prep-release.yml

name: Prepare Release
on:
  workflow_dispatch:
    inputs:
      bump:
        description: 'Version bump mode'
        required: true
        default: 'patch'
        type: choice
        options:
          - patch
          - minor
          - major

permissions:
  contents: write
  pull-requests: write

jobs:
  prep-release:
    name: Prepare release branch and PR
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7
        with:
          fetch-tags: true
          fetch-depth: 0

      - name: Configure git
        run: |
          git config --global user.name "github-actions[bot]"
          git config --global user.email "41898282+github-actions[bot]@users.noreply.github.com"

      - name: Resolve previous release tag
        id: prev-tag
        run: |
          PREV_TAG=$(git tag --list 'v[0-9]*.[0-9]*.[0-9]*' --sort=-version:refname | grep -E '^v[0-9]+\.[0-9]+\.[0-9]+$' | head -1)
          if [ -z "$PREV_TAG" ]; then
            PREV_TAG="v0.0.0"
            echo "::warning::No existing tags matching 'v[0-9]*.[0-9]*.[0-9]*' found; defaulting to v0.0.0"
          else
            echo "Previous release tag: ${PREV_TAG}"
          fi
          echo "PREV_TAG=${PREV_TAG}" >> "$GITHUB_OUTPUT"

      - name: Compute target version
        id: version
        run: |
          PREV_TAG="${{ steps.prev-tag.outputs.PREV_TAG }}"
          # Strip leading 'v'
          VERSION="${PREV_TAG#v}"
          # Split into components
          MAJOR=$(echo "$VERSION" | cut -d. -f1)
          MINOR=$(echo "$VERSION" | cut -d. -f2)
          PATCH=$(echo "$VERSION" | cut -d. -f3)
          BUMP="${{ inputs.bump }}"
          case "$BUMP" in
            patch)
              PATCH=$((PATCH + 1))
              ;;
            minor)
              MINOR=$((MINOR + 1))
              PATCH=0
              ;;
            major)
              MAJOR=$((MAJOR + 1))
              MINOR=0
              PATCH=0
              ;;
          esac
          TARGET_VERSION="${MAJOR}.${MINOR}.${PATCH}"
          echo "Target version: ${TARGET_VERSION}"
          echo "TARGET_VERSION=${TARGET_VERSION}" >> "$GITHUB_OUTPUT"

      - name: Derive branch and PR title
        id: meta
        run: |
          TARGET_VERSION="${{ steps.version.outputs.TARGET_VERSION }}"
          BRANCH="prep-release-${TARGET_VERSION}"
          PR_TITLE="Prepare ${TARGET_VERSION} release"
          echo "BRANCH=${BRANCH}" >> "$GITHUB_OUTPUT"
          echo "PR_TITLE=${PR_TITLE}" >> "$GITHUB_OUTPUT"

      - name: Check if release branch already exists
        id: branch-check
        run: |
          BRANCH="${{ steps.meta.outputs.BRANCH }}"
          if git ls-remote --exit-code --heads origin "${BRANCH}" > /dev/null 2>&1; then
            echo "Branch ${BRANCH} already exists on remote"
            echo "EXISTS=true" >> "$GITHUB_OUTPUT"
          else
            echo "Branch ${BRANCH} does not exist on remote"
            echo "EXISTS=false" >> "$GITHUB_OUTPUT"
          fi

      - name: Create or switch to release branch
        run: |
          BRANCH="${{ steps.meta.outputs.BRANCH }}"
          EXISTS="${{ steps.branch-check.outputs.EXISTS }}"
          if [ "$EXISTS" = "true" ]; then
            git fetch origin "${BRANCH}"
            git checkout "${BRANCH}"
            git merge --no-edit origin/main || { git merge --abort; exit 1; }
          else
            git checkout main
            git pull origin main
            git checkout -b "${BRANCH}"
          fi

      - name: Apply version bump to Makefile
        run: |
          TARGET_VERSION="${{ steps.version.outputs.TARGET_VERSION }}"
          sed -i "s/^VERSION ?= .*/VERSION ?= ${TARGET_VERSION}/" Makefile
          if git diff --quiet Makefile; then
            echo "Makefile already has VERSION ?= ${TARGET_VERSION}"
          else
            echo "Makefile updated: VERSION set to ${TARGET_VERSION}"
          fi

      - uses: actions/setup-go@b7ad1dad31e06c5925ef5d2fc7ad053ef454303e # v7
        with:
          go-version-file: 'go.mod'
          cache: true
          cache-dependency-path: go.sum

