#!/usr/bin/env bash
#
# pre-push: build libakstdlib and run the test harnesses before anything leaves
# this machine.
#
# Install (once per clone):
#
#     git config core.hooksPath .githooks
#
# Runs by default, a few seconds all in:
#
#     * default build      + ctest
#     * ASan/UBSan build   + ctest
#
# Opt in to the slow harness (~25 minutes -- it rebuilds and re-runs the whole
# suite once per mutant):
#
#     AKSL_HOOK_MUTATION=1 git push
#
# Bypass everything (git's own escape hatch):
#
#     git push --no-verify
#
# Builds go under .git/aksl-prepush so the hook never disturbs whatever is in
# your own build/ directory. Override with AKSL_HOOK_BUILD_DIR if you want them
# somewhere else.

set -u

# Keep in sync with the --threshold in .gitea/workflows/ci.yaml, so a push that
# would fail CI fails here first.
MUTATION_THRESHOLD="${AKSL_MUTATION_THRESHOLD:-40}"

ZERO_SHA=0000000000000000000000000000000000000000

root=$(git rev-parse --show-toplevel) || exit 1
cd "$root" || exit 1

# git feeds us one line per ref being pushed. A push that only *deletes* refs
# has no commits to test, so there is nothing to do. An empty stdin (nothing to
# push) lands here too, which is equally fine to skip.
has_updates=0
while read -r _local_ref local_sha _remote_ref _remote_sha; do
    if [ "$local_sha" != "$ZERO_SHA" ]; then
        has_updates=1
    fi
done
if [ "$has_updates" -eq 0 ]; then
    exit 0
fi

if [ ! -f deps/libakerror/CMakeLists.txt ]; then
    echo "pre-push: deps/libakerror is empty. Run:" >&2
    echo "    git submodule update --init --recursive" >&2
    exit 1
fi

builddir="${AKSL_HOOK_BUILD_DIR:-$(git rev-parse --git-dir)/aksl-prepush}"
mkdir -p "$builddir" || exit 1
logfile="$builddir/last.log"

# Run a step quietly; on failure, dump what it said and abort the push.
run() {
    if ! "$@" > "$logfile" 2>&1; then
        echo >&2
        echo "pre-push: FAILED: $*" >&2
        echo "---------------------------------------------------------------" >&2
        cat "$logfile" >&2
        echo "---------------------------------------------------------------" >&2
        echo "pre-push: push aborted. Use 'git push --no-verify' to override." >&2
        exit 1
    fi
}

echo "pre-push: default build + ctest"
run cmake -S . -B "$builddir/default"
run cmake --build "$builddir/default"
run ctest --test-dir "$builddir/default" --output-on-failure

echo "pre-push: sanitizer build + ctest"
run cmake -S . -B "$builddir/asan" -DAKSL_SANITIZE=ON
run cmake --build "$builddir/asan"
run ctest --test-dir "$builddir/asan" --output-on-failure

if [ "${AKSL_HOOK_MUTATION:-0}" = "1" ]; then
    echo "pre-push: mutation testing, threshold ${MUTATION_THRESHOLD}% (this takes a while)"
    # Deliberately not wrapped in run(): this one is slow enough that you want
    # to watch it make progress.
    if ! python3 scripts/mutation_test.py \
            --target src/stdlib.c \
            --threshold "$MUTATION_THRESHOLD"; then
        echo >&2
        echo "pre-push: mutation score below ${MUTATION_THRESHOLD}%. Push aborted." >&2
        echo "pre-push: use 'git push --no-verify' to override." >&2
        exit 1
    fi
fi

echo "pre-push: OK"
exit 0