=begin
= netcdf_cutter.rb
== 概要
:ORG_data に格納される NCEP 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 1-1-1 00:00:00"}

dtype = "NCEP"
phys = "time"

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

#############  以下メインルーチン  ##############
require "numru/netcdf"
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  long_name = nc.var(var).att("long_name").get
p  title = nc.att("title").get
nc.close

if title 
p  $title = title
else 
p  $title = long_name
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)
year = date.year
leap_flag = date.leap?
  # non_leap_year : [31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31]
  # leap_year     : [31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31]  

if leap_flag 
  index = NArray[0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335, 366]*4
else
  index = NArray[0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365]*4 
end

# 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 "NCEP-ncattr.conf.rb"

require "netcdf_miss-dcchart"


for i in 0..8
  start = gphys.coord(gphys.axnames.index(phys)).val[index[i]]
  endded = gphys.coord(gphys.axnames.index(phys)).val[index[i+1]-1]
  output = "daily_#{pname}_#{year}-0#{i+1}_#{dtype}.nc"
  p "now making "+output

  # title 属性にデータの年月を加える.
  newtitle = title.sub(/^4x\ *[D|d]aily/, long_name+',')
  newtitle = newtitle.sub(/(#{year})/, '')
  gphys.cut(phys=>start..endded).save(output, $global_attr, nil, {"title", newtitle+"(#{year}-0#{i+1})"}, $history)
  
  p "done"
end
for i in 9..11
  start = gphys.coord(gphys.axnames.index(phys)).val[index[i]]
  endded = gphys.coord(gphys.axnames.index(phys)).val[index[i+1]-1]
  output = "daily_#{pname}_#{year}-#{i+1}_#{dtype}.nc"
  p "now making "+output

  # title 属性にデータの年月を加える.
  newtitle = title.sub(/^4x\ *[D|d]aily/, long_name+',')
  newtitle = newtitle.sub(/(#{year})/, '')
  gphys.cut(phys=>start..endded).save(output, $global_attr, nil, {"title", newtitle+"(#{year}-0#{i+1})"}, $history)

  p "done"
end