#!/usr/bin/env bash
# Fast-forward the repo to origin/main before deploying.
# Sourced by scripts/run/deploy.sh and deploy scripts — do not execute directly.
#
# Requires a clean working tree (no uncommitted changes).

sync_main() {
  local repo_root="${1:?repo root required}"

  if ! git -C "$repo_root" rev-parse --is-inside-work-tree &>/dev/null; then
    echo "ERROR: not a git repository: $repo_root" >&2
    return 1
  fi

  if [[ -n "$(git -C "$repo_root" status --porcelain)" ]]; then
    echo "ERROR: uncommitted changes — commit or discard before deploying" >&2
    git -C "$repo_root" status --short >&2
    return 1
  fi

  echo "==> Syncing with origin/main (ff-only)..."
  git -C "$repo_root" fetch origin main
  git -C "$repo_root" merge --ff-only origin/main
  echo "  at $(git -C "$repo_root" rev-parse --short HEAD)"
}