masspkg

#!/bin/bash
#
# masspkg - The MassOS Package Manager.
# Copyright (C) 2022 MassOS Developers.
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <https://www.gnu.org/licenses/>.
#
# Set version and copyright year.
VER="1.1.0"
CP_YEAR="2022"
# Exit on error.
set -e
# Location of the configuration file.
cfg="/etc/masspkg.conf"
# Set invocation.
invocation="$(basename $0)"
# Ensure we are root.
if [ $EUID -ne 0 ]; then
  echo "Error: $invocation must be run as root." >&2
  exit 1
fi
# Set architecture.
sys_arch="$(uname -m)"
# Die (exit on error) function.
die() {
  test -z "$@" || echo "$@" >&2
  exit 1
}
mf_err() {
  echo "Error: Manifest file is corrupted or has syntax errors." >&2
  exit 1
}
# Function to check if function.
is_function() {
  type -t "$1" | grep -q 'function'
}
# Check and source the configuration file.
if [ ! -e "$cfg" ]; then
  die "Error: Configuration file $cfg was not found."
fi
. /etc/masspkg.conf 2>/dev/null || true
if [ -z "$repo" ]; then
  die "Error: You must define a remote repository in $cfg."
elif [ -z "$datadir" ]; then
  die "Error: Must set a data directory (e.g. /var/lib/masspkg) in $cfg."
fi
# Create the data directory if it doesn't exist.
if [ ! -d "$datadir" ]; then
  if [ -e "$datadir" ]; then
    die "Error: $datadir exists but is not a directory; cannot use it."
  else
    mkdir -p "$datadir"
  fi
fi
# Setup the data directory structure if not present.
mkdir -p "$datadir"/{cache,extracted,manifest}
# If a backup file does not exist, try to create it.
test -e "$cfg.orig" || (cp "$cfg" "$cfg.orig" 2>/dev/null || true)
# Clean up any residue from previous runs.
rm -rf "$datadir"/cache/*
# Unset any potentially conflicting environment variables.
unset friendly fdep not_in ok_packages pkg_deps the_list to_rm to_upd
# Set arguments, ignoring the operation specifier.
operation="$1"
if [ ! -z "$2" ]; then
  shift
  args="$@"
else
  unset args
fi
# Usage/help function.
help() {
  echo "masspkg - The MassOS Package Manager."
  echo "Version $VER - Copyright (C) $CP_YEAR MassOS Developers."
  echo
  echo "$invocation install - Install one or more package(s)."
  echo "$invocation update  - Scan for and install package update(s)."
  echo "$invocation remove  - Remove one or more package(s)."
  echo "$invocation list    - List installed package(s)."
  echo "$invocation info    - Get information about a particular package."
  echo
  echo "This is free software. For the license, see /usr/share/massos/LICENSE"
  echo "on a MassOS system, or visit <https://www.gnu.org/licenses/gpl.html>."
}
# Install function.
operation_install() {
  if [ -z "$args" ]; then
    echo "Error: You must specify at least one package to install." >&2
    echo >&2
    echo "Usage: $invocation install <package-name>" >&2
    exit 1
  fi
  # Check if packages are installed.
  for pkg in $args; do
    if grep -Fqx -- "$pkg" "$builtins" 2>/dev/null; then
      echo "$pkg is already installed as part of your system."
    elif [ -e "$datadir/manifest/$pkg.manifest" ]; then
      . "$datadir/manifest/$pkg.manifest" 2>/dev/null || mf_err
      if [ "$installed_as_dependency" = "True" ]; then
        echo "$pkg is already installed as a dependency of another package."
        echo "Marking $pkg as manually installed."
        sed -e 's/as_dependency="True"/as_dependency="False"/' \
        -i "$datadir/manifest/$pkg.manifest"
      else
        echo "$pkg is already installed."
      fi
    else
      not_in="$not_in $pkg"
    fi
  done
  if [ -z "$not_in" ]; then
    exit 0
  fi
  # Try to fetch the package metadata.
  for pkg in $not_in; do
    curl --fail-with-body -Ls "$repo/$sys_arch/manifest/$pkg.manifest" \
    -o "$datadir/cache/$pkg.manifest" 2>/dev/null ||
    (rm -rf "$datadir"/cache/*; die "Error: Could not locate package $pkg.")
