#!/usr/bin/env ruby

# Copyright (C) 2007-2011 Martin A. Hansen.

# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; either version 2
# of the License, or (at your option) any later version.

# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.

# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.

# http://www.gnu.org/copyleft/gpl.html

# >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>><<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<

# This program is part of the Biopieces framework (www.biopieces.org).

# >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> DESCRIPTION <<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<

# Calculate n50 for sequences in the stream.

# >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>><<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<


require 'maasha/biopieces'

casts = []
casts << {:long=>'no_stream', :short=>'x', :type=>'flag', :mandatory=>false, :default=>nil, :allowed=>nil, :disallowed=>nil}
casts << {:long=>'data_out',  :short=>'o', :type=>'file', :mandatory=>false, :default=>nil, :allowed=>nil, :disallowed=>nil}

options = Biopieces.options_parse(ARGV, casts)

total   = 0
lengths = []

Biopieces.open(options[:stream_in], options[:stream_out]) do |input, output|
  input.each_record do |record|
    output.puts record unless options[:no_stream]

    if record[:SEQ]
      total   += record[:SEQ].length
      lengths << record[:SEQ].length
    end
  end
end

new_record = {}
count      = 0

lengths.sort.reverse.each do |length|
  count += length

  if count >= total * 0.50
    new_record["N50"] = length
    break
  end
end

Biopieces.open(nil, options[:data_out]) do |input, output|
  output.puts new_record
end


# >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>><<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<


__END__