ceremony/lib/forge-forgejo.sh

#!/usr/bin/env bash
# lib/forge-forgejo.sh — the Forgejo backend: /api/v1 over curl + jq
# (issue #188, term 1). Sourced by lib/forge.sh when forge_detect says
# forgejo; never sourced directly, and never at the same time as the github
# backend — they define the same verbs on purpose.
#
# curl+jq rather than a CLI because that is what the runner has. The image
# this instance runs jobs in (ghcr.io/catthehacker/ubuntu:act-22.04, probe
# task 278) carries curl, jq and node, and has neither `gh` nor `stoke`.

# forgejo_api_base — the /api/v1 root, from the runner's own environment.
# GITHUB_API_URL already IS the /api/v1 root on a Forgejo runner (measured:
# https://forgejo.heavyduty.builders/api/v1). CEREMONY_FORGE_API overrides
# it for tests and for anyone driving this outside Actions.
forgejo_api_base() {
  local base="${CEREMONY_FORGE_API:-${GITHUB_API_URL:-}}"
  if [ -z "$base" ]; then
    echo "forgejo_api_base: no GITHUB_API_URL or CEREMONY_FORGE_API — cannot reach the forge (#188)" >&2
    return 1
  fi
  # Every verb in this backend interpolates $REPO into its path, and every
  # one of them reaches the network through here — so this is the one place
  # that can make `repos//…` impossible.
  #
  # THE TRAP, measured on this instance with REPO unset (#191, caught by
  # @kimi on !193 before it shipped):
  #
  #   forge_release_exists 0.4.1  -> "no", rc 0   (repos//releases/tags/0.4.1
  #                                                404s; a repo-less path read
  #                                                as "the release does not
  #                                                exist" — and the
  #                                                nothing-exists assert would
  #                                                then proceed to CREATE)
  #   forge_commit_pulls <sha>    -> "[]", rc 0   (a commit that HAS a merged
  #                                                PR behind it, read as none)
  #
  # A workflow `run:` shell carries no `set -u`, so an unset REPO expands
  # empty and 404s into a fabricated fact instead of crashing. That is the
  # exact failure #191 exists to remove, so it refuses here rather than
  # anywhere later.
  if [ -z "${REPO:-}" ]; then
    echo "forgejo_api_base: REPO is empty — refusing to address 'repos//…', whose 404 would read as a fact (#191)" >&2
    return 1
  fi
  printf '%s\n' "${base%/}"
}

# forgejo_page_url <endpoint> <page> — pure, so the page-size contract is
# testable without a network. Returns the endpoint with this backend's OWN
# paging parameters applied.
#
# THE TRAP THIS EXISTS TO REMOVE, measured 2026-08-02 against
# heavy-duty/rig (137 issues and PRs) and heavy-duty/ceremony on GitHub:
#
#   ?per_page=100   GitHub: 100 items      Forgejo: 30 items  (IGNORED)
#   ?limit=100      GitHub:  30 items      Forgejo: 50 items  (capped)
#
# Each forge silently ignores the other's page-size parameter, answers
# HTTP 200 with valid JSON, and says nothing. Every call site in this repo
# was written GitHub-shaped, so a verbatim port would have swept 30 of
# rig's 137 and printed "reconciled." — acceptance criterion 2 failing
# green, and the same "degraded read that does not report it degraded"
# failure class this whole issue exists to kill.
#
# So NO CALL SITE NAMES A PAGE SIZE. The backend owns it. Fixing the
# boundary once beats fixing nine call sites and trusting the tenth — the
# same argument that chose shape C over B, one level down.
#
# 50 is not a preference: Forgejo caps a page at MAX_RESPONSE_ITEMS (50 on
# this instance) whatever you ask for, so asking for more cannot help and
# pagination is mandatory rather than an optimisation.
forgejo_page_url() {
  local endpoint="${1:?forgejo_page_url: endpoint required}" page="${2:?forgejo_page_url: page required}"
  # Strip any page-size parameter a caller left behind, in either dialect,
  # rather than trusting that none did: this function is the one place that
  # decides paging, and a stray per_page= would be exactly the silent
  # truncation above.
  local clean="$endpoint"
  clean="$(printf '%s' "$clean" | sed -E 's/([?&])(per_page|limit|page)=[0-9]+/\1/g; s/[?&]+$//; s/([?&])&+/\1/g')"
  case "$clean" in
    *\?) printf '%slimit=50&page=%s\n' "$clean" "$page" ;;
    *\?*) printf '%s&limit=50&page=%s\n' "$clean" "$page" ;;
    *) printf '%s?limit=50&page=%s\n' "$clean" "$page" ;;
  esac
}

