#!/usr/bin/env perl
# Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
#
# SPDX-License-Identifier: curl
#
# bad[:=]correct
#
# If separator is '=', the string will be compared case sensitively.
# If separator is ':', the check is done case insensitively.
#
# To add white listed uses of bad words that are removed before checking for
# the bad ones:
#
# ---(accepted word)
#

use strict;
use warnings;

use File::Basename;

my @whitelist = (
    # ignore what looks like URLs
    '(^|\W)((https|http|ftp):\/\/[a-z0-9\-._~%:\/?\#\[\]\@!\$&\'\(\)*+,;=]+)',
    # remove bolded sections
    '\*\*.*?\*\*',
    # remove backticked texts
    '\`.*?\`'
    );
my %alt;
my %exactcase;
my $skip_indented = 1;

if($ARGV[0] eq "-a") {
    shift @ARGV;
    $skip_indented = 0;
}
my %wl;
if($ARGV[0] eq "-w") {
    shift @ARGV;
    my $file = shift @ARGV;
    open(W, "<$file") or die "Cannot open '$file': $!";
    while(<W>) {
        if(/^#/) {
            # allow #-comments
            next;
        }
        if(/^([^:]*):(\d*):(.*)/) {
            $wl{"$1:$2:$3"}=1;
            #print STDERR "whitelisted $1:$2:$3\n";
        }
    }
    close(W);
}

my @w;
my @exact;
while(<STDIN>) {
    chomp;
    if($_ =~ /^#/) {
        next;
    }
    if($_ =~ /^---(.+)/) {
        push @whitelist, $1;
    }
    elsif($_ =~ /^(.*)([:=])(.*)/) {
        my ($bad, $sep, $better)=($1, $2, $3);
        if($sep eq "=") {
            $alt{$bad} = $better;
            push @exact, $bad;
        }
        else {
            $alt{lc($bad)} = $better;
            push @w, $bad;
        }
    }
}

# Build a single combined regex for case-insensitive words
my $re_ci;
if(@w) {
    my $pat = join('|', map { quotemeta($_) } @w);
    $re_ci = qr/\b($pat)\b/i;
}

# Build a single combined regex for case-sensitive (exact) words
my $re_cs;
if(@exact) {
    my $pat = join('|', map { quotemeta($_) } @exact);
    $re_cs = qr/\b($pat)\b/;
}

# Build a single combined regex for removing whitelisted content
my $re_wl;
my $pat = join('|', map { $_ } @whitelist);
$re_wl = qr/($pat)/;

my $errors = 0;

sub highlight {
    my ($p, $w, $in, $f, $l, $lookup) = @_;

    my $c = length($p)+1;
    my $ch;

    my $dir = dirname($f);
    $ch = $dir . "/" . "::" . $w;
    if($wl{$ch}) {
        # whitelisted dirname + word
        return;
    }
    my $updir = dirname($dir);
    if($dir ne $updir) {
        $ch = $updir . "/" . "::" . $w;
        if($wl{$ch}) {
            # whitelisted upper dirname + word
            return;
        }
    }
    $ch = $f . "::" . $w;
    if($wl{$ch}) {
        # whitelisted filename + word
        return;
    }
    $ch = "$f:$l:$w";
    if($wl{$ch}) {
        # whitelisted filename + line + word
        return;
    }

    print STDERR  "$f:$l:$c: error: found bad word \"$w\"\n";
    printf STDERR " %4d | %s\n", $l, $in;
    printf STDERR "      | %*s^%s\n", length($p), " ",
        "~" x (length($w)-1);
    printf STDERR " maybe use \"%s\" instead?\n", $alt{$lookup};
    $errors++;
}

sub file {
    my ($f) = @_;
    my $l = 0;
    open(F, "<$f");
    while(<F>) {
        my $in = $_;
        $l++;
        chomp $in;
        if($skip_indented && $in =~ /^    /) {
            next;
        }
        # remove the link part
        $in =~ s/(\[.*\])\(.*\)/$1/g;
        # remove whitelisted patterns (pre-compiled)
        if($re_wl) {
            $in =~ s/${re_wl}//ig;
        }
        # case-insensitive bad words
        if($re_ci) {
            if($in =~ /^(.*)$re_ci/i) {
                highlight($1, $2, $in, $f, $l, lc($2));
            }
        }
        # case-sensitive (exact) bad words
        if($re_cs) {
            if($in =~ /^(.*)$re_cs/) {
                highlight($1, $2, $in, $f, $l, $2);
            }
        }
    }
    close(F);
}

my @filemasks = @ARGV;
open(my $git_ls_files, '-|', 'git', 'ls-files', '--', @filemasks) or die "Failed running git ls-files: $!";
my @files;
while(my $each = <$git_ls_files>) {
    chomp $each;
    push @files, $each;
}
close $git_ls_files;

my $onum = scalar(@files);
my $num;
for my $e (@files) {
    #printf STDERR "Complete: %d%%\r", $num++ * 100 / $onum;
    file($e);
}

exit $errors;