bot-pr-title.yml

name: Bot PR Title Format

on:
  pull_request_target:
    types: [opened, edited, reopened, synchronize]

permissions:
  contents: read
  pull-requests: read
  statuses: write

jobs:
  check-title:
    name: Check bot PR title format
    runs-on: ubuntu-latest
    env:
      GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
      BOT_LOGIN: "ai-agent-kxrpc[bot]"
      STATUS_CONTEXT: "Bot PR Title Format"
      TITLE_PATTERN: '^KRPC-[0-9]+: .+'

    steps:
      - name: Skip if PR is not bot-authored
        id: verify-bot
        run: |
          PR_AUTHOR="${{ github.event.pull_request.user.login }}"
          if [ "$PR_AUTHOR" != "$BOT_LOGIN" ]; then
            echo "PR author is '$PR_AUTHOR', not '$BOT_LOGIN'. Skipping."
            echo "skip=true" >> "$GITHUB_OUTPUT"
          else
            echo "skip=false" >> "$GITHUB_OUTPUT"
          fi

      - name: Validate PR title
        id: validate
        if: steps.verify-bot.outputs.skip == 'false'
        env:
          PR_TITLE: ${{ github.event.pull_request.title }}
        run: |
          echo "Title: $PR_TITLE"
          echo "Pattern: $TITLE_PATTERN"

          if [[ "$PR_TITLE" =~ $TITLE_PATTERN ]]; then
            echo "state=success" >> "$GITHUB_OUTPUT"
            echo "description=Title starts with KRPC-XXX: prefix" >> "$GITHUB_OUTPUT"
            echo "PR title matches required format."
          else
            echo "state=failure" >> "$GITHUB_OUTPUT"
            echo "description=Title must start with 'KRPC-<number>: '" >> "$GITHUB_OUTPUT"
            echo "::error::PR title '$PR_TITLE' must start with 'KRPC-<number>: ' (e.g. 'KRPC-123: Fix something')."
          fi

      - name: Set commit status
        run: |
          REPO="${{ github.repository }}"
          PR_SHA="${{ github.event.pull_request.head.sha }}"
          PR_NUMBER="${{ github.event.pull_request.number }}"

          if [ "${{ steps.verify-bot.outputs.skip }}" == "true" ]; then
            STATE="success"
            DESCRIPTION="Skipped (not a bot PR)"
          else
            STATE="${{ steps.validate.outputs.state }}"
            DESCRIPTION="${{ steps.validate.outputs.description }}"
          fi

          gh api --method POST "repos/$REPO/statuses/$PR_SHA" \
            --field state="$STATE" \
            --field context="$STATUS_CONTEXT" \
            --field description="$DESCRIPTION" \
            --field target_url="https://github.com/$REPO/pull/$PR_NUMBER" > /dev/null

          if [ "$STATE" != "success" ]; then
            exit 1
          fi