#!/usr/bin/env bash
#
# Mirror the wilm branch onto gitea from a bundle carried over from the work PC.
#
# WHY THIS EXISTS
#
# wilm is maintained on the corporate GitHub (ge-aero) from the work PC. This
# dev box is off the GE network and has no account there, so it can neither
# fetch nor push that branch. The only way wilm reaches gitea is:
#
#   1. WORK PC:  fetch-wilm-branch.cmd     (read-only, writes the bundle)
#   2. Carry     shopdb-flask-wilm.bundle  onto a drive this PC can read
#   3. HERE:     tools/mirror-wilm.sh
#
# Gitea is therefore the mirror of record for wilm and is ALWAYS lagging: it is
# only as fresh as the last bundle somebody carried across. This script prints
# the bundle's age for exactly that reason - a mirror that looks authoritative
# and is a week old is worse than no mirror.
#
# It never pushes anything TO wilm. That branch belongs to the other site and
# merging into it is a work-PC operation against GitHub.
set -euo pipefail

REPO=/home/camp/projects/shopdb-flask
BUNDLE="${1:-/home/camp/pxe-images/github/shopdb-flask-wilm.bundle}"

if [ ! -r "$BUNDLE" ]; then
  echo "No bundle at $BUNDLE" >&2
  echo "Run fetch-wilm-branch.cmd on the work PC and copy it across." >&2
  exit 1
fi

if ! git bundle list-heads "$BUNDLE" | grep -q 'refs/remotes/origin/wilm'; then
  echo "$BUNDLE does not contain origin/wilm." >&2
  echo "It is a bundle for something else - do not use it." >&2
  exit 1
fi

age_days=$(( ( $(date +%s) - $(stat -c %Y "$BUNDLE") ) / 86400 ))
echo "Bundle: $BUNDLE"
echo "Made:   $(stat -c %y "$BUNDLE" | cut -d. -f1)  (${age_days} day(s) ago)"
if [ "$age_days" -ge 2 ]; then
  echo "WARNING: this bundle is ${age_days} days old. Whatever it pushes to" >&2
  echo "gitea will look current and will not be." >&2
fi

cd "$REPO"
git fetch "$BUNDLE" 'refs/remotes/origin/wilm:refs/heads/wilm' --force
echo "wilm is now $(git log --oneline -1 wilm)"

# wilm sits on the PUBLICATION lineage (the scrubbed history that goes to
# GitHub), which shares no ancestor with our internal main/wj/dev. That is why
# the mirror is useful for reading and useless for merging: git will refuse to
# merge unrelated histories, and it is right to.
if ! git merge-base wilm main >/dev/null 2>&1; then
  echo
  echo "NOTE: wilm shares no ancestry with main/wj/dev in this repo - it is on"
  echo "      the publication lineage. Compare it in the publication repo"
  echo "      (/home/camp/projects/shopdb-flask-pub), not here."
fi

"$REPO/tools/git-push.sh" wilm