#!/usr/bin/env perl

# Copyright (c) 2015 Christian Jaeger, copying@christianjaeger.ch
# This is free software. See the file COPYING.md that came bundled
# with this file.

use strict; use warnings; use warnings FATAL => 'uninitialized';

# find modules from functional-perl working directory (not installed)
use Cwd 'abs_path';
our ($mydir, $myname); BEGIN {
    my $location= (-l $0) ? abs_path ($0) : $0;
    $location=~ /(.*?)([^\/]+?)_?\z/s or die "?";
    ($mydir, $myname)=($1,$2);
}
use lib "$mydir/../lib";


sub usage {
    print "usage: $myname csvfile xmlfile

  Variant of csv_to_xml with shorter code. Only supports one csvfile.

";
    exit (@_ ? 1 : 0);
}

use Getopt::Long;
our $verbose=0;
GetOptions("verbose"=> \$verbose,
           "help"=> sub{usage},
           ) or exit 1;
usage unless @ARGV==2;

our ($inpath, $outpath)=@ARGV;

use FP::Text::CSV qw(csv_file_to_rows);
use PXML::Serialize;

# create tag functions for the following XML tag names. Casing is
# preserved for the output, but the tag functions are all-uppercase
# (to try to avoid name conflicts and for better visibility) and
# replace the minus with the underscore.
use PXML::Tags qw(myexample protocol-version records record a b c d);

# create a data structure describing an XML document, partially lazily
MYEXAMPLE
  (PROTOCOL_VERSION ("0.123"),
   RECORDS
   (# read lazy list of rows from CSV file
    csv_file_to_rows($inpath, {eol=> "\n", sep_char=> ";"})
    # skip the header row
    ->rest
    # map rows to XML elements
    ->map(sub {
              my ($a,$b,$c,$d)= @{$_[0]};
              RECORD A($a), B($b), C($c), D($d)
          })))
  # print data structure to disk, forcing its evaluation as needed
  ->xmlfile($outpath);


# XXX this may not actually use constant memory on your Perl. Work
# still needs to be done.

