#!/bin/sh
set -e

PROJECT_NAME="FAQd"
PROJECT_RELEASES_URL="https://forge.cadoles.com/Cadoles/emissary/releases"
PROJECT_DESTDIR="."
PROJECT_FILE_BASENAME="faqd"
PROJECT_PLATFORM_SUFFIX="$(uname -s)_$(uname -m)"

function main {
    test -z "${PROJECT_VERSION}" && PROJECT_VERSION="$(curl -sfL -o /dev/null -w %{url_effective} "${PROJECT_RELEASES_URL}/latest" |
        rev |
        cut -f1 -d'/'|
        rev)"

    # Check version variable initialization
    test -z "${PROJECT_VERSION}" && {
        echo "Unable to get ${PROJECT_NAME} version !" >&2
        exit 1
    }

    test -z "${PROJECT_TMPDIR}" && PROJECT_TMPDIR="$(mktemp -d)"
    export TAR_FILE="${PROJECT_TMPDIR}/${PROJECT_FILE_BASENAME}_${PROJECT_VERSION}_${PROJECT_PLATFORM_SUFFIX}.tar.gz"

    (
        cd "${PROJECT_TMPDIR}"

        # Download project
        echo "Downloading ${PROJECT_NAME} ${PROJECT_VERSION}..."
        curl -sfLo "${TAR_FILE}" \
            "${PROJECT_RELEASES_URL}/download/${PROJECT_VERSION}/${PROJECT_FILE_BASENAME}_${PROJECT_VERSION}_${PROJECT_PLATFORM_SUFFIX}.tar.gz" ||
            ( echo  "Error while downloading ${PROJECT_NAME} !" >&2 && exit 1 )
        
        # Download checksums
        curl -sfLo "checksums.txt" "${PROJECT_RELEASES_URL}/download/${PROJECT_VERSION}/checksums.txt"
        
        echo "Verifying checksum..."
        check_sum ||
            ( echo  "Error while verifying checksums !" >&2 && exit 1 )
    )

    # Extracting archive files
    tar -xf "${TAR_FILE}" -C "${PROJECT_TMPDIR}"

    # Moving downloaded binary to destination directory
    mv -f "${PROJECT_TMPDIR}/${PROJECT_FILE_BASENAME}" "${PROJECT_DESTDIR}/"

    echo "You can now use '${PROJECT_DESTDIR}/${PROJECT_FILE_BASENAME}', enjoy !"
}

function check_sum {
    set -o pipefail
    cat checksums.txt | grep ${PROJECT_FILE_BASENAME}_*_${PROJECT_PLATFORM_SUFFIX}.tar.gz | sha256sum -c
    set +o pipefail
}

main $@