#!/bin/bash
set -euo pipefail

# Usage: ./edit-deb-fixed.sh <input.deb> <output.deb> <new_package> <new_description>

if [ $# -lt 4 ]; then
  echo "Usage: $0 <input.deb> <output.deb> <new_package> <new_description>"
  exit 1
fi

ORIG_DEB="$1"
MOD_DEB="$2"
NEW_PACKAGE="$3"
NEW_DESCRIPTION="$4"

if [ ! -e "$ORIG_DEB" ]; then
  echo "Error: input .deb not found: $ORIG_DEB"
  exit 1
fi

ORIG_DEB_ABS="$(readlink -f "$ORIG_DEB")"
MOD_DEB_ABS="$(readlink -f "$MOD_DEB" 2>/dev/null || printf "%s/%s" "$(pwd)" "$MOD_DEB")"

TMPDIR="$(mktemp -d)"
cleanup() {
  rm -rf "$TMPDIR"
}
trap cleanup EXIT

cd "$TMPDIR"

# 1) Распаковать deb
ar x "$ORIG_DEB_ABS"

# 2) Найти control.tar.*
shopt -s nullglob
controls=(control.tar.*)
if [ ${#controls[@]} -eq 0 ]; then
  echo "Error: control.tar.* not found inside the .deb"
  exit 1
fi
control_file="${controls[0]}"
EXT="${control_file##*.}"

# 3) Распаковать control
mkdir control
tar -xpf "$control_file" -C control

if [ ! -f control/control ]; then
  echo "Error: control file 'control/control' is missing"
  exit 1
fi

# 4) Правим Package и Description
awk -v pkg="$NEW_PACKAGE" -v desc="$NEW_DESCRIPTION" '
  BEGIN{pkg_done=0; desc_done=0}
  /^Package: / && !pkg_done { print "Package: " pkg; pkg_done=1; next }
  /^Description: / && !desc_done { print "Description: " desc; desc_done=1; next }
  { print }
' control/control > control/control.new
mv control/control.new control/control

# 5) Пересобрать control.tar.* с root:root
rm -f "$control_file"
case "$EXT" in
  gz)
    tar --sort=name --owner=0 --group=0 -cpzf control.tar.gz -C control .
    ;;
  xz)
    tar --sort=name --owner=0 --group=0 -cpJf control.tar.xz -C control .
    ;;
  zst)
    if tar --help 2>&1 | grep -q -- '--zstd'; then
      tar --sort=name --owner=0 --group=0 --zstd -cpf control.tar.zst -C control .
    else
      tar --sort=name --owner=0 --group=0 -cpf - -C control . | zstd -19 -c -o control.tar.zst
    fi
    ;;
  *)
    echo "Error: unknown control archive extension: .$EXT"
    exit 1
    ;;
esac

# 6) Найти и распаковать data.tar.*
data_files=(data.tar.*)
if [ ${#data_files[@]} -eq 0 ]; then
  echo "Error: data.tar.* not found in the .deb"
  exit 1
fi
data_file="${data_files[0]}"
DATA_EXT="${data_file##*.}"

mkdir data
tar -xpf "$data_file" -C data

# 7) Пересобрать data.tar.* с root:root
rm -f "$data_file"
case "$DATA_EXT" in
  gz)
    tar --sort=name --owner=0 --group=0 -cpzf data.tar.gz -C data .
    ;;
  xz)
    tar --sort=name --owner=0 --group=0 -cpJf data.tar.xz -C data .
    ;;
  zst)
    if tar --help 2>&1 | grep -q -- '--zstd'; then
      tar --sort=name --owner=0 --group=0 --zstd -cpf data.tar.zst -C data .
    else
      tar --sort=name --owner=0 --group=0 -cpf - -C data . | zstd -19 -c -o data.tar.zst
    fi
    ;;
  *)
    echo "Error: unknown data archive extension: .$DATA_EXT"
    exit 1
    ;;
esac

# 8) Собрать новый deb
ar rcs "$MOD_DEB_ABS" debian-binary "control.tar.$EXT" "data.tar.$DATA_EXT"

# 9) Проверка
echo "✅ Done. New package created at: $MOD_DEB_ABS"
dpkg-deb -I "$MOD_DEB_ABS" || true