#!/bin/bash
# Generate an rpm %changelog entry for this release and prepend it to
# the spec's existing %changelog section.
#
# Usage: generate-rpm-changelog.sh <spec-file> <version>
#
# Collects commits since the previous v* tag, drops the bump-version
# chore commits generated by CI, and writes a dated entry attributed
# to $CHANGELOG_AUTHOR (defaults to the gitea-actions bot identity).

set -euo pipefail

SPEC="$1"
VERSION="$2"
AUTHOR="${CHANGELOG_AUTHOR:-Gitea Actions <actions@git.lair.cafe>}"

if [ ! -f "$SPEC" ]; then
  echo "error: spec file not found: $SPEC" >&2
  exit 1
fi

# Find the previous release tag (exclude the current tag at HEAD).
PREV_TAG=$(git describe --tags --abbrev=0 --match='v*' HEAD^ 2>/dev/null || echo "")

if [ -n "$PREV_TAG" ]; then
  RANGE="${PREV_TAG}..HEAD"
  LOG=$(git log --no-merges --pretty=format:'- %s' "$RANGE" \
          | grep -v '^- chore: bump version' \
          | grep -v '^- Merge ' \
          || true)
else
  LOG=""
fi

if [ -z "$LOG" ]; then
  LOG="- No user-visible changes"
fi

DATE=$(LC_ALL=C date -u +'%a %b %d %Y')
ENTRY="* ${DATE} ${AUTHOR} - ${VERSION}-1
${LOG}
"

# Prepend the entry to the %changelog section.
TMP=$(mktemp)
awk -v entry="$ENTRY" '
  inserted == 0 && /^%changelog[[:space:]]*$/ {
    print
    print entry
    inserted = 1
    next
  }
  { print }
' "$SPEC" > "$TMP"

if ! grep -q '^%changelog' "$SPEC"; then
  echo "error: no %changelog section in $SPEC — refusing to mangle" >&2
  rm -f "$TMP"
  exit 1
fi

mv "$TMP" "$SPEC"

echo "Added changelog entry for ${VERSION}:"
echo "$ENTRY"