# Copyright (C) 2011-2014 Tanaka Akira  <akr@fsij.org>
#
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Tb::Cmd.subcommands << 'cut'

Tb::Cmd.default_option[:opt_cut_v] = nil

def (Tb::Cmd).op_cut
  op = OptionParser.new
  op.banner = "Usage: tb cut [OPTS] FIELD,... [TABLE]\n" +
    "Select columns."
  define_common_option(op, "hNo", "--no-pager")
  op.def_option('-v', 'invert match') { Tb::Cmd.opt_cut_v = true }
  op
end

Tb::Cmd.def_vhelp('cut', <<'End')
Example:

  % cat tst.csv
  a,b,c
  0,1,2
  4,5,6
  % tb cut a,c tst.csv
  a,c
  0,2
  4,6
  % tb cut -v a tst.csv
  b,c
  1,2
  5,6
End

def (Tb::Cmd).main_cut(argv)
  op_cut.parse!(argv)
  exit_if_help('cut')
  err('no fields given.') if argv.empty?
  fs = split_field_list_argument(argv.shift)
  argv = ['-'] if argv.empty?
  Tb::CatReader.open(argv, Tb::Cmd.opt_N) {|tblreader|
    if Tb::Cmd.opt_cut_v
      er = Tb::Enumerator.new {|y|
        tblreader.with_header {|header0|
          if header0
            y.set_header header0 - fs
          end
        }.each {|pairs|
          y.yield pairs.reject {|k, v| fs.include? k }
        }
      }
      output_tbenum(er)
    else
      er = Tb::Enumerator.new {|y|
        y.set_header fs
        tblreader.each {|pairs|
          y.yield pairs.reject {|k, v| !fs.include?(k) }
        }
      }
      output_tbenum(er)
    end
  }
end

