#!/bin/bash
# Keep two codex exec jobs running by topping up when fewer are active.
# Usage:
#   tools/codex-keep-two.sh <tmux_session> "Task A" "Task B" ["Task C" ...]
# Notes:
#   - Detects only real `codex exec` processes via ps/awk (avoids self-matches).
#   - Starts tasks in order, cycling if more top-ups are needed.

set -euo pipefail

if [ $# -lt 2 ]; then
  echo "Usage: $0 <tmux_session> \"Task A\" \"Task B\" [\"Task C\" ...]" >&2
  exit 1
fi

SESSION="$1"; shift
TASKS=("$@")
if [ ${#TASKS[@]} -eq 0 ]; then
  echo "Provide at least one task string." >&2
  exit 1
fi

CODEX_PROC_PATTERN=${CODEX_PROC_PATTERN:-'codex .* exec'}
CODEX_COUNT_MODE=${CODEX_COUNT_MODE:-sentinel}
WORK_DIR="$HOME/.codex-async-work"
RUN_DIR="$WORK_DIR/running"

list_running() {
  if command -v pgrep >/dev/null 2>&1; then
    pgrep -af -- "$CODEX_PROC_PATTERN" | grep -v 'pgrep' || true
  else
    ps -eo pid=,args= | grep -E -- "$CODEX_PROC_PATTERN" | grep -v grep || true
  fi
}

count_running() {
  case "$CODEX_COUNT_MODE" in
    sentinel)
      local cnt=0
      if [ -d "$RUN_DIR" ]; then
        for f in "$RUN_DIR"/codex-*.run; do
          [ -e "$f" ] || continue
          pid=$(awk -F': ' '/^pid:/{print $2; exit}' "$f" 2>/dev/null || true)
          if [ -n "$pid" ] && ! kill -0 "$pid" 2>/dev/null; then
            rm -f "$f" 2>/dev/null || true
            continue
          fi
          cnt=$((cnt+1))
        done
      fi
      if [ "${cnt:-0}" -eq 0 ]; then
        if command -v pgrep >/dev/null 2>&1; then
          pgrep -f -- "$CODEX_PROC_PATTERN" \
            | xargs -r -I {} sh -c 'ps -o pgid= -p "$1" 2>/dev/null' _ {} \
            | awk '{print $1}' | grep -E '^[0-9]+$' | sort -u | wc -l | tr -d ' ' || echo 0
        else
          list_running | wc -l | tr -d ' ' || echo 0
        fi
      else
        echo "$cnt"
      fi
      ;;
    pgid)
      if command -v pgrep >/dev/null 2>&1; then
        pgrep -f -- "$CODEX_PROC_PATTERN" \
          | xargs -r -I {} sh -c 'ps -o pgid= -p "$1" 2>/dev/null' _ {} \
          | awk '{print $1}' | grep -E '^[0-9]+$' | sort -u | wc -l | tr -d ' ' || echo 0
      else
        list_running | wc -l | tr -d ' ' || echo 0
      fi
      ;;
    proc|*)
      list_running | wc -l | tr -d ' ' || echo 0
      ;;
  esac
}

RUNNING_RAW=$(count_running)
# Sanitize: take first line, strip spaces, ensure numeric
RUNNING=$(printf "%s" "$RUNNING_RAW" | head -n1 | tr -d '[:space:]')
case "$RUNNING" in
  ''|*[!0-9]*) RUNNING=0 ;;
esac
echo "[keep-two] 実際のcodexプロセス数: ${RUNNING}"
NEED=$((2 - RUNNING))
if [ $NEED -le 0 ]; then
  echo "[keep-two] already running: $RUNNING (>=2)."
  exit 0
fi

echo "[keep-two] running=$RUNNING, starting $NEED top-up task(s)."

idx=0
for ((i=0; i<NEED; i++)); do
  TASK="${TASKS[$idx]}"; idx=$(((idx+1) % ${#TASKS[@]}))
  echo "[keep-two] start: $TASK"
  CODEX_ASYNC_DETACH=1 ./tools/codex-async-notify.sh "$TASK" "$SESSION" >/dev/null 2>&1 || true
done

echo "[keep-two] now running: $(count_running)"