# The outline of this workflow is something that the GitHub Security team warns against
# here: https://securitylab.github.com/research/github-actions-preventing-pwn-requests. But
# due to this workflow only running a git diff check and not building or publishing anything,
# there is no harm in checking out the PR HEAD code.
#
# All the code checked out in this workflow should be considered untrusted. This workflow must
# never call any makefiles or scripts. It must never be changed to run any code from the checkout.

# This workflow posts a message to a PR to remind maintainers that there are website/ changes
# in the PR and if they need to be cherry-picked to the stable-website branch, the
# 'type/docs-cherrypick' label needs to be applied.

on:
  pull_request_target:
    types: [opened]
    # Runs on PRs to main and all release branches
    branches:
      - main
      - release/*

jobs:
  # checks that a 'type/docs-cherrypick' label is attached to PRs with website/ changes
  website-check:
    # If there's already a `type/docs-cherrypick` label or an explicit `pr/no-docs` label, we ignore this check 
    if: >-
      !contains(github.event.pull_request.labels.*.name, 'type/docs-cherrypick') &&
      !contains(github.event.pull_request.labels.*.name, 'pr/no-docs')
    runs-on: ubuntu-latest

    steps:
      - uses: actions/checkout@v2
        with:
          ref: ${{ github.event.pull_request.head.sha }}
          fetch-depth: 0 # by default the checkout action doesn't checkout all branches
      - name: Check for website/ dir change in diff
        run: |
          # check if there is a diff in the website/ directory
          website_files=$(git --no-pager diff --name-only HEAD "$(git merge-base HEAD "origin/${{ github.event.pull_request.base.ref }}")" -- website/)

          # If we find changed files in the website/ directory, we post a comment to the PR
          if [ -n "$website_files" ]; then
            # post PR comment to GitHub to check if a 'type/docs-cherrypick' label needs to be applied to the PR
            echo "website-check: Did not find a 'type/docs-cherrypick' label, posting a reminder in the PR"
            github_message="🤔 This PR has changes in the \`website/\` directory but does not have a \`type/docs-cherrypick\` label. If the changes are for the next version, this can be ignored. If they are updates to current docs, attach the label to auto cherrypick to the \`stable-website\` branch after merging."
            curl -s -H "Authorization: token ${{ secrets.PR_COMMENT_TOKEN }}" \
                -X POST \
                -d "{ \"body\": \"${github_message}\"}" \
                "https://api.github.com/repos/${GITHUB_REPOSITORY}/issues/${{ github.event.pull_request.number }}/comments"
          fi