prepare-release.yml

name: Prepare Release

on:
  workflow_dispatch:
    inputs:
      release_type:
        description: 'Release type'
        required: true
        type: choice
        options:
          - beta
          - rc
          - stable
        default: stable
      version_override:
        description: 'Version override (optional, e.g., 0.1.0). Defaults to Directory.Build.props without -develop.'
        required: false
        type: string

concurrency:
  group: prepare-release
  cancel-in-progress: false

jobs:
  prepare-release:
    name: Create Release PR
    runs-on: ubuntu-latest
    permissions:
      contents: write
      pull-requests: write
    steps:
      - name: Checkout develop
        uses: actions/checkout@v5
        with:
          ref: develop
          fetch-depth: 0
          token: ${{ secrets.RELEASE_PAT }}

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

      - name: Compute release version
        id: version
        shell: bash
        run: |
          if [ -n "${{ github.event.inputs.version_override }}" ]; then
            VERSION="${{ github.event.inputs.version_override }}"
          else
            VERSION=$(sed -n 's|.*<Version>\(.*\)</Version>.*|\1|p' Directory.Build.props | head -1)
            VERSION="${VERSION%%-*}"
          fi

          RELEASE_TYPE="${{ github.event.inputs.release_type }}"

          if [ -z "$VERSION" ]; then
            echo "::error::Could not resolve release version."
            exit 1
          fi

          if ! echo "$VERSION" | grep -Eq '^[0-9]+\.[0-9]+\.[0-9]+$'; then
            echo "::error::Release version must be a stable SemVer core like 0.1.0; got '$VERSION'."
            exit 1
          fi

          if [ "$RELEASE_TYPE" = "stable" ]; then
            SEMVER="$VERSION"
            TAG="v${VERSION}"
          else
            LATEST_TAG=$(git tag -l "v${VERSION}-${RELEASE_TYPE}.*" --sort=-v:refname | head -1)
            if [ -z "$LATEST_TAG" ]; then
              NEXT_NUM=1
            else
              CURRENT_NUM="${LATEST_TAG##*.}"
              NEXT_NUM=$((CURRENT_NUM + 1))
            fi

            SEMVER="${VERSION}-${RELEASE_TYPE}.${NEXT_NUM}"
            TAG="v${SEMVER}"
          fi

          echo "version=${VERSION}" >> "$GITHUB_OUTPUT"
          echo "semver=${SEMVER}" >> "$GITHUB_OUTPUT"
          echo "tag=${TAG}" >> "$GITHUB_OUTPUT"
          echo "release_type=${RELEASE_TYPE}" >> "$GITHUB_OUTPUT"

      - name: Check for conflicts
        shell: bash
        run: |
          TAG="${{ steps.version.outputs.tag }}"
          BRANCH="release/${TAG}"

          if git rev-parse "${TAG}" >/dev/null 2>&1; then
            echo "::error::Tag ${TAG} already exists."
            exit 1
          fi

          if git ls-remote --heads origin "${BRANCH}" | grep -q .; then
            echo "::error::Branch ${BRANCH} already exists on the remote."
            exit 1
          fi

          if curl -fsS https://api.nuget.org/v3-flatcontainer/terminal.gui.cli/index.json \
            | jq -r '.versions[]' | grep -Fxq "${{ steps.version.outputs.semver }}"; then
            echo "::error::Terminal.Gui.Cli ${{ steps.version.outputs.semver }} already exists on NuGet.org."
            echo "::error::Choose a new version_override."
            exit 1
          fi

          if gh pr list --state open --base main --head "${BRANCH}" --json number --jq 'length' | grep -vq '^0$'; then
            echo "::error::An open release PR already exists for ${BRANCH}."
            exit 1
          fi
        env:
          GH_TOKEN: ${{ secrets.RELEASE_PAT }}

      - name: Create release branch
        shell: bash
        run: |
          BRANCH="release/${{ steps.version.outputs.tag }}"
          git checkout -b "$BRANCH"
          git push origin "$BRANCH"

      - name: Create Pull Request
        env:
          GH_TOKEN: ${{ secrets.RELEASE_PAT }}
          SEMVER: ${{ steps.version.outputs.semver }}
          TAG: ${{ steps.version.outputs.tag }}
          RELEASE_TYPE: ${{ steps.version.outputs.release_type }}
        shell: bash
        run: |
          BRANCH="release/${TAG}"

          if [ "$RELEASE_TYPE" = "stable" ]; then
            PRERELEASE_NOTE=""
          else
            PRERELEASE_NOTE="This is a **${RELEASE_TYPE}** pre-release."
          fi

          cat > /tmp/pr_body.md << EOF2
          ## Release ${TAG}

          ${PRERELEASE_NOTE}

          **Version:** \`${SEMVER}\`
          **NuGet Package:** \`Terminal.Gui.Cli ${SEMVER}\`

          ### What happens when this PR is merged

          1. The **Finalize Release** workflow creates tag \`${TAG}\`
          2. The **Release** workflow builds and pushes \`Terminal.Gui.Cli ${SEMVER}\` to NuGet.org
          3. A **GitHub Release** is created with auto-generated notes
          4. A **back-merge PR** from \`main\` -> \`develop\` is opened

          ### Checklist

          - [ ] CI passes on this PR
          - [ ] Version looks correct: \`${SEMVER}\`
          - [ ] Release notes reviewed
          EOF2

          gh pr create \
            --base main \
            --head "$BRANCH" \
            --title "Release ${TAG}" \
            --body-file /tmp/pr_body.md