#!/usr/bin/perl -w
# chkpath2.pl
# 14/07/2020 - Re-worked the partial matching, to not report false positive
# 22/05/2020 - Allow 'path\sub' to also be matched
# 2018-01-16 - add info if no find given
# 14/12/2015 - missing a path?
# 01/03/2015 - More UI updates
# 18/05/2014 - Improve UI 0=not found, 1=found, others use error
use strict;
use warnings;

my ($dir,$sdir);
my $verbosity = 0;
my $check_partial = 1;

sub VERB1() { return ($verbosity >= 1); }
sub VERB2() { return ($verbosity >= 2); }
sub VERB5() { return ($verbosity >= 5); }
sub VERB9() { return ($verbosity >= 9); }

sub prt($) { print shift; }

my $find_path = '';
my $ret = 0;
my $path_env = $ENV{"PATH"};

sub add_escape($) {
    my $txt = shift;
    my $ntxt = '';
    my $len = length($txt);
    my ($i,$ch);
    for ($i = 0; $i < $len; $i++) {
        $ch = substr($txt,$i,1);
        if ($ch eq '\\') {
            $ntxt .= '\\';
        } elsif ($ch eq ':') {
            $ntxt .= '\\';
        }
        $ntxt .= $ch;
    }
    return $ntxt;
}

sub path_d2u($) {
	my ($du) = shift;
	$du =~ s/\\/\//g;
	return $du;
}


sub same_dir($$) {
    my ($dir1,$dir2) = @_;
    my $len1 = length($dir1);
    my $len2 = length($dir2);
    return 0 if ($len1 != $len2);
    my ($i,$ch1,$ch2);
    $dir1 =~ s/\\/\//g;
    $dir2 =~ s/\\/\//g;
    for ($i = 0; $i < $len1; $i++) {
        $ch1 = uc(substr($dir1,$i,1));
        $ch2 = uc(substr($dir2,$i,1));
        return 0 if ($ch1 ne $ch2);
    }
    return 1;
}

# assumed if (part_the_same($dir,$find_path))
sub part_the_same($$) {
    my ($dir1,$dir2) = @_;
    my $len1 = length($dir1);
    my $len2 = length($dir2);
    return 0 if ($len1 == 0);
    return 0 if ($len2 == 0);
    if ($len2 > $len1) {
        prt("[v9] no partial, since find $len2 '$dir2' is greater than test $len1 '$dir1'\n") if (VERB9());
        return 0;
    }
    # NB: '/(\\|\/)/' used in other scripts, FAILS!!!!
    ##################################################
    my @arr1 = split(/\\|\//,$dir1);
    my @arr2 = split(/\\|\//,$dir2);
    $len1 = scalar @arr1;
    $len2 = scalar @arr2;
    my ($sub1,$sub2,$i,$j,$i2);
    $j = 0;
    $sub2 = lc($arr2[$j]);
    for ($i = 0; $i < $len1; $i++) {
        $sub1 = lc($arr1[$i]);
        $i2 = $i + 1;
        if ($sub1 eq $sub2) { # got a match, of 1 item
            if ($len2 == 1) {
                prt("[v9] found partial since only matching 1 '$sub1'\n") if (VERB9());
                return 1;
            }
            if ($i2 < $len1) { # we have more dir
                $sub1 = lc($arr1[$i2]); # so get next
                for ($j = 1; $j < $len2; $j++) {
                    $sub2 = lc($arr2[$j]); # get next of find
                    last if ($sub1 ne $sub2); # match failed
                    $i2++;  # go to next in dir
                    if ($i2 < $len1) {
                        $sub1 = lc($arr1[$i2]); # so get next
                    } else {
                        $sub1 = '';
                    }
                }
                if ($j == $len2) {
                    prt("[v9] found partial '$dir2' in '$dir1' on last matching '$sub1'\n") if (VERB9());
                    return 1;
                }
            } else {
                prt("[v9] partial failed '$dir2' in '$dir1', on '$sub2' since no more dir\n") if (VERB9());
            }
        }
    }
    prt("[v9] partial failed '$dir2' in '$dir1'...\n") if (VERB9());
    return 0;
}