# forge_api [--paginate] <endpoint> [--jq <expr>]
#
# --paginate walks page= until a short page, then PROVES the walk was
# complete by comparing what it collected against the server's declared
# x-total-count. @kimi-reviewer-andresmgsl's hardening (#4699): a MISSING
# header is a loud refusal, not a pass. Header exposure is a server setting
# (access-control-expose-headers), and an instance that withholds it would
# make the completeness check compare null to a number — the guard itself
# degrading silently, which is the failure class re-entering through the
# door built to stop it.
forge_api() {
  local paginate=false endpoint="" jqexpr="" have_jq=false
  while [ $# -gt 0 ]; do
    case "$1" in
      --paginate) paginate=true ;;
      --jq) jqexpr="$2"; have_jq=true; shift ;;
      -*) ;;
      *) [ -n "$endpoint" ] || endpoint="$1" ;;
    esac
    shift
  done
  [ -n "$endpoint" ] || { echo "forge_api: endpoint required" >&2; return 1; }

  local base token
  base="$(forgejo_api_base)" || return 1
  token="${GH_TOKEN:-${GITHUB_TOKEN:-${FORGEJO_TOKEN:-}}}"

  local hdr body
  hdr="$(mktemp)"; body="$(mktemp)"
  # shellcheck disable=SC2064 # the paths are fixed at trap time on purpose
  trap "rm -f '$hdr' '$body'" RETURN

  if [ "$paginate" = false ]; then
    if ! curl -sS -D "$hdr" -o "$body" \
      -H "Authorization: token $token" -H 'Accept: application/json' \
      "$base/$endpoint"; then
      echo "forge_api: request failed: $endpoint" >&2
      return 1
    fi
    forgejo_http_ok "$hdr" "$endpoint" || return 1
    if [ "$have_jq" = true ]; then jq -r "$jqexpr" <"$body"; else cat "$body"; fi
    return 0
  fi

  # Paginated: accumulate into ONE array and apply --jq once at the end.
  # gh --paginate applies --jq per page and concatenates; for the `.[] | …`
  # shapes every call site here uses, the two are identical, and merging
  # first is what makes the completeness assert possible at all.
  local page=1 total="" got=0 n all="[]" pagejson
  while :; do
    if ! curl -sS -D "$hdr" -o "$body" \
      -H "Authorization: token $token" -H 'Accept: application/json' \
      "$base/$(forgejo_page_url "$endpoint" "$page")"; then
      echo "forge_api: request failed: $endpoint (page $page)" >&2
      return 1
    fi
    forgejo_http_ok "$hdr" "$endpoint" || return 1

    # Re-read on EVERY page, not once (#4712). A board that changes size
    # under the walk was invisible: page 1 declaring 4 and page 2 declaring
    # 9 stopped at 4 believing itself whole. A moving total means the read
    # cannot have been atomic, so it is refused rather than reconciled.
    local page_total
    page_total="$(forgejo_total_count "$hdr")" || return 1
    if [ -z "$total" ]; then
      total="$page_total"
    elif [ "$page_total" != "$total" ]; then
      cat >&2 <<EOF
forge_api: the declared total for '$endpoint' changed between pages — $total then $page_total (#188).
  The collection moved under the walk, so no page set can be proven whole.
  Refusing rather than reconciling a board that is already out of date.
EOF
      return 1
    fi

    pagejson="$(cat "$body")"
    # A 200 whose body is not a collection counted as zero items (#4712),
    # so an error object or a scalar arriving where a list belongs read as
    # a complete EMPTY collection whenever the declared total was 0.
    if [ "$(jq -r 'type' <<<"$pagejson" 2>/dev/null)" != array ]; then
      cat >&2 <<EOF
forge_api: '$endpoint' did not return a collection (#188).
  Expected a JSON array; got: $(head -c 200 <<<"$pagejson")
  Refusing: a body this shim cannot count must not be counted as empty.
EOF
      return 1
    fi
    n="$(jq 'length' <<<"$pagejson")"
    [ "$n" -gt 0 ] || break
    all="$(jq -s '.[0] + .[1]' <<<"$all"$'\n'"$pagejson")"
    got=$((got + n))
    [ "$got" -lt "$total" ] || break
    page=$((page + 1))
  done

  # The assert. A short read here is the silent-truncation bug arriving by
  # another route, so it is fatal rather than a warning.
  if [ "$got" -ne "$total" ]; then
    cat >&2 <<EOF
forge_api: incomplete gather for '$endpoint' — collected $got of $total declared (#188).
  Refusing rather than reconciling a partial board: a sweep over part of the
  queue that reports success is the failure this shim exists to prevent.
EOF
    return 1
  fi

  if [ "$have_jq" = true ]; then jq -r "$jqexpr" <<<"$all"; else printf '%s\n' "$all"; fi
}

