name: Create Release Branch

on:
  pull_request:
    types:
      - closed
    branches:
      - main

permissions:
  contents: write
  pull-requests: write

jobs:
  create-release-branch:
    runs-on: ubuntu-latest
    if: >
      github.event.pull_request.merged == true &&
      startsWith(github.event.pull_request.head.ref, 'version-bump/')
    steps:
    - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd  # v6.0.2
      with:
        ref: ${{ github.event.pull_request.merge_commit_sha }}
        fetch-depth: 0

    - uses: cashapp/activate-hermit@e49f5cb4dd64ff0b0b659d1d8df499595451155a # v1
    - uses: astral-sh/setup-uv@61cb8a9741eeb8a550a1b8544337180c0fc8476b  # v7.2.0

    - name: Extract version and base branch
      env:
        GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
      run: |
        VERSION=$(just get-tag-version)
        BASE_BRANCH="${{ github.event.pull_request.base.ref }}"
        echo "version=$VERSION" >> $GITHUB_ENV
        echo "base_branch=$BASE_BRANCH" >> $GITHUB_ENV
        echo "Version: $VERSION"
        echo "Base branch: $BASE_BRANCH"

        PRIOR_TAG=$(just get-prior-version "$VERSION")
        if [[ -z "$PRIOR_TAG" ]]; then
          echo "No prior version (first release), using first commit"
          PRIOR_TAG=$(git rev-list --max-parents=0 HEAD)
        fi
        echo "prior_ref=$PRIOR_TAG" >> $GITHUB_ENV
        echo "Prior ref: $PRIOR_TAG"

    - name: Create release branch
      run: |
        git config --local user.email "41898282+github-actions[bot]@users.noreply.github.com"
        git config --local user.name "github-actions[bot]"

        BRANCH_NAME="release/${{ env.version }}"
        git switch -c "$BRANCH_NAME"

        # Add an empty commit so GitHub can represent this as a PR
        git commit --allow-empty --message "chore(release): open release branch for ${{ env.version }}"

        git push origin "$BRANCH_NAME"

        HEAD_REF=$(git rev-parse HEAD)
        echo "branch_name=$BRANCH_NAME" >> $GITHUB_ENV
        echo "head_ref=$HEAD_REF" >> $GITHUB_ENV

    - name: Generate release notes
      uses: ./.github/actions/generate-release-pr-body
      with:
        version: ${{ env.version }}
        head_ref: ${{ env.head_ref }}
        prior_ref: ${{ env.prior_ref }}

    - name: Create Release PR
      run: |
        PR_URL=$(gh pr create \
          -B "${{ env.base_branch }}" \
          -H "${{ env.branch_name }}" \
          --title "chore(release): release version ${{ env.version }}" \
          --body-file pr_body.txt)
        echo "pr_url=$PR_URL" >> $GITHUB_ENV
      env:
        GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}

    - name: Post release checklist comment
      run: |
        sed 's/{{VERSION}}/${{ env.version }}/g' RELEASE_CHECKLIST.md > checklist_comment.md
        gh pr comment "${{ env.pr_url }}" --body-file checklist_comment.md
      env:
        GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}