    # Check architecture.
    . "$datadir/cache/$pkg.manifest" 2>/dev/null || mf_err
    if [ "$arch" != "$sys_arch" ] && [ "$arch" != "any" ]; then
      rm -rf "$datadir"/cache/*
      die "Error: $pkg does not support architecture $sys_arch."
    fi
    ok_packages="$ok_packages $pkg"
  done
  # Check dependencies (needs to be a function so we can use it recursively).
  check_deps() {
    unset deps
    . "$datadir/cache/$1.manifest" 2>/dev/null || mf_err
    if [ ! -z "$deps" ]; then
      for dp in $deps; do
        # Check if dependency is installed as part of the system.
        if ! grep -Fqx -- "$dp" "$builtins" 2>/dev/null; then
          if [ ! -e "$datadir/cache/$dp.manifest" ] && \
          [ ! -e "$datadir/manifest/$dp.manifest" ]; then
            curl --fail-with-body -Ls "$repo/$sys_arch/manifest/$dp.manifest" \
            -o "$datadir/cache/$dp.manifest" 2>/dev/null ||
            (rm -rf "$datadir"/cache/*;
            die "Error: Could not satisfy dependency $dp of package $1.")
            pkg_deps="$pkg_deps $dp"
            check_deps "$dp"
          fi
        fi
      done
    fi
  }
  for pkg in $ok_packages; do
    check_deps $pkg || die
  done
  # Display packages to be installed.
  for i in $ok_packages; do
    . "$datadir/cache/$i.manifest" 2>/dev/null || mf_err
    friendly="$friendly, $pkgname=$pkgver"
  done
  friendly="$(echo "$friendly" | sed 's/, //')"
  if [ -z "$pkg_deps" ]; then
    fdep="None"
  else
    for i in $pkg_deps; do
      . "$datadir/cache/$i.manifest" 2>/dev/null || mf_err
      fdep="$fdep, $pkgname=$pkgver"
    done
    fdep="$(echo "$fdep" | sed 's/, //')"
  fi
  echo "Packages you've chosen install: $friendly"
  echo "Dependencies needed by those packages: $fdep"
  echo "Total packages to install: $(wc -w <<< "$friendly $pkg_deps")"
  echo
  read -p "Proceed with the installation? [Y/n] " proceed_inst
  proceed_inst="${proceed_inst:0:1}"
  proceed_inst=$(echo "$proceed_inst" | tr '[:upper:]' '[:lower:]')
  if [ "$proceed_inst" = "n" ]; then
    rm -rf "$datadir"/cache/*
    exit 1
  fi
  # Download all packages; dependencies first.
  for i in $pkg_deps $ok_packages; do
    . "$datadir/cache/$i.manifest" 2>/dev/null || mf_err
    echo "Downloading $i=$pkgver..."
    curl --fail-with-body -Ls \
    "$repo/$sys_arch/archives/$i-$pkgver-$arch.tar.xz" -o \
    "$datadir/cache/$i-$pkgver-$arch.tar.xz" 2>/dev/null ||
    (rm -rf "$datadir"/cache/*; die "Error: Failed to download package $i.")
  done
  # Once everything has downloaded, extract them to the extraction directory.
  for i in $pkg_deps $ok_packages; do
    . "$datadir/cache/$i.manifest" 2>/dev/null || mf_err
    echo "Unpacking $i=$pkgver..."
    test ! -e "$datadir/extracted/$i-$pkgver-$arch" ||
    rm -rf "$datadir/extracted/$i-$pkgver-$arch"
    mkdir -p "$datadir/extracted/$i-$pkgver-$arch"
    tar -xpf "$datadir/cache/$i-$pkgver-$arch.tar.xz" -C \
    "$datadir/extracted/$i-$pkgver-$arch" 2>/dev/null ||
    (rm -rf "$datadir/extracted/$i-$pkgver-$arch"; rm -rf "$datadir"/cache/*;
    die "Error: Could not unpack package $i.")
  done
  # Install the packages.
  pushd "$datadir/extracted" >/dev/null
  for i in $pkg_deps $ok_packages; do
    . "$datadir/cache/$i.manifest" 2>/dev/null || mf_err
    echo "Installing $i=$pkgver..."