      - name: Run changelog engine (release mode)
        id: changelog_engine
        env:
          MODE: release
          TARGET_VERSION: ${{ steps.version.outputs.TARGET_VERSION }}
          CHANGELOG_PATH: CHANGELOG.md
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
        run: go run ./scripts/changelog run-engine
      - name: Commit release preparation
        run: |
          TARGET_VERSION="${{ steps.version.outputs.TARGET_VERSION }}"
          git add Makefile CHANGELOG.md
          if git diff --cached --quiet; then
            echo "No changes to commit for release preparation; Makefile and CHANGELOG.md already match target ${TARGET_VERSION}."
            exit 0
          fi
          git commit -m "chore(release): prepare ${TARGET_VERSION}"

      - name: Push release branch
        env:
          GH_AW_CI_TRIGGER_TOKEN: ${{ secrets.GH_AW_CI_TRIGGER_TOKEN }}
        run: |
          BRANCH="${{ steps.meta.outputs.BRANCH }}"
          git push origin "${BRANCH}"
          if [ -n "${GH_AW_CI_TRIGGER_TOKEN}" ]; then
            SERVER_URL="${GITHUB_SERVER_URL#https://}"
            SERVER_URL="${SERVER_URL#http://}"
            git remote set-url origin "https://x-access-token:${GH_AW_CI_TRIGGER_TOKEN}@${SERVER_URL}/${GITHUB_REPOSITORY}.git"
            git commit --allow-empty -m "chore: trigger CI"
            git push origin "${BRANCH}"
          else
            echo "::warning::GH_AW_CI_TRIGGER_TOKEN is not set; CI will not be triggered automatically"
          fi

      - name: Check if release PR already exists
        id: pr-check
        env:
          GH_TOKEN: ${{ github.token }}
        run: |
          BRANCH="${{ steps.meta.outputs.BRANCH }}"
          PR_URL=$(gh pr list --head "${BRANCH}" --state open --json url --jq '.[0].url')
          if [ -n "$PR_URL" ]; then
            echo "PR already exists: ${PR_URL}"
            echo "EXISTS=true" >> "$GITHUB_OUTPUT"
            echo "PR_URL=${PR_URL}" >> "$GITHUB_OUTPUT"
          else
            echo "No open PR found for branch ${BRANCH}"
            echo "EXISTS=false" >> "$GITHUB_OUTPUT"
          fi

      - name: Create release PR
        if: steps.pr-check.outputs.EXISTS == 'false'
        env:
          GH_TOKEN: ${{ github.token }}
        run: |
          BRANCH="${{ steps.meta.outputs.BRANCH }}"
          PR_TITLE="${{ steps.meta.outputs.PR_TITLE }}"
          TARGET_VERSION="${{ steps.version.outputs.TARGET_VERSION }}"
          printf '%s\n' \
            "This pull request prepares the ${TARGET_VERSION} release." \
            "" \
            "## Changes" \
            "" \
            "- Bumps \`VERSION\` in \`Makefile\` to \`${TARGET_VERSION}\`" \
            "- Regenerates the \`## [${TARGET_VERSION}]\` section in \`CHANGELOG.md\` via the shared changelog engine (release range: previous tag to this branch HEAD)" \
            "" \
            "## Checklist" \
            "" \
            "- [ ] Changelog section looks correct" \
            "- [ ] Version bump is correct" \
            > /tmp/pr-body.txt
          gh pr create \
            --head "${BRANCH}" \
            --base main \
            --title "${PR_TITLE}" \
            --body-file /tmp/pr-body.txt \
            --label no-changelog

      - name: Report outcome
        run: |
          TARGET_VERSION="${{ steps.version.outputs.TARGET_VERSION }}"
          BRANCH="${{ steps.meta.outputs.BRANCH }}"
          PR_EXISTS="${{ steps.pr-check.outputs.EXISTS }}"
          PR_URL="${{ steps.pr-check.outputs.PR_URL }}"
          echo "Release preparation complete"
          echo "  Target version : ${TARGET_VERSION}"
          echo "  Branch         : ${BRANCH}"
          echo "  Compare range  : ${{ steps.changelog_engine.outputs.compare_range }}"
          echo "  Section header : ${{ steps.changelog_engine.outputs.section_header }}"
          echo "  Has PRs in range: ${{ steps.changelog_engine.outputs.has_prs }}"
          echo "  User-facing changelog entries: ${{ steps.changelog_engine.outputs.has_user_facing_changes }}"
          if [ "$PR_EXISTS" = "true" ]; then
            echo "  PR             : ${PR_URL} (reused)"
          else
            echo "  PR             : created"
          fi