name: Comment on the PR with Playwright results

on:
  workflow_run:
    workflows: ["Playwright Tests"]
    types:
      - completed
permissions: {}
jobs:
  playwright_comment:
    runs-on: ubuntu-latest
    permissions:
      pull-requests: write
    if: >
      github.event.workflow_run.event == 'pull_request' &&
      github.event.workflow_run.conclusion == 'success'
    steps:
      - name: Grab playwright-output from PR run
        uses: dawidd6/action-download-artifact@71072fbb1229e1317f1a8de6b04206afb461bd67 # pin@v2
        continue-on-error: true
        with:
          github_token: ${{ secrets.GITHUB_TOKEN }}
          run_id: ${{ github.event.workflow_run.id }}
          name: playwright-output

      - name: Grab master-screenshots-outcome from PR run
        uses: dawidd6/action-download-artifact@71072fbb1229e1317f1a8de6b04206afb461bd67 # pin@v2
        continue-on-error: true
        with:
          github_token: ${{ secrets.GITHUB_TOKEN }}
          run_id: ${{ github.event.workflow_run.id }}
          name: master-screenshots-outcome

      - name: Load artifacts into environment variables
        id: playwright
        run: |
          EOF=$(dd if=/dev/urandom bs=15 count=1 status=none | base64)
          echo "PLAYWRIGHT_OUTPUT<<$EOF" >> $GITHUB_OUTPUT
          cat ./playwright-output >> $GITHUB_OUTPUT
          echo "$EOF" >> $GITHUB_OUTPUT
          echo "MASTER_SCREENSHOTS_OUTCOME<<$EOF" >> $GITHUB_OUTPUT
          cat ./master-screenshots-outcome >> $GITHUB_OUTPUT
          echo "$EOF" >> $GITHUB_OUTPUT
          echo "FAILED=$(grep -c '^ *[0-9] failed$' $GITHUB_OUTPUT)" >> $GITHUB_OUTPUT

      # this is required because github.event.workflow_run.pull_requests is not available for PRs from forks
      - name: "Get PR information"
        uses: potiuk/get-workflow-origin@e2dae063368361e4cd1f510e8785cd73bca9352e # pin@v1_5
        id: source-run-info
        with:
          token: ${{ secrets.GITHUB_TOKEN }}
          sourceRunId: ${{ github.event.workflow_run.id }}

      - name: "[Comment] Couldn't download screenshots from master branch"
        uses: mshick/add-pr-comment@dd126dd8c253650d181ad9538d8b4fa218fc31e8 # pin@v2
        if: steps.playwright.outputs.MASTER_SCREENSHOTS_OUTCOME == 'failure'
        with:
          issue: ${{ steps.source-run-info.outputs.pullRequestNumber }}
          message: |
            :heavy_exclamation_mark: Could not fetch screenshots from master branch, so had nothing to make a visual comparison against; please check the "master-screenshots" step in the workflow run and rerun it before merging.

      - name: "[Comment] Success: No visual differences introduced by this PR"
        uses: mshick/add-pr-comment@dd126dd8c253650d181ad9538d8b4fa218fc31e8 # pin@v2
        if: steps.playwright.outputs.MASTER_SCREENSHOTS_OUTCOME != 'failure' && steps.playwright.outputs.FAILED == 0
        with:
          issue: ${{ steps.source-run-info.outputs.pullRequestNumber }}
          message: |
            :heavy_check_mark: No visual differences introduced by this PR.

            <a href="${{ github.server_url }}/${{ github.repository }}/actions/runs/${{ github.event.workflow_run.id }}#artifacts">View Playwright Report</a> (note: open the "playwright-report" artifact)

      - name: "[Comment] Warning: Visual differences introduced by this PR"
        uses: mshick/add-pr-comment@dd126dd8c253650d181ad9538d8b4fa218fc31e8 # pin@v2
        if: steps.playwright.outputs.MASTER_SCREENSHOTS_OUTCOME != 'failure' && steps.playwright.outputs.FAILED != 0
        with:
          issue: ${{ steps.source-run-info.outputs.pullRequestNumber }}
          message: |
            :warning: Visual differences introduced by this PR; please validate if they are desirable.

            <a href="${{ github.server_url }}/${{ github.repository }}/actions/runs/${{ github.event.workflow_run.id }}#artifacts">View Playwright Report</a> (note: open the "playwright-report" artifact)