#!/usr/bin/env bash
# vim: tabstop=4 shiftwidth=4 expandtab
topdir="$( dirname $(cd $(dirname ${BASH_SOURCE[0]}) && pwd) )"
cachedir="${topdir}/cache"
datadir="${topdir}/share"
spexdir="${topdir}/spex"

release_server="http://irtfweb.ifa.hawaii.edu/~spex/Spextool"
releases=(
    1.4 
    1.5
    2.0
    2.1
    2.2
    2.3
    3.1
    3.2
    3.3
    3.4
    4.0
    4.0.1
    4.0.2
    4.0.3
    4.1
)
dependencies=(
    https://github.com/wlandsman/IDLAstro/archive/refs/heads/master.tar.gz 1 IDLAstro
    https://idlastro.gsfc.nasa.gov/ftp/coyote_astron.tar.gz 1 coyote
    https://pages.physics.wisc.edu/~craigm/idl/down/cmtotal.tar.gz 0 cmtotal
)

archive_suffix="tar.gz"
archive_name="Spextool"
archive_version=

pushd() {
    command pushd "$1" &>/dev/null
}

popd() {
    command popd &>/dev/null
}

msg_error() {
    echo "ERROR: $@" >&2
}

msg_warn() {
    echo "WARN: $@" >&2
}

msg_info() {
    echo "INFO: $@" >&2
}

idl_exists() {
    ([ type -a idl ] || [ type -p idl ]) && [ -n "$IDL_DIR" ]
}

initialize() {
    mkdir -p "$spexdir" \
        "$cachedir" \
        "$datadir"

    if ! idl_exists; then
        msg_warn IDL is not initialized, or not installed.
    fi
}

release_list() {
    local fmt="%-10s %-10s\n"
    local installed=()
    echo "==========="
    echo " Available"
    echo "==========="
    for x in "${releases[@]}"; do
        mark=""
        if release_exists $x; then
            installed+=($x)
            continue
        fi
        echo "  $x"
    done

    if (( ${#installed[@]} )); then
        echo
        echo "==========="
        echo " Installed"
        echo "==========="
        for x in "${installed[@]}"; do
            echo "  $x"
        done
    fi
}

release_exists() {
    local version="$1"
    test -d "$spexdir/$version"
}

release_download() {
    local version="$1"
    local package="${archive_name}_v${version}.${archive_suffix}"

    pushd "$cachedir"
        if [ -f "$package" ]; then
            msg_info Using cached package: $package
        else
            msg_info Downloading: $package
            if ! curl -L -O "$release_server/$package"; then
                msg_err Unable to download $package
                return 1
            fi
        fi
    popd
    echo "$cachedir/$package $version"
}

dep_install() {
    pushd "$cachedir"
        for ((i=0; i < ${#dependencies[@]}; i+=3)); do 
            local dep="${dependencies[i]}"
            local archive="$(basename $dep)"
            if [ -f "$archive" ]; then
                continue
            fi
            msg_info Downloading: $dep
            if ! curl -L -O "$dep"; then
                msg_error Unable to download $dep
                return 1
            fi
        done

        for ((i=0; i < ${#dependencies[@]}; i+=3)); do 
            local archive="$(basename ${dependencies[i]})"
            local strip_level="${dependencies[i+1]}"
            local dname="${dependencies[i+2]}"
            local dest="${datadir}/${dname}"
            if [ -d "$dest" ]; then
                msg_info $dname is already installed
                continue
            fi
            mkdir -p "$dest"
            msg_info Installing dependency: $dname
            tar -xf "$archive" --strip-components=$strip_level -C "$dest"
        done
    popd
}

release_install() {
    local package="$1"
    local version="$2"
    pushd "${spexdir}"
        mkdir -p ${version}
        msg_info Installing: v${version}
        tar -xf "$package" --strip-components=1 -C ${version}
    popd
}


usage() {
    echo "usage: $(basename $0) [-h] {command} [arg ...]"
    echo
    echo "Arguments:"
    echo "  --help    -h        this message"
    echo
    echo "Commands:"
    echo "  clean               Remove cached packages/archives"
    echo "  list                List available spextool releases"
    echo "  install {release}   Install a spextool release"
    echo
}

version=4.1

# main()
initialize

if (( $# < 1 )); then
    msg_error Not enough arguments
    usage
    exit 1
fi

while [[ $# != 0 ]]; do
    key="$1"
    case "$key" in
        -h|--help)
            usage
            exit 0
            ;;
        clean)
            do_clean=1
            ;;
        list)
            do_list=1
            ;;
        install)
            do_install=1
            version=$2
            if [ -z "$version" ]; then
                msg_error install requires a release version
                release_list
                exit 1
            fi
            shift
            ;;
        *)
            ;;
    esac
    shift
done

if (( do_clean )); then
    msg_info Cleaning: $cachedir
    if [ -z "$cachedir" ] || [ "$cachedir" = "/" ]; then
        msg_error "Refusing to clean unsafe path: '$cachedir'"
        exit 1
    fi
    rm -rf "$cachedir"/*
elif (( do_list )); then
    release_list
elif (( do_install )); then
    if release_exists $version; then
        msg_info $archive_name v$version is already installed
    else
        read package package_version <<< $(release_download $version)
        release_install $package $package_version
    fi
    dep_install
fi