prepare_ppa_package

#!/bin/bash

set -o errexit
set -o pipefail
set -o nounset

################################################################################
# Constants
################################################################################

c_supported_distros=(jammy focal bionic)
c_supported_copyrights=(apache artistic bsd gpl gpl2 gpl3 isc lgpl lgpl2 lgl3 mit) # from the dh_make manpage
c_default_section=utils
export c_changelog_description="Upstream version"

declare -A c_required_packages=([dh_make]=dh-make [debuild]=devscripts [cowbuilder]=cowbuilder)

# Version 9 requires special treatment - debhelper_build_depedency.
declare -A c_debhelper_distro_versions=([jammy]=13 [focal]=12 [bionic]=11)
c_package_ppa_version=1
# Requires a subdirectory named <distroname> for each distro build environment.
c_pbuilder_distros_base_path="/var/cache/pbuilder/distros"
c_pbuilder_output_dir="/var/cache/pbuilder/result"

c_help="Usage: $(basename "$0") [options] <project_directory>

Requires the following packages to be installed: $(IFS=,; echo "${c_required_packages[*]}").

Parameters:

-c|--cowbuild:              Build with cowbuilder before uploading
-u|--no-upload:             Don't upload the package
-t|--no-test:               Don't execute the test target (overrides the \`dh_auto_test\` rule)

Environment-variable parameters (mandatory):

- \$PPA_PAK_PACKAGE_NAME
- \$PPA_PAK_VERSION
- \$PPA_PAK_COPYRIGHT         : Filename of the copyright file, or (supported) copyright name (see below)
- \$PPA_PAK_PPA_ADDRESS
- \$PPA_PAK_EMAIL
- \$PPA_PAK_DESCRIPTION
- \$PPA_PAK_HOMEPAGE

Environment-variable parameters (optional):

- \$PPA_PAK_BUILD_DEPS        : Comma-separed list of build dependencies
- \$PPA_PAK_DEPS              : Comma-separed list of dependencies
- \$PPA_PAK_DISTROS:          : Comma-separed list of distros to build; defaults to all the supported ones (see below)
- \$PPA_PAK_LONG_DESCRIPTION  : Long package description; defaults to the value of \$PPA_PAK_DESCRIPTION
- \$PPA_PAK_SECTION           : Package section; defaults to \`$c_default_section\`
- \$PPA_PAK_VCS_BROWSER       : Source project homepage
- \$PPA_PAK_VCS_GIT           : Source project git address

The supported standard copyrights are: $(IFS=,; echo "${c_supported_copyrights[*]}").
The supported distributions are: $(IFS=,; echo "${c_supported_distros[*]}").

Example (mandatory -> optional -> command):

    export PPA_PAK_PACKAGE_NAME='ruby2.5'
    export PPA_PAK_VERSION='2.5.8-sav1'
    export PPA_PAK_COPYRIGHT=~/build/ruby-2.7.1/BSDL
    export PPA_PAK_PPA_ADDRESS='ppa:saverio/ruby-test-4'
    export PPA_PAK_EMAIL='saverio.notexists@gmail.com'
    export PPA_PAK_DESCRIPTION='Interpreter of object-oriented scripting language Ruby'
    export PPA_PAK_HOMEPAGE='https://www.ruby-lang.org/'

    export PPA_PAK_BUILD_DEPS='autoconf,automake,bison,ca-certificates' # incomplete
    export PPA_PAK_DEPS='libgmp-dev'
    export PPA_PAK_DISTROS='bionic,focal,jammy'
    export PPA_PAK_LONG_DESCRIPTION=\$'Ruby is the\ninterpreted scripting language\nfor quick and easy'
    export PPA_PAK_SECTION='interpreters'
    export PPA_PAK_VCS_BROWSER='https://github.com/ruby/ruby/'
    export PPA_PAK_VCS_GIT='https://github.com/ruby/ruby.git'

    $(basename "$0") ~/build/ruby-2.7.1
"

################################################################################
# Variables
################################################################################

v_cowbuild=  # `1`: true; anything else: false
v_no_upload= # `1`: true; anything else: false
v_no_test=   # `1`: true; anything else: false
v_project_directory=

export v_package_name=
export v_package_version_with_debian=
v_dhmake_copyright_options=()
export v_ppa_address=
export v_author_email=
export v_description=
export v_homepage=

export v_build_depends=()
export v_depends=()
export v_build_distros=()
export v_long_description=
export v_section=
export v_vcs_browser=
export v_vcs_git=

