#!/usr/bin/env bash

die() {
    echo "ERROR: $@"
    exit 1
}

run() {
    echo "$@"
    "$@" || die "$?"
}

verbose=
vprint() {
    [[ -n ${verbose} ]] || return 0

    echo "$@"
}

usage() {
    echo "A tool to sync package from ::haskell to ::gentoo."
    echo ""
    echo "Usage: $0 [ -- verbose ] [ --help ] [ cat/pkg... ]"
    echo ""
    echo "Usage examples:"
    echo " \$ $0 dev-haskell/xss-sanitize"
    die "no args"
}

find_prog() {
    local var_name=$1
    local prog_name=${!1}

    echo -n "Resolving ${var_name} as ... "
    type -P "${prog_name}" || die "failed to find '${var_name}=${prog_name}'."
}


# options parser
while :; do
    case "$1" in
        -v | --verbose  ) verbose=1; shift ;;
        -h | --help     ) usage ;;
        -c | --continue ) ebuild_needs_regeneration=no; shift ;;
        -a | --auto     ) autoversion=yes; shift ;;
        --              ) shift; break ;;
        *               ) break ;;
    esac
done

# defaults, can be ovverided as:
#    ebuild_prog=~/bin/e $0 <args>
: ${ebuild_prog:=ebuild}
: ${repoman_prog:=repoman}

find_prog ebuild_prog
find_prog repoman_prog

get_latest_pv() {
    local repo=$1 cp=$2 cpv pv
    cpv=$(portageq best_visible / "${cp}::${repo}")
    pv=${cpv#${cp}-}
    echo "${pv}"
}

make_ebuild_path() {
    local repo=$1 cp=$2 pv=$3 pn
    pn=${cp#*/}
    echo "$(portageq get_repo_path / "${repo}")/${cp}/${pn}-${pv}.ebuild"
}

sync_cp() {
    local cp=$1 haskell_pv gentoo_pv haskell_e gentoo_e new_e

    haskell_pv=$(get_latest_pv 'haskell' "${cp}")
    gentoo_pv=$(get_latest_pv  'gentoo'  "${cp}")

    haskell_e=$(make_ebuild_path 'haskell' "${cp}" "${haskell_pv}")
    gentoo_e=$(make_ebuild_path  'gentoo'  "${cp}" "${gentoo_pv}")
    new_e=$(make_ebuild_path     'gentoo'  "${cp}" "${haskell_pv}")

    git diff --color "${gentoo_e}" "${haskell_e}" | cat
    run cp "${haskell_e}" "${new_e}"


    pushd "$(dirname "${new_e}")"
    {
        run $repoman_prog manifest
        run $repoman_prog full

        FEATURES="strict stricter test ${FEATURES}" \
            run $ebuild_prog "${new_e}" clean install

        run git add --all .
        run $repoman_prog commit -m "${cp}: bump up to ${haskell_pv}"
        git diff --color "${gentoo_e}" "${new_e}" | cat
    }
    popd

    run $ebuild_prog "${new_e}" clean
}

for cp in "$@"; do
    sync_cp "${cp}"
done