data range will be deleted in one go" ) do|l|
    options[:limit] = l
  end
  
  options[:transaction] = nil
  opts.on( '-t', '--transaction', "Set wheather to delete everything in transaction, by default OFF. should speed up things." ) do|t|
    options[:transaction] = t
  end

  options[:experimental] = nil
  opts.on( '-e', '--experimental', "Set if you want to try to delete old calls withoud actualy sending DELETE, by default OFF. should speed up things. in that case only end and transaction and drop_old prameters counts" ) do|e|
    options[:experimental] = e
  end

  options[:preserve] = nil
  opts.on( '-P', '--preserve', "Do not drop table with old calls. could be user if one if afraid to loose data or wants to make a backup. makes sence only if experimental 'deletion' was used." ) do|p|
    options[:preserve] = p
  end

  opts.on( '-h', '--help', 'Display this screen' ) do
    puts opts
    puts
    exit
  end
end

optparse.parse!

#---------- SET CORECT PARAMS TO SCRIPT ! ---------------

Debug_file = '/tmp/delete_old_calls.log'
Database_name = options[:name].to_s.empty?  ? 'mor'  : options[:name]
Database_username = options[:user].to_s.empty?  ? 'mor'  : options[:user]
Database_password = options[:pasw].to_s.empty?  ? 'mor'  : options[:pasw]
Database_host =  options[:host].to_s.empty? ? 'localhost'  : options[:host]
Count_all =  options[:all].to_s.empty? ? 0  : options[:all]

#begin
  #---------- connect to DB ----------------------
  ActiveRecord::Base.establish_connection(:adapter => "mysql", :database => Database_name, :username => Database_username, :password => Database_password, :host => Database_host)
  ActiveRecord::Base.connection

  #------------- Debug model ----------------
  class Debug

    def Debug.debug(msg)
      File.open(Debug_file, "a") { |f|
        f << msg.to_s
        f << "\n"
      }
      #puts msg.to_s
    end

  end

  #------------------ Main -------------------
  Debug.debug("\n*******************************************************************************************************")
  Debug.debug("#{Time.now().to_s(:db)} --- STARTING TO DELETE OLD CALLS ")

  if options[:start] and options[:end]
    condition = "calldate BETWEEN '#{options[:start]}' AND '#{options[:end]}'"
  elsif options[:end]
    condition = "calldate < '#{options[:end]}'"
  else
    raise 'ValueError. Must specify end of period'
  end

  if options[:experimental]
    Debug.debug("#{Time.now().to_s(:db)} --- using experimental call deletion method ")
    #it would be cool to drop indexes and then to receate them cause innodb can disable only unique key checks
    ActiveRecord::Base.connection.execute("CREATE TABLE tmp_calls LIKE calls");
    ActiveRecord::Base.connection.execute("START TRANSACTION") if options[:transaction]
    ActiveRecord::Base.connection.execute("INSERT INTO tmp_calls SELECT * FROM calls WHERE calldate > '#{options[:end]}'")
    ActiveRecord::Base.connection.execute("COMMIT") if options[:transaction]
    ActiveRecord::Base.connection.execute("RENAME TABLE calls TO old_calls, tmp_calls TO calls")
    if !options[:preserve]
      Debug.debug("#{Time.now().to_s(:db)} --- droping table with old calls ")
      ActiveRecord::Base.connection.execute("DROP TABLE old_calls")
    else
      Debug.debug("#{Time.now().to_s(:db)} --- preserving table with old calls. you can can backup those calls any time.")
    end
  elsif options[:limit].to_i > 0
    begin
      ActiveRecord::Base.connection.execute("START TRANSACTION") if options[:transaction]
      rows_affected = ActiveRecord::Base.connection.delete("DELETE FROM calls WHERE #{condition} LIMIT #{options[:limit].to_i}")
      ActiveRecord::Base.connection.execute("COMMIT") if options[:transaction]
    end while rows_affected > 0
  else
    ActiveRecord::Base.connection.execute("START TRANSACTION") if options[:transaction]
    ActiveRecord::Base.connection.execute("DELETE FROM calls WHERE #{condition}")
    ActiveRecord::Base.connection.execute("COMMIT") if options[:transaction]
  end

  Debug.debug("#{Time.now().to_s(:db)} --- updateing call count information in card.call_count")
  ActiveRecord::Base.connection.execute("UPDATE cards JOIN (SELECT COUNT(*) call_count, card_id FROM calls WHERE card_id > 0 GROUP BY card_id) calls ON(calls.card_id = cards.id) SET cards.call_count = calls.call_count;")
  
  ActiveRecord::Base.remove_connection

  Debug.debug("#{Time.now().to_s(:db)} --- FINISED DELETING OLD CALLS ")