#!/bin/bash

set -e

[ -e /etc/default/pkgsync ] && . /etc/default/pkgsync

EXCLUSION_LIST="${EXCLUSION_LIST:-/etc/pkgsync/pkg_exclude.list}"
BLACKLIST_LIST="${BLACKLIST_LIST:-/etc/pkgsync/pkg_blacklist.list}"
REMOVE_LIST="${REMOVE_LIST:-/etc/pkgsync/pkg_remove.list}"
INSTALL_LIST="${INSTALL_LIST:-/etc/pkgsync/pkg_install.list}"
PRESTART_SCRIPT="${PRESTART_SCRIPT:-/etc/pkgsync/pkg_prestart.sh}"
FINISH_SCRIPT="${FINISH_SCRIPT:-/etc/pkgsync/pkg_finish.sh}"
TMP_DIR="${TMP_DIR:-/tmp}"

[ -x "$PRESTART_SCRIPT" ] && "$PRESTART_SCRIPT"

# we really don't care if these exist or not or are empty, we just want empty files if so
grep -v '^#' "$EXCLUSION_LIST" 2>/dev/null | sort -u > "$TMP_DIR/pkg_exclude.list"   || true
grep -v '^#' "$BLACKLIST_LIST" 2>/dev/null | sort -u > "$TMP_DIR/pkg_blacklist.list" || true
grep -v '^#' "$REMOVE_LIST"    2>/dev/null | sort -u > "$TMP_DIR/pkg_remove.list"    || true
grep -v '^#' "$INSTALL_LIST"   2>/dev/null | sort -u > "$TMP_DIR/pkg_install.list"   || true

# get our explicitly installed packages, minus hardware-specific exclusions
pacman -Qq | sort | comm -23 - "$TMP_DIR/pkg_exclude.list" > "$TMP_DIR/mypkgs_with_exclusions.txt"

# exclude packages to remove
comm -23 "$TMP_DIR/mypkgs_with_exclusions.txt" "$TMP_DIR/pkg_remove.list" > "$TMP_DIR/mypkgs_with_exclusions_without_remove.txt"

# list of packages to remove, with our blacklist excluded
comm -12 "$TMP_DIR/mypkgs_with_exclusions.txt" "$TMP_DIR/pkg_remove.list" | comm -23 - "$TMP_DIR/pkg_blacklist.list" > "$TMP_DIR/pkg_toremove.list"

# combine our packages with shared installed list, excluding remove
sort -u "$TMP_DIR/mypkgs_with_exclusions_without_remove.txt" "$TMP_DIR/pkg_install.list" | comm -23 - "$TMP_DIR/pkg_remove.list" > "$TMP_DIR/pkg_installed.list"

# list of packages to install, with our blacklist excluded
comm -13 "$TMP_DIR/mypkgs_with_exclusions_without_remove.txt" "$TMP_DIR/pkg_installed.list" | comm -23 - "$TMP_DIR/pkg_blacklist.list" > "$TMP_DIR/pkg_toinstall.list"

# packages already on this computer not in the shared install list we need to put in there
comm -23 "$TMP_DIR/pkg_installed.list" "$TMP_DIR/pkg_install.list" > "$TMP_DIR/pkg_ourinstall.list"

# offer to install missing packages
if [ -s "$TMP_DIR/pkg_toinstall.list" ]
then
    yn=l
    while [[ ! "$yn" =~ ^[YyNnAaQqBb]$ ]]
    do
        read -p "Install new packages? (yes/no/list/abort/blacklist)..." -n 1 yn
        echo
        [[ "$yn" =~ ^[Ll]$ ]] && cat "$TMP_DIR/pkg_toinstall.list"
    done
    [[ "$yn" =~ ^[Yy]$ ]] && pacman -S --needed --confirm - < "$TMP_DIR/pkg_toinstall.list"
    [[ "$yn" =~ ^[Bb]$ ]] && cat "$TMP_DIR/pkg_toinstall.list" >> "$BLACKLIST_LIST"
    [[ "$yn" =~ ^[AaQq]$ ]] && exit 1
fi

# offer to remove packages
if [ -s "$TMP_DIR/pkg_toremove.list" ]
then
    yn=l
    while [[ ! "$yn" =~ ^[YyNnAaQqBb]$ ]]
    do
        read -p "Remove packages? (yes/no/list/abort/blacklist)..." -n 1 yn
        echo
        [[ "$yn" =~ ^[Ll]$ ]] && cat "$TMP_DIR/pkg_toremove.list"
    done
    [[ "$yn" =~ ^[Yy]$ ]] && pacman -Ru --confirm - < "$TMP_DIR/pkg_toremove.list"
    [[ "$yn" =~ ^[Bb]$ ]] && cat "$TMP_DIR/pkg_toremove.list" >> "$BLACKLIST_LIST"
    [[ "$yn" =~ ^[AaQq]$ ]] && exit 1
fi

# offer to update install list, if it changed
if [ -s "$TMP_DIR/pkg_ourinstall.list" ]
then
    yn=l
    while [[ ! "$yn" =~ ^[YyNnAaQqEe]$ ]]
    do
        read -p "Append packages unique to this computer to install list and run finish script? (yes/no/list/abort/exclude)..." -n 1 yn
        echo
        [[ "$yn" =~ ^[Ll]$ ]] && cat "$TMP_DIR/pkg_ourinstall.list"
    done
    [[ "$yn" =~ ^[Yy]$ ]] && cat "$TMP_DIR/pkg_ourinstall.list" >> "$INSTALL_LIST"
    [[ "$yn" =~ ^[Ee]$ ]] && cat "$TMP_DIR/pkg_ourinstall.list" >> "$EXCLUSION_LIST"
    [[ "$yn" =~ ^[AaQq]$ ]] && exit 1
    [ -x "$FINISH_SCRIPT" ] && "$FINISH_SCRIPT"
fi

rm -f "$TMP_DIR/pkg_exclude.list" "$TMP_DIR/pkg_blacklist.list" "$TMP_DIR/pkg_remove.list" "$TMP_DIR/mypkgs_with_exclusions.txt" "$TMP_DIR/mypkgs_with_exclusions_without_remove.txt" "$TMP_DIR/pkg_toremove.list" "$TMP_DIR/pkg_installed.list" "$TMP_DIR/pkg_toinstall.list" "$TMP_DIR/pkg_ourinstall.list"