name: close-stale-prs

on:
  workflow_dispatch:
    inputs:
      dryRun:
        description: "Log actions without closing PRs"
        type: boolean
        default: false
  schedule:
    - cron: "0 6 * * *"

permissions:
  contents: read
  issues: write
  pull-requests: write

jobs:
  close-stale-prs:
    runs-on: ubuntu-latest
    steps:
      - name: Close inactive PRs
        uses: actions/github-script@v8
        with:
          github-token: ${{ secrets.GITHUB_TOKEN }}
          script: |
            const DAYS_INACTIVE = 60
            const cutoff = new Date(Date.now() - DAYS_INACTIVE * 24 * 60 * 60 * 1000)
            const { owner, repo } = context.repo
            const dryRun = context.payload.inputs?.dryRun === "true"

            core.info(`Dry run mode: ${dryRun}`)
            core.info(`Cutoff date: ${cutoff.toISOString()}`)

            const query = `
              query($owner: String!, $repo: String!, $cursor: String) {
                repository(owner: $owner, name: $repo) {
                  pullRequests(first: 100, states: OPEN, after: $cursor) {
                    pageInfo {
                      hasNextPage
                      endCursor
                    }
                    nodes {
                      number
                      title
                      author {
                        login
                      }
                      createdAt
                      commits(last: 1) {
                        nodes {
                          commit {
                            committedDate
                          }
                        }
                      }
                      comments(last: 1) {
                        nodes {
                          createdAt
                        }
                      }
                      reviews(last: 1) {
                        nodes {
                          createdAt
                        }
                      }
                    }
                  }
                }
              }
            `

            const allPrs = []
            let cursor = null
            let hasNextPage = true

            while (hasNextPage) {
              const result = await github.graphql(query, {
                owner,
                repo,
                cursor,
              })

              allPrs.push(...result.repository.pullRequests.nodes)
              hasNextPage = result.repository.pullRequests.pageInfo.hasNextPage
              cursor = result.repository.pullRequests.pageInfo.endCursor
            }

            core.info(`Found ${allPrs.length} open pull requests`)

            const stalePrs = allPrs.filter((pr) => {
              const dates = [
                new Date(pr.createdAt),
                pr.commits.nodes[0] ? new Date(pr.commits.nodes[0].commit.committedDate) : null,
                pr.comments.nodes[0] ? new Date(pr.comments.nodes[0].createdAt) : null,
                pr.reviews.nodes[0] ? new Date(pr.reviews.nodes[0].createdAt) : null,
              ].filter((d) => d !== null)

              const lastActivity = dates.sort((a, b) => b.getTime() - a.getTime())[0]

              if (!lastActivity || lastActivity > cutoff) {
                core.info(`PR #${pr.number} is fresh (last activity: ${lastActivity?.toISOString() || "unknown"})`)
                return false
              }

              core.info(`PR #${pr.number} is STALE (last activity: ${lastActivity.toISOString()})`)
              return true
            })

            if (!stalePrs.length) {
              core.info("No stale pull requests found.")
              return
            }

            core.info(`Found ${stalePrs.length} stale pull requests`)

            for (const pr of stalePrs) {
              const issue_number = pr.number
              const closeComment = `Closing this pull request because it has had no updates for more than ${DAYS_INACTIVE} days. If you plan to continue working on it, feel free to reopen or open a new PR.`

              if (dryRun) {
                core.info(`[dry-run] Would close PR #${issue_number} from ${pr.author.login}: ${pr.title}`)
                continue
              }

              await github.rest.issues.createComment({
                owner,
                repo,
                issue_number,
                body: closeComment,
              })

              await github.rest.pulls.update({
                owner,
                repo,
                pull_number: issue_number,
                state: "closed",
              })

              core.info(`Closed PR #${issue_number} from ${pr.author.login}: ${pr.title}`)
            }