#!/bin/bash
# Block PRs by preventing pushes to arbitrary feature branches.
# Gas Town agents push to main (crew) or polecat/* branches (polecats).
# PRs are for external contributors only.

# Allowed patterns:
#   main, beads-sync  - Direct work branches
#   polecat/*         - Polecat working branches (Refinery merges these)

while read local_ref local_sha remote_ref remote_sha; do
  # Skip tags - they're allowed for releases
  if [[ "$remote_ref" == refs/tags/* ]]; then
    continue
  fi

  branch="${remote_ref#refs/heads/}"

  case "$branch" in
    main|beads-sync|polecat/*)
      # Allowed branches
      ;;
    *)
      # Allow feature branches when contributing to upstream (fork workflow).
      # If an 'upstream' remote exists, this is a contribution setup where
      # feature branches are needed for PRs. See: #848
      if ! git remote get-url upstream &>/dev/null; then
        echo "ERROR: Invalid branch for Gas Town agents."
        echo ""
        echo "Blocked push to: $branch"
        echo ""
        echo "Allowed branches:"
        echo "  main        - Crew workers push here directly"
        echo "  polecat/*   - Polecat working branches"
        echo "  beads-sync  - Beads synchronization"
        echo ""
        echo "Do NOT create PRs. Push to main or let Refinery merge polecat work."
        exit 1
      fi
      ;;
  esac
done

exit 0