################################################################################
# MAIN STAGES
################################################################################

function decode_commandline_options {
  eval set -- "$(getopt --options hcut --long help,cowbuild,no-upload,no-test -- "$@")"

  while true ; do
    case "$1" in
      -h|--help)
        echo "$c_help"
        exit 0 ;;
      -c|--cowbuild)
        v_cowbuild=1
        shift ;;
      -u|--no-upload)
        v_no_upload=1
        shift ;;
      -t|--no-test)
        v_no_test=1
        shift ;;
      --)
        shift
        break ;;
    esac
  done

  if [[ $# -ne 1 ]]; then
    echo "$c_help"
    exit 1
  fi

  v_project_directory=$1
}

function check_and_set_env_variables {
  v_package_name=$PPA_PAK_PACKAGE_NAME
  v_package_version_with_debian=$PPA_PAK_VERSION

  if [[ -f "$PPA_PAK_COPYRIGHT" ]]; then
    v_dhmake_copyright_options=(--copyright custom --copyrightfile "$PPA_PAK_COPYRIGHT")
  else
    v_dhmake_copyright_options=(--copyright "$PPA_PAK_COPYRIGHT")
  fi

  v_ppa_address=$PPA_PAK_PPA_ADDRESS
  v_author_email=$PPA_PAK_EMAIL
  v_description=$PPA_PAK_DESCRIPTION
  v_homepage=$PPA_PAK_HOMEPAGE

  if [[ ${PPA_PAK_BUILD_DEPS:-} == *' '* ]]; then
    >&2 echo "The variable \$PPA_PAK_BUILD_DEPS can't contain spaces; use comma to separate the packages."
    exit 1
  else
    mapfile -td, v_build_depends < <(echo -n "${PPA_PAK_BUILD_DEPS:-}")
  fi

  if [[ ${PPA_PAK_DEPS:-} == *' '* ]]; then
    >&2 echo "The variable \$PPA_PAK_DEPS can't contain spaces; use comma to separate the packages."
    exit 1
  else
    mapfile -td, v_depends < <(echo -n "${PPA_PAK_DEPS:-}")
  fi

  if [[ ${PPA_PAK_DISTROS:-} != "" ]]; then
    mapfile -td, v_build_distros < <(echo -n "$PPA_PAK_DISTROS")
  else
    v_build_distros=("${c_supported_distros[@]}")
  fi

  v_section=${PPA_PAK_SECTION:-$c_default_section}
  v_vcs_browser=${PPA_PAK_VCS_BROWSER:-}
  v_vcs_git=${PPA_PAK_VCS_GIT:-}

  while IFS= read -r description_line; do
    [[ -z $description_line ]] && description_line=.
    v_long_description+=" $description_line"$'\n'
  done <<< ${PPA_PAK_LONG_DESCRIPTION:-$v_description}
}

function check_required_packages {
  for executable in "${!c_required_packages[@]}"; do
    if [[ ! -x "$(command -v "$executable")" ]]; then
      local package=${c_required_packages[$executable]}
      >&2 echo "The executable \`$executable\` hasn't been found; please install the package \`$package\`".
      exit 1
    fi
  done
}

function switch_directory {
  cd "$v_project_directory"
}

function create_debian_metadata {
  rm -rf debian

  # The phony name is replaced at upload time.
  #
  dh_make -p "${v_package_name}_1.2.3-foo4~bar5" --yes --single --native "${v_dhmake_copyright_options[@]}" --email "$v_author_email"
  rm debian/*.ex debian/*.EX

  # The version change part of this file is performed at the distro cycle.
  #
  # `dch` takes care of this, however, it doesn't allow editing of an existing entry.
  #
  # Sample:
  #
  #     ruby2.5 (1.2.3-foo4~bar5) unstable; urgency=medium
  #
  #       * Initial Release.
  #
  #      -- Saverio Miroddi <saverio.xxx@gmail.com>  Thu, 21 May 2020 11:58:40 +0200
  #
  perl -i -pe 's/Initial Release/$ENV{c_changelog_description}/' debian/changelog

  if [[ ${#v_build_depends[@]} -gt 0 ]]; then
    build_depends=$(IFS=,; echo "${v_build_depends[*]}") perl -i -pe 's/^Build-Depends: .*\K/,$ENV{build_depends}/' debian/control
  fi

  if [[ ${#v_depends[@]} -gt 0 ]]; then
    depends=$(IFS=,; echo "${v_depends[*]}") perl -i -pe 's/^Depends: .*\K/,$ENV{depends}/' debian/control
  fi

  perl -i -pe 's/^Section: \K.*/$ENV{v_section}/'                        debian/control
  perl -i -pe 's/^Homepage: \K.*/$ENV{v_homepage}/'                      debian/control
  perl -i -pe 's/^Description: \K.*/$ENV{v_description}/'                debian/control
  perl -i -pe 's/^ <insert long description.*/$ENV{v_long_description}/' debian/control

  [[ -n $v_vcs_browser ]] && perl -i -pe 's/^#(Vcs-Browser:).*/$1 $ENV{v_vcs_browser}/' debian/control
  [[ -n $v_vcs_git     ]] && perl -i -pe 's/^#(Vcs-Git:).*/$1 $ENV{v_vcs_git}/'         debian/control

  # Leave the default as is (`any`); we select architectures built via PPA.
  #
  # perl -i -pe 's/^(Architecture:) .*/$1 amd64/' debian/control

