action.yml

name: 'venv setup'
description: 'configures venv, python and caches'

inputs:
  python-version:
    description: "Version range or exact version of Python or PyPy to use, using SemVer's version range syntax."
  cache-dependency-path:
    description: "Requirement files to install. Can be a glob pattern."
    default: '**/requirements*.txt'
  venv-dir:
    default: '.venv'
  install-cmd:
    description: 'Command to install python dependencies.'

outputs:
  cache-hit:
    description: "A boolean value to indicate if a cache was restored"
    value: ${{ steps.cache-venv.outputs.cache-hit }}

runs:
  using: 'composite'
  steps:
    - uses: thebrowsercompany/check-python-exists@6334b969448dd1526acacf8ba093bfbd3c5dce64
      id: setup-python
      with:
        python-version: ${{ inputs.python-version }}
        is-self-hosted: ${{ !startsWith(runner.name, 'GitHub Actions') }}
    
    - name: Check venv
      id: check-venv
      shell: bash
      run: |
        # Will either print the directory to the venv, or `None` if it is not set.
        VENV=$("${{ steps.setup-python.outputs.python-path }}" -c "import os; print(os.environ.get('VIRTUAL_ENV'))")
        if [ "$VENV" = "None" ]; then
          echo "No venv detected. Setting up venv."
          echo "already_venv=false" >> "$GITHUB_OUTPUT"
        else
          echo "Python venv already detected. Skipping the rest of venv setup."
          echo "already_venv=true" >> "$GITHUB_OUTPUT"
        fi

    - name: SHA the install command
      if: steps.check-venv.outputs.already_venv == 'false'
      id: install-cmd-sha
      shell: bash
      # macOS doesn't include shasum256 and Windows doesn't include shasum, so
      # use python.
      run: |
        CMD_HASH="$(echo '${{ inputs.install-cmd }}' | python3 -c 'import hashlib,sys;print(hashlib.sha256(sys.stdin.buffer.read()).hexdigest())')"
        echo -n "install-cmd-sha=$CMD_HASH" >> $GITHUB_OUTPUT

    - uses: actions/cache@1bd1e32a3bdc45362d1e726936510720a7c30a57 # v4.2.0
      if: steps.check-venv.outputs.already_venv == 'false'
      id: cache-venv
      with:
        path: ${{ inputs.venv-dir }}
        key: setup-venv-${{ runner.os }}-py-${{ steps.setup-python.outputs.python-version }}-${{ steps.setup-python.outputs.python-path }}-${{ hashFiles(inputs.cache-dependency-path) }}-${{ steps.install-cmd-sha.outputs.install-cmd-sha }}

    - name: Create venv
      # cache-hit is a weird tribool string: https://github.com/actions/cache/issues/1466
      if: steps.cache-venv.outputs.cache-hit != 'true' && steps.check-venv.outputs.already_venv == 'false'
      shell: bash
      run: |
        '${{ steps.setup-python.outputs.python-path }}' -m venv ${{ inputs.venv-dir }}

    - name: venv save env (posix)
      if: runner.os != 'Windows' && steps.check-venv.outputs.already_venv == 'false'
      shell: bash
      run: |
        source ${{ inputs.venv-dir }}/bin/activate
        echo "VIRTUAL_ENV=${VIRTUAL_ENV}" >> $GITHUB_ENV
        echo "${VIRTUAL_ENV}/bin" >> $GITHUB_PATH

    - name: venv save env (windows)
      if: runner.os == 'Windows' && steps.check-venv.outputs.already_venv == 'false'
      shell: pwsh
      run: |
        ${{ inputs.venv-dir }}\Scripts\Activate.ps1
        echo "$Env:VIRTUAL_ENV"
        echo "VIRTUAL_ENV=$Env:VIRTUAL_ENV" >> $Env:GITHUB_ENV
        echo "$Env:VIRTUAL_ENV\Scripts" >> $Env:GITHUB_PATH

    - run: echo $PATH
      if: steps.check-venv.outputs.already_venv == 'false'
      shell: bash

    - run: ${{ inputs.install-cmd }}
      if: inputs.install-cmd != '' && steps.cache-venv.outputs.cache-hit != 'true' && steps.check-venv.outputs.already_venv == 'false'
      shell: bash