#!/bin/bash

# meld-pkgbuilds - search, download, cache and compare PKGBUILDs
# across Parabola abslibre and various upstreams
#
# Copyright (C) 2023 bill-auger <bill-auger@programmer.net>
#
# SPDX-License-Identifier: AGPL-3.0-or-later
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero 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 Affero General Public License for more details.
#
# You should have received a copy of the GNU Affero General Public License
# along with this program.  If not, see <https://www.gnu.org/licenses/>.
#
#
# NOTE: you should create a /packages directory and install 'pacman-all.conf' to /etc
#
# NOTE: FSDG warning: this program is capable of locating and downloading build recipes
#       which are not be FSDG-fit. It is mainly useful for merging upstream changes into
#       PKGBUILDs which Parabola replaces; but should be used cautiously. The usual reason
#       why Parabola replaces those packages is because the upstream source or recipes are
#       not FSDG-fit; so you must apply your own judgement when using this tool.


readonly DEBUG=0

readonly ARCH_DIR=/packages/arch
readonly ARTIX_DIR=/packages/artix
readonly AUR_DIR=/packages/aur
readonly ABSLIBRE_DIR=/packages/abslibre
readonly ARCH_URL=https://gitlab.archlinux.org/archlinux/packaging
readonly ARTIX_URL=https://gitea.artixlinux.org
readonly AUR_URL=https://aur.archlinux.org

readonly CAQUA='\033[00;36m'
readonly CYELLOW='\033[01;33m'
readonly CEND='\033[00m'

readonly CLONE_MSG="attempting to clone from"

PKGNAME_RX= # deferred
SORT=       # deferred
PKGNAME=    # deferred


MeldPkgbuilds()
{
  DBG()  { echo -e "${CAQUA}DEBUG: $@${CEND}"     >&2 ; }
  WARN() { echo -e "${CYELLOW}WARNING: $@${CEND}" >&2 ; }

  get_repo()
  {
    LANG=C sudo pacman --config /etc/pacman-all.conf -Syi ${PKGNAME} 2>/dev/null  | \
    grep ^Repository | sort ${SORT} | head -n 1 | cut -d : -f 2 | tr -d ' '
  }

  find_statefile()
  {
    local state_dir="${ARCH_DIR}"/state
    local statefile="$(find "${state_dir}"/{core,extra,multilib}-{any,$(uname -m)} \
                            -maxdepth 2 -type f -name ${PKGNAME} 2> /dev/null      )"

    echo "${statefile}"
    [[ -n "${statefile}" ]]
  }

  verify_writable_dir() # ("target_dir")
  {
    local target_dir="$1"
    local param_err_msg="invalid targ# NOTE: you should install 'pacman-all.conf'et_dir '${target_dir}' - quitting"
    local perms_err_msg="lacking write permission for '${target_dir}' - quitting"

    [[ -n "${target_dir}" ]] || ! echo "${param_err_msg}" || return 1
    mkdir -p "${target_dir}" || ! echo "${perms_err_msg}" || return 1
  }

  clone_or_pull() # (git_url "target_dir")
  {
    # eg: | $ARCH_URL                                     |        | $PKGNAME  |
    # eg: https://gitlab.archlinux.org/archlinux/packaging/packages/qutebrowser.git

    local git_url=$1
    local target_dir="$2"

if (( DEBUG )) ; then ([[ ! -d "${target_dir}"/.git ]]              &&
                       DBG "git clone ${git_url} \"${target_dir}\"" ||
                       DBG "(cd \"${target_dir}\" ; git pull ;)"     ) >&2 ;  fi

    if   [[ ! -d "${target_dir}"/.git ]]
    then git clone ${git_url} "${target_dir}" 2>&1
    else (cd "${target_dir}" ; git fetch &> /dev/null ; git pull ;)
#     fi &> /dev/null
    fi | grep -E 'Cloning|Fast-forward|Already up to date.'
  }

  find_pkgbuild_dirs() # ("pkgbuilds_dir")
  {
    local pkgbuilds_dir="$1"

    dirname $(find "${pkgbuilds_dir}" -path "*/${PKGNAME}/PKGBUILD" | sort ${SORT}) 2> /dev/null
  }

  find_pkgbuild_dir() # ("pkgbuilds_dir")
  {
    find_pkgbuild_dirs "$1" | head -n 1
  }


