name: docs.vlang.io deploy

### Regenerate https://docs.vlang.io/ (the GitHub Pages site served from the
### `main` branch of https://github.com/vlang/docs ), on every change to
### doc/docs.md that lands on master.
###
### Historically docs.vlang.io was updated by the FreeBSD machine that also runs
### cmd/tools/fast/fast.v . When that single machine stops, the site silently
### goes stale (see issue #27038, where it was stuck at the 2026-02-09 snapshot).
### Generating and deploying from CI removes that single point of failure, the
### same way modules.vlang.io is deployed from module_docs_ci.yml .

on:
  workflow_dispatch:
  push:
    branches:
      - master
    paths:
      - 'doc/docs.md'
      - '**/docs_site_ci.yml'

# Allow only one concurrent deployment, skipping runs queued between the run in-progress and latest queued.
# However, do NOT cancel in-progress runs as we want to allow these production deployments to complete.
concurrency:
  group: docs_site-${{ github.workflow }}-${{ github.ref }}
  cancel-in-progress: ${{ !contains(github.ref, 'master')}}

jobs:
  deploy-docs-site:
    runs-on: ubuntu-latest
    timeout-minutes: 20
    steps:
      - uses: actions/checkout@v7
      - uses: ./.github/actions/cache-apt-packages-action
      - name: Build V
        run: make -j4 && ./v symlink
      - name: Install dependencies (the docs generator uses the markdown module)
        run: ./v retry -- ./v install markdown

      - name: Generate the HTML pages from doc/docs.md
        run: |
          set -e
          # The generator (the `generator` branch of vlang/docs) fetches
          # doc/docs.md from the master branch of vlang/v, transforms it into one
          # HTML page per section, and writes them into its own output/ folder.
          rm -rf docs_generator
          ./v retry -- git clone --depth=1 --branch generator https://github.com/vlang/docs docs_generator
          ./v run docs_generator/.
          [ -f docs_generator/output/introduction.html ]

      - name: Deploy to vlang/docs (main branch -> docs.vlang.io)
        if: github.event_name != 'pull_request' && github.repository == 'vlang/v' && github.ref == 'refs/heads/master'
        run: |
          set -e
          git config --global user.email "[email protected]"
          git config --global user.name "vlang-bot"

          COMMIT_HASH="$(git rev-parse --short HEAD)"
          COMMIT_MSG="$(git log -1 --pretty='%s' HEAD)"

          rm -rf docs_site
          ./v retry -- git clone --depth=1 --branch main "https://vlang-bot:${{ secrets.VLANG_BOT_SECRET }}@github.com/vlang/docs.git" docs_site

          # The legacy FreeBSD uploader (cmd/tools/fast/fast.v) may still be
          # pushing to vlang/docs main too, so our push can be rejected as
          # non-fast-forward. `v retry` would only rerun the same push, never
          # fetching the new tip, so retry here by re-syncing onto the latest main
          # and pushing again. The sync is idempotent, so re-applying it on top of
          # whatever landed meanwhile is safe.
          deploy_attempts=5
          for attempt in $(seq 1 "${deploy_attempts}"); do
            git -C docs_site fetch --depth=1 origin main
            git -C docs_site reset --hard FETCH_HEAD

            # Sync the freshly generated pages onto the published site. --delete so
            # that pages/assets removed or renamed in doc/docs.md do not linger as
            # stale files, but protect the site-only files at the repo root that the
            # generator does not produce (git metadata, CNAME, .nojekyll, README.md,
            # favicon.ico and the legacy build.vsh).
            rsync -a --delete \
              --exclude '/.git' \
              --exclude '/.gitattributes' \
              --exclude '/.gitignore' \
              --exclude '/.nojekyll' \
              --exclude '/CNAME' \
              --exclude '/README.md' \
              --exclude '/favicon.ico' \
              --exclude '/build.vsh' \
              docs_generator/output/ docs_site/

            git -C docs_site add -A
            # `git diff --cached --quiet` exits 0 with nothing staged, 1 when there
            # are staged changes, and >1 on a real error - so only 1 means "deploy".
            set +e
            git -C docs_site diff --cached --quiet
            diff_rc=$?
            set -e
            if [ "${diff_rc}" -eq 0 ]; then
              echo "docs.vlang.io is already up to date for ${COMMIT_HASH}; nothing to deploy."
              exit 0
            elif [ "${diff_rc}" -ne 1 ]; then
              echo "::error::git diff --cached failed with exit code ${diff_rc}" >&2
              exit "${diff_rc}"
            fi
            git -C docs_site commit -m "update docs for commit ${COMMIT_HASH} - ${COMMIT_MSG}"

            if git -C docs_site push origin main; then
              echo "docs.vlang.io updated for ${COMMIT_HASH} (attempt ${attempt})."
              exit 0
            fi
            echo "push to vlang/docs main was rejected (attempt ${attempt}/${deploy_attempts}); refetching and retrying..."
          done
          echo "::error::could not push to vlang/docs main after ${deploy_attempts} attempts" >&2
          exit 1