name: Stale PR Management
on:
  schedule:
    - cron: "0 0 * * *"
  workflow_dispatch:
  pull_request_target:
    types:
      - labeled

jobs:
  stale-prs:
    runs-on: ubuntu-latest
    permissions:
      pull-requests: write
      issues: write
      contents: read
    steps:
      - name: Handle stale PRs
        uses: actions/github-script@v7
        with:
          script: |
            const now = new Date();
            const owner = context.repo.owner;
            const repo = context.repo.repo;
            
            // --- When stale label is added, comment immediately ---
            if (context.eventName === "pull_request_target" && context.payload.action === "labeled") {
              const label = context.payload.label?.name;
              if (label === "stale") {
                const author = context.payload.pull_request.user.login;
                await github.rest.issues.createComment({
                  owner,
                  repo,
                  issue_number: context.payload.pull_request.number,
                  body: `@${author} This PR has been marked as stale. It will be closed if no new commits are added in 7 days.`
                });
              }
              return;
            }
            
            // --- Scheduled run: check all stale PRs ---
            const { data: prs } = await github.rest.pulls.list({
              owner,
              repo,
              state: "open",
              per_page: 100
            });
            
            for (const pr of prs) {
              const hasStale = pr.labels.some(l => l.name === "stale");
              if (!hasStale) continue;
              
              // Get timeline events to find when stale label was added
              const { data: events } = await github.rest.issues.listEvents({
                owner,
                repo,
                issue_number: pr.number,
                per_page: 100
              });
              
              // Find the most recent time the stale label was added
              const staleLabelEvents = events
                .filter(e => e.event === "labeled" && e.label?.name === "stale")
                .sort((a, b) => new Date(b.created_at) - new Date(a.created_at));
              
              if (staleLabelEvents.length === 0) continue;
              
              const staleLabelDate = new Date(staleLabelEvents[0].created_at);
              const daysSinceStale = (now - staleLabelDate) / (1000 * 60 * 60 * 24);
              
              // Check for new commits since stale label was added
              const { data: commits } = await github.rest.pulls.listCommits({
                owner,
                repo,
                pull_number: pr.number
              });
              
              const lastCommitDate = new Date(commits[commits.length - 1].commit.author.date);
              const author = pr.user.login;
              
              // If there are new commits after the stale label, remove it
              if (lastCommitDate > staleLabelDate) {
                await github.rest.issues.removeLabel({
                  owner,
                  repo,
                  issue_number: pr.number,
                  name: "stale"
                });
                await github.rest.issues.createComment({
                  owner,
                  repo,
                  issue_number: pr.number,
                  body: `@${author} Recent activity detected. Removing stale label.`
                });
              }
              // If 7 days have passed since stale label, close the PR
              else if (daysSinceStale > 7) {
                await github.rest.pulls.update({
                  owner,
                  repo,
                  pull_number: pr.number,
                  state: "closed"
                });
                await github.rest.issues.createComment({
                  owner,
                  repo,
                  issue_number: pr.number,
                  body: `@${author} Closing stale PR due to inactivity (no commits for 7 days after stale label).`
                });
              }
            }