  local blacklist_entry=$(libreblacklist get ${PKGNAME} 2> /dev/null)
  local arch_dir="$(    find_pkgbuild_dir ${ARCH_DIR}    )"
  local artix_dir="$(   find_pkgbuild_dir ${ARTIX_DIR}   )"
  local aur_dir="$(     find_pkgbuild_dir ${AUR_DIR}     )"
  local abslibre_dir="$(find_pkgbuild_dir ${ABSLIBRE_DIR})"
  local is_nonsystemd
  local cached_dir
  local upstream
  local upstream_url
  local source_dir
  local statefile
  local arch
  local pkgver


(( DEBUG )) && DBG "PKGNAME='$PKGNAME'"
(( DEBUG )) && DBG "arch_dir='$arch_dir'"
(( DEBUG )) && DBG "artix_dir='$artix_dir'"
(( DEBUG )) && DBG "aur_dir='$aur_dir'"
(( DEBUG )) && DBG "abslibre_dir='$abslibre_dir'"


  if   [[ -n "${blacklist_entry}" ]]
  then echo "blacklist reason: $(libreblacklist get-reason <<<${blacklist_entry})"
  else echo "pkgname: '${PKGNAME}' is not blacklisted"
  fi

  if   [[ -n "${arch_dir}${artix_dir}${aur_dir}${abslibre_dir}" ]]
  then echo "cached PKGBUILDs:"
       find_pkgbuild_dirs ${ARCH_DIR}     | sed 's|^|  |'
       find_pkgbuild_dirs ${ARTIX_DIR}    | sed 's|^|  |'
       find_pkgbuild_dirs ${AUR_DIR}      | sed 's|^|  |'
       find_pkgbuild_dirs ${ABSLIBRE_DIR} | sed 's|^|  |'
  fi

  # consult the arch 'state' repo first
  echo "consulting arch state repo ...."
  clone_or_pull ${ARCH_URL}/state.git "${ARCH_DIR}"/state
  ((! $?)) && echo "synchronized state repo" || WARN "failed to synchronize state repo"
  if   statefile="$(find_statefile)"
  then repo=$(basename $(dirname "${statefile}"))
       arch=${repo##*-} ; repo=${repo%-*} ;
       pkgver=$(cut -d ' ' -f 2 ${statefile}) # [pkgbase pkgver git-tag checksum]

       # eg: 'qutebrowser' (extra/any)
       echo "found statefile for '${PKGNAME}' (${arch}/${repo} ${pkgver})"
  else WARN "statefile not found for '${PKGNAME}'"
  fi


(( DEBUG )) && DBG "abslibre_dir='$abslibre_dir'"
(( DEBUG )) && DBG "pkgbuild='$pkgbuild'"
(( DEBUG )) && DBG "upstream='$upstream' upstream_url='$upstream_url'"
(( DEBUG )) && DBG "source_dir(init)='${source_dir}'"
# (( DEBUG )) && exit 0
# (( DEBUG )) && source_dir=''


  # set abslibre target directory
  is_nonsystemd=$( [[ "${abslibre_dir}"        =~ /nonsystemd(-testing)?/[^/]*$ ||   \
                      "$(get_repo ${PKGNAME})" =~ ^nonsystemd(-testing)?$       ||   \
                      -z "${statefile}"                                         ]] ; \
                   echo $((! $?))                                                  ; )
  cached_dir="${abslibre_dir}"
  if   [[ -z "${abslibre_dir}" ]]
  then if   [[ -n "${statefile}" ]]
       then if   (( is_nonsystemd ))
            then abslibre_dir="${ABSLIBRE_DIR}"/nonsystemd/${PKGNAME}
            else abslibre_dir="${ABSLIBRE_DIR}"/libre/${PKGNAME}
            fi
       else if   (( is_nonsystemd ))
            then abslibre_dir="${ABSLIBRE_DIR}"/nonsystemd/${PKGNAME}
            else abslibre_dir="${ABSLIBRE_DIR}"/pcr/${PKGNAME}
            fi
       fi
  fi

