#!/usr/bin/bash

VERSION="3.2"
IGREEN="\033[0;92m"     # Intense Green
IYELLOW="\033[0;93m"    # Intense Yellow
IRED='\033[0;91m'       # Red
NO_COLOR="\033[0m"      # Text Reset
TMP="/tmp/update"
DATE="$(date +"%Y-%m-%dT%H:%M:%S%:z")"  # RFC 3339 date-time https://datatracker.ietf.org/doc/html/rfc3339#section-5.6

trap interrupt_function INT

interrupt_function() {
    echo -e "${IRED}\nInterrupt has been detected${NO_COLOR}"
    if [ -f /var/lib/pacman/db.lck ]; then
        echo -e "${IRED}Trying to unlock the pacman db. Please enter your password.${NO_COLOR}"
        su --command="rm --force /var/lib/pacman/db.lck"
    fi
    [[ -d $TMP ]] && rm --recursive --force "$TMP"
    [[ -f "$BACKUP_LOCATION"/before-backup_"$DATE".tar.zst.new ]] && rm --force "$BACKUP_LOCATION"/before-backup_"$DATE".tar.zst.new
    [[ -f "$BACKUP_LOCATION"/after-backup_"$DATE".tar.zst.new ]] && rm --force "$BACKUP_LOCATION"/after-backup_"$DATE".tar.zst.new
    exit 1
}

help() {
    echo "Usage: update [OPTION]"
    echo "options:"
    echo "--help         displays this message"
    echo "--preview      shows a preview of pkg's and flatpaks which can be updated"
    echo "--version      prints out the version number"
}

source "$HOME"/.config/update.conf || echo -e "${IRED}No config found${NO_COLOR}" || exit 1

if [[ ${1:0:2} == \-\- ]]; then
    case "${1:2}" in
        help)
            help ;;
        preview)
            "$PACMAN_WRAPPER" -Syy
            "$PACMAN_WRAPPER" --query --upgrades
            [[ -x /usr/bin/flatpak ]] && flatpak remote-ls --updates ;;
        version)
            echo "$VERSION" ;;
        ?)
            help; exit 1;;
    esac
    exit 0
fi

check_for_valid_backup_location() {
    if [ ! -d $1 ]; then
        echo -e "${IYELLOW}$1 doesn't exist${NO_COLOR}"
        read -p "Do you want to create the path and continue? [y/N]" input
        case $input in
            [Yy]) mkdir --parents "$1" ;;
            [Nn]) exit 0;;
            * ) exit 0 ;;
        esac
    fi
}

if [ $BACKUP_LOCATION ]; then
    check_for_valid_backup_location "$BACKUP_LOCATION"
else
    echo -e "${IRED}No BACKUP_LOCATION in $HOME/.config/update.conf specified${NO_COLOR}"
    exit 1
fi
[[ $SECONDARY_BACKUP_LOCATION ]] && check_for_valid_backup_location "$SECONDARY_BACKUP_LOCATION"

lock_pacman_db() {
    if [ -f /var/lib/pacman/db.lck ]; then
        echo -e "${IYELLOW}->${NO_COLOR} /var/lib/pacman/db.lck exists"
        echo -e "${IYELLOW}->${NO_COLOR} there might be another instance of pacman running. exiting..."
        exit 1
    fi

    echo -e "${IYELLOW}Trying to lock the pacman db. Please enter your password.${NO_COLOR}"
    su --command="touch /var/lib/pacman/db.lck"
}

unlock_pacman_db() {
    echo -e "${IYELLOW}Trying to unlock the pacman db. Please enter your password.${NO_COLOR}"
    su --command="rm --force /var/lib/pacman/db.lck"
}

delete_oldest_backup() {
    if [[ $(find $BACKUP_LOCATION -name '*$1*' -exec printf %c {} + | wc -c) -ge $BACKUP_AMOUNT ]]; then
        rm --force $(find "$BACKUP_LOCATION" -name '*$1*' | sort -rn | head -1)
    fi
}

before_backup() {
    lock_pacman_db

    [[ -d $TMP ]] && rm --recursive --force "$TMP"
    mkdir --parents "$TMP"/before-backup_"$DATE" "$TMP"/after-backup_"$DATE"

    pacman --verbose --query > "$TMP"/before-backup_"$DATE"/pacman-before.txt
    [[ -x /usr/bin/flatpak ]] && flatpak list --all --show-details > "$TMP"/before-backup_"$DATE"/flatpak-before.txt

    tar --create --zstd --file "$TMP"/before-backup_"$DATE".tar.zst.new "$TMP"/before-backup_"$DATE" /var/lib/pacman/local
    cp "$TMP"/before-backup_"$DATE".tar.zst.new "$BACKUP_LOCATION"
    [[ $SECONDARY_BACKUP_LOCATION ]] && cp "$TMP"/before-backup_"$DATE".tar.zst.new "$SECONDARY_BACKUP_LOCATION"

    unlock_pacman_db
}

after_backup() {
    lock_pacman_db

    pacman --verbose --query > "$TMP"/after-backup_"$DATE"/pacman-after.txt
    [[ -x /usr/bin/flatpak ]] && flatpak list --all --show-details > "$TMP"/after-backup_"$DATE"/flatpak-after.txt
    tar --create --zstd --file "$TMP"/after-backup_"$DATE".tar.zst.new "$TMP"/after-backup_"$DATE"

    cp "$TMP"/after-backup_"$DATE".tar.zst.new "$BACKUP_LOCATION"
    [[ $SECONDARY_BACKUP_LOCATION ]] && cp "$TMP"/after-backup_"$DATE".tar.zst.new "$SECONDARY_BACKUP_LOCATION"

    delete_oldest_backup after-backup
    mv "$BACKUP_LOCATION"/after-backup_"$DATE".tar.zst.new "$BACKUP_LOCATION"/after-backup_"$DATE".tar.zst
    [[ $SECONDARY_BACKUP_LOCATION ]] && mv "$SECONDARY_BACKUP_LOCATION"/after-backup_"$DATE".tar.zst.new "$SECONDARY_BACKUP_LOCATION"/after-backup_"$DATE".tar.zst

    delete_oldest_backup before-backup
    mv "$BACKUP_LOCATION"/before-backup_"$DATE".tar.zst.new "$BACKUP_LOCATION"/before-backup_"$DATE".tar.zst
    [[ $SECONDARY_BACKUP_LOCATION ]] && mv "$SECONDARY_BACKUP_LOCATION"/before-backup_"$DATE".tar.zst.new "$SECONDARY_BACKUP_LOCATION"/before-backup_"$DATE".tar.zst

    unlock_pacman_db
    rm --recursive --force "$TMP"
}

update() {
    "$PACMAN_WRAPPER"
    if [[ -x /usr/bin/flatpak ]]; then
        flatpak update --assumeyes
        flatpak list --all --show-details > "$TMP"/after-backup_"$DATE"/flatpak-after.txt
    fi
}

before_backup && echo -e "${IGREEN}before-backup complete${NO_COLOR}"
update
after_backup && echo -e "${IGREEN}after-backup complete${NO_COLOR}"