#!/usr/bin/ruby
#
# smart-track.rb
# written by antonone_
#
# visit http://anadoxin.org/blog
#

require 'date'

$disks = { 
	:home   => "/dev/sda", 
	:win7   => "/dev/sdb", 
	:system => "/dev/sdc" 
};

$confdir = "/var/log/smart-track"

$infos = []

class SmartInfo
	attr_accessor(:bad_blocks, :temp, :dev, :caption, :pending)

	def to_s()
		"%s,%s,%d,%d,%d" % [ @dev, @caption, @bad_blocks, @temp, @pending ]
	end
end

def read_smart(devices, symbol)
	info = SmartInfo.new()

	device = devices[symbol]
	info.dev = device
	info.caption = symbol.to_s

	`smartctl -a #{device}`.each() do |line|
		info.bad_blocks = $2.to_i if(line =~ /(\d+) Reallocated_Sector_Ct.*-[ ]+(\d+)/i  && $1.to_i() == 5)
		info.temp = $2.to_i       if(line =~ /(\d+) Temperature_Celsius.*-[ ]+(\d+)/i    && $1.to_i() == 194)
		info.pending = $2.to_i    if(line =~ /(\d+) Current_Pending_Sector.*-[ ]+(\d+)/i && $1.to_i() == 197)
	end

	return(info)
end

def lock(name)
	1.times() do
		if(File.exists?("#{$confdir}/.lock_#{name}"))
			sleep(1)
			redo
		else
			File.open("#{$confdir}/.lock_#{name}", "w") do |fp| fp.write("locked") end
		end
	end
end

def unlock(name)
	File.unlink("#{$confdir}/.lock_#{name}")
rescue

end

def get_last_state()
	IO.readlines("#{$confdir}/last_state").join().to_i
rescue Errno::ENOENT
	return 0
end

def put_last_state(last_state)
	File.open("#{$confdir}/last_state", "w") do |fp| fp.write(last_state) end
end

def save_state(infos)
	last_state = get_last_state()
	last_state += 1

	File.open("#{$confdir}/state_%05d" % [ last_state ], "w") do |fp| infos.each() do |info| fp.write("#{info}\n") end end

	put_last_state(last_state)
end

def load_prev_info()
	last_state = get_last_state()
	infos = []

	IO.readlines("#{$confdir}/state_%05d" % [ last_state ]).each() do |line|
		info = SmartInfo.new()

		info.dev,info.caption,info.bad_blocks,info.temp,info.pending = line.split(',').map() do |i| i.strip() end

		info.bad_blocks = info.bad_blocks.to_i
		info.temp = info.temp.to_i
		info.pending = info.pending.to_i

		infos << info
	end

	return infos
rescue Errno::ENOENT
	return infos
end

begin
	lock("glob")
	prev_infos = load_prev_info()

	$disks.each() do |key,value|
		info = read_smart($disks, key)
		$infos << info
	
		prev_infos.each() do |prev_info|
			if(prev_info.dev == info.dev)
				if(info.bad_blocks > prev_info.bad_blocks)
					`/home/antek/bin/sms self "Uwaga, zwiekszona ilosc bad blockow na dysku #{info.dev} - wczesniej: #{prev_info.bad_blocks}, teraz: #{info.bad_blocks}."`
				end

				if(info.pending > prev_info.pending)
					`/home/antek/bin/sms self "Uwaga, zwiekszona ilosc pending sectors na dysku #{info.dev} - wczesniej: #{prev_info.pending}, teraz: #{info.pending}."`
				end
			end
		end
	end

	save_state($infos)
	unlock("glob")
rescue
	unlock("glob")
end