#!/usr/bin/env bash

main(){
    os='';
    arch='';
    case $(uname) in
        Linux)
            os='linux';
            case $(uname -m) in
                i386 | i686) arch='386' ;;
                x86_64 | amd64) arch='amd64' ;;
                armv8 | arm64 | aarch64) arch='arm64' ;;
                *) echo 'unsupported CPU' && exit 1 ;;
            esac;
            ;;
        *)
            echo 'unsupported OS' && exit 1 ;;
    esac;
    build_arch=$os_$arch;

    if [ -z "$PROG_PATH" ] || [ -z "$PROG_NAME" ] || [ -z "$REPO" ]; then
        usage
        exit 1
    fi
    echo "Update for $REPO"
    api_url="https://$API_DOMAIN/repos/$REPO/releases/latest"
    dl_url=$(curl -sSf $api_url | grep -i $build_arch | grep browser_download_url | cut -d '"' -f 4)
    dl_url=$(echo $dl_url | sed -i -r s/$GH_DOMAIN/$DL_DOMAIN/g)

    curr_ver=$($PROG_PATH/$PROG_NAME -v)
    if (echo $dl_url | grep -i $curr_ver) >/dev/null 2>&1; then
        echo "Already latest version!"
    else
        tmp_dir="/tmp/$(cat /dev/urandom | tr -dc 'a-zA-Z0-9' | fold -w 32 | head -n 1)"
        mkdir -p "$tmp_dir"
        pushd "$tmp_dir" >/dev/null
        ext=$(echo $dl_url | awk -F'.' '{print $NF}')
        if (echo $ext | grep -i zip) >/dev/null 2>&1; then
            curl -Sfo pkg.zip "$dl_url"
            unzip -o pkg.zip
        else
            curl -Sfo pkg.tar.$ext "$dl_url"
            tar -xvf pkg.tar.$ext
        fi
        if [ ! -z "$PKG_DIR" ]; then
            cd $PKG_DIR
        fi
        cp -f "$PROG_NAME" "$PROG_PATH/"

        echo "Update Complete ($curr_ver -> $($PROG_PATH/$PROG_NAME -v))!"
        popd >/dev/null
        rm -rf "$tmp_dir"
        if [ ! -z "$SRV_NAME" ]; then
            systemctl restart $SRV_NAME
        fi
    fi
}

usage(){
    echo "Usage: $0 [OPTIONS]";
    echo "Options:";
    echo "    -p <PATH>        Program path";
    echo "    -n <NAME>        Program name";
    echo "    -r <REPO>        Github repo";
    echo "    -d <DIR>         Dir inside package";
    echo "    -s <SERVICE>     Service name";
    echo "    -a <API>         API domain";
    echo "    -b <DOWNLOAD>    Download domain";
}

PROG_PATH=
PROG_NAME=
REPO=
PKG_DIR=
SRV_NAME=
API_DOMAIN=api.github.com
GH_DOMAIN=github.com
DL_DOMAIN=github.com
while getopts ":p:n:r:d:s:a:b:" OPT; do
    case $OPT in
        p)
            PROG_PATH=$OPTARG;
            ;;
        n)
            PROG_NAME=$OPTARG;
            ;;
        r)
            REPO=$OPTARG;
            ;;
        d)
            PKG_DIR=$OPTARG;
            ;;
        s)
            SRV_NAME=$OPTARG;
            ;;
        a)
            API_DOMAIN=$OPTARG;
            ;;
        b)
            DL_DOMAIN=$OPTARG;
            ;;
        :)
            echo "Option -$OPTARG requires an argument.";
            exit 1;;
        ?)
            echo "Invalid Option: -$OPTARG";
            usage;
            exit 1;;
    esac;
done;

main