#!/usr/bin/env bash
# Export every commit in work/ above the `base` tag back into patches/.
#
# This is the CraftBukkit/Spigot `rebuildPatches.sh` step and the only way
# changes leave work/. Run it after every commit you make in work/.

source "$(dirname "${BASH_SOURCE[0]}")/lib.sh"

assert_work_ready
cd "$WORK_DIR" || die "cannot enter $WORK_DIR"

if [[ -n "$(git status --porcelain)" ]]; then
  warn "work/ has uncommitted changes -- they will NOT be exported."
  warn "Commit them first:  cd work && git add -A && git commit"
fi

n="$(git rev-list --count "$BASE_TAG..HEAD")"
info "Exporting $n commit(s) above $BASE_TAG -> patches/"

mkdir -p "$PATCHES_DIR"
# Clear first: dropping or reordering commits in work/ must not leave orphaned
# patch files behind, and format-patch only ever writes, never deletes.
rm -f "$PATCHES_DIR"/*.patch

if [[ "$n" -eq 0 ]]; then
  info "No commits above $BASE_TAG -- patches/ is now empty."
  exit 0
fi

# --zero-commit    the "From <sha>" line would otherwise change on every single
#                  rebase, producing a diff in every patch file for no reason
# --full-index     full blob hashes give `git am --3way` something to fall back
#                  on when context has drifted
# --no-signature   drops the trailing "-- \n2.47.3" git version banner
# --no-stat / -N   match Spigot's output shape (no diffstat, no "[PATCH n/m]")
git format-patch \
  --quiet \
  --no-stat \
  -N \
  --zero-commit \
  --full-index \
  --no-signature \
  --output-directory "$PATCHES_DIR" \
  "$BASE_TAG"

info "patches/ now holds $(count_patches) patch file(s):"
for f in "$PATCHES_DIR"/*.patch; do
  printf '     %s\n' "$(basename "$f")"
done