name: Update Helm charts

on:
  release:
    types:
      - published

permissions:
  contents: write
  pull-requests: write

concurrency:
  group: update-helm-charts
  cancel-in-progress: false

jobs:
  update:
    name: Propose chart update
    if: ${{ github.repository_owner == 'henrygd' && startsWith(github.event.release.tag_name, 'v') && !github.event.release.prerelease }}
    runs-on: ubuntu-latest
    env:
      BRANCH: automation/update-helm-app-version
      RELEASE_TAG: ${{ github.event.release.tag_name }}
      AUTOMATION_TOKEN: ${{ secrets.CR_TOKEN || github.token }}

    steps:
      - name: Checkout main
        uses: actions/checkout@v7
        with:
          ref: main
          token: ${{ env.AUTOMATION_TOKEN }}

      - name: Update chart versions
        id: update
        run: |
          version="${RELEASE_TAG#v}"
          if [[ ! "$version" =~ ^[0-9]+\.[0-9]+\.[0-9]+$ ]]; then
            echo "Unsupported software release version: $version" >&2
            exit 1
          fi

          changed=false
          for chart in supplemental/helm/beszel-agent supplemental/helm/beszel-hub; do
            current_app_version=$(awk -F '"' '/^appVersion:/ { print $2 }' "$chart/Chart.yaml")
            if [[ "$current_app_version" == "$version" ]]; then
              echo "$chart already uses appVersion $version"
              continue
            fi

            newest_version=$(printf '%s\n' "$current_app_version" "$version" | sort -V | tail -n 1)
            if [[ "$newest_version" != "$version" ]]; then
              echo "Skipping stale update of $chart from $current_app_version to $version"
              continue
            fi

            chart_version=$(awk '/^version:/ { print $2 }' "$chart/Chart.yaml")
            if [[ ! "$chart_version" =~ ^([0-9]+)\.([0-9]+)\.([0-9]+)$ ]]; then
              echo "Unsupported chart version in $chart/Chart.yaml: $chart_version" >&2
              exit 1
            fi
            next_chart_version="${BASH_REMATCH[1]}.${BASH_REMATCH[2]}.$((BASH_REMATCH[3] + 1))"

            NEW_APP_VERSION="$version" NEW_CHART_VERSION="$next_chart_version" \
              perl -pi -e 's/^appVersion:.*$/appVersion: "$ENV{NEW_APP_VERSION}"/; s/^version:.*$/version: $ENV{NEW_CHART_VERSION}/' \
              "$chart/Chart.yaml"
            OLD_APP_VERSION="$current_app_version" NEW_APP_VERSION="$version" \
              perl -pi -e 's/\Q$ENV{OLD_APP_VERSION}\E/$ENV{NEW_APP_VERSION}/g' "$chart/README.md"

            echo "$chart: appVersion $current_app_version -> $version, chart $chart_version -> $next_chart_version"
            changed=true
          done

          echo "changed=$changed" >> "$GITHUB_OUTPUT"

      - name: Open or update pull request
        if: steps.update.outputs.changed == 'true'
        env:
          GH_TOKEN: ${{ env.AUTOMATION_TOKEN }}
        run: |
          version="${RELEASE_TAG#v}"
          title="chore(helm): update app version to ${version}"
          body="Updates the Helm charts for [Beszel ${version}](${GITHUB_SERVER_URL}/${GITHUB_REPOSITORY}/releases/tag/${RELEASE_TAG}) and bumps their chart patch versions. Merging this pull request publishes the updated charts to GHCR."

          git config user.name "github-actions[bot]"
          git config user.email "41898282+github-actions[bot]@users.noreply.github.com"
          git checkout -B "$BRANCH"
          git add supplemental/helm/beszel-agent/Chart.yaml \
            supplemental/helm/beszel-agent/README.md \
            supplemental/helm/beszel-hub/Chart.yaml \
            supplemental/helm/beszel-hub/README.md
          git commit -m "$title"

          git fetch origin "$BRANCH" || true
          git push --force-with-lease origin "HEAD:refs/heads/${BRANCH}"

          pr_number=$(gh pr list --head "$BRANCH" --base main --state open --json number --jq '.[0].number')
          if [[ -n "$pr_number" ]]; then
            gh pr edit "$pr_number" --title "$title" --body "$body"
          else
            gh pr create --base main --head "$BRANCH" --title "$title" --body "$body"
          fi