#! /usr/bin/env ruby
# coding: utf-8

require "comana"
require "optparse"
require "pp"

##Analyze options
COMMAND_NAME = File.basename("#{__FILE__}")
OPTIONS = {}
op = OptionParser.new
op.banner = <<HERE
Usage: #{COMMAND_NAME} subcommand [options] [hosts]
Subcommands:
  ping    # Ping: o and x indicate OK and N/A, respectively.
  alive   # Ping only alive: show alive hostname
  cwd     # cwd of processes owned by ssh login user.
  ps      # Info from ps.
  cpuinfo # CPU information from /proc/cpuinfo.
  meminfo # memory information from /proc/meminfo.
  load    # the highest process
For example,
  #{COMMAND_NAME} ping                # for all hosts 
  #{COMMAND_NAME} ping host01 host02
  #{COMMAND_NAME} ping -g host_series
  #{COMMAND_NAME} ping -u             # update cached data
HERE

op.on("-u", "--update" , "Update cache"){OPTIONS[:update] = true}
op.on("-g", "--group"  , "Indicate group of hosts"    ){OPTIONS[:group] = true}
op.on("-q", "--quiet"  , "No output 'Wainting for...'"){OPTIONS[:quiet] = true}
op.parse!(ARGV)

## Analyze subcommand
subcommand = ARGV.shift
requirement = {}
case subcommand
when "ping"
  requirement[:ping] = true
when "alive"
  requirement[:ping] = true
when "cwd"
  requirement[:cwd] = true
when "ps"
  requirement[:ps] = true
when "cpuinfo"
  requirement[:cpuinfo] = true
when "meminfo"
  requirement[:meminfo] = true
when "load"
  requirement[:ps] = true
  requirement[:cwd] = true
else
  puts op.help
  exit
end

## Return selected hosts
def target_hosts
  cs = Comana::ClusterSetting.load_file
  groups = {}
  cs.groups.each do |key, val|
    cluster = key
    groups[key] = val["members"]
  end
  hs = Comana::HostSelector.new groups
  if OPTIONS[:group]
    hosts = []
    ARGV.each do |group|
      begin
        hosts << hs.select_group(group)
      rescue Comana::HostSelector::NoEntryError
        $stderr.puts "Unknown group: #{group}"
      end
    end
    hosts.flatten!
  else
    hosts = ARGV
  end
  hosts = hs.select_all if ARGV.empty?
  hosts
end

def time_ago(uptime)
  if uptime
    second = (Time.now - uptime).to_i
    if second >= 86400
      result = sprintf("%2s days ago", second / 86400)
    elsif second >= 3600
      result = sprintf("%2s hours ago", second / 3600)
    elsif second >= 60
      result = sprintf("%2s min  ago", second / 60)
    else
      result = sprintf("%2s sec  ago", second)
    end
  else #e.g., not exist cache file
    result = "need_update"
  end
  return result
end

## Collect information
hostinspectors = target_hosts.map { |host| Comana::HostInspector.new(host) }
if OPTIONS[:update]
  Thread.abort_on_exception = true
  threads = {}
  hostinspectors.each do |hi|
    threads[hi] = Thread.start do
      hi.update_ping if requirement[:ping]
      hi.update_cwd  if requirement[:cwd]
      hi.update_ps   if requirement[:ps]
      hi.update_cpuinfo   if requirement[:cpuinfo]
      hi.update_meminfo   if requirement[:meminfo]
    end
  end
  threads.each do |hi, thread|
    print "Waiting for #{hi.hostname}...\n" unless OPTIONS[:quiet]
    thread.join              # wait until all processes are completed
  end
end

## Output
hostinspectors.each do |hi|
  # oldest update
  oldest_key, val = requirement.min_by {|key,val| hi.time_updated(key.to_s)}
  hostname = hi.hostname
  timeago  = time_ago( hi.time_updated(oldest_key.to_s))
  hosttime = sprintf("%-10s (%12s) ",
         hi.hostname, time_ago( hi.time_updated(oldest_key.to_s)))
  begin
    case subcommand
    when "ping"
      if hi.fetch('ping')
        hosttime += "o"
      else
        hosttime += "x"
      end
      puts hosttime
    when "alive"
      puts hostname if hi.fetch('ping')
    when "cwd"
      puts hosttime
      hi.fetch('cwd').each do |pid, cwd|
        printf("  %5s %s\n", pid, cwd)
      end
    when "ps"
      puts hosttime
      hi.fetch('ps').each do |pid, ps|
        printf("  %-10s %5s\n", hi.hostname, pid)
      end
    when "cpuinfo"
      result = hosttime
      begin
        cpuinfo = hi.fetch('cpuinfo')
        result += sprintf("%2d_cores  %s\n",
               cpuinfo.size, cpuinfo[0]["model name"].gsub(/ +/, '_'))
      rescue
        result += sprintf("not_obtained\n")
      end
      puts result
    when "meminfo"
      result = hosttime
      meminfo = hi.fetch('meminfo')
      result += sprintf("%s\n", meminfo['MemTotal'])
      puts result
    when "load"
      result = hosttime
      ps      = hi.fetch("ps")
      cwd     = hi.fetch("cwd")
      pid, process = ps.max_by {|key, val| val['cpu'].to_f}
      command = File.basename(process['command'].split[0])
      result += sprintf("%5s %8s %5.1f %5.1f %20s %s\n",
             pid, process['user'], process['cpu'], process['mem'],
            command, cwd[pid])
      puts result
    end
  rescue Comana::HostInspector::NoUpdateFile
    puts hosttime + "------------"
  rescue NoMethodError # 主にデータを取れなかった時用
    puts hosttime + "------------"
  end
end