name: Update cinny submodule

on:
  workflow_dispatch:
    inputs:
      cinny_sha:
        description: cinny commit SHA to pin (default: origin/main)
        required: false
        type: string

concurrency:
  group: update-cinny-submodule
  cancel-in-progress: true

jobs:
  bump:
    runs-on: ubuntu-latest
    steps:
      - name: Checkout repository
        uses: actions/checkout@v4
        with:
          fetch-depth: 0
          submodules: false
          token: ${{ secrets.GITHUB_TOKEN }}
          ref: master

      - name: Update cinny submodule
        id: bump
        run: |
          set -euo pipefail

          ORIGIN_URL=$(git remote get-url origin)
          ORIGIN_URL=${ORIGIN_URL%/}
          ORIGIN_URL=${ORIGIN_URL%.git}
          BASE_URL=${ORIGIN_URL%/*}
          CINNY_URL="${BASE_URL}/cinny.git"
          echo "Rewriting submodule URL to ${CINNY_URL}"
          git config submodule.cinny.url "${CINNY_URL}"
          git submodule sync --recursive
          git submodule update --init --recursive

          TARGET_SHA="${{ inputs.cinny_sha }}"
          git -C cinny fetch origin main

          if [ -n "${TARGET_SHA}" ]; then
            git -C cinny checkout --detach "${TARGET_SHA}"
          else
            git -C cinny checkout --detach origin/main
          fi

          NEW_SHA=$(git -C cinny rev-parse HEAD)
          OLD_SHA=$(git rev-parse HEAD:cinny)
          SUBJECT=$(git -C cinny log -1 --pretty=%s)

          echo "old=${OLD_SHA}"
          echo "new=${NEW_SHA}"
          echo "subject=${SUBJECT}"

          if [ "${OLD_SHA}" = "${NEW_SHA}" ]; then
            echo "changed=false" >> "$GITHUB_OUTPUT"
            echo "cinny already at ${NEW_SHA}; nothing to do"
            exit 0
          fi

          git add cinny
          git config user.name "GitHub Actions"
          git config user.email "actions@github.com"
          git commit -m "Bump cinny: ${SUBJECT}"

          {
            echo "changed=true"
            echo "sha=${NEW_SHA}"
          } >> "$GITHUB_OUTPUT"

      - name: Push submodule bump
        if: steps.bump.outputs.changed == 'true'
        run: |
          set -euo pipefail
          for attempt in 1 2 3; do
            git fetch origin master
            git rebase origin/master || {
              git rebase --abort || true
              echo "Failed to rebase submodule bump onto latest master"
              exit 1
            }
            if git push origin HEAD:master; then
              echo "Pushed cinny bump (${{ steps.bump.outputs.sha }})"
              exit 0
            fi
            echo "Push rejected on attempt ${attempt}, retrying"
          done
          echo "Failed to push submodule bump after 3 attempts"
          exit 1