name: release

# Manual, path-scoped release helper for master.
#
# `master` is BOTH the distribution branch (users download the script here)
# AND the default branch that hosts the scheduled CI workflows
# (autoupdate / stale / vuln-watch). `source-build` is a build-OUTPUT branch.
#
# We therefore never merge source-build into master: that would drag source-build's
# whole tree, including the *absence* of the master-only workflows.
# Instead we copy only the assembled artifact files across, and cut GitHub
# releases from master directly.
#
# Two independent manual actions to run against the `master` branch:
#
#   1. sync-from-source-build : commit the assembled files (everything on
#                               source-build EXCEPT .github/) onto master.
#   2. draft-github-release   : create a DRAFT GitHub release from the script
#                               currently on master, with an auto-drafted
#                               changelog.

on:
  workflow_dispatch:
    inputs:
      action:
        description: What to do
        type: choice
        required: true
        default: sync-from-source-build
        options:
          - sync-from-source-build
          - draft-github-release

permissions:
  contents: write

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

jobs:
  # ---------------------------------------------------------------------------
  # 1. Copy assembled files from source-build onto master (no .github/).
  # ---------------------------------------------------------------------------
  sync-from-source-build:
    if: inputs.action == 'sync-from-source-build'
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v6
        with:
          ref: master
          fetch-depth: 0
          persist-credentials: true

      - name: sync assembled files from source-build
        run: |
          set -eu
          git fetch --no-tags origin source-build

          # Every top-level entry on source-build EXCEPT .github/ (master keeps
          # its own CI). Computed dynamically so any new top-level artifact is
          # picked up automatically.
          readarray -t paths < <(git ls-tree --name-only origin/source-build | grep -vxF '.github')
          echo "Syncing: ${paths[*]}"

          # Mirror source-build exactly for those paths, removing first so that
          # deletions/renames inside doc/ etc. propagate too.
          for p in "${paths[@]}"; do rm -rf -- "$p"; done
          git checkout origin/source-build -- "${paths[@]}"
          git add --all -- "${paths[@]}"

          if git diff --cached --quiet; then
            echo "master already up to date with source-build; nothing to sync."
            exit 0
          fi

          ver=$(grep -m1 "^VERSION=" spectre-meltdown-checker.sh | cut -d"'" -f2)
          sb=$(git rev-parse origin/source-build)
          sbdate=$(git log -1 --format=%ai origin/source-build)

          git config user.name  "github-actions[bot]"
          git config user.email "41898282+github-actions[bot]@users.noreply.github.com"
          git commit -m "release: sync v${ver} from source-build

 built from source-build commit ${sb}
 dated ${sbdate}"
          git push origin HEAD:master

  # ---------------------------------------------------------------------------
  # 2. Draft a GitHub release from the script currently on master.
  # ---------------------------------------------------------------------------
  draft-github-release:
    if: inputs.action == 'draft-github-release'
    runs-on: ubuntu-latest
    env:
      GH_TOKEN: ${{ github.token }}
    steps:
      - uses: actions/checkout@v6
        with:
          ref: master
          fetch-depth: 0
          persist-credentials: true

      - name: draft a release from the current master script
        run: |
          set -eu
          ver=$(grep -m1 "^VERSION=" spectre-meltdown-checker.sh | cut -d"'" -f2)
          tag="v${ver}"

          if gh release view "$tag" >/dev/null 2>&1; then
            echo "A release for $tag already exists; refusing to recreate." >&2
            echo "Delete it first if needed." >&2
            exit 1
          fi

          # Draft the changelog from the source-build commits assembled since the
          # previous published release. We locate the source-build commit whose
          # built VERSION equals the last release tag, then list what came after.
          git fetch --no-tags origin source-build
          last_tag=$(gh release list --exclude-drafts --limit 1 --json tagName --jq '.[0].tagName // empty')
          old_ver="${last_tag#v}"

          base=""
          if [ -n "$old_ver" ]; then
            while read -r h; do
              v=$(git show "$h:spectre-meltdown-checker.sh" 2>/dev/null | grep -m1 "^VERSION=" | cut -d"'" -f2 || true)
              if [ "$v" = "$old_ver" ]; then base="$h"; break; fi
            done < <(git rev-list --max-count=500 origin/source-build)
          fi

          {
            echo "## ${tag}"
            echo
            if [ -n "$base" ]; then
              git log --no-merges --format='- %s' "${base}..origin/source-build"
            else
              echo "_Could not determine the previous release point automatically — please fill in the changelog. Last 30 assembled commits below as a starting point:_"
              echo
              git log --no-merges --format='- %s' --max-count=30 origin/source-build
            fi
          } > notes.md

          echo "----- draft notes -----"; cat notes.md; echo "-----------------------"

          gh release create "$tag" \
            --draft \
            --target "$GITHUB_SHA" \
            --title "$tag" \
            --notes-file notes.md \
            spectre-meltdown-checker.sh

          echo "Draft release $tag created."