execute_notebooks.yml

# Execute the jupyter notebooks, push them to dedicate branches,
# and trigger ReadTheDocs in the linked repository.

# This workflow was largely inspired by the following wradlib-notebooks CI task:
# https://github.com/wradlib/wradlib-notebooks/blob/main/.github/workflows/main.yml
name: Execute jupyter notebooks

env:
  # URL for the external repository linked with the notebooks in this project.
  LINKED_REPO: pySTEPS/pysteps

on:
  push:
    branches: [ main, dev ]
  pull_request:
    branches: [ main, dev ]

jobs:
  run_notebooks:
    name: Execute jupyter notebooks
    runs-on: "ubuntu-latest"

    defaults:
      run:
        shell: bash -l {0}

    outputs:
      rtd_branch: ${{steps.get_nb_render_branch.outputs.render_branch}}

    steps:
      - name: Checkout repository
        uses: actions/checkout@v2

      - name: Install mamba and create environment
        uses: mamba-org/provision-with-micromamba@main
        with:
          environment-file: environment.yml
          environment-name: doc_builder
          extra-specs: python=3.8

      - name: Checkout linked repository
        uses: actions/checkout@v2
        with:
          repository: ${{ env.LINKED_REPO }}
          path: ${{ env.LINKED_REPO }}

      - name: Install package from the linked repository
        working-directory: ${{ env.LINKED_REPO }}
        run: |
          pip install .
          # Since actions/checkout@v2 only checkouts a single commit without tags let's fetch the tags
          git fetch --all --tags
          git log HEAD

      - name: Install pysteps-data
        run: |
          python ci/fetch_pysteps_data.py $HOME/pysteps_data
          python -c "import pysteps; print(pysteps.config_fname())"          

      - name: Determine destination branch for the rendered notebooks and the RTD branch
        id: get_nb_render_branch
        working-directory: ${{ env.LINKED_REPO }}
        run: |
          ########################################
          # Find the branch that trigger the event
          if [[ "${GITHUB_EVENT_NAME}" == "push" ]]; then
            event_branch=$(echo ${GITHUB_REF##*/})
          elif [[ "${GITHUB_EVENT_NAME}" == "pull_request" ]]; then
            event_branch=$(echo $GITHUB_BASE_REF)
          else
            event_branch=unknown
          fi
          echo "::set-output name=event_branch::${event_branch}"

          ####################################################################
          # Check if the Linked repository current commit corresponds to a tag
          LINKED_REPO_TAG=$(git name-rev --name-only --tags HEAD)
          echo "::set-output name=linked_repo_tag::${LINKED_REPO_TAG}"

          ###################################
          # Determine destination branch name
          if [[ "${LINKED_REPO_TAG}" == "undefined" ]]; then
            # Not a tagged version
            if [[ "${event_branch}" == "dev" ]]; then
              echo "::set-output name=render_branch::test"
            else
              echo "::set-output name=render_branch::latest"
            fi
          else
            # Save tagged versions in their own branch
            echo "::set-output name=render_branch::${LINKED_REPO_TAG}"
          fi

      - name: Execute notebooks
        working-directory: ./notebooks
        run: |
          jupyter nbconvert --to notebook --inplace --execute ./*.ipynb          

      - name: Print debug information
        env:
          RENDER_BRANCH: ${{steps.get_nb_render_branch.outputs.render_branch}}
          EVENT_BRANCH: ${{steps.get_nb_render_branch.outputs.event_branch}}
          LINKED_REPO_TAG: ${{steps.get_nb_render_branch.outputs.linked_repo_tag}}
        run: |
          echo "EVENT_BRANCH=${EVENT_BRANCH}"
          echo "LINKED_REPO_TAG=${LINKED_REPO_TAG}"
          echo "GITHUB_SHA=${GITHUB_SHA}"
          echo "RENDER_BRANCH=${RENDER_BRANCH}"

      - name: Commit notebooks
        env:
          RENDER_BRANCH: ${{steps.get_nb_render_branch.outputs.render_branch}}
        run: |
          git config user.name 'github-actions[bot]'
          git config user.email 'github-actions[bot]@users.noreply.github.com'

          # Checkout changes in an orphan branch first.
          # We want to update  only the notebooks.
          git checkout --orphan tmp
          git reset
          git add -A notebooks
          git commit -m "Rendering $GITHUB_SHA"

          # Clean rest of the files.
          git clean -d -f -f

          # Switch to destination branch
          action=$(git ls-remote --exit-code --heads origin ${RENDER_BRANCH} > /dev/null || echo "push")
          if [ "$action" != "push" ] ; then
            git fetch origin ${RENDER_BRANCH}
            # If it exits, merge the changes and push.
            git merge --strategy=ours --allow-unrelated-histories origin/${RENDER_BRANCH} -m "Commit"

            # Add changes to the RENDER_BRANCH.
            git checkout -b ${RENDER_BRANCH} origin/${RENDER_BRANCH}
            git merge --squash tmp
            git commit --allow-empty -m "Rendering $GITHUB_SHA"
          fi
          #Otherwise, the next task will push the orpahn branch.

      - name: Push changes
        uses: ad-m/github-push-action@master
        with:
          github_token: ${{ secrets.GITHUB_TOKEN }}
          branch: ${{steps.get_nb_render_branch.outputs.render_branch}}

#  trigger_rtd:
#      # Task adapted from the wradlib project
#      # https://github.com/wradlib/wradlib-notebooks/blob/main/.github/workflows/render_notebooks.yml
#      needs: [run_notebooks]
#      name: Trigger readthedocs
#      runs-on: ubuntu-latest
#      defaults:
#        run:
#          shell: bash -l {0}
#      env:
#        RTD_TOKEN: ${{ secrets.RTD_TOKEN }}
#        RTD_URL: ${{ secrets.RTD_URL }}
#        RTD_BRANCH: ${{ needs.run_notebooks.outputs.rtd_branch }}
#      steps:
#      - name: Trigger readthedocs for the corresponding branch (latest or tag)
#        run: |
#          # Ignore triggering if this workflow was triggered by the dev branch.
#          if [[ "${RTD_BRANCH}" != "test" ]]; then
#            curl -X POST -d "branches=${RTD_BRANCH}" -d "token=${RTD_TOKEN}" "${RTD_URL}"
#          fi