    # Run pre_install steps.
    if $(is_function pre_install); then
      pre_install || true
    fi
    cp -a "$i-$pkgver-$arch"/* / 2>/dev/null ||
    (rm -rf "$datadir"/cache/*; rm -rf "$datadir/extracted/$i-$pkgver-$arch";
    die "Error: Failed to install package $i.")
    # Run post_install steps.
    if $(is_function post_install); then
      post_install || true
    fi
    unset pre_install post_install
  done
  popd >/dev/null
  # Move manifest files to $datadir/manifest.
  for i in $pkg_deps; do
    echo 'installed_as_dependency="True"' >> "$datadir/cache/$i.manifest"
    mv "$datadir/cache/$i.manifest" "$datadir/manifest/$i.manifest"
  done
  for i in $ok_packages; do
    echo 'installed_as_dependency="False"' >> "$datadir/cache/$i.manifest"
    mv "$datadir/cache/$i.manifest" "$datadir/manifest/$i.manifest"
  done
  # Clean up anything left over.
  rm -rf "$datadir"/cache/*
  # Final message.
  echo "The installation was successful."
  exit 0
}
# Update function.
operation_update() {
  installed="$(ls -A "$datadir/manifest")"
  if [ -z "$installed" ]; then
    echo "You don't currently have any packages installed."
    exit 0
  fi
  for i in $installed; do
    curl --fail-with-body -Ls "$repo/$sys_arch/manifest/$i" -o \
    "$datadir/cache/$i" || continue
    # Compare package versions to determine whether an update is needed.
    . "$datadir/manifest/$i" 2>/dev/null || mf_err
    localver="$pkgver"
    . "$datadir/cache/$i" 2>/dev/null || mf_err
    remotever="$pkgver"
    if [ "$localver" != "$remotever" ]; then
      to_upd="$to_upd $pkgname"
    fi
  done
  if [ -z "$to_upd" ]; then
    echo "No updates are available."
    rm -rf "$datadir"/cache/*
    exit 0
  fi
  # Show information and a confirmation prompt.
  echo "$(wc -w <<< "$to_upd") packages will be updated:"
  echo
  for i in $to_upd; do
    . "$datadir/manifest/$i.manifest" 2>/dev/null || mf_err
    localver="$pkgver"
    . "$datadir/cache/$i.manifest" 2>/dev/null || mf_err
    remotever="$pkgver"
    echo "$pkgname: $localver --> $remotever"
  done
  echo
  read -p "Proceed with the update? [Y/n] " proceed_upd
  proceed_upd="${proceed_upd:0:1}"
  proceed_upd=$(echo "$proceed_upd" | tr '[:upper:]' '[:lower:]')
  if [ "$proceed_upd" = "n" ]; then
    rm -rf "$datadir"/cache/*
    exit 1
  fi
  # Download all the packages.
  for i in $to_upd; do
    . "$datadir/cache/$i.manifest" 2>/dev/null || mf_err
    echo "Downloading $i=$pkgver..."
    curl --fail-with-body -Ls \
    "$repo/$sys_arch/archives/$i-$pkgver-$arch.tar.xz" -o \
    "$datadir/cache/$i-$pkgver-$arch.tar.xz" 2>/dev/null ||
    (rm -rf "$datadir"/cache/*; die "Error: Failed to download package $i.")
  done
  # Once everything has downloaded, extract them to the extraction directory.
  for i in $to_upd; do
    . "$datadir/cache/$i.manifest" 2>/dev/null || mf_err
    echo "Unpacking $i=$pkgver..."
    rm -rf "$datadir/extracted/$i-$pkgver-$arch"
    mkdir -p "$datadir/extracted/$i-$pkgver-$arch"
    tar -xpf "$datadir/cache/$i-$pkgver-$arch.tar.xz" -C \
    "$datadir/extracted/$i-$pkgver-$arch" 2>/dev/null ||
    (rm -rf "$datadir/extracted/$i-$pkgver-$arch"; rm -rf "$datadir"/cache/*;
    die "Error: Could not unpack package $i.")
  done
  # Install the updated packages.
  pushd "$datadir/extracted" >/dev/null
  for i in $to_upd; do
    . "$datadir/cache/$i.manifest" 2>/dev/null || mf_err
    echo "Updating $i=$pkgver..."
