#!/bin/bash
# coord-sweep.sh - close the FYI backlog across every mailbox on this machine,
# deterministically and without a model. Archives directed messages whose sender
# declared reply-expected: no and whose filename timestamp is older than a grace
# window. Prints one line per message and a summary; writes a log line per
# closure.
#
# WHY THIS EXISTS. A notice needs no answer, but it is still re-injected at every
# session start until someone closes it by hand. Across enough repositories that
# hand-closing IS the manual work the mailbox was supposed to remove, and the
# pending count - the operator's only signal - drowns in messages that were never
# going to be acted on. This closes exactly that class and nothing else.
#
# ONE MECHANICALLY DECIDABLE CLASS, NEVER A JUDGEMENT. A message that owes a
# reply is never touched, at any age, with any flag. Answering it would mean
# deciding something on the receiving repo's behalf, which is the one thing this
# system exists to keep a session from doing. If that ever needs to change, the
# answer is a session in that repo, not a wider net here.
#
# THE LOG IS NOT OPTIONAL, and the reason is a real gap: a directed message has
# no seen-tracking (only broadcasts do), so this script cannot tell "seen and
# ignored" from "never delivered". A notice to a repo left unopened for the whole
# window is closed UNREAD. That is the accepted tradeoff, and the log is the only
# thing standing between it and a silent disappearance.
#
# DRY-RUN IS THE DEFAULT, inverted from every other script here. The others print
# or deliver; this one destroys pending state, so the safe direction has to be the
# one you get by forgetting a flag.
#
# Usage: coord-sweep.sh [--write] [--days <n>] [--log <path>]
#   --write        actually close. Without it nothing is archived and no log is
#                  written - the run only reports what it would have done.
#   --days <n>     grace window in days (default 14). 0 means "any age".
#   --log <path>   log file (default $CLAUDE_COORD_DIR/_sweep.log).
# Env: CLAUDE_COORD_DIR overrides the mailbox root.
# Exit: 0 on success, including when there is nothing to close. 2 on usage error.
# ASCII only, bash 3.2 safe.
set -u
export LC_ALL=C

COORD="${CLAUDE_COORD_DIR:-$HOME/.claude/coord}"
DIR="$(cd "$(dirname "$0")" && pwd)"
# No `${VAR:-fallback}` on an engine path, ever: a fallback silently routes
# through whatever happens to sit at the alternate location instead of failing
# loud. That defect shipped twice here (board.sh, then coord-send.sh).
DONE="$DIR/coord-done.sh"

WRITE=0
DAYS=14
LOG=""

while [ $# -gt 0 ]; do
  case "$1" in
    --write) WRITE=1; shift ;;
    # bash 3.2: `shift 2` past the end of $# is a no-op -> would loop forever.
    --days) [ $# -ge 2 ] || { echo "coord-sweep: --days requires a value" >&2; exit 2; }
            DAYS="$2"; shift 2 ;;
    --log)  [ $# -ge 2 ] || { echo "coord-sweep: --log requires a value" >&2; exit 2; }
            LOG="$2"; shift 2 ;;
    -h|--help) grep '^#' "$0" | sed 's/^# \{0,1\}//'; exit 0 ;;
    # Strict, unlike coord-inbox.sh. That one is lenient because failing a
    # SessionStart over a stray flag is worse than ignoring it; this one is not
    # on that path and closes messages, so a typo must stop it.
    *) echo "coord-sweep: unknown argument: $1" >&2; exit 2 ;;
  esac
done

case "$DAYS" in
  ''|*[!0-9]*) echo "coord-sweep: --days must be a non-negative integer: $DAYS" >&2; exit 2 ;;
esac
[ -x "$DONE" ] || { echo "coord-sweep: cannot find coord-done.sh at $DONE" >&2; exit 2; }
[ -n "$LOG" ] || LOG="$COORD/_sweep.log"

# Cutoff as a plain 14-digit number, so the comparison is integer arithmetic
# rather than string collation. BSD date (macOS); a failure here must stop the
# run, because a missing cutoff would otherwise read as "close everything".
CUTOFF="$(date -u -v-"${DAYS}"d +%Y%m%d%H%M%S 2>/dev/null)"
case "$CUTOFF" in
  [0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9]) ;;
  *) echo "coord-sweep: could not compute a cutoff date" >&2; exit 2 ;;
esac
NOW="$(date -u +%Y-%m-%dT%H:%M:%SZ)"

