name: Auto-merge automation PRs

on:
  # Trigger when CI checks complete on PRs
  pull_request:
    types: [opened, synchronize, labeled]
  # Also trigger when check suites complete
  check_suite:
    types: [completed]

permissions:
  contents: write
  pull-requests: write

jobs:
  auto-merge:
    name: Auto-merge
    runs-on: ubuntu-latest
    # Only run for PRs created by agentic workflows (labeled "automation")
    if: >-
      (github.event_name == 'pull_request' &&
       contains(github.event.pull_request.labels.*.name, 'automation')) ||
      github.event_name == 'check_suite'

    steps:
      - name: Enable auto-merge for automation PRs
        uses: actions/github-script@v7
        with:
          script: |
            // Find the PR number depending on the trigger event
            let prNumber;
            if (context.eventName === 'pull_request') {
              prNumber = context.payload.pull_request.number;
            } else if (context.eventName === 'check_suite') {
              // Find PRs associated with this check suite
              const prs = context.payload.check_suite.pull_requests;
              if (!prs || prs.length === 0) {
                console.log('No PRs associated with this check suite');
                return;
              }
              prNumber = prs[0].number;
            }

            if (!prNumber) {
              console.log('No PR number found');
              return;
            }

            // Get the PR details
            const { data: pr } = await github.rest.pulls.get({
              owner: context.repo.owner,
              repo: context.repo.repo,
              pull_number: prNumber,
            });

            // Only auto-merge PRs with the "automation" label
            const hasAutomationLabel = pr.labels.some(l => l.name === 'automation');
            if (!hasAutomationLabel) {
              console.log(`PR #${prNumber} does not have the "automation" label, skipping`);
              return;
            }

            // Check if all CI checks have passed
            const { data: checks } = await github.rest.checks.listForRef({
              owner: context.repo.owner,
              repo: context.repo.repo,
              ref: pr.head.sha,
            });

            const pending = checks.check_runs.filter(c =>
              c.name !== 'Auto-merge' && c.status !== 'completed'
            );
            const failed = checks.check_runs.filter(c =>
              c.name !== 'Auto-merge' && c.status === 'completed' && c.conclusion !== 'success' && c.conclusion !== 'skipped'
            );

            if (pending.length > 0) {
              console.log(`PR #${prNumber} has ${pending.length} pending checks, will retry when they complete`);
              return;
            }

            if (failed.length > 0) {
              console.log(`PR #${prNumber} has ${failed.length} failed checks, not merging:`);
              failed.forEach(c => console.log(`  - ${c.name}: ${c.conclusion}`));
              return;
            }

            // All checks passed — merge the PR
            console.log(`All checks passed for PR #${prNumber}, merging...`);
            try {
              await github.rest.pulls.merge({
                owner: context.repo.owner,
                repo: context.repo.repo,
                pull_number: prNumber,
                merge_method: 'merge',
              });
              console.log(`PR #${prNumber} merged successfully`);
            } catch (error) {
              console.log(`Failed to merge PR #${prNumber}: ${error.message}`);
            }