name: labels-sweep
# Reusable sweep half of the labels automation — the reconcile + issueflow
# jobs that rode labels.yml until #209. Triggers and permissions live in the
# caller; docs/CONSUMERS.md carries the complete caller stub
# (workflow_dispatch plus the hourly cron, which relocated here with the
# sweep). Board events still yield a sweep within seconds: labels.yml's
# trigger job dispatches this workflow's caller on every event it used to
# run reconcile on.
#
# Detached on purpose (#209): every sweep covers every open PR and all
# sweeps serialize through ONE shared concurrency group, so GitHub's
# one-running-plus-one-pending queue records every extra run as CANCELLED.
# That displacement is semantically lossless — the surviving sweep does the
# displaced run's work — but while the sweep rode pull_request_target runs
# the ❌ landed on that PR's checks and read as red CI, with no manual
# escape hatch: GitHub refuses to rerun a queue-displaced run (crew#250).
# And displacement is the steady state of a working fleet, not a spike —
# one panel request emits one review_requested event per reviewer, so
# every review round over-fills the one-running-plus-one-pending queue.
# Here a displaced run attaches to no PR: the cancellations live on the
# Actions tab only.
#
# Bootstrap semantics: a manual dispatch of the caller bootstraps the
# taxonomy (its `bootstrap` input defaults to "yes"), exactly what
# dispatching the labels caller did before the split. The trigger job's
# dispatches carry bootstrap=no — ~20 label upserts per sweep is too chatty
# for every board event, the same reason cron runs never bootstrapped.
#
# This cannot loop: reconciler writes use GITHUB_TOKEN, and GitHub does not
# create workflow runs from GITHUB_TOKEN-raised events (the trigger's
# workflow_dispatch is one of the two documented exemptions; this workflow
# dispatches nothing). Agent writes use a PAT and therefore do trigger —
# exactly the asymmetry wanted.
on:
  workflow_call:
    inputs:
      bootstrap:
        description: >-
          Bootstrap the label taxonomy before sweeping. The CALLER passes
          this through from its own workflow_dispatch input. The measured
          invariant (ceremony#215): the value must be DECLARED here and
          EXPLICITLY passed — on this instance the called workflow did not
          see the caller's event inputs as an implicit substitute (runs
          459/523 bootstrapped on a bootstrap=no dispatch) while the
          top-level caller received the value in both contexts (probe runs
          6/7). Absent means "no": an event- or cron-woken sweep must never
          re-upsert ~20 labels.
        type: string
        required: false
        default: "no"
      pr_workflow_name:
        description: >-
          The `name:` of the consumer's PR-facing labels caller, exported
          to the reconcile step as SELF_WORKFLOW so the sweep can leave
          the label machinery's own check entries (scope, trigger) out of
          its CI verdict: a red trigger means "fix the caller", which no
          PR edit can do, so it must never count toward blocker:ci-red.
          Read by the #208 reconciler; harmless to earlier ones.
        type: string
        required: false
        default: labels

env:
  # A called workflow arrives without its repository. Keep this literal pin
  # aligned with the ceremony release consumed by callers (issue #9 D3).
  CEREMONY_SELF_REF: "0.6.1"

jobs:
  reconcile:
    runs-on: ubuntu-latest
    # ONE shared group: every reconcile sweeps every open PR, so cron and
    # dispatched runs must serialize or two sweeps race the same PR's labels
    # and both pass the request-the-human-once guard.
    concurrency:
      group: labels-reconcile
      cancel-in-progress: false
    steps:
      # No PR code is ever checked out or executed: the sweep checks out
      # the consumer's default branch and the pinned ceremony
      # implementation only. Keep it that way.
      - uses: actions/checkout@v4
        with:
          repository: ${{ github.repository }}
          ref: ${{ github.event.repository.default_branch }}
      - uses: actions/checkout@v4
        # The self-consumption bypass — release.yml's twin, and load-bearing
        # for the same reason (#11): ceremony's own labels bootstrap must
        # run BEFORE any release tag exists for this checkout to fetch — the
        # release label the merge door reads is created by that dispatch, so
        # without the bypass the first release deadlocks on its own pin. The
        # base-branch checkout above already IS ceremony on the dogfood
        # path.
        if: github.repository != 'heavy-duty/ceremony'
        with:
          repository: heavy-duty/ceremony
          ref: ${{ env.CEREMONY_SELF_REF }}
          path: .ceremony-src
      # Two steps, mutually exclusive `if:`s, because a `uses:` path must be
      # a literal — the same fork release.yml's CEREMONY_DIR env line
      # papers over for `run:` steps, which composite `uses:` has no
      # equivalent of.
      #
      # bootstrap: read from the DECLARED workflow_call input and nothing
      # else. The old gate read `github.event.inputs.bootstrap` from inside
      # this called workflow, and on this instance that context arrived
      # empty (runs 459/523: every dispatch-woken sweep bootstrapped on a
      # bootstrap=no body) while the top-level caller received the value in
      # both contexts (probe runs 6/7) — ceremony#215. The reliable channel
      # is declare-and-pass, so that is the only one used. The caller passes
      # the value through `with.bootstrap`; anything not exactly yes|no is
      # fed through for labels-reconcile's own validation to judge, so a
      # typo refuses loudly instead of silently bootstrapping.
      - name: reconcile state + stale
        if: github.repository != 'heavy-duty/ceremony'
        uses: ./.ceremony-src/actions/labels-reconcile
        with:
          bootstrap: ${{ inputs.bootstrap }}
        env:
          GH_TOKEN: ${{ github.token }}
          REPO: ${{ github.repository }}
          SELF_WORKFLOW: ${{ inputs.pr_workflow_name }}
      - name: reconcile state + stale (dogfood — the workspace IS ceremony)
        if: github.repository == 'heavy-duty/ceremony'
        uses: ./actions/labels-reconcile
        with:
          bootstrap: ${{ inputs.bootstrap }}
        env:
          GH_TOKEN: ${{ github.token }}
          REPO: ${{ github.repository }}
          SELF_WORKFLOW: ${{ inputs.pr_workflow_name }}
      - name: reconcile issue flow
        if: github.repository != 'heavy-duty/ceremony'
        uses: ./.ceremony-src/actions/issueflow-reconcile
        env:
          GH_TOKEN: ${{ github.token }}
          REPO: ${{ github.repository }}
      - name: reconcile issue flow (dogfood — the workspace IS ceremony)
        if: github.repository == 'heavy-duty/ceremony'
        uses: ./actions/issueflow-reconcile
        env:
          GH_TOKEN: ${{ github.token }}
          REPO: ${{ github.repository }}