sub give_help {
    prt("chkpath [options] path_to_find\n");
    prt("options:\n");
    prt(" --help (-h or -?) = This help and exit 0\n");
    prt(" --verb[n]    (-v) = Bump or set verbosity (0,1,2,5,9) def=$verbosity\n");
    prt("\n");
    prt(" Try to match exactly the path_to_find, with those in the PATH environment variable.\n");
    prt(" If no exact match, try for a partial match.\n");
    prt(" Exit(0) if neither exact nor patial found\n");
    prt(" Exit(1) if either found.\n");
    prt(" Exit(2) if some error.\n");
}

foreach $dir (@ARGV) {
    if ($dir =~ /^-/) {
        $sdir = $dir;
        $sdir = substr($sdir,1) while ($sdir =~ /^-/);
        if ($sdir =~ /^v/) {
            $verbosity++;
            if ($sdir =~ /^v.*(\d+)$/) {
                $verbosity = $1;
            } else {
                $sdir = substr($sdir,1);
                while ($sdir =~ /^v/) {
                    $sdir = substr($sdir,1);
                    $verbosity++;
                }
            }
        } elsif (($sdir =~ /^h/)||($sdir eq '?')) {
            give_help();
            exit 0;
        } else {
            prt("Unknown command [$dir]!\n");
            $ret = 3;   # set ERROR
            prt("Exit with [$ret]\n");
            exit $ret;
        }
    } else {
        $find_path = $dir;
        prt("Finding path [$find_path]\n") if (VERB5());
    }
}

my $fcnt = 0;
my $dcnt = 0;
my $notfnd = 0;
if (defined $path_env) {
	my @folds = split(/;/,$path_env);
    $fcnt = scalar @folds;
	prt( "Got $fcnt directories...\n" ) if (VERB5());
    my $len = length($find_path);
    my $find = add_escape($find_path);
    my ($len2);
    my $edir = '';
    my $msg = '';
    my $ccnt = '';
    my $pcnt = 0;
    foreach $dir (@folds) {
        $len2 = length($dir);
        next if ($len2 == 0);
        $dcnt++;
        $ccnt = sprintf("%2d",$dcnt);
        if ( -d $dir) {
            $msg = 'ok';
        } else {
            $msg = 'NF!';
            $notfnd++;
        }
        $edir = add_escape($dir);
        if ($len2 == 0) {
            prt("[v9] $ccnt of $fcnt: Skip blank dir\n") if (VERB9());
            next;
        }
        prt("[v9] $ccnt of $fcnt: Compare '$dir' $msg, with '$find_path'\n") if (VERB9());
        if ($len) {
            if (same_dir($dir,$find_path)) {
                $ret = 1;   # set SUCCESS
                prt("$ccnt of $fcnt: Found [$dir] $msg\n") if (VERB1());
                last;
            }
        } else {
            if ($dcnt == 1) {
                prt("No 'path' given to find, so just listing ALL env 'PATH'...\n");
            }
            prt("$ccnt: [$dir] $msg\n");
        }
    }
    if (!$ret && $len && $check_partial) {
        prt("[v9] No exact match found, so try for a partial match...\n") if (VERB9());
        foreach $dir (@folds) {
            $pcnt++;
            $len2 = length($dir);
            next if ($len2 == 0);
            if (part_the_same($dir,$find_path)) {
                $ret = 1;   # set SUCCESS
                prt("[v2] No exact match found, but found the following PARTIAL...\n") if (VERB2());
                prt("$pcnt of $fcnt: Found [$dir] with [$find_path]\n") if (VERB1());
                # last;
            }
        }
    }
}

if (length($find_path) == 0) {
    prt("Note: Given NO path to find... so list all $dcnt ($fcnt) in 'PATH'...");
    if ($notfnd > 0) {
        prt(" $notfnd path not found...");
    }
    $notfnd = $fcnt - $dcnt;
    if ($notfnd) {
        prt(" skipped $notfnd blank...");
    }
    prt("\n");
    $ret = 2;   # set ERROR
}
prt("Exit with [$ret]\n") if (VERB1());
exit $ret;

# eof