[ -d "$COORD" ] || { echo "coord-sweep: nothing to close (no mailbox root at $COORD)"; exit 0; }

# Does this message owe a reply? Absent field means YES: every message written
# before 0.11.0 lacks it, so absence keeps meaning what it always meant. The read
# is bounded to the frontmatter block - a body line is untrusted cross-repo input
# and must not be able to close its own message by claiming "reply-expected: no"
# at column 0. Duplicated from coord-count.sh rather than shared: each script
# here must run standalone.
owes_reply() {
  [ "$(head -1 "$1" 2>/dev/null)" = "---" ] || return 0
  [ "$(grep -c '^---$' "$1" 2>/dev/null)" -ge 2 ] || return 0
  sed -n '2,/^---$/p' "$1" 2>/dev/null | grep -q '^reply-expected: no$' && return 1
  return 0
}

# Frontmatter field for the log line. Control characters are stripped because
# this is untrusted content on its way into a file the operator reads.
field() {
  sed -n '2,/^---$/p' "$2" 2>/dev/null | grep "^$1: " | head -1 \
    | sed "s/^$1: //" | tr -d '\000-\037' | cut -c1-120
}

CLOSED=0
for d in "$COORD"/*; do
  [ -d "$d" ] || continue
  name="$(basename "$d")"
  # Reserved engine namespace. _broadcast is storage, not a correspondent, and
  # archiving out of it would retire an announcement for every repo that has not
  # read it yet - an unauthenticated retract. That is coord-send --retract's job,
  # and it checks the sender.
  case "$name" in _*) continue ;; esac
  [ -d "$d/inbox" ] || continue

  for m in "$d/inbox"/*.md; do
    [ -e "$m" ] || continue
    base="$(basename "$m")"

    # Age comes free from the filename prefix; nothing inside the file is
    # trusted for it. A name the grammar does not produce has no readable age,
    # and an unreadable age must never be treated as old - fail-safe, not
    # fail-open.
    ts="${base%%-*}"
    case "$ts" in
      [0-9][0-9][0-9][0-9][0-9][0-9][0-9][0-9]T[0-9][0-9][0-9][0-9][0-9][0-9]Z) ;;
      *) continue ;;
    esac
    num="$(printf '%s' "$ts" | tr -dc '0-9')"
    [ "$num" -lt "$CUTOFF" ] || continue

    owes_reply "$m" && continue

    if [ "$WRITE" -eq 1 ]; then
      # Read the fields BEFORE closing: coord-done.sh moves the file to archive,
      # so a log line built afterwards describes a path that no longer exists and
      # silently logs empty values - which defeats the only safeguard this script
      # has against a notice vanishing unread.
      mfrom="$(field from "$m")"
      msubj="$(field subject "$m")"
      # Through the engine, never `mv`: coord-done.sh owns the filename grammar
      # and the archive layout, and it refuses _broadcast on its own.
      if "$DONE" --repo "$name" "$base" >/dev/null 2>&1; then
        printf '%s\t%s\t%s\tfrom=%s\tsubject=%s\n' \
          "$NOW" "$name" "$base" "$mfrom" "$msubj" >> "$LOG"
        echo "closed: $name/$base"
        CLOSED=$((CLOSED + 1))
      else
        echo "coord-sweep: failed to close $name/$base" >&2
      fi
    else
      echo "would close: $name/$base"
      CLOSED=$((CLOSED + 1))
    fi
  done
done

if [ "$CLOSED" -eq 0 ]; then
  echo "coord-sweep: nothing to close (cutoff ${CUTOFF}, ${DAYS} days)"
elif [ "$WRITE" -eq 1 ]; then
  echo "coord-sweep: $CLOSED message(s) closed (cutoff ${CUTOFF}, ${DAYS} days). Log: $LOG"
else
  echo "coord-sweep: $CLOSED message(s) would close (cutoff ${CUTOFF}, ${DAYS} days). Re-run with --write."
fi

exit 0