    # Run pre_upgrade steps.
    if $(is_function pre_upgrade); then
      pre_upgrade || true
    fi
    # Update the package.
    cp -a "$pkgname-$pkgver-$arch"/* / 2>/dev/null ||
    (rm -rf "$datadir"/cache/*; rm -rf "$datadir/extracted/$i-$pkgver-$arch";
    die "Error: Failed to update package $i.")
    # Run post_upgrade steps.
    if $(is_function post_upgrade); then
      post_upgrade || true
    fi
    unset pre_upgrade post_upgrade
  done
  popd >/dev/null
  # Clean up the old directories and move the new manifest files.
  for i in $to_upd; do
    . "$datadir/manifest/$i.manifest" 2>/dev/null || mf_err
    if [ "$installed_as_dependency" = "True" ]; then
      echo 'installed_as_dependency="True"' >> "$datadir/cache/$i.manifest"
    else
      echo 'installed_as_dependency="False"' >> "$datadir/cache/$i.manifest"
    fi
    mv "$datadir/cache/$i.manifest" "$datadir/manifest/$i.manifest"
  done
  # Clean up anything left over.
  rm -rf "$datadir"/cache/*
  # Final message.
  echo "The update was successful."
  exit 0
}
# Remove function.
operation_remove() {
  if [ -z "$args" ]; then
    echo "Error: You must specify at least one package to remove." >&2
    echo >&2
    echo "Usage: $invocation remove <package-name>" >&2
    exit 1
  fi
  # Check if packages are actually installed.
  for pkg in $args; do
    if grep -Fqx -- "$pkg" "$builtins" 2>/dev/null; then
      die "Error: $pkg is part of your system. Cannot remove it."
    elif [ -e "$datadir/manifest/$pkg.manifest" ]; then
      to_rm="$to_rm $pkg"
    else
      echo "$pkg is not installed."
    fi
  done
  if [ -z "$to_rm" ]; then
    exit 0
  fi
  # Check if removing the package would break dependencies of other packages.
  installed="$(ls -A "$datadir/manifest" | sed "/$to_rm.manifest/d")"
  for i in $installed; do
    . "$datadir/manifest/$i" 2>/dev/null || mf_err
    for j in $to_rm; do
      if echo "$deps" | grep -Fqw -- "$j"; then
        die "Error: $pkg is a dependency of $pkgname. Cannot remove it."
      fi
    done
  done
  # Display packages to be removed.
  for i in $to_rm; do
    . "$datadir/manifest/$i.manifest" 2>/dev/null || mf_err
    friendly="$friendly, $pkgname=$pkgver"
  done
  friendly="$(echo "$friendly" | sed 's/, //')"
  echo "Packages you've chosen remove: $friendly"
  echo "Total packages to remove: $(wc -w <<< "$friendly")"
  echo
  read -p "Proceed with the removal? [Y/n] " proceed_rm
  proceed_rm="${proceed_rm:0:1}"
  proceed_rm=$(echo "$proceed_rm" | tr '[:upper:]' '[:lower:]')
  if [ "$proceed_rm" = "n" ]; then
    rm -rf "$datadir"/cache/*
    exit 1
  fi
  # Remove each package.
  pushd "$datadir/extracted" >/dev/null
  for i in $to_rm; do
    . "$datadir/manifest/$i.manifest" 2>/dev/null || mf_err
    echo "Removing $i=$pkgver..."
