name: Deploy Docs

on:
  push:
    branches: [main]
  workflow_dispatch:

jobs:
  deploy:
    runs-on: ubuntu-22.04

    steps:
      - uses: actions/checkout@v4

      - name: Set up Python 3.10
        uses: actions/setup-python@v5
        with:
          python-version: '3.10'

      - name: Setup mdBook
        uses: peaceiris/actions-mdbook@v2
        with:
          mdbook-version: 'latest'

      - name: Run mdBook regression tests
        run: |
          python3 -m unittest discover -s tests -p 'test_prepare_mdbook.py'
          python3 -m unittest discover -s tests -p 'test_prepare_mdbook_zh.py'
          python3 -m unittest discover -s tests -p 'test_assemble_docs_publish_tree.py'
          python3 -m unittest discover -s tests -p 'test_ensure_book_resources.py'
          python3 -m unittest discover -s tests -p 'test_image_references.py'

      - name: Build v2 (EN + ZH) with mdBook
        run: bash build_mdbook_v2.sh

      - name: Build v1 (EN + ZH) with mdBook
        run: bash build_mdbook_v1.sh

      - name: Verify build outputs
        run: |
          for d in .mdbook-v2/book .mdbook-v2-zh/book .mdbook-v1/book .mdbook-v1-zh/book; do
            if [ ! -f "$d/index.html" ]; then
              echo "ERROR: $d/index.html not found"
              exit 1
            fi
            echo "OK: $d/index.html exists"
          done

      - name: Assemble and deploy to openmlsys.github.io
        env:
          DEPLOY_KEY: ${{ secrets.DEPLOY_KEY }}
        run: |
          # DEPLOY_KEY is the private half of a write-enabled deploy key on openmlsys.github.io.
          key_file="${RUNNER_TEMP}/deploy_key"
          known_hosts="${RUNNER_TEMP}/known_hosts"
          printf '%s\n' "${DEPLOY_KEY}" > "${key_file}"
          chmod 600 "${key_file}"
          echo "github.com ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIOMqqnkVzrm0SdG6UOoqKLsabgH5C9okWi0dh2l9GKJl" > "${known_hosts}"
          export GIT_SSH_COMMAND="ssh -i ${key_file} -o IdentitiesOnly=yes -o UserKnownHostsFile=${known_hosts} -o StrictHostKeyChecking=yes"

          git clone git@github.com:openmlsys/openmlsys.github.io.git

          python3 tools/assemble_docs_publish_tree.py \
            --destination-root openmlsys.github.io \
            --docs-subdir docs \
            --v2-en-source .mdbook-v2/book \
            --v2-zh-source .mdbook-v2-zh/book \
            --v1-en-source .mdbook-v1/book \
            --v1-zh-source .mdbook-v1-zh/book

          cd openmlsys.github.io
          git config user.name "github-actions[bot]"
          git config user.email "github-actions[bot]@users.noreply.github.com"
          git add docs

          if git diff --cached --quiet; then
            echo "No changes to commit"
          else
            git commit -m "deploy: update docs from ${GITHUB_REPOSITORY}@${GITHUB_SHA}"
            git push
          fi