  # set upstream source
  if   (( is_nonsystemd ))
  then [[ -z "${artix_dir}" ]] && echo "PKGBUILD not found in artix cache"
       upstream=artix ; upstream_url=${ARTIX_URL}/packages/${PKGNAME}.git ;
       source_dir="${ARTIX_DIR}"/${PKGNAME}
  else [[ -z "${arch_dir}"  ]] && echo "PKGBUILD not found in arch cache"
       upstream=arch  ; upstream_url=${ARCH_URL}/packages/${PKGNAME}.git ;
       source_dir="${ARCH_DIR}"/${PKGNAME}
  fi

  # warnings
  [[ -z "${arch_dir}"  || -z "${aur_dir}"                       ]] || WARN "multiple upstream PKGBUILDs found (arch and AUR)"
  [[ -z "${artix_dir}" || -z "${aur_dir}"                       ]] || WARN "multiple upstream PKGBUILDs found (artix and AUR)"
  (( $(find_pkgbuild_dirs ${ABSLIBRE_DIR} | wc -l) < 2          )) || WARN "multiple abslibre PKGBUILDs found (use --reverse if necessary)"
  [[ -z "${cached_dir}" || "${abslibre_dir}" == "${cached_dir}" ]] || WARN "orphaned abslibre_dir: '${pkgbuild}' (cleanup manually)"

  # sanity checks
  verify_writable_dir "${source_dir}"   || exit 1
  verify_writable_dir "${abslibre_dir}" || exit 1


  # search arch or artix VCS for PKGBUILD
  if   [[ "$(curl -s -w '%{http_code}' -o /dev/null ${upstream_url%.git})" == 200 ]]
  then [[ -f "${source_dir}"/PKGBUILD ]] && echo "syncronizing ${upstream} ...." ||
                                            echo "${CLONE_MSG} ${upstream} ...."
       clone_or_pull ${upstream_url} "${source_dir}"
  else WARN "${upstream} repo not found for '${PKGNAME}'"
  fi

  # search AUR VCS for PKGBUILD
  if   [[ -f "${source_dir}"/PKGBUILD ]]
  then echo "PKGBUILD found in ${upstream}"
  else echo "PKGBUILD not found in ${upstream} ... ${CLONE_MSG} AUR ...."
       source_dir="${AUR_DIR}"/${PKGNAME} # posibbly same as $aur_dir
       verify_writable_dir "${source_dir}" || exit 1

       [[ -f "${source_dir}"/PKGBUILD ]] && echo "PKGBUILD found in AUR cache"
       clone_or_pull ${AUR_URL}/${PKGNAME}.git     "${source_dir}"
       [[ -f "${source_dir}"/PKGBUILD ]] ||
       clone_or_pull ${AUR_URL}/${PKGNAME}-git.git "${source_dir}"
       [[ -f "${source_dir}"/PKGBUILD ]] && echo "PKGBUILD found in AUR" ||
       [[ ! -d "${source_dir}"/.git   ]] || WARN "VCS is empty: ${source_dir}"
  fi

  [[ -f ${source_dir}/PKGBUILD ]] || ! echo "PKGBUILD not found - quitting" || return 1


(( DEBUG )) && DBG "source_dir(final)='${source_dir}'"


  if   [[ ! -f "${abslibre_dir}"/PKGBUILD ]]
  then echo "no such parabola PKGBUILD - seeding from upstream"

       # copy upstream recipe files and recurse
       mkdir -p "${abslibre_dir}"
       cp -a "${source_dir}"/* "${abslibre_dir}"/
  fi


(( DEBUG )) && DBG "DEBUG done - set DEBUG=0 to launch meld" && return


  echo -e "\nlaunching meld on:\n"
  ls -l "${source_dir}"/ "${abslibre_dir}"/ ; echo ;
  (set -x ; meld "${source_dir}"/ "${abslibre_dir}"/)

  return 0
}


readonly PKGNAME_RX='^[-@\._\+0-9a-z]+$' ;
readonly SORT=$( [[ "$1" == '--reverse'   ]] && echo "$1" ) ; [[ -z "${SORT}" ]] || shift ;
readonly PKGNAME=$(    [[ "$1" =~ ${PKGNAME_RX} ]] && echo "$1" )

(( $# == 1         )) || ! echo "invalid params"        || exit 1
[[ -n "${PKGNAME}" ]] || ! echo "invalid pkgname: '$1'" || exit 1


MeldPkgbuilds