#!/usr/bin/env bash
# Minify HTML files from src/ to production versions in this directory.
# Adapted from /Users/Akasha/Development/ontoref/assets/web/minify.sh.
# Usage: ./minify.sh

set -euo pipefail

BASE_DIR="$(cd "$(dirname "$0")" && pwd)"
FILES=("index.html")

minify_file() {
    local filename="$1"
    local SRC_FILE="${BASE_DIR}/src/${filename}"
    local OUT_FILE="${BASE_DIR}/${filename}"
    local TEMP_FILE="${OUT_FILE}.tmp"

    if [ ! -f "$SRC_FILE" ]; then
        echo "  Source file not found: $SRC_FILE (skipping)"
        return 0
    fi

    echo ""
    echo "Minifying ${filename}..."
    echo "  Input:  $SRC_FILE"
    echo "  Output: $OUT_FILE"

    perl -e "
use strict;
use warnings;

open(my \$fh, '<', '$SRC_FILE') or die \$!;
my \$content = do { local \$/; <\$fh> };
close(\$fh);

# Preserve <pre>, <code>, and <textarea> blocks verbatim.
my @preserved;
\$content =~ s{(<(pre|code|textarea)\b[^>]*>.*?</\2>)}{
  push @preserved, \$1;
  '__PRESERVED_' . (\$#preserved) . '__';
}gies;

# Remove HTML comments
\$content =~ s/<!--.*?-->//gs;

# Compress CSS (remove block comments and collapse whitespace)
\$content =~ s/(<style[^>]*>)(.*?)(<\/style>)/
  my \$before = \$1;
  my \$style  = \$2;
  my \$after  = \$3;
  \$style =~ s{\/\*.*?\*\/}{}gs;
  \$style =~ s{\s+}{ }gs;
  \$style =~ s{\s*([{}:;,>+~])\s*}{\$1}gs;
  \$before . \$style . \$after;
/gies;

# Compress JavaScript (strip line comments and collapse whitespace)
\$content =~ s/(<script[^>]*>)(.*?)(<\/script>)/
  my \$before = \$1;
  my \$script = \$2;
  my \$after  = \$3;
  \$script =~ s{\/\/[^\n\r]*}{}g;
  \$script =~ s{\s+}{ }gs;
  \$script =~ s{\s*([{}();,])\s*}{\$1}gs;
  \$before . \$script . \$after;
/gies;

# Remove whitespace between tags
\$content =~ s/>\s+</></gs;

# Compress general whitespace
\$content =~ s/\s+/ /gs;

# Trim
\$content =~ s/^\s+|\s+\$//g;

# Restore preserved blocks
\$content =~ s/__PRESERVED_(\d+)__/\$preserved[\$1]/g;

open(my \$out, '>', '$TEMP_FILE') or die \$!;
print \$out \$content;
close(\$out);
" || {
        echo "Minification failed"
        rm -f "$TEMP_FILE"
        exit 1
    }

    mv "$TEMP_FILE" "$OUT_FILE"

    original=$(wc -c <"$SRC_FILE")
    minified=$(wc -c <"$OUT_FILE")
    saved=$((original - minified))
    percent=$((saved * 100 / original))

    echo ""
    echo "  Compression statistics:"
    printf "    Original:  %6d bytes\n" "$original"
    printf "    Minified:  %6d bytes\n" "$minified"
    printf "    Saved:     %6d bytes (%d%%)\n" "$saved" "$percent"
    echo "  ${filename} ready for production"
}

echo "Starting HTML minification..."

for file in "${FILES[@]}"; do
    minify_file "$file"
done

echo ""
echo "All files minified successfully."