flake-freshness.yml

name: Flake Input Freshness
on:
    workflow_dispatch:
    schedule:
        - cron: "0 8 * * 1"

concurrency:
    group: flake-freshness
    cancel-in-progress: false

permissions:
    issues: write
    contents: read

jobs:
    check-freshness:
        runs-on: ubuntu-latest
        steps:
            - name: Checkout flake.lock
              uses: actions/checkout@v6.0.2
              with:
                  sparse-checkout: flake.lock
                  sparse-checkout-cone-mode: false

            - name: Check input ages
              id: freshness
              run: |
                  echo "## 📅 Flake Input Freshness Report" >> $GITHUB_STEP_SUMMARY
                  echo "" >> $GITHUB_STEP_SUMMARY

                  now=$(date +%s)
                  stale_inputs=""

                  for input in $(jq -r '.nodes | keys[]' flake.lock | grep -v root); do
                    last_modified=$(jq -r ".nodes.\"$input\".locked.lastModified // empty" flake.lock)
                    if [ -n "$last_modified" ]; then
                      age_days=$(( (now - last_modified) / 86400 ))
                      if [ "$age_days" -gt 90 ]; then
                        stale_inputs="${stale_inputs}- **${input}**: ${age_days} days old\n"
                        echo "⚠️ $input: $age_days days since last update" >> $GITHUB_STEP_SUMMARY
                      else
                        echo "✅ $input: $age_days days" >> $GITHUB_STEP_SUMMARY
                      fi
                    fi
                  done

                  if [ -n "$stale_inputs" ]; then
                    echo "has_stale=true" >> "$GITHUB_OUTPUT"
                    {
                      echo "stale_list<<EOF"
                      echo -e "$stale_inputs"
                      echo "EOF"
                    } >> "$GITHUB_OUTPUT"
                  else
                    echo "has_stale=false" >> "$GITHUB_OUTPUT"
                    echo "" >> $GITHUB_STEP_SUMMARY
                    echo "✅ All inputs updated within the last 90 days" >> $GITHUB_STEP_SUMMARY
                  fi

            - name: Create issue for stale inputs
              if: steps.freshness.outputs.has_stale == 'true'
              uses: actions/github-script@v8
              with:
                  script: |
                      const { owner, repo } = context.repo;
                      const title = '📅 Stale Flake Inputs Detected';

                      const { data: issues } = await github.rest.issues.listForRepo({
                        owner, repo,
                        state: 'open',
                        labels: 'maintenance',
                        creator: 'github-actions[bot]',
                      });

                      const existing = issues.find(i => i.title === title);
                      const staleList = `${{ steps.freshness.outputs.stale_list }}`;
                      const body = [
                        '## Stale Flake Inputs',
                        '',
                        'The following inputs have not been updated in over 90 days:',
                        '',
                        staleList,
                        '',
                        'Consider running `nix flake update` or updating specific inputs.',
                        '',
                        '---',
                        '*Generated by Flake Freshness Check*',
                      ].join('\n');

                      if (existing) {
                        await github.rest.issues.update({ owner, repo, issue_number: existing.number, body });
                      } else {
                        await github.rest.issues.create({ owner, repo, title, body, labels: ['maintenance'] });
                      }