#!/bin/bash
# SPDX-License-Identifier: LGPL-2.1-or-later
set -e
set -o nounset

if ((${NO_SYNC:-0})); then
    exit 0
fi

PKG_SUBDIR="$(realpath --canonicalize-missing "pkg/$DISTRIBUTION" --relative-to "$PWD")"

if [[ -d "$PKG_SUBDIR/.git" ]]; then
    if [[ "$(git -C "$PKG_SUBDIR" rev-parse HEAD)" == "$GIT_COMMIT" ]]; then
        exit 0
    fi

    # If work is being done on the packaging rules in a separate branch, don't touch the checkout.
    if ! git -C "$PKG_SUBDIR" merge-base --is-ancestor HEAD "origin/$GIT_BRANCH"; then
        EXIT_STATUS=$?
        if [[ $EXIT_STATUS -eq 1 ]]; then
            exit 0
        else
            exit $EXIT_STATUS
        fi
    fi
fi

if [[ ! -e "$PKG_SUBDIR" ]] || [[ -z "$(ls --almost-all "$PKG_SUBDIR")" ]]; then
    # The repository on Salsa has the full upstream sources, so it's a waste of
    # space to redownload and duplicate everything, so do a sparse checkout as
    # we only need the packaging directory anyway.
    if [[ -n "${GIT_SUBDIR:-}" ]]; then
        sparse=(--no-checkout --filter=tree:0)
    else
        sparse=()
    fi

    git clone "$GIT_URL" --branch "$GIT_BRANCH" "${sparse[@]}" "$PKG_SUBDIR"
    if [[ -n "${GIT_SUBDIR:-}" ]]; then
        # --no-cone is needed to check out only one top-level directory
        git -C "$PKG_SUBDIR" sparse-checkout set --no-cone "${GIT_SUBDIR:-}"
    fi
else
    git -C "$PKG_SUBDIR" remote set-url origin "$GIT_URL"
    git -C "$PKG_SUBDIR" fetch origin "$GIT_BRANCH"
fi

git -C "$PKG_SUBDIR" -c advice.detachedHead=false checkout "$GIT_COMMIT"