    # Run pre_remove steps.
    if $(is_function pre_remove); then
      pre_remove || true
    fi
    # Remove the package.
    for j in $(find "$i-$pkgver-$arch" -type f,l | sed "s/$i-$pkgver-$arch//");
    do
      rm -f "$j" 2>/dev/null || die "Error: Failed to remove package $i."
    done
    # Remove empty directories.
    for j in $(find "$i-$pkgver-$arch" -type d | sed "s/$i-$pkgver-$arch//");
    do
      if [ ! "$(ls -A "$j")" ]; then
        rmdir "$j" 2>/dev/null ||
        echo "Warning: Failed to remove directory $j." >&2
      fi
    done
    # Run post_remove steps.
    if $(is_function post_remove); then
      post_remove || true
    fi
    unset pre_remove post_remove
    # Remove the installed manifest file.
    rm -f "$datadir/manifest/$i.manifest"
    # Finally, remove the extracted data directory.
    rm -rf "$i-$pkgver-$arch"
  done
  popd >/dev/null
  # Clean up anything left over.
  rm -rf "$datadir"/cache/*
  # Final message.
  echo "The removal was successful."
  exit 0
}
# List packages function.
operation_list() {
  if [ "$(ls "$datadir/manifest")" ]; then
    for i in "$datadir"/manifest/*.manifest; do
      . "$i" || mf_err
      if [ "$installed_as_dependency" = "True" ]; then
        the_list="$the_list $pkgname=$pkgver(automatic)"
      else
        the_list="$the_list $pkgname=$pkgver"
      fi
    done
  fi
  if [ -z "$the_list" ]; then
    echo "You don't currently have any packages installed."
  else
    echo "Your installed packages:"
    echo
    echo "$the_list" | column
    echo
    echo "The total number of installed packages is $(wc -w <<< "$the_list")."
  fi
  exit 0
}
# Get information about a particular package function.
operation_info() {
  if [ -z "$args" ]; then
    echo "Error: You must specify a package to get information about." >&2
    echo >&2
    echo "Usage: $invocation info <package-name>" >&2
    exit 1
  fi
  # Only get information about one package.
  pkg="$(echo "$args" | cut -d' ' -f1)"
  # Check if the package is installed as part of the system.
  if grep -Fqx -- "$pkg" "$builtins" 2>/dev/null; then
    echo "$pkg is installed as part of your system."
    exit 0
  elif [ -e "$datadir/manifest/$pkg.manifest" ]; then
    # Get information from installed manifest, if possible.
    . "$datadir/manifest/$pkg.manifest" 2>/dev/null || mf_err
    # Allow displaying of dependencies in a friendly way.
    if [ -z "$deps" ]; then
      fdep="None"
    else
      for i in $deps; do
        fdep="$fdep, $i"
      done
      fdep="$(echo "$fdep" | sed 's/, //')"
    fi
    # Display the information.
    echo "Package name:     $pkgname"
    echo "Package version:  $pkgver"
    echo "Description:      $description"
    echo "Dependencies:     $fdep"
    echo "CPU architecture: $arch"
    echo "Homepage:         $homepage"
    echo "Maintainer:       $maintainer"
    echo "License:          $license"
    echo
    if [ "$installed_as_dependency" = "True" ]; then
      echo "This package is installed as a dependency of another package."
    else
      echo "This package is installed."
    fi
  else
    # Try to fetch the information from the remote repo.
    curl --fail-with-body -Ls "$repo/$sys_arch/manifest/$pkg.manifest" \
    -o "$datadir/cache/$pkg.manifest" 2>/dev/null ||
    (rm -rf "$datadir"/cache/*; die "Error: Could not locate package $pkg.")
    . "$datadir/cache/$pkg.manifest" 2>/dev/null || mf_err
    # Allow displaying of dependencies in a friendly way.
    if [ -z "$deps" ]; then
      fdep="None"
    else
      for i in $deps; do
        fdep="$fdep, $i"
      done
      fdep="$(echo "$fdep" | sed 's/, //')"
    fi
    # Display the information.
    echo "Package name:     $pkgname"
    echo "Package version:  $pkgver"
    echo "Description:      $description"
    echo "Dependencies:     $fdep"
    echo "CPU architecture: $arch"
    echo "Homepage:         $homepage"
    echo "Maintainer:       $maintainer"
    echo "License:          $license"
  fi
}
# Check argument(s) passed and do the necessary operation.
case "$operation" in
  install) operation_install ;;
  update) operation_update ;;
  remove) operation_remove ;;
  list) operation_list ;;
  info) operation_info ;;
  help|-h|-help|--help) help; exit 0 ;;
  version|-v|-V|-version|--version) help | head -n2; help | tail -n3; exit 0 ;;
  *) help >&2; exit 1 ;;
esac