#!/bin/sh
#
# update-bare-repo.sh <bare>

set -eu
set -o pipefail

TMP_BEFORE=$(mktemp) || exit 1
TMP_AFTER=$(mktemp) || { rm -f "$TMP_BEFORE"; exit 1; }
TMP_CHANGES=$(mktemp) || { rm -f "$TMP_BEFORE" "$TMP_AFTER"; exit 1; }

REPO=$2
cd "$1"

cleanup() {
        rm -f "$TMP_BEFORE" "$TMP_AFTER" "$TMP_CHANGES"
}
trap cleanup EXIT INT TERM

# Save refs before update
git for-each-ref --format='%(refname) %(objectname)' "refs/heads/" >"$TMP_BEFORE" 2>/dev/null

# Update
if ! git fetch --all --prune --tags --verbose ; then
        echo "git remote update failed" >&2
        exit 3
fi

git for-each-ref --format='%(refname:short)' refs/heads | while read br; do
if git show-ref --verify --quiet refs/remotes/origin/"$br"; then
        target_sha=$(git rev-parse "origin/$br")
        curr_sha=$(git rev-parse refs/heads/"$br")
        if [ "$target_sha" != "$curr_sha" ]; then
                echo "Updating $br -> origin/$br ($(git rev-parse --short "origin/$br"))"
                git update-ref refs/heads/"$br" "$target_sha" || { echo "Failed to update $br"; exit 1; }
        else
                echo "Up-to-date: $br"
        fi
else
        echo "No origin/$br, skipping"
fi
done

# Save refs after update
git for-each-ref --format='%(refname) %(objectname)' "refs/heads/" >"$TMP_AFTER" 2>/dev/null

# Produce changed refs: oldsha newsha refname
# If a ref did not exist before, oldsha = 000...0
awk 'NR==FNR{m[$1]=$2;next} {
     old=m[$1];
     if(old=="") old="0000000000000000000000000000000000000000";
     if(old!=$2) print old, $2, $1
}' "$TMP_BEFORE" "$TMP_AFTER" >"$TMP_CHANGES"

# If no changes, exit
if [ ! -s "$TMP_CHANGES" ]; then
        echo "No remote changes detected for ${REPO}."
        exit 0
fi


# Call the real post-receive hook with stdin lines
# emulate server hook environment
GIT_DIR=$(git rev-parse --git-dir 2>/dev/null) || { echo "Not a git repository." >&2; exit 4; }

# Export GIT_DIR for the hook
export GIT_DIR
export GITEA_PUSHER_ID=1
export GITEA_REPO_NAME=${REPO}
export GITEA_REPO_USER_NAME=FreeBSD
export SSH_ORIGINAL_COMMAND=gitea-internal

forgejo hook post-receive < "${TMP_CHANGES}"

# Exit with hook status
exit $?