OdysseyDecomp/.github/workflows/pr-status-label-review.yml

name: Add "status:"-label to PRs based on current state

on:
  workflow_run:
    workflows:
      - PR-Review submitted
    types: [completed]

permissions:
  pull-requests: write
  issues: write

jobs:
  review_update:
    runs-on: ubuntu-latest
    steps:
      - name: 'Download artifact'
        uses: actions/github-script@v9
        with:
          script: |
            let allArtifacts = await github.rest.actions.listWorkflowRunArtifacts({
               owner: context.repo.owner,
               repo: context.repo.repo,
               run_id: context.payload.workflow_run.id,
            });
            let matchArtifact = allArtifacts.data.artifacts.filter((artifact) => {
              return artifact.name == "review-event"
            })[0];
            let download = await github.rest.actions.downloadArtifact({
               owner: context.repo.owner,
               repo: context.repo.repo,
               artifact_id: matchArtifact.id,
               archive_format: 'zip',
            });
            const fs = require('fs');
            const path = require('path');
            const temp = '${{ runner.temp }}/artifacts';
            if (!fs.existsSync(temp)){
              fs.mkdirSync(temp);
            }
            fs.writeFileSync(path.join(temp, 'review-event.zip'), Buffer.from(download.data));            

      - name: 'Unzip artifact'
        run: unzip "${{ runner.temp }}/artifacts/review-event.zip" -d "${{ runner.temp }}/artifacts"

      - name: Update status labels based on review
        uses: actions/github-script@v9
        with:
          script: |
            const fs = require('fs');
            const data = JSON.parse(fs.readFileSync('${{ runner.temp }}/artifacts/event.json', 'utf8'));

            const owner = data.repository.owner;
            const repo = data.repository.name;
            const prNumber = data.pull_request.number;
            const reviewState = data.review.state;
            const reviewBody = data.review.body;

            const changeLabel = async (currentLabels, newLabel) => {
              // Remove all "status:[...]" labels
              for (const label of currentLabels) {
                await github.rest.issues.removeLabel({
                  owner,
                  repo,
                  issue_number: prNumber,
                  name: label.name
                }).catch(() => {}) // ignore if already removed
              }

              // Add new label
              await github.rest.issues.addLabels({
                owner,
                repo,
                issue_number: prNumber,
                labels: [newLabel]
              })
              core.info(`Added label: ${newLabel}`)
            }

            const { data: existingLabels } = await github.rest.issues.listLabelsOnIssue({
              owner,
              repo,
              issue_number: prNumber
            })
            const statusLabels = existingLabels.filter(l => l.name.startsWith('status:'))
            const is_approved = statusLabels.some(l => l.name === 'status:approved' || l.name === 'status:ready to merge')
            
            // https://github.com/Reviewable/Reviewable/issues/1163
            // other users cannot approve reviewers, requires permissions to actually say `reviewState == 'approved'`
            const approve = reviewState === 'approved' || reviewBody.includes("complete! all files reviewed, all discussions resolved")

            const R = data.review.reviewer;      // reviewer
            const P = data.pull_request.author;  // PR author
            const O = owner;                     // repo owner (by repo name)

            let new_label = null;

            if (is_approved && approve) {
              core.info('PR is already approved and review is another approval. No label change needed.')
              return;
            }

            if (approve && R === O) {
              newLabel = 'status:approved'  // standard way of approval: owner appoves PR
            } else if (approve && P === O && R !== O) {
              newLabel = 'status:approved'  // if owner is author, someone else must approve
            } else if (P === R) {
              newLabel = 'status:waiting for review'
            } else if (P !== R && !approve) {
              newLabel = 'status:waiting for author'
            } else {
              core.info('No matching condition for new label.')
              core.info(`Review state: ${reviewState}, PR author: ${P}, Reviewer: ${R}, Repo owner: ${O}`)
            }

            if (newLabel) {
              await changeLabel(statusLabels, newLabel)
            }