#!/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 NOVIEW=""                           # disable viewing the PKGBUILD
declare -g NOCONF=""                           # disable extra confirmations
declare -i CACHE=0                             # keep cached package downloads
readonly BUILD_DIR="$HOME/.cache/aur_builds"   # AUR build directory
readonly AUR_ADDR="https://aur.archlinux.org"  # AUR web address
readonly PKG_ADDR="$AUR_ADDR/packages"         # AUR package address

## ----------------------------------------------------------------- ##

readonly SCRIPT="$(readlink -f "$0")" # real path to this file
declare -a AUR_PKGS=()                # array of AUR packages
declare -a PAC_PKGS=()                # array of official packages

usage() { # show the standard UNIX style help message.. usage: usage
    cat <<- EOF
baph - Basic AUR Package Helper, a simple script to install and update packages

usage: baph <operation> [package(s)] [options]

operations:
    baph {-h --help}
    baph {-u --update}  [package(s)] [options]
    baph {-i --install} <package(s)> [options]

options:
    --noview      Skip viewing the PKGBUILD for AUR packages and dependencies
    --noconfirm   Skip most confirmations when building also passed to pacman

EOF
}

#-- Utility functions --#

msg() { printf "$1\e[0m \e[1m$2\e[0m\n"; }
die() { printf "\e[1m\e[31merror:\e[0m $1\n"; exit ${2:-1}; }

comp() { # compare AUR package versions, returns 0 or 1.. usage: comp "package" "current version"
    NEW="$(curl --silent "$PKG_ADDR/$1" | awk '/Details:/ {sub(/<\/h.?>/, ""); print $4}')"
    [[ -n $NEW && "$2" == "$NEW" ]] && return 0 || return 1
}

yesno() { # only shown when not using --noconfirm, returns 0 or 1.. usage: yesno "question"
    if [[ $NOCONF ]]; then
        printf "\n\e[34m::\e[0m \e[1m$1? [Y/n]\e[0m "; read -r conf
        [[ $conf =~ [nN] ]] && return 1  # return non zero when confirm n/N
    fi
    return 0
}

#-- Update functions --#

prepupdate() { # prep for package update.. usage: prepupdate
    (( ${#AUR_PKGS[@]} == 0 )) || update # exits here if passed packages to update
    sudo pacman -Syyu $NOCONF || exit 1
    AUR_PKGS=($(pacman -Qqm 2>/dev/null))
    (( ${#AUR_PKGS[@]} == 0 )) && msg '\e[34m::' "No AUR packages installed.." || update
}

update() { # check update for each package in AUR_PKGS=().. usage: update
    local cur
    local up=()
    msg '\e[34m::' "Synchronizing AUR package versions..."
    for i in "${AUR_PKGS[@]}"; do
        ver="$(pacman -Qs "^$i$" 2>/dev/null | awk 'NR==1 {print $2}')"
        if [[ $ver ]]; then
            comp "$i" "$ver" && printf "$i-$ver --> up to date\n" || up+=("$i")
        else
            msg '\e[33m::' "$i is not installed.. skipping"
        fi
    done
    msg '\e[34m::' "Starting AUR package upgrade..."
    if (( ${#up[@]} > 0 )); then
        printf "\n\e[1mPackages (${#up[@]})\e[0m  %s\n\n" "${up[@]}"
        for i in "${up[@]}"; do
            getpkg "$i"
        done
    else
        printf " there is nothing to do\n"
    fi
    exit 0
}

#-- Install functions --#

prepinstall() { # loop package arrays if set and install each.. usage: prepinstall
    (( ${#PAC_PKGS[@]} == 0 && ${#AUR_PKGS[@]} == 0 )) && die "no targets specified" 2
    (( ${#PAC_PKGS[@]} > 0 )) && sudo pacman -S ${PAC_PKGS[*]} $NOCONF
    for pkg in "${AUR_PKGS[@]}"; do
        response="$(curl --silent --head "$PKG_ADDR/$pkg" | awk 'NR==1 {print $2}')"
        (( response == 200 )) || die "$response response from $PKG_ADDR/$pkg"
        getpkg "$pkg" || msg '\e[33m::' "Exiting $pkg build early"
    done
}

getpkg() { # install an AUR package.. usage: getpkg "package"
    local bd="$BUILD_DIR/$1"
    local pkgbuild="$bd/PKGBUILD"

    comp "$1" && msg '\e[1m'$'\e[33mwarning:' "$1-$OLD is up to date -- reinstalling"
    (( CACHE == 1 )) || rm -rf "$bd" >/dev/null 2>&1
    [[ -d $bd ]] || mkdir -p "$bd"

    if [[ ! -e $pkgbuild || $CACHE -eq 0 ]]; then
        git clone "$AUR_ADDR/$1" "$bd" || die "failed to clone $AUR_ADDR/$1"
    elif [[ -e $pkgbuild ]]; then
        cd "$bd"
        git pull || die "failed to pull from $AUR_ADDR/$1"
    fi

    [[ -e $pkgbuild ]] && cd "$bd" || die "$bd doesn't contain a PKGBUILD"
    view "$1" "$pkgbuild" && { yesno "Continue building $1" || return 1; }
    buildpkg "$1" "$pkgbuild"
    return 0
}

view() { # view PKGBUILD.. usage: view "package" "/path/to/PKGBUILD"
    if ! [[ $NOVIEW ]]; then
        yesno "View the PKGBUILD for $1" || return 1
        if hash nvim >/dev/null 2>&1; then
            nvim -n -R -u "$(find /usr/share/nvim/ -wholename '*/macros/less.vim')" "$2"
        elif hash vim >/dev/null 2>&1; then
            vim -n -R -u "$(find /usr/share/vim/ -wholename '*/macros/less.vim')" "$2"
        else
            less -P " -- Viewing PKGBUILD for $1 -- (press q to exit)" "$2"
        fi
    fi
}

buildpkg() { # build package.. usage: buildpkg "package" "/path/to/PKGBUILD"
    eval "$(cat "$BUILD_DIR/$1/PKGBUILD")"
    (( ${#validpgpkeys[@]} > 0 )) && importkeys ${validpgpkeys[*]}
    (( ${#depends[@]} > 0 )) && builddeps "$1" ${depends[*]}
    makepkg -sicr
}

importkeys() { # import PGP keys from package.. usage: importkeys ${KEYS[@]}
    for key in "$@"; do
        pacman-key --list-keys | grep -q "$key" && continue
        msg '\e[33m::' "resolving missing key $key"
        gpg --receive-keys "$key"
        sudo pacman-key -r "$key" && sudo pacman-key --lsign-key "$key"
    done
}

builddeps() { # build package depends.. usage: builddeps "package" ${DEPENDS[@]}
    local pdir="$1"; shift
    for i in "$@"; do
        depend="$(sed 's/[=<>]=\?[0-9]*\?\.\?[0-9]*\?\.\?[0-9]*\?//g' <<< "$i")"
        available="$(pacman -Ssq "^$depend$" 2>/dev/null)"
        [[ $available ]] && continue
        msg '\e[33m::' "resolving AUR dependency -> $depend"
        getpkg "$depend" || die "failed to build dependency $depend"
    done
    cd "$BUILD_DIR/$pdir"
}

#-- Argument parsing & execution --#

pkg_args() { # parse additional command line arguments.. usage: pkg_args $@
    for i in "$@"; do case $i in
        --noview) NOVIEW="--noview" ;;
        --noconfirm) NOCONF="--noconfirm" ;;
        --*|-[a-z]) die "invalid option -- '$i'" ;;
        *) pacman -Ssq "^$i$" >/dev/null 2>&1 && PAC_PKGS+=("$i") || AUR_PKGS+=("$i")
    esac done
}

# catch Ctrl-C and exit
trap 'die "^C caught.."' SIGINT

if (( $# == 0 )); then
    die "no operation specified (use -h for help)" 2
elif ! hash pacman git curl >/dev/null 2>&1; then
    die "this script requires the following packages installed: pacman git curl"
else
    for arg in "$@"; do case $arg in
        --help|-h) usage && exit 0 ;;
        --update|-u) shift; pkg_args "$@"; prepupdate; break ;;
        --install|-i) shift; pkg_args "$@"; prepinstall; break ;;
        *) die "invalid option -- '$arg'"
    esac done
    [[ $CACHE -eq 0 && -d $BUILD_DIR ]] && rm -rf "$BUILD_DIR" >/dev/null 2>&1
fi