#!/bin/sh

pecho() { printf %s\\n "$*"; }
log() { pecho "$@"; }
warning() { log "::warning::$@"; }
error() { log "::error::$@"; }
fatal() { error "$@"; exit 1; }
try() { "$@" || fatal "'$@' failed"; }

# actions/checkout@v2 only makes a clone if Git is v2.18 or later, and this
# test requires a clone.
git_ver=$(try dpkg-query -f '${Version}' -W git) || exit 1
dpkg --compare-versions "${git_ver}" ge '1:2.18~' || {
    warning "This test requires Git v2.18 or later"
    exit 0
}

dist_tarball=$(ls ddclient-*.tar.gz) \
    || fatal "'make dist' must be run before this test"

tmpdir=$(try mktemp -d) || exit 1
# newer git versions are particular about file ownership which can be ignored here
git config --global --add safe.directory /__w/ddclient/ddclient || true

log "Copying contents of Git repository..."
try git archive --format=tar --prefix=git-repo/ HEAD \
    | try tar -C "${tmpdir}" -xv || exit 1
(
    try cd "${tmpdir}"/git-repo
    # Delete files checked into Git that shouldn't be in the distribution
    # tarball.
    try rm -rf \
        .envrc \
        .github \
        .gitignore \
        docs/ipv6-design-doc.md \
        docs/ProviderGuidelines.md \
        shell.nix \
        ;
    # TODO: Delete this next line once support for Automake 1.11 is dropped and
    # tap-driver.sh is removed from the Git repository. It is deleted here to
    # avoid a spurious diff.
    try rm -f build-aux/tap-driver.sh
) || exit 1

log "Extracting distribution tarball..."
try tar -C "${tmpdir}" -xvzf "${dist_tarball}"
try mv "${tmpdir}/${dist_tarball%.tar.gz}" "${tmpdir}"/dist-tarball
(
    try cd "${tmpdir}"/dist-tarball
    # Delete generated files
    try rm -rf \
        Makefile.in \
        aclocal.m4 \
        build-aux/install-sh \
        build-aux/missing \
        build-aux/tap-driver.sh \
        configure \
        ;
) || exit 1

log "Comparing Git repository with distribution tarball..."
cd "${tmpdir}"
diff -qNr git-repo dist-tarball >/dev/null || {
    error "Unexpected diff between the repo and the distribution tarball."
    error "You may need to add a file to EXTRA_DIST in Makefile.am."
    error "Diff output:"
    diff -uNr git-repo dist-tarball \
        | while IFS= read -r line; do error "${line}"; done
    exit 1
}
log "No difference"