name: Docs

on:
  pull_request:
  push:
    branches:
      - nightly
      - main
      - release/*
  workflow_dispatch:

jobs:
  build:
    uses: pytorch/test-infra/.github/workflows/linux_job.yml@main
    with:
      repository: pytorch/vision
      upload-artifact: docs
      script: |
        set -euo pipefail

        export PYTHON_VERSION=3.8
        export GPU_ARCH_TYPE=cpu
        export GPU_ARCH_VERSION=''
        ./.github/scripts/setup-env.sh
        
        # Prepare conda
        CONDA_PATH=$(which conda)
        eval "$(${CONDA_PATH} shell.bash hook)"
        conda activate ci
        # FIXME: not sure why we need this. `ldd torchvision/video_reader.so` shows that it
        #  already links against the one pulled from conda. However, at runtime it pulls from
        #  /lib64
        # Should we maybe always do this in `./.github/scripts/setup-env.sh` so that we don't
        # have to pay attention in all other workflows?
        export LD_LIBRARY_PATH="${CONDA_PREFIX}/lib:${LD_LIBRARY_PATH}"
        
        cd docs
        
        echo '::group::Install doc requirements'
        pip install --progress-bar=off -r requirements.txt
        echo '::endgroup::'
        
        echo '::group::Build HTML docs'
        # The runner does not have sufficient memory to run with as many processes as their are
        # cores (`-j auto`). Thus, we limit to a single process (`-j 1`) here.
        sed -i -e 's/-j auto/-j 1/' Makefile
        make html
        echo '::endgroup::'
        
        mv build/html "${RUNNER_ARTIFACT_DIR}"

  upload-preview:
    if: github.event_name == 'pull_request'
    needs: [build]
    runs-on: [self-hosted, linux.2xlarge]
    steps:
      - uses: actions/download-artifact@v3
        with:
          name: docs

      - name: Upload docs preview
        uses: seemethere/upload-artifact-s3@v5
        with:
          retention-days: 14
          s3-bucket: doc-previews
          if-no-files-found: error
          path: html
          s3-prefix: pytorch/vision/${{ github.event.pull_request.number }}