action.yml

name: GitHub tagger
description: Bump and push git tag

inputs:
  token:
    description: Required for permission to tag the repo.
    required: true
  with_month:
    description: Add the month number as a second part of the tag.
    default: false
  add_tag:
    description: Add a tag to the commit.
    default: true
outputs:
  new_tag:
    description: 'Generated tag'
    value: ${{ steps.new-tag-step.outputs.tag }}
  old_tag:
    description: 'Old tag'
    value: ${{ steps.old-tag-step.outputs.tag }}
runs:
  using: composite
  steps:
    - name: Get existing comment
      uses: actions/checkout@v4
      with:
        fetch-depth: 0
    - name: Search for existing tag
      id: find-tag
      shell: bash
      run: |
        echo "tag=$(git tag -l --points-at ${{ github.event.pull_request.head.sha || github.sha }})" >> $GITHUB_OUTPUT
    - name: Raise error if tag already exists
      if: ${{ steps.find-tag.outputs.tag }}
      uses: actions/github-script@v7
      with:
        script: |
          core.setFailed('Tag (${{ steps.find-tag.outputs.tag }}) already exists on current commit (${{ github.event.pull_request.head.sha || github.sha }})')
    - name: Setup python
      uses: actions/setup-python@v5
      with:
        python-version: '3.x'
    - name: Get current tag
      shell: bash
      id: old-tag-step
      run: |
        echo "tag=$(git describe --tags --first-parent --abbrev=0)" >> $GITHUB_OUTPUT
    - name: Get new tag
      id: new-tag-step
      shell: python
      run: |
        import os
        import re
        from datetime import date

        old_tag = '${{ steps.old-tag-step.outputs.tag }}'
        with_month = '${{ inputs.with_month }}' == 'true'
        today = date.today()

        if with_month:
          # e.g. 2022.5.10
          if re.match(r'\d{4}\.\d{1,2}\.\d+', old_tag):
            year, month, build = map(int, old_tag.split('.'))
          else:
            year, month, build = 0, 0, 0
          if today.year != year or today.month != month:
            build = 0
          build += 1
          new_tag = f'{today.year}.{today.month}.{build}'

        else:
          # e.g. 2022.146
          if old_tag:
            year, build = [int(x) if x.isdigit() else 0 for x in old_tag.split('.', maxsplit=1)]
          else:
            year, build  = 0, 0
          if today.year != year:
            build = 0
          build += 1
          new_tag = f'{today.year}.{build}'

        with open(os.getenv("GITHUB_OUTPUT"), 'w') as f:
            print(f'tag={new_tag}', file=f)
    - name: GitHub tag bump
      if: inputs.add_tag == 'true'
      uses: anothrNick/github-tag-action@f278d49d30cdd8775cc3e7dd00b5ee11686ee297 # 1.38.0
      env:
        GITHUB_TOKEN: ${{ inputs.token }}
        CUSTOM_TAG: ${{ steps.new-tag-step.outputs.tag }}