name: CI testing

# see: https://help.github.com/en/actions/reference/events-that-trigger-workflows
# Trigger the workflow on push or pull request
on: [push, pull_request]

jobs:
  build:

    runs-on: ${{ matrix.os }}
    strategy:
      fail-fast: false
      # max-parallel: 6
      matrix:
        os: [ubuntu-18.04, windows-2019, macOS-10.15]
        python-version: [3.6, 3.7, 3.8]
        requires: ['minimal', 'latest']
        exclude:
          # excludes PT 1.3 as it is missing on pypi
          - python-version: 3.8
            requires: 'minimal'
          # TODO: temporary fix till hanging jobs on macOS for py38 is resolved
          - python-version: 3.8
            os: macOS-10.15

    # Timeout: https://stackoverflow.com/a/59076067/4521646
    timeout-minutes: 15
    steps:
    - uses: actions/checkout@v2
    - name: Set up Python ${{ matrix.python-version }}
      uses: actions/setup-python@v1
      with:
        python-version: ${{ matrix.python-version }}

    # Github Actions: Run step on specific OS: https://stackoverflow.com/a/57948488/4521646
    - name: Setup macOS
      if: runner.os == 'macOS'
      run: |
        brew install libomp  # https://github.com/pytorch/pytorch/issues/20030
        brew install openmpi  # Horovod on macOS requires OpenMPI, Gloo not currently supported

    - name: Setup Windows
      if: runner.os == 'windows'
      run: |
        python -c "lines = [line for line in open('requirements-extra.txt').readlines() if not line.startswith('horovod')] ; open('requirements-extra.txt', 'w').writelines(lines)"

    # TODO: remove after https://github.com/pytorch/pytorch/issues/32186 is resolved
    - name: Setup Windows on Latest
      if: runner.os == 'windows' && matrix.requires == 'latest'
      run: |
        python -c "req = open('requirements.txt').read().replace('torch>=1.3', 'torch<1.5') ; open('requirements.txt', 'w').write(req)"

    # versions <= 1.3 may have issues on mac with some BLAS ops due to missing mkl (https://github.com/pytorch/pytorch/issues/18996)
    - name: Setup MacOS Minimal
      if: runner.os == 'macOS' && matrix.requires == 'minimal'
      run : |
        python -c "req = open('requirements.txt').read().replace('torch>=1.3', 'torch>=1.4') ; open('requirements.txt', 'w').write(req)"

    - name: Set min. dependencies
      if: matrix.requires == 'minimal'
      run: |
        python -c "req = open('requirements.txt').read().replace('>', '=') ; open('requirements.txt', 'w').write(req)"
        python -c "req = open('requirements-extra.txt').read().replace('>', '=') ; open('requirements-extra.txt', 'w').write(req)"

    # Note: This uses an internal pip API and may not always work
    # https://github.com/actions/cache/blob/master/examples.md#multiple-oss-in-a-workflow
    - name: Get pip cache
      id: pip-cache
      run: |
        python -c "from pip._internal.locations import USER_CACHE_DIR; print('::set-output name=dir::' + USER_CACHE_DIR)"

    - name: Cache pip
      uses: actions/cache@v1
      with:
        path: ${{ steps.pip-cache.outputs.dir }}
        key: ${{ runner.os }}-${{ matrix.python-version }}-${{ matrix.requires }}-pip-${{ hashFiles('requirements.txt') }}-${{ hashFiles('requirements-extra.txt') }}
        restore-keys: |
          ${{ runner.os }}-${{ matrix.python-version }}-${{ matrix.requires }}-pip-

    - name: Install dependencies
      run: |
        # python -m pip install --upgrade --user pip
        pip install -r requirements.txt -U -f https://download.pytorch.org/whl/torch_stable.html -q
        HOROVOD_BUILD_ARCH_FLAGS="-mfma" pip install -r ./tests/requirements-devel.txt -q
        # pip install tox coverage
        python --version
        pip --version
        pip list
      shell: bash

    - name: Reinstall Horovod if necessary
      if: runner.os != 'windows' && matrix.python-version != '3.8'
      run: |
        HOROVOD_BUILT=$(python -c "import horovod.torch; horovod.torch.nccl_built(); print('SUCCESS')")
        if [[ $HOROVOD_BUILT != "SUCCESS" ]]; then
          pip uninstall -y horovod
          HOROVOD_BUILD_ARCH_FLAGS="-mfma" pip install --no-cache-dir $(grep "horovod" requirements-extra.txt)
        fi
        horovodrun --check-build
      shell: bash

    - name: Cache datasets
      uses: actions/cache@v1
      with:
        path: tests/Datasets # This path is specific to Ubuntu
        # Look to see if there is a cache hit for the corresponding requirements file
        key: mnist-dataset

    - name: Tests
      # env:
      #   TOXENV: py${{ matrix.python-version }}
      run: |
        # tox --sitepackages
        # flake8 .
        coverage run --source pytorch_lightning -m py.test pytorch_lightning tests -v --junitxml=junit/test-results-${{ runner.os }}-${{ matrix.python-version }}-${{ matrix.requires }}.xml
        coverage report

    - name: Upload pytest test results
      uses: actions/upload-artifact@master
      with:
        name: pytest-results-${{ runner.os }}-${{ matrix.python-version }}-${{ matrix.requires }}
        path: junit/test-results-${{ runner.os }}-${{ matrix.python-version }}-${{ matrix.requires }}.xml
      # Use always() to always run this step to publish test results when there are test failures
      if: always()

    - name: Package Setup
      run: |
        check-manifest
        python setup.py check --metadata --strict
        python setup.py sdist
        twine check dist/*
    #- name: Try install package
    #  if: ! startsWith(matrix.os, 'windows')
    #  run: |
    #    virtualenv vEnv ; source vEnv/bin/activate
    #    pip install --editable . ; cd .. & python -c "import pytorch_lightning ; print(pytorch_lightning.__version__)"
    #    deactivate ; rm -rf vEnv

    - name: Statistics
      if: success()
      run: |
         coverage report