  # Enable verbose log; helps debugging.
  #
  perl -i -pe 's/.*(export DH_VERBOSE).*/$1=1/' debian/rules

  # The `dh_dwz` target fails, because `dwz` finds nothing compressible, so we disable it.
  #
  printf $'override_dh_dwz:\n\techo Skipping dh_dwz target\n\n' >> debian/rules

  # Build using the default builder configuration, which is:
  #
  #     ./configure --build=x86_64-linux-gnu --prefix=/usr --includedir=\${prefix}/include --mandir=\${prefix}/share/man
  #       --infodir=\${prefix}/share/info --sysconfdir=/etc --localstatedir=/var --disable-silent-rules --libdir=\${prefix}/lib/x86_64-linux-gnu
  #       --runstatedir=/run --disable-maintainer-mode --disable-dependency-tracking`
  #
  # Otherwise, `dpkg-deb` (in the `dh_builddeb` target) complains that files are installed under
  # `/usr/local` (which breaks the debian standard).
  #
  # printf $'override_dh_auto_configure:\n\t./configure --prefix=/usr/local\n\n' >> debian/rules

  # Another target with `/usr/local` problems. See: https://unix.stackexchange.com/a/386838.
  #
  # printf $'override_dh_usrlocal:\n\techo Skipping dh_usrlocal target\n\n' >> debian/rules

  # Disable testing.
  #
  if [[ $v_no_test == "1" ]]; then
    printf $'override_dh_auto_test:\n\techo Skipping dh_auto_test target\n\n' >> debian/rules
  fi
}

function hold_sudo_permissions {
  sudo -v

  while true; do
    sudo -n true
    sleep 60
    kill -0 "$$" || exit
  done 2>/dev/null &
}

function build_and_upload_package {
  for distribution in "${v_build_distros[@]}"; do
    local package_version_with_ppa=${v_package_version_with_debian}~${distribution}${c_package_ppa_version}
    local package_name_with_version_with_ppa="${v_package_name}_${package_version_with_ppa}"

    echo ">>> Building $package_name_with_version_with_ppa ($distribution)"

    # See previous note about `dch` unfitness.
    #
    sed -i -E "1c$v_package_name ($package_version_with_ppa) ${distribution}; urgency=medium" debian/changelog

    # debuild uses the `debhelper-compat (= ...)` dependency version to find the compatibility level,
    # However, on xenial, the package is `debhelper`, so this strategy can't be used.
    #
    debhelper_dependency=$(prepare_debhelper_dependency "${c_debhelper_distro_versions[$distribution]}") \
      perl -i -pe 's/debhelper-compat \(.+?\)/$ENV{debhelper_dependency}/' debian/control

    # Options order matters!
    #
    # `--no-tgz-check`:  don't search for the original when a debian version is present
    # `--no-lintian`:    save time; for testing purposes
    # `-d`:              skip the dependency checks, due to `debhelper` on xenial (debuild assumes
    #                    that the build happens on the same machine)
    # `-S`:              build a source package; `--build=source` is equivalent, but oddly, doesn't find
    #                    the changes file during build
    # `-Zgzip`:          fast compression; for testing purposes.
    # `--tar-ignore=//`: the invoke `dpkg-source` filters out some files, including `.gitignore`, which
    #                    are needed (!!) by some bundled gems this sets a phony pattern.
    #
    # Creates `debian/files`, which can be ignored.
    #
    debuild --no-tgz-check --no-lintian -d -S -Zgzip --tar-ignore=//

    if [[ $v_cowbuild == "1" ]]; then
      sudo cowbuilder --build --basepath "$c_pbuilder_distros_base_path/$distribution" --distribution "$distribution" "../${package_name_with_version_with_ppa}.dsc"
      echo ">>> Built package: $c_pbuilder_output_dir/${package_name_with_version_with_ppa}_amd64.deb"
    fi

    if [[ $v_no_upload != "1" ]]; then
      dput "$v_ppa_address" "../${package_name_with_version_with_ppa}_source.changes"
    fi

    echo "--------------------------------------------------------------------------------"
  done
}

################################################################################
# HELPERS
################################################################################

# Creates `debian/compat`, if required, and returns the build-dependency package
# definition.
#
# $1: debhelper version
#
function prepare_debhelper_dependency {
  if [[ $1 -le 9 ]]; then
    # Insanity. In case of v9:
    #
    # - the package is `debhelper`;
    # - debuild requires `debian/compat` to be specified; but it must not be specified
    #   when the package is `debhelper-compat` (v11+);
    # - `= 9` doesn't work (the current package version is `9.20160115ubuntu3`), although,
    #   with `debhelper-compat`, `= X` works with versions `X.Y` (eg. `11.2`).
    #
    echo -n "debhelper (>= 9)"
    echo "9" > debian/compat
  else
    echo -n "debhelper-compat (= $1)"
  fi
}

################################################################################
# EXECUTION
################################################################################

decode_commandline_options "$@"
check_and_set_env_variables
check_required_packages
switch_directory
create_debian_metadata
[[ $v_cowbuild == "1" ]] && hold_sudo_permissions
build_and_upload_package