#!/bin/bash

# Simple tool to update and install AUR packages for Arch Linux
#
# Written by Nathaniel Maia, September 2018
#
# This software is provided free of charge and WITHOUT warranty


declare -g PKGS=()   # array of AUR packages
declare -g NOVIEW=0  # view the PKGBUILD of each AUR package
declare -g NOCONF=0  # no confirmation after viewing the PKGBUILD
declare -g BDIR="$HOME/.cache/aur_builds"   # AUR build directory
declare -g AUR="https://aur.archlinux.org"  # AUR address

readonly SCRIPT="$(readlink -f $0)"
readonly BASENAME="${0#*/}"

usage() {
    cat <<- EOF
B.A.P.H - Basic AUR Package Helper

A simple and short script that allows installing and updating packages

USAGE:  $NAME [OPTIONS] [PACKAGE]

OPTIONS:
        --help,-h      Display this message
        --update,-u    Update all AUR packages on the system
        --noview,-n    Skip viewing the PKGBUILD for AUR packages
        --noconfirm    Skip confirmation after viewing the PKGBUILD
EOF
    exit 0
}

die() {
    echo "$1" && exit ${2:-0}
}

comp() {
    old="$(pacman -Qs "^$1$" | awk 'NR==1 {print $2}')"
    new="$(curl --silent $AUR/packages/$1 | awk '/Details:/ {sub(/<\/h.?>/, ""); print $4}')"
    [[ "$old" == "$new" ]] && return 0 || return 1
}

buildp() {
    local p="$1"
    # evaluating the PKGBUILD could be dangerous but is short
    # the user has either viewed and confirmed it or doesn't care and passed --noconfirm
    eval "$(cat "$BDIR/$p/PKGBUILD")"
    for d in ${depends[@]}; do
        pacman -Ssq "^$d$" >/dev/null 2>&1 || $SCRIPT --noview --noconfirm "$d"
    done
    makepkg -sicr
}

update() {
    sudo pacman -Syyu
    local installed
    installed="$(pacman -Qqm 2>/dev/null)"
    if [[ $installed ]]; then
        echo "Info: Updating AUR packages"
        for p in $(echo $installed); do
            comp "$p" && echo "$p  ->  up to date" || $SCRIPT --noview --noconfirm "$p"
        done
    else
        echo "Info: No AUR packages installed..."
    fi
    exit 0
}

install() {
    local p="$1"

    if pacman -Qsq "^$p$" >/dev/null 2>&1; then
        comp "$p" && echo "Warning: $p already installed and up to date"
    fi

    rm -rf "$BDIR/$p" >/dev/null 2>&1
    mkdir -p "$BDIR/$p"

    if ! git clone $AUR/$p.git $BDIR/$p; then
        die "Error: Git clone failed" 1
    elif [[ ! -e $BDIR/$p/PKGBUILD ]]; then
        die "Error: $BDIR/$p is missing a PKGBUILD" 1
    else
        cd "$BDIR/$p"

        if [[ $NOVIEW -eq 0 ]]; then
            less -P " -- Viewing PKGBUILD for $p -- (press q to exit)" PKGBUILD
        fi

        if [[ $NOCONF -eq 0 ]]; then
            printf "\n\nDo you want to continue installing $p? [Y/n]: " && read -r conf
        fi

        if [[ $NOCONF -eq 1 || $conf =~ [yY] ]]; then
            buildp "$p"
        else
            echo "Info: Exiting $p build process early"
        fi

        cd $HOME && rm -rf "$BDIR/$p" >/dev/null 2>&1
    fi
}

if ! hash git curl >/dev/null 2>&1; then
    die "Error: This requires git and curl installed" 1
fi

# command line arguments
for arg in $@; do case $arg in
    --help|-h)   usage    ;;
    --update|-u) update   ;;
    --noview|-n) NOVIEW=1 ;;
    --noconfirm) NOCONF=1 ;;
    *) PKGS+=($arg)
esac done

if [[ ${#PKGS[@]} -eq 0 ]]; then
    die "Error: Requires at least one package to install" 2
else
    for pkg in ${PKGS[@]}; do
        if pacman -Ssq "^$pkg$" >/dev/null 2>&1; then
            sudo pacman -S "$pkg"
        elif curl --silent --head $AUR/packages/$pkg | head -n 1 | grep -q '200'; then
            install "$pkg"
        else
            die "Error: Failed response from $AUR/packages/$pkg" 1
        fi
    done
fi

exit 0