name: Update release notes

on:
  # Update release notes whenever production is updated, keeping next.mdx (and the
  # draft GitHub release synced by the skill) in step with each dotcom release —
  # the same production push that deploys dotcom and publishes the `next` package.
  # Production only: a push to main must not trigger a notes run on every merge.
  # Release-notes PR titles carry `[skip ci]` so their squash-merge commits skip main
  # push workflows. Branch commits omit the marker so required PR checks run.
  push:
    branches:
      - production
  workflow_dispatch:

concurrency:
  group: update-release-notes

defaults:
  run:
    shell: bash

permissions:
  contents: read

jobs:
  update-release-notes:
    name: 'Update release notes with Claude Code'
    timeout-minutes: 30
    runs-on: ubuntu-latest

    steps:
      - name: Generate GH token
        id: generate_token
        uses: tibdex/github-app-token@b62528385c34dbc9f38e5f4225ac829252d1ea92
        with:
          app_id: ${{ secrets.HUPPY_APP_ID }}
          private_key: ${{ secrets.HUPPY_PRIVATE_KEY }}

      - name: Check out code
        uses: actions/checkout@v6
        with:
          persist-credentials: false
          fetch-depth: 0
          token: ${{ steps.generate_token.outputs.token }}

      - name: Configure git credentials
        run: git config --global url."https://x-access-token:${{ steps.generate_token.outputs.token }}@github.com/".insteadOf "https://github.com/"

      - name: Run our setup
        uses: ./.github/actions/setup

      - name: Configure git
        run: |
          git config --global user.name 'huppy-bot[bot]'
          git config --global user.email '128400622+huppy-bot[bot]@users.noreply.github.com'

      - name: Create branch
        id: branch
        run: |
          BRANCH_NAME="release-notes/update-$(date +%Y%m%d-%H%M%S)"
          git checkout -b "$BRANCH_NAME"
          echo "branch_name=$BRANCH_NAME" >> "$GITHUB_OUTPUT"

      # Recorded before the skill runs so the close step below can tell an
      # already-open PR from an earlier run apart from the one this run opens.
      - name: Find open release notes PRs
        id: existing_prs
        run: |
          {
            echo 'numbers<<PR_LIST_EOF'
            gh pr list --state open --base main --limit 100 --json number,headRefName \
              --jq '.[] | select(.headRefName | test("^(release-notes/update-|update-release-notes-)")) | .number'
            echo 'PR_LIST_EOF'
          } >> "$GITHUB_OUTPUT"
        env:
          GH_TOKEN: ${{ steps.generate_token.outputs.token }}

      - name: Install Claude Code
        run: npm install -g @anthropic-ai/claude-code

      - name: Run update-release-notes skill
        run: |
          claude --dangerously-skip-permissions --print "/update-release-notes"
        env:
          ANTHROPIC_API_KEY: ${{ secrets.ANTHROPIC_API_KEY }}
          GH_TOKEN: ${{ steps.generate_token.outputs.token }}

      - name: Check for changes
        id: changes
        run: |
          if [ -z "$(git status --porcelain)" ]; then
            echo "has_changes=false" >> "$GITHUB_OUTPUT"
          else
            echo "has_changes=true" >> "$GITHUB_OUTPUT"
          fi

      - name: Commit and push
        if: steps.changes.outputs.has_changes == 'true'
        run: |
          git add -A
          git commit -m "Update release notes"
          git push -u origin "${{ steps.branch.outputs.branch_name }}"

      - name: Create PR
        if: steps.changes.outputs.has_changes == 'true'
        run: |
          gh pr create \
            --title "docs(releases): update release notes [skip ci]" \
            --body "$(cat <<'EOF'
          In order to keep the release notes up to date, this PR adds entries for PRs merged since the last update.

          ### Change type

          - [x] `other`

          ### Test plan

          - [ ] Unit tests
          - [ ] End to end tests
          EOF
          )" \
            --base main \
            --head "${{ steps.branch.outputs.branch_name }}" \
            --label "docs-hotfix-please"
        env:
          GH_TOKEN: ${{ steps.generate_token.outputs.token }}

      # Each run regenerates the notes from scratch, so a PR opened by this run
      # supersedes any release notes PR left open by an earlier run. The PR may come
      # from the step above or from the skill itself, so this compares the currently
      # open PRs against the ones recorded before the skill ran rather than relying on
      # a single known PR number. When this run opened nothing, the older PR is still
      # the pending update and is left alone.
      - name: Close superseded PRs
        run: |
          EXISTING="${{ steps.existing_prs.outputs.numbers }}"
          CURRENT=$(gh pr list --state open --base main --limit 100 --json number,headRefName \
            --jq '.[] | select(.headRefName | test("^(release-notes/update-|update-release-notes-)")) | .number')

          NEW_PRS=$(comm -13 <(echo "$EXISTING" | sort) <(echo "$CURRENT" | sort))
          if [ -z "$NEW_PRS" ]; then
            echo "This run did not open a release notes PR, nothing to supersede"
            exit 0
          fi

          # The new PR is already open at this point, so a failure to tidy up an old
          # one is a warning, not a reason to fail the run.
          NEWEST=$(echo "$NEW_PRS" | sort -n | tail -n 1)
          echo "$EXISTING" | while read -r PR; do
            [ -n "$PR" ] || continue
            echo "Closing superseded release notes PR #$PR"
            gh pr close "$PR" --delete-branch --comment "Superseded by #$NEWEST." \
              || echo "Warning: could not close #$PR"
          done
        env:
          GH_TOKEN: ${{ steps.generate_token.outputs.token }}

      - name: No changes
        if: steps.changes.outputs.has_changes == 'false'
        run: echo "No release notes updates needed"