#!/usr/bin/perl -w
use strict;
use Data::Dumper;
use POSIX qw( );
use Getopt::Std qw( getopts );

( my $Script = $0 ) =~ s{^.*/}{};

our ( $VERSION, $DATE ) = do {
    my ( $ver, $date ) =
      q{$Id: fStar-coordinates,v 1.0 2006-10-06 cfdadmin Exp $} =~
      m{\s+(\d+\.\d+).*?\s+(\d{4}[-/]\d{2}[-/]\d{2})\s*};
    $date =~ s{/}{-}g;    # ISO-formatted

    ( $ver, $date );
};

# for simplicity - use '..' as rootDir and pwd as caseDir
my %config = (
    rootDir => "..",
    caseDir => do { ( my $x = POSIX::getcwd ) =~ s{^.*/}{}; $x },
    output  => "constant/coordinateSystems",
);

# -------------------------------------------------------------------------
sub usage {
    $! = 0;               # clean exit

    warn "@_\n" if @_;
    die <<"USAGE";
usage:
    $Script [OPTION] <file1.inp> ... <fileN.inp>

options:
  -h        usage
  -w        write to $config{output}

Extract Star-CD coordinate system information from the input files
and print in a form suitable for OpenFOAM

version $VERSION ($DATE)
copyright (c) 2006 Mark Olesen <Mark.Olesen\@ArvinMeritor.com>
USAGE
}

# -------------------------------------------------------------------------
my %opt;
getopts( "hw", \%opt ) or usage();
$opt{h} and usage();
@ARGV or usage();

# degrees -> rad (PI/4)
use constant PI => 4 * atan2( 1, 1 );

sub deg2rad {
    map { $_ * ( PI / 180 ) } @_;
}

sub millimeter2meter {
    map { $_ * 0.001 } @_;
}

sub FoamDivider {
    "// " . ( "* " x 37 ) . "//\n";
}

if ( $opt{w} ) {
    my $output = $config{output};
    ( my $dir = $output ) =~ s{/[^/]+$}{};
    -d $dir or mkdir $dir;

    warn "writing $output\n";
    open STDOUT, "> $output", or die "cannot open '$output'\n";
}

# -------------------------------------------------------------------------
#
# create header -  simple substitutions
#
my $header = do { local $/; <DATA> };
{
    my %var = ( CASE => $config{caseDir} || "", OBJECT => "coordinateSystems" );
    ( my $text = $header ) =~ s/%{\s*([_A-Z]+)\s*}/ $var{$1} || '' /eg;

    print $text;
}

# -------------------------------------------------------------------------

# handle lines with
# LOCAL csysId csysType originX originY originZ rotXY rotYZ rotZY
#
while (<>) {
    s/^\s*loca\w*\s+(\d+)\s+\w+//i or next;
    my $csysId = $1;
    my @a = map { $_ + 0 } split;

    @a >= 6 or next;    # require 6 fields
    my ( $origx, $origy, $origz, $rotxy, $rotyz, $rotzy ) = @a;

    # origin: mm -> m
    my @origin = millimeter2meter( $origx, $origy, $origz );

    # rotation: deg -> rad
    my ( $rotZ, $rotX, $rotY ) = deg2rad( $rotxy, $rotyz, $rotzy );

    # z axis
    my @axis = (
    sin($rotX) * cos($rotY) * sin($rotZ) + sin($rotY) * cos($rotZ),
    sin($rotY) * sin($rotZ) - sin($rotX) * cos($rotY) * cos($rotZ),
    cos($rotX) * cos($rotY),
    );

    my @dir = (
    cos($rotY) * cos($rotZ) - sin($rotX) * sin($rotY) * sin($rotZ),
    cos($rotY) * sin($rotZ) + sin($rotX) * sin($rotY) * cos($rotZ),
    -cos($rotX) * sin($rotY),
    );

    for ( @axis, @dir ) {
    if ( abs($_) <= 1e-8 ) {
        $_ = 0;
    }
    else {
        $_ = sprintf "%.8f", $_;
        s{\.?0+$}{};
    }
    }

    print << "PRINT";

coordinateSystem_$csysId
{
    type Cartesian;
    origin (@origin);
    axis (@axis);
    direction (@dir);
    // starcdRotation ($rotxy $rotyz $rotzy);
}
PRINT
}

print "\n", FoamDivider;

# -------------------------------------------------------------------------

__DATA__
/*------------------------------*- c-mode -*---------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | foam-extend: Open Source CFD                    |
|  \\    /   O peration     | Version:     4.0                                |
|   \\  /    A nd           | Web:         http://www.foam-extend.org         |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/

FoamFile
{
    version 2.0;
    format ascii;

    root "..";
    case "%{CASE}";
    instance "constant";
    local "";

    note "persistent data for pro-STAR <-> OpenFOAM translation";
    class dictionary;
    object %{OBJECT};
}

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //