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# to you under the Apache License, Version 2.0 (the
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#
#     http://www.apache.org/licenses/LICENSE-2.0
#
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# under the License.

name: PR effort label

# Labels a pull request when it first asks for review, then re-checks the whole
# open set once a day. A push changes the diff and so can change the tier, but
# subscribing to every push would run this hundreds of times a day to correct a
# label nobody is misled by in the meantime; the daily sweep absorbs that drift
# and doubles as the recovery path for any event this misses.
on:
  pull_request_target:
    types: [opened, reopened, ready_for_review]
    branches: [main]
  schedule:
    - cron: "23 4 * * *"
  workflow_dispatch:
    inputs:
      dry_run:
        description: Log the tier each open pull request would get without writing labels.
        required: false
        default: false
        type: boolean

permissions:
  contents: read
  pull-requests: write

concurrency:
  group: pr-effort-label-${{ github.event.pull_request.number || github.workflow }}
  cancel-in-progress: ${{ github.event_name == 'pull_request_target' }}

jobs:
  label:
    runs-on: ubuntu-latest
    timeout-minutes: 10

    steps:
      # pull_request_target runs with a writable token, so the ref is pinned to
      # the trusted default-branch commit rather than left to the event's
      # default: pull_request_review and friends resolve to refs/pull/N/merge,
      # and this job imports the checked-out script.
      - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
        with:
          ref: ${{ github.sha }}
          persist-credentials: false

      - uses: actions/github-script@3a2844b7e9c422d3c10d287c895573f7108da1b3 # v9.0.0
        env:
          DRY_RUN: ${{ inputs.dry_run || false }}
        with:
          script: |
            const path = require("node:path")
            const { pathToFileURL } = require("node:url")

            const { planLabels } = await import(
              pathToFileURL(path.join(process.env.GITHUB_WORKSPACE, "scripts/pr-effort.mjs")).href
            )

            const { owner, repo } = context.repo

            // Reviewing a tier boundary or an exclusion means seeing it against
            // real pull requests, which is this same sweep minus the writes.
            const dryRun = process.env.DRY_RUN === "true"

            const targets = context.payload.pull_request
              ? [context.payload.pull_request.number]
              : (
                  await github.paginate(github.rest.pulls.list, {
                    owner,
                    repo,
                    state: "open",
                    per_page: 100,
                  })
                ).map((pull) => pull.number)

            for (const pull_number of targets) {
              const [files, current] = await Promise.all([
                github.paginate(github.rest.pulls.listFiles, { owner, repo, pull_number, per_page: 100 }),
                github.paginate(github.rest.issues.listLabelsOnIssue, {
                  owner,
                  repo,
                  issue_number: pull_number,
                  per_page: 100,
                }),
              ])

              const plan = planLabels(
                files,
                current.map((label) => label.name),
              )

              if (dryRun) {
                core.info(
                  `#${pull_number}: ${plan.label} (${plan.lines} readable lines)` +
                    ` +[${plan.addLabels.join(", ")}] -[${plan.removeLabels.join(", ")}]`,
                )
                continue
              }

              if (plan.addLabels.length > 0) {
                await github.rest.issues.addLabels({
                  owner,
                  repo,
                  issue_number: pull_number,
                  labels: plan.addLabels,
                })
              }

              for (const name of plan.removeLabels) {
                try {
                  await github.rest.issues.removeLabel({ owner, repo, issue_number: pull_number, name })
                } catch (error) {
                  // Another run may have removed it first; anything else is real.
                  if (error.status !== 404) throw error
                }
              }

              core.info(`#${pull_number}: ${plan.label} (${plan.lines} readable lines)`)
            }