#!/bin/bash
# pacman downloader in bash
# requires: curl and tar

# the repo name and URL (includes OS)
REPO_NAME="my-repo"
ARCH=$(uname -m)
REPO_URL="https://packages.yourpacmanrepo.com/$ARCH"

VERBOSE=0

vecho () {
    if [ "$VERBOSE" = "1" ]; then
        echo "=> $@"
    fi
}

# used to store the downloaded file
OUTPUT=""
TARGET=""

# arrays where we will store package names and versions
declare -a packages

# load all package and version info into the hash
sync_packages () {
    # download the repo info
    vecho "Fetching .gz repo info from: $REPO_URL/$REPO_NAME.files"
    RES=$(curl -s $REPO_URL/$REPO_NAME.files | tar tzf - | grep /$ | sed 's/.$//')

    # copy the data into our package arrays
    while read -r line; do
        packages+=("$line")
    done <<< "$RES"
}

list_packages() {
    # sync the repo info
    sync_packages

    # print the package names
    for i in "${!packages[@]}"; do
        # if verbose print version and arch too
        if [ "$VERBOSE" = "1" ]; then
            echo "${packages[$i]}-$ARCH"
        else
            echo "${packages[$i]}"
        fi
    done
    return 0
}

search_package() {
    # sync the repo info
    sync_packages

    vecho "Searching for matches for package: $1"

    # search for the package
    for i in "${!packages[@]}"; do
        if [[ "${packages[$i]}" =~ $1 ]]; then
            echo "${packages[$i]}"
        fi
    done

    vecho "Package not found: $1"
    return 1
}

download_package() {
    TARGET=$1
    # if we end with $ARCH, remove it
    if [ "${TARGET: -${#ARCH}}" = "$ARCH" ]; then
        TARGET=${TARGET:0:-${#ARCH}}
    fi

    # download the package
    OUTPUT=$1-$ARCH.pkg.tar.xz
    vecho "Fetching .tar.xz package from: $REPO_URL/$OUTPUT"
    curl --output $OUTPUT -s $REPO_URL/$OUTPUT
    return $?
}

extract_package() {
    # first download it
    download_package $1

    # then extract it
    vecho "Extracting package contents to $TARGET"
    mkdir -p $TARGET
    tar xf $OUTPUT -C $TARGET
    return $?
}

# main args loop
while [ "$1" != "" ]
do
    # on -v or --verbose, set verbose mode
    if [ "$1" = "-v" ] || [ "$1" = "--verbose" ]; then
        VERBOSE=1
    fi

    # on -l or --list, list packages
    if [ "$1" = "-l" ] || [ "$1" = "--list" ]; then
        list_packages
        exit $?
    fi

    # on -d or --download, download package
    if [ "$1" = "-d" ] || [ "$1" = "--download" ]; then
        download_package $2
        echo "Downloaded to $OUTPUT"
        exit $?
    fi

    # on -x or --extract, download and extract package
    if [ "$1" = "-x" ] || [ "$1" = "--extract" ]; then
        extract_package $2
        echo "Downloaded $OUTPUT, and extracted to $TARGET"
        exit $?
    fi

    # on -s or --search, search for package
    if [ "$1" = "-s" ] || [ "$1" = "--search" ]; then
        search_package $2
        exit $?
    fi

    shift
done

# display help info
echo "Usage: $0 [options] [package]"
echo "Options:"
echo "  -l, --list        List all packages"
echo "  -s, --search      Return a list of matching packages"
echo "  -d, --download    Download package by name"
echo "  -x, --extract     Download and extract package"
# TODO: add install, but might mess up filesystem and stuff
# echo "  -i, --install     Download, extract, and install package"
echo "  -v, --verbose     Verbose output"
echo "  -h, --help        Display this help message"
echo "Examples:"
echo "  $0 -l"
echo "  $0 -d ouija_board-1.0.0-1"
echo "  $0 -s ouija_board"