# forgejo_total_count <header-file> — the declared size of the collection.
# Absent is fatal (#4699): without it the completeness assert cannot run,
# and an assert that cannot run must not silently pass.
forgejo_total_count() {
  local hdr="$1" total
  total="$(tr -d '\r' <"$hdr" | awk 'tolower($1) == "x-total-count:" { print $2 }' | tail -n1)"
  if [ -z "$total" ]; then
    cat >&2 <<EOF
forge_api: this forge did not send x-total-count — cannot prove the gather is complete (#188).
  The header is exposed by a server setting (access-control-expose-headers).
  Refusing: an unprovable read must not be reported as a whole one.
EOF
    return 1
  fi
  # Validate before it reaches arithmetic (#4712). `X-Total-Count:
  # not-a-number` used to sail through and become the bound the walk was
  # compared against — a guard whose own input was never checked.
  case "$total" in
    '' | *[!0-9]*)
      cat >&2 <<EOF
forge_api: x-total-count is not a non-negative integer: '$total' (#188).
  Refusing: the completeness bound must be a number, or the assert that
  uses it proves nothing.
EOF
      return 1
      ;;
  esac
  printf '%s\n' "$total"
}

# forgejo_http_ok <header-file> <endpoint> — a non-2xx is named, not
# swallowed. gh exits non-zero on HTTP failure; curl does not without -f,
# and -f would throw away the body that says why.
forgejo_http_ok() {
  local hdr="$1" endpoint="$2" code
  code="$(tr -d '\r' <"$hdr" | awk '/^HTTP\// { c = $2 } END { print c }')"
  case "$code" in
    2*) return 0 ;;
    *)
      echo "forge_api: HTTP $code from '$endpoint'" >&2
      return 1
      ;;
  esac
}

# --- the verbs the reconcilers use, over /api/v1 --------------------------
# Three asymmetries with gh, all measured against this instance on
# 2026-08-02 using a scratch repo (never a live board):
#
#   1. Adding labels takes NAMES         POST /issues/{n}/labels {"labels":["x"]}  -> 200
#      Removing one takes a numeric ID   DELETE /issues/{n}/labels/x               -> 422
#                                        DELETE /issues/{n}/labels/149             -> 204
#      So a removal must resolve name -> id first. gh hides this; the shim
#      cannot.
#
#   2. Assignees are SET, not added and removed. PATCH /issues/{n} takes the
#      whole list ({"assignees":[]} clears it, 201), so --remove-assignee is
#      a read-modify-write rather than a delete.
#
#   3. There is no statusCheckRollup. The portable equivalent is the
#      combined commit status, GET /commits/{sha}/status, which returns
#      {state, statuses[]}.

# forgejo_label_ids — name<TAB>id for every label in the repo, read once per
# call site that needs it. Paginated through forge_api, so a repo with more
# than one page of labels cannot silently lose the tail (#188).
forgejo_label_ids() {
  forge_api --paginate "repos/$REPO/labels" --jq '.[] | "\(.name)\t\(.id)"'
}

# forge_issue_edit <n> [--add-label X]… [--remove-label X]… [--add-assignee U]… [--remove-assignee U]…
# gh's flag surface, translated. Accepts comma-separated values, as gh does.
forge_issue_edit() {
  local n="${1:?forge_issue_edit: number required}"
  shift
  local add_labels=() rm_labels=() add_assignees=() rm_assignees=() v
  # Unknown flags REFUSE (#4743). The github backend forwards whatever it is
  # given to `gh`, which fails on a flag it does not know; dropping it here
  # instead would turn a port typo into a green no-op — a mutation that
  # silently did not happen, which is precisely this issue's failure class
  # arriving inside the fix for it.
  while [ $# -gt 0 ]; do
    case "$1" in
      --add-label | --remove-label | --add-assignee | --remove-assignee)
        if [ "$#" -lt 2 ]; then
          echo "forge_issue_edit: $1 requires a value (#188)" >&2
          return 1
        fi
        IFS=, read -ra v <<<"$2"
        case "$1" in
          --add-label) add_labels+=("${v[@]}") ;;
          --remove-label) rm_labels+=("${v[@]}") ;;
          --add-assignee) add_assignees+=("${v[@]}") ;;
          --remove-assignee) rm_assignees+=("${v[@]}") ;;
        esac
        shift
        ;;
      *)
        echo "forge_issue_edit: unknown flag '$1' — refusing rather than silently skipping the edit (#188)" >&2
        return 1
        ;;
    esac
    shift
  done

  # THE LABEL DELTA (#192). Removal used to be a per-label
  # `DELETE .../labels/{id}` loop. On this instance that call returns HTTP 500
  # for EVERY removal under the token the sweep actually holds — measured
  # under a real Actions token inside a workflow, probe run 701:
  #
  #   POST   /issues/{n}/labels  ["probe-a","probe-b"]  -> 200
  #   DELETE /issues/{n}/labels/{id}                    -> 500   labels unchanged
  #   PUT    /issues/{n}/labels  {"labels":[<id>]}      -> 200
  #   PUT    /issues/{n}/labels  {"labels":[]}          -> 200   (full clear)
  #
  # A PAT gets 204 on the same DELETE, which is why this survived a week
  # unseen: it fails only for `${{ github.token }}`, and only inside Actions.
  # Net effect before this fix: on Forgejo the state machine could only ever
  # ADD labels — every `state:*` transition needing the previous state cleared,
  # and every `blocker:*` that should lift, was inert.
  #
  # So a removal is expressed as a full-set PUT, exactly as the assignee branch
  # below expresses its own delta as one PATCH — read current, compute wanted,
  # write once.
  #
  # AN ADD-ONLY CALL KEEPS ITS ADDITIVE POST, deliberately. ceremony#128 lost
  # its `release` label — the merge door's declared-intent read — to a
  # read-modify-write that clobbered a label set two seconds after a builder
  # wrote it, and `forge_labels_add` is pinned against ever doing that
  # (test/forge-backends.test.sh). The read-modify-write window is real and is
  # accepted HERE and only here, where the caller has asked to REMOVE something
  # and no additive verb can express that.
  if [ "${#rm_labels[@]}" -gt 0 ]; then
    local current want_pairs ids id name payload
    local want_ids=() missing=()
    # name<TAB>id straight from the ISSUE payload. Preserved labels carry
    # their authoritative id here already, so they need no second lookup —
    # re-resolving them through the repository-wide list would make
    # preservation depend on a paginated read that has nothing to do with
    # this issue, and an incomplete one would drop a bystander
    # (@codex-reviewer-andresmgsl). Only ADDED names need forgejo_label_ids.
    current="$(forge_api "repos/$REPO/issues/$n" \
      --jq '[.labels[]? | "\(.name)\t\(.id)"] | join("\n")')" || return 1
    # The rows are name<TAB>id, so removals filter on the NAME field — a
    # whole-line match would never fire against a pair.
    want_pairs="$(
      awk -F '\t' 'NR==FNR { drop[$0]=1; next } !($1 in drop)' \
        <(printf '%s\n' "${rm_labels[@]}") \
        <(printf '%s\n' "$current" | grep -v '^$')
    )"
    while IFS=$'\t' read -r name id; do
      [ -n "$name" ] || continue
      want_ids+=("$id")
    done <<<"$want_pairs"
    if [ "${#add_labels[@]}" -gt 0 ]; then
      ids="$(forgejo_label_ids)" || return 1
      for name in "${add_labels[@]}"; do
        # already on the issue? its id is in want_ids already
        awk -F '\t' -v want="$name" '$1 == want { found=1 } END { exit !found }' \
          <<<"$want_pairs" && continue
        id="$(awk -F '\t' -v want="$name" '$1 == want { print $2; exit }' <<<"$ids")"
        if [ -z "$id" ]; then missing+=("$name"); continue; fi
        want_ids+=("$id")
      done
    fi
    # An add-label the repo does not carry refuses BEFORE the write. A PUT
    # that silently dropped an unresolvable name would remove a label nobody
    # asked to remove — a destructive write dressed as a partial success.
    if [ "${#missing[@]}" -gt 0 ]; then
      echo "forge_issue_edit: #$n: no label id on $REPO for: ${missing[*]} — refusing to PUT a set that would drop it" >&2
      return 1
    fi
    # NOTHING TO CHANGE, NOTHING TO WRITE. The reconcilers call
    # --remove-label unconditionally to converge state, so most calls here ask
    # to remove a label the issue does not carry. Writing the unchanged set
    # back would open the read-modify-write window of ceremony#128 for no
    # state change at all; the GET above is already the proof the sweep
    # reached the forge (@codex-reviewer-andresmgsl). gh's own behaviour on an
    # absent --remove-label is likewise a no-op.
    local current_ids
    current_ids="$(printf '%s\n' "$current" | grep -v '^$' | cut -f2 | sort -n | tr '\n' ' ')"
    if [ "$(printf '%s\n' ${want_ids[@]+"${want_ids[@]}"} | grep -v '^$' | sort -n | tr '\n' ' ')" = "$current_ids" ]; then
      return 0
    fi
    payload="$(printf '%s\n' ${want_ids[@]+"${want_ids[@]}"} \
      | jq -R 'select(. != "") | tonumber' | jq -sc '{labels: .}')"
    forgejo_write PUT "repos/$REPO/issues/$n/labels" "$payload" >/dev/null || return 1
  elif [ "${#add_labels[@]}" -gt 0 ]; then
    local payload
    payload="$(printf '%s\n' "${add_labels[@]}" | jq -R . | jq -sc '{labels: .}')"
    forgejo_write POST "repos/$REPO/issues/$n/labels" "$payload" >/dev/null || return 1
  fi

  if [ "${#add_assignees[@]}" -gt 0 ] || [ "${#rm_assignees[@]}" -gt 0 ]; then
    local current want payload
    current="$(forge_api "repos/$REPO/issues/$n" --jq '[.assignees[]?.login] | join("\n")')" || return 1
    want="$(
      {
        printf '%s\n' "$current"
        [ "${#add_assignees[@]}" -gt 0 ] && printf '%s\n' "${add_assignees[@]}"
      } | grep -v '^$' | sort -u
    )"
    if [ "${#rm_assignees[@]}" -gt 0 ]; then
      want="$(grep -vxF -f <(printf '%s\n' "${rm_assignees[@]}") <<<"$want" || true)"
    fi
    payload="$(printf '%s' "$want" | jq -R . | jq -sc '{assignees: [.[] | select(. != "")]}')"
    forgejo_write PATCH "repos/$REPO/issues/$n" "$payload" >/dev/null || return 1
  fi
}

forge_issue_comment() {
  local n="${1:?forge_issue_comment: number required}" body="${2?forge_issue_comment: body required}"
  forgejo_write POST "repos/$REPO/issues/$n/comments" "$(jq -nc --arg b "$body" '{body: $b}')" >/dev/null
}

forge_pr_list() {
  forge_api --paginate "repos/$REPO/pulls?state=open" --jq '.[].number'
}

# forge_pr_view <n> — the {mergeable, statusCheckRollup} shape the state
# machine reads, assembled from the two places Forgejo keeps it. The rollup
# is mapped into the node shape checks_state already parses, so the decision
# code is untouched.
forge_pr_view() {
  local n="${1:?forge_pr_view: number required}" pr sha status
  pr="$(forge_api "repos/$REPO/pulls/$n")" || return 1
  sha="$(jq -r '.head.sha // ""' <<<"$pr")"
  [ -n "$sha" ] || { echo "forge_pr_view: PR $n has no head sha" >&2; return 1; }
  status="$(forge_api "repos/$REPO/commits/$sha/status")" || return 1
  jq -n --argjson pr "$pr" --argjson st "$status" '
    {
      mergeable: (if $pr.mergeable == true then "MERGEABLE"
                  elif $pr.mergeable == false then "CONFLICTING"
                  else "UNKNOWN" end),
      statusCheckRollup: [
        $st.statuses[]? | {
          __typename: "StatusContext",
          context: .context,
          state: (.status | ascii_upcase),
          # checks_state groups repeated contexts and takes the NEWEST by
          # [.startedAt, .createdAt, .completedAt]. Without a timestamp the
          # winner would be decided by incidental array order, so a stale
          # re-run could outrank the live verdict (#4743). The combined
          # status carries both fields; measured on this instance.
          createdAt: .created_at,
          completedAt: .updated_at
        }
      ]
    }'
}

forge_label_list() { forge_api --paginate "repos/$REPO/labels" --jq '.[].name'; }

# forge_label_create — an UPSERT, matching `gh label create --force` (#4743).
# bootstrap_labels creates every declared label on every workflow_dispatch, so
# the second dispatch must update rather than conflict; a plain POST onto an
# existing name aborts the bootstrap under set -e.
forge_label_create() {
  local name="${1:?}" color="${2:?}" desc="${3:-}" ids id payload
  payload="$(jq -nc --arg n "$name" --arg c "$color" --arg d "$desc" '{name:$n,color:$c,description:$d}')"
  ids="$(forgejo_label_ids)" || return 1
  id="$(awk -F '\t' -v want="$name" '$1 == want { print $2; exit }' <<<"$ids")"
  if [ -n "$id" ]; then
    forgejo_write PATCH "repos/$REPO/labels/$id" "$payload" >/dev/null
  else
    forgejo_write POST "repos/$REPO/labels" "$payload" >/dev/null
  fi
}

forge_label_delete() {
  local name="${1:?}" ids id
  ids="$(forgejo_label_ids)" || return 1
  id="$(awk -F '\t' -v want="$name" '$1 == want { print $2; exit }' <<<"$ids")"
  [ -n "$id" ] || return 0
  forgejo_write DELETE "repos/$REPO/labels/$id" '' >/dev/null
}

# forgejo_write <method> <endpoint> <json-body> — every mutation goes through
# here so a non-2xx is named rather than swallowed, the same contract
# forgejo_http_ok gives reads.
forgejo_write() {
  local method="$1" endpoint="$2" payload="$3" base token hdr body rc
  base="$(forgejo_api_base)" || return 1
  token="${GH_TOKEN:-${GITHUB_TOKEN:-${FORGEJO_TOKEN:-}}}"
  hdr="$(mktemp)"; body="$(mktemp)"
  if [ -n "$payload" ]; then
    curl -sS -X "$method" -D "$hdr" -o "$body" \
      -H "Authorization: token $token" -H 'Content-Type: application/json' \
      -d "$payload" "$base/$endpoint"
  else
    curl -sS -X "$method" -D "$hdr" -o "$body" \
      -H "Authorization: token $token" "$base/$endpoint"
  fi
  rc=$?
  if [ "$rc" -ne 0 ]; then
    rm -f "$hdr" "$body"
    echo "forge: $method $endpoint failed to send" >&2
    return 1
  fi
  if ! forgejo_http_ok "$hdr" "$method $endpoint"; then
    head -c 300 "$body" >&2; echo >&2
    rm -f "$hdr" "$body"
    return 1
  fi
  cat "$body"
  rm -f "$hdr" "$body"
}

# forge_labels_add <n> <label…> — the additive label write (ceremony#128; see
# the github twin). POST /issues/{n}/labels adds the named labels and removes
# nothing, and it takes NAMES — measured, unlike the removal path, which
# needs ids.
forge_labels_add() {
  local n="${1:?forge_labels_add: number required}"
  shift
  [ "$#" -gt 0 ] || return 0
  forgejo_write POST "repos/$REPO/issues/$n/labels" \
    "$(printf '%s\n' "$@" | jq -R . | jq -sc '{labels: .}')" >/dev/null
}

# forge_request_reviewer <n> <user> — ask <user> for a verdict.
#
# This endpoint DOES exist here, contrary to an earlier reading of mine
# (#4698) which recorded requested_reviewers as having no sub-resource at
# all. What is true is narrower: Forgejo serves POST and DELETE on it and no
# GET, so a GET probe answers 404 — and a POST naming a user who does not
# exist answers 404 as well, for a different reason. Measured on a scratch
# repo: POST with a real user who lacks read access is 422 ("Reviewer can't
# read"), and 201 once they have it.
#
# The READ stays retired regardless (term 4): the field is stale here even on
# merged PRs, so outstanding verdicts come from /pulls/{n}/reviews at the
# current head SHA. It is the write that has an answer.
forge_request_reviewer() {
  local n="${1:?}" user="${2:?}"
  forgejo_write POST "repos/$REPO/pulls/$n/requested_reviewers" \
    "$(jq -nc --arg u "$user" '{reviewers: [$u]}')" >/dev/null
}

# forge_timeline <n> — JSON array of timeline events projected into the
# GitHub shape the reconcilers already select on. Measured mapping (#4849):
#
#   |                  | GitHub                         | Forgejo              |
#   | event kind       | .event == "labeled"/"unlabeled"| .type == "label"     |
#   | add vs remove    | the two event names            | .body "1" / ""       |
#   | actor            | .actor.login (no .user)        | .user.login (no .actor) |
#
# Status is captured BEFORE jq so an unreadable read cannot report as an
# empty timeline — the two states the ruling ladder must tell apart (#4853).
forge_timeline() {
  local n="${1:?forge_timeline: number required}" raw
  raw="$(forge_api --paginate "repos/$REPO/issues/$n/timeline")" || return 1
  jq '
    [.[]
      | select(.type == "label")
      | {
          event: (if .body == "1" then "labeled" else "unlabeled" end),
          actor: {login: (.user.login // "")},
          label: {name: (.label.name // "")},
          created_at: .created_at
        }
    ]
  ' <<<"$raw"
}

# forge_pr_activity <n> — one ISO timestamp per line of real PR activity.
# Forgejo has no flat /pulls/{n}/comments (HTTP 404, measured #4844); inline
# review comments live under /pulls/{n}/reviews/{id}/comments. Only reviews
# with comments_count > 0 are fetched, so a board with none costs zero
# extra requests.
forge_pr_activity() {
  local n="${1:?forge_pr_activity: number required}" reviews rid
  forge_api --paginate "repos/$REPO/issues/$n/comments" --jq '.[].created_at' || return 1
  forge_api --paginate "repos/$REPO/pulls/$n/commits" --jq '.[].commit.committer.date' || return 1
  reviews="$(forge_api --paginate "repos/$REPO/pulls/$n/reviews")" || return 1
  while IFS= read -r rid; do
    [ -n "$rid" ] || continue
    forge_api --paginate "repos/$REPO/pulls/$n/reviews/$rid/comments" \
      --jq '.[].created_at' || return 1
  done < <(jq -r '.[] | select((.comments_count // 0) > 0) | .id' <<<"$reviews")
}

# --- the release door's facts (#191) --------------------------------------
# Two reads the merge and tag doors depend on. Both answer a QUESTION, and
# both distinguish "the read completed and the answer is no" from "the read
# did not complete" — the distinction lib/facts.sh got wrong before #191,
# where any failure became a definite `no` and a release ceremony was
# silently demoted to a bare push.
#
# Measured on forgejo.heavyduty.builders (8.0.3+gitea-1.22.0), 2026-08-04:
#
#   GET /repos/{o}/{r}/releases/tags/0.4.0   -> 200   (present)
#   GET /repos/{o}/{r}/releases/tags/9.9.9   -> 404   (absent — a real answer)
#
#   GET /repos/{o}/{r}/commits/{sha}/pull    -> 200, a SINGLE PR object
#   GET /repos/{o}/{r}/commits/{sha}/pulls   -> 404 page not found
#   ...on a commit with no PR                -> 404 {"message":"pull request
#                                                    does not exist …"}
#
# The singular/plural split is the asymmetry: GitHub serves an ARRAY at
# /pulls, Forgejo serves one OBJECT at /pull. Both verbs below emit the
# GitHub shape — a JSON array — so lib/facts.sh carries one jq expression
# for both forges, which is the whole point of the shim.

# forgejo_read_code <endpoint> <body-file> — the raw GET, printing the HTTP
# status on stdout. Separate from forge_api because these two call sites
# must SEE a 404 rather than have it collapsed into a failure.
forgejo_read_code() {
  local endpoint="$1" body="$2" base token hdr rc
  base="$(forgejo_api_base)" || return 1
  token="${GH_TOKEN:-${GITHUB_TOKEN:-${FORGEJO_TOKEN:-}}}"
  hdr="$(mktemp)"
  curl -sS -D "$hdr" -o "$body" -H "Authorization: token $token" "$base/$endpoint"
  rc=$?
  if [ "$rc" -ne 0 ]; then
    rm -f "$hdr"
    echo "forge: GET $endpoint failed to send" >&2
    return 1
  fi
  tr -d '\r' <"$hdr" | awk '/^HTTP\// { c = $2 } END { print c }'
  rm -f "$hdr"
}

# forge_release_exists <tag> — prints `yes` or `no`. A non-zero exit means
# the read did not complete and the answer is UNKNOWN; the caller must not
# treat that as `no` (#191).
forge_release_exists() {
  local tag="${1:?forge_release_exists: tag required}" body code
  body="$(mktemp)"
  code="$(forgejo_read_code "repos/$REPO/releases/tags/$tag" "$body")" || { rm -f "$body"; return 1; }
  rm -f "$body"
  case "$code" in
    2*) echo yes ;;
    404) echo no ;;
    *)
      echo "forge_release_exists: HTTP $code reading release '$tag' — the answer is unknown, not 'no'" >&2
      return 1
      ;;
  esac
}

# forge_commit_pulls <sha> — the pull requests whose merge produced <sha>, as
# a JSON ARRAY in GitHub's shape. An empty array is a completed read that
# found nothing; a non-zero exit is a read that did not complete.
forge_commit_pulls() {
  local sha="${1:?forge_commit_pulls: sha required}" body code out
  body="$(mktemp)"
  code="$(forgejo_read_code "repos/$REPO/commits/$sha/pull" "$body")" || { rm -f "$body"; return 1; }
  case "$code" in
    2*)
      # One object -> a one-element array, so the call site's jq is the
      # same expression it runs against GitHub.
      if ! out="$(jq -c '[.]' <"$body" 2>/dev/null)"; then
        rm -f "$body"
        echo "forge_commit_pulls: unreadable JSON for '$sha'" >&2
        return 1
      fi
      printf '%s\n' "$out"
      ;;
    404) printf '[]\n' ;;
    *)
      rm -f "$body"
      echo "forge_commit_pulls: HTTP $code reading the PR for '$sha' — the answer is unknown, not 'none'" >&2
      return 1
      ;;
  esac
  rm -f "$body"
}

# --- the release door's writes (#191) -------------------------------------
# Confirmed against this instance's own swagger, 2026-08-04:
#
#   POST /repos/{o}/{r}/tags                  -> exists   (tag creation)
#   GET  /repos/{o}/{r}/git/refs              -> GET ONLY (no POST)
#   POST /repos/{o}/{r}/releases              -> exists
#   POST /repos/{o}/{r}/releases/{id}/assets  -> exists
#
# The asymmetry worth naming: GitHub creates a tag by POSTing a ref to
# /git/refs; Forgejo does not serve POST there at all and creates tags at
# /tags instead. A 1:1 port of the gh call would 404 forever.

# forge_tag_create <tag> <sha>
forge_tag_create() {
  local tag="${1:?forge_tag_create: tag required}" sha="${2:?forge_tag_create: sha required}"
  forgejo_write POST "repos/$REPO/tags" \
    "$(jq -nc --arg t "$tag" --arg s "$sha" '{tag_name:$t,target:$s}')" >/dev/null
}

# forgejo_urlencode <string> — percent-encode one query VALUE. jq is already
# a hard dependency of this backend, and @uri is its one correct answer; a
# hand-rolled sed class is how the next unescaped character gets through.
forgejo_urlencode() {
  jq -rn --arg s "${1-}" '$s|@uri'
}

# forge_release_create <tag> <title> <notes-file> [asset…] — publishes, then
# uploads each asset to the created release. The release id comes back from
# the create, so no second lookup is needed.
forge_release_create() {
  local tag="${1:?forge_release_create: tag required}" title="${2:?forge_release_create: title required}"
  local notes="${3:?forge_release_create: notes file required}" out id base token
  shift 3
  out="$(forgejo_write POST "repos/$REPO/releases" \
    "$(jq -nc --arg t "$tag" --arg n "$title" --rawfile b "$notes" \
        '{tag_name:$t,name:$n,body:$b,draft:false,prerelease:false}')")" || return 1
  id="$(printf '%s' "$out" | jq -r '.id // empty')"
  [ -n "$id" ] || { echo "forge_release_create: the create returned no release id" >&2; return 1; }
  [ "$#" -gt 0 ] || return 0
  base="$(forgejo_api_base)" || return 1
  token="${GH_TOKEN:-${GITHUB_TOKEN:-${FORGEJO_TOKEN:-}}}"
  local f name
  for f in "$@"; do
    [ -e "$f" ] || continue
    # The asset name is a QUERY VALUE, and the hook contract permits any
    # file the consumer drops in RELEASE_ASSETS_DIR. Raw interpolation broke
    # on a space (curl exits 3 on the malformed URL) and silently changed
    # the name on '&', '#', '+' and '%' — `gh release create` handled those,
    # so a 1:1 port had to as well (#191, found by @codex on !193).
    name="$(forgejo_urlencode "$(basename "$f")")"
    curl -sS -f -X POST -H "Authorization: token $token" \
      -F "attachment=@$f" \
      "$base/repos/$REPO/releases/$id/assets?name=$name" >/dev/null \
      || { echo "forge_release_create: asset upload failed for '$f'" >&2; return 1; }
  done
}

# forge_pr_create <head> <base> <title> <body> <label…> — POST /pulls takes
# label IDs, not names (the same asymmetry the issue-label writes carry), so
# the names are resolved first through forgejo_label_ids.
forge_pr_create() {
  local head="${1:?forge_pr_create: head required}" base="${2:?forge_pr_create: base required}"
  local title="${3:?forge_pr_create: title required}" body="${4:?forge_pr_create: body required}"
  shift 4
  local ids='[]' map name id
  if [ "$#" -gt 0 ]; then
    map="$(forgejo_label_ids)" || return 1
    ids='['
    for name in "$@"; do
      id="$(printf '%s\n' "$map" | awk -F'\t' -v n="$name" '$1 == n { print $2; exit }')"
      [ -n "$id" ] || { echo "forge_pr_create: no label '$name' in this repo" >&2; return 1; }
      ids="$ids$id,"
    done
    ids="${ids%,}]"
  fi
  forgejo_write POST "repos/$REPO/pulls" \
    "$(jq -nc --arg h "$head" --arg b "$base" --arg t "$title" --arg d "$body" \
        --argjson l "$ids" '{head:$h,base:$b,title:$t,body:$d,labels:$l}')" >/dev/null
}