=begin
= netcdf_cutter.rb
== 概要
:ORG_data に格納される CMAP オリジナルデータを 1 ヵ月毎に分割するスクリプト.

== USAGE
  $ netcdf_cutter.rb ファイル名 変数

=end
var_attr= {"units"=>"hours since 1979-1-1 00:00:00"}

dtype = "CMAP"
phys = "time"

# exchange time units "hours" => "date&time" 
def time2date(jd)
  dates = jd/24
  jd_ext = Date.jd(dates)
  seireki_gannen = Date.valid_date?(1979,1,1)
  date = jd_ext + seireki_gannen 
  return date
end

#############  以下メインルーチン  ##############
require "numru/netcdf"
module NumRu
  class NetCDFVar
    alias put scaled_put
    alias get scaled_get
  end
end

require "numru/ggraph"
include NumRu

require "getopts"

#======= ruby 1.6 で Date::parse をつかうためのおまじない
class Hash
  alias values_at indices # values_at は ruby-1.6 には無いメソッドなので
end
#=======

file = Array.new
ARGV.each do |i| 
  if i =~ /.nc$/ then
    p i
    file << i
  end
end


if ARGV[ARGV.size-1] =~ /.nc$/ then
  var = NetCDF.open(file[0], "r").var_names[-1]  
else 
  var = ARGV[ARGV.size-1]
end

pname = var.to_s.upcase #=> 物理量を get.

#--------------------------------------
# title を得る. もしなければ, longname をそれとする.
nc = NetCDF.open(file[0])
p  longname = nc.var(var).att("long_name").get
#  title = nc.att("title").get
   title = nil
nc.close

if title 
p  $title = title
else 
p  $title = longname
end

#  gphys オープン
#
gphys = GPhys::NetCDF_IO.open(file[0], var)

start_time = gphys.coord(gphys.axnames.index(phys)).val[0]

date = time2date(start_time)
startyear = date.year

# 設定部分
## 追加メソッド定義ファイル
require "libgphys-n.rb"
## 属性設定ファイル
require "CMAP-ncattr.conf.rb"


time_coord = gphys.coord(gphys.axnames.index(phys))
num = time_coord.val

0.upto(num.size-1) do |i|
  year = startyear + (i+1)/12
  amari = (i+1)%12
  if amari < 10 && amari > 0 
    output = "#{pname}_#{year}-0#{amari}_#{dtype}.nc"
  elsif amari == 0
    output = "#{pname}_#{year}-12_#{dtype}.nc"
  else
    output = "#{pname}_#{year}-#{amari}_#{dtype}.nc"
  end
  p "now making "+output
  gphys.cut(phys=>num[i]).save(output, $global_attr, nil, nil, $history)
  p "done"
end