#!/usr/bin/env bash
# openclaw-watchdog — Monitor OpenClaw gateway, auto-recover from crashes
# https://github.com/jlgrimes/openclaw-watchdog
# MIT License — Jared Grimes

set -euo pipefail

# ─── Configuration (all overridable via env vars) ────────────────────────────
OPENCLAW_CONFIG_PATH="${OPENCLAW_CONFIG_PATH:-$HOME/.openclaw/config.yaml}"
HEALTH_URL="${HEALTH_URL:-http://localhost:3000/health}"
CHECK_INTERVAL="${CHECK_INTERVAL:-30}"          # seconds between checks
FAIL_THRESHOLD="${FAIL_THRESHOLD:-3}"           # consecutive failures before escalation
WATCHDOG_LOG="${WATCHDOG_LOG:-$HOME/.openclaw/watchdog.log}"
GOOD_CONFIG_PATH="${GOOD_CONFIG_PATH:-$HOME/.openclaw/config.yaml.good}"

# Notification settings (Telegram + ntfy)
TELEGRAM_BOT_TOKEN="${TELEGRAM_BOT_TOKEN:-}"
TELEGRAM_CHAT="${TELEGRAM_CHAT:-1793951355}"
NTFY_URL="${NTFY_URL:-}"
NTFY_TOPIC="${NTFY_TOPIC:-}"

# Legacy Discord settings (optional, for backwards compat)
DISCORD_CHANNEL_ID="${DISCORD_CHANNEL_ID:-}"
DISCORD_BOT_TOKEN="${DISCORD_BOT_TOKEN:-}"

# ─── State ────────────────────────────────────────────────────────────────────
fail_count=0
alerted=false        # true after SOS sent, prevents spam
was_down=false       # tracks if we're recovering

# ─── Logging ──────