name: Sequential Navigation Soak Comment

on:
  workflow_run:
    workflows: [Sequential Navigation Soak]
    types: [completed]

# This workflow runs from the default branch. It never executes the measured
# PR binary and only renders bounded numeric fields from the downloaded artifact.
permissions:
  actions: read
  contents: read
  pull-requests: write

jobs:
  comment:
    name: Update PR soak comment
    if: >-
      github.event.workflow_run.event == 'pull_request' &&
      github.event.workflow_run.conclusion != 'cancelled' &&
      github.event.workflow_run.pull_requests[0].head.repo.id == github.event.repository.id &&
      github.event.workflow_run.actor.login != 'dependabot[bot]'
    runs-on: ubuntu-latest
    timeout-minutes: 10
    steps:
      - name: Checkout trusted comment renderer
        uses: actions/checkout@v4
        with:
          persist-credentials: false
          ref: ${{ github.event.repository.default_branch }}

      - name: Download soak evidence
        id: evidence
        continue-on-error: true
        uses: actions/download-artifact@d3f86a106a0bac45b974a628896c90dbdf5c8093 # v4
        with:
          name: sequential-navigation-soak-results
          path: sequential-navigation-soak-results
          github-token: ${{ secrets.GITHUB_TOKEN }}
          run-id: ${{ github.event.workflow_run.id }}

      - name: Render trusted PR comment
        id: render
        env:
          PYTHONPATH: moli-benchmark
          RUN_URL: https://github.com/${{ github.repository }}/actions/runs/${{ github.event.workflow_run.id }}
          CONCLUSION: ${{ github.event.workflow_run.conclusion }}
          EVIDENCE_OUTCOME: ${{ steps.evidence.outcome }}
        run: |
          if [[ "$EVIDENCE_OUTCOME" == success && -f sequential-navigation-soak-results/comparison.json ]]; then
            python3 -m moli_benchmark.sequential_navigate_ci comment \
              --input sequential-navigation-soak-results/comparison.json \
              --run-url "$RUN_URL" \
              --conclusion "$CONCLUSION" \
              --output sequential-navigation-soak-comment.md
            echo "has_comparison=true" >> "$GITHUB_OUTPUT"
          else
            python3 -m moli_benchmark.sequential_navigate_ci infrastructure-comment \
              --run-url "$RUN_URL" \
              --conclusion "$CONCLUSION" \
              --output sequential-navigation-soak-comment.md
            echo "has_comparison=false" >> "$GITHUB_OUTPUT"
          fi

      - name: Post PR soak comment
        uses: actions/github-script@f28e40c7f34bde8b3046d885e986cb6290c5673b # v7
        env:
          COMMENT_PATH: sequential-navigation-soak-comment.md
          COMPARISON_PATH: sequential-navigation-soak-results/comparison.json
          HAS_COMPARISON: ${{ steps.render.outputs.has_comparison }}
        with:
          script: |
            const fs = require('fs');
            const run = context.payload.workflow_run;
            const association = run.pull_requests?.[0];
            if (!association) {
              core.notice('No pull request is associated with this workflow run.');
              return;
            }

            const pull = await github.rest.pulls.get({
              owner: context.repo.owner,
              repo: context.repo.repo,
              pull_number: association.number,
            });
            if (pull.data.head.sha !== association.head.sha) {
              core.notice('Skipping a stale Sequential Navigation Soak result.');
              return;
            }

            if (process.env.HAS_COMPARISON === 'true') {
              const comparison = JSON.parse(fs.readFileSync(process.env.COMPARISON_PATH, 'utf8'));
              const compared = await github.rest.repos.compareCommitsWithBasehead({
                owner: context.repo.owner,
                repo: context.repo.repo,
                basehead: `${association.base.sha}...${association.head.sha}`,
              });
              const expectedCommonAncestor = compared.data.merge_base_commit?.sha;
              if (
                comparison.schema !== 'moli.sequential-navigation.comparison.v1' ||
                comparison.expected_navigations !== 200 ||
                comparison.head?.sha !== association.head.sha ||
                comparison.base?.sha !== expectedCommonAncestor
              ) {
                core.setFailed(
                  'Sequential Navigation Soak artifact identities do not match the PR.'
                );
                return;
              }
            }

            const body = fs.readFileSync(process.env.COMMENT_PATH, 'utf8');
            const marker = '<!-- moli-sequential-navigation-soak -->';
            if (!body.includes(marker) || Buffer.byteLength(body, 'utf8') > 32 * 1024) {
              core.setFailed('Rendered soak comment is missing its marker or exceeds 32 KiB.');
              return;
            }
            const comments = await github.paginate(github.rest.issues.listComments, {
              owner: context.repo.owner,
              repo: context.repo.repo,
              issue_number: association.number,
              per_page: 100,
            });
            const existing = comments.find(
              (comment) =>
                comment.user?.login === 'github-actions[bot]' &&
                comment.body?.includes(marker)
            );
            if (existing) {
              await github.rest.issues.updateComment({
                owner: context.repo.owner,
                repo: context.repo.repo,
                comment_id: existing.id,
                body,
              });
            } else {
              await github.rest.issues.createComment({
                owner: context.repo.owner,
                repo: context.repo.repo,
                issue_number: association.number,
                body,
              });
            }