name: Prepare Release PR

on:
    workflow_dispatch:
        inputs:
            version:
                description: Release version, for example 0.25.81
                required: true
                type: string
            base_branch:
                description: Base branch for the release PR
                required: false
                type: string
                default: main
            release_branch:
                description: Release branch name. Defaults to the version with dots replaced by underscores.
                required: false
                type: string
            allow_empty_updates:
                description: Allow an empty Unreleased section
                required: false
                type: boolean
                default: false

jobs:
    prepare:
        runs-on: ubuntu-latest
        permissions:
            contents: write
            pull-requests: write
        steps:
            - uses: actions/checkout@v4
              with:
                  ref: ${{ inputs.base_branch }}
                  fetch-depth: 0
                  submodules: recursive

            - name: Use Node.js
              uses: actions/setup-node@v4
              with:
                  node-version: "24.x"
                  cache: npm

            - name: Install dependencies
              run: npm ci

            - name: Prepare release changes
              id: prepare
              env:
                  VERSION: ${{ inputs.version }}
                  RELEASE_BRANCH_INPUT: ${{ inputs.release_branch }}
                  ALLOW_EMPTY_UPDATES: ${{ inputs.allow_empty_updates }}
              run: |
                  set -euo pipefail
                  git config user.name "github-actions[bot]"
                  git config user.email "41898282+github-actions[bot]@users.noreply.github.com"

                  BRANCH="${RELEASE_BRANCH_INPUT}"
                  if [[ -z "${BRANCH}" ]]; then
                    BRANCH="${VERSION//./_}"
                  fi

                  if git ls-remote --exit-code --heads origin "${BRANCH}" >/dev/null 2>&1; then
                    echo "Release branch already exists: ${BRANCH}" >&2
                    exit 1
                  fi

                  git switch -c "${BRANCH}"
                  npm version "${VERSION}" --no-git-tag-version
                  node utils/release-notes.mjs prepare "${VERSION}"
                  npm run pretty:json

                  git add package.json package-lock.json manifest.json versions.json updates.md src/apps/cli/package.json src/apps/webpeer/package.json src/apps/webapp/package.json
                  git diff --cached --check
                  git commit -m "Releasing ${VERSION}"
                  git push --set-upstream origin "${BRANCH}"

                  echo "branch=${BRANCH}" >> "$GITHUB_OUTPUT"

            - name: Create draft release PR
              env:
                  GH_TOKEN: ${{ github.token }}
                  VERSION: ${{ inputs.version }}
                  BASE_BRANCH: ${{ inputs.base_branch }}
                  RELEASE_BRANCH: ${{ steps.prepare.outputs.branch }}
              run: |
                  cat > /tmp/release-pr-body.md <<EOF
                  ## Release checklist

                  - [ ] Review and polish \`updates.md\`
                  - [ ] Confirm \`manifest.json\`, \`versions.json\`, and workspace package versions
                  - [ ] Confirm CI has passed
                  - [ ] Run the finalise release workflow after the PR head is fixed
                  - [ ] Merge this PR after the draft or pre-release has been created
                  EOF

                  gh pr create \
                    --base "${BASE_BRANCH}" \
                    --head "${RELEASE_BRANCH}" \
                    --draft \
                    --title "Releasing ${VERSION}" \
                    --body-file /tmp/release-pr-body.md