github-tagclean

#!/bin/bash
set -euo pipefail

if [[ $# -lt 1 ]]; then
    echo "Usage: $0 <keep-tag>"
    exit 1
fi

KEEP_TAG="$1"
REPO_URL="git@github.com:username/reponame.git"
REPO_NAME="dots-tag-cleanup"

WORKDIR=$(mktemp -d)
cd "$WORKDIR"

git clone --bare "$REPO_URL" "$REPO_NAME"
cd "$REPO_NAME"

# Fetch tags (clean remote references)
git fetch --tags --prune

# Get remote tags (without ^{} annotated tags)
REMOTE_TAGS=$(git ls-remote --tags origin \
  | grep -v '\^{}' \
  | awk '{print $2}' \
  | sed 's|refs/tags/||' \
  | sort -r)

# Keep the 7 newest + the one passed as argument
LATEST_7=$(echo "$REMOTE_TAGS" | head -n 7)
TAGS_TO_KEEP=$(printf "%s\n%s" "$KEEP_TAG" "$LATEST_7" | sed '/^\s*$/d' | sort -u)

# Get all local tags (works in bare repo)
LOCAL_TAGS=$(git for-each-ref --format='%(refname:strip=2)' refs/tags \
  | sed '/^\s*$/d' \
  | sort -u)

# Tags to delete = all local tags not in the keep list
TAGS_TO_DELETE=$(comm -23 <(echo "$LOCAL_TAGS") <(echo "$TAGS_TO_KEEP"))

echo "== Local Tags =="
echo "$LOCAL_TAGS"
echo
echo "== Tags to Keep (7 latest + KEEP_TAG) =="
echo "$TAGS_TO_KEEP"
echo
echo "== Tags to Delete =="
echo "$TAGS_TO_DELETE"
echo

if [[ -z "${TAGS_TO_DELETE//[$'\n']/}" ]]; then
    echo "No tags to delete – all clean."
else
    for tag in $TAGS_TO_DELETE; do
        echo "Deleting tag: $tag"
        git tag -d "$tag"
        git push origin ":refs/tags/$tag"
    done
fi

cd /
rm -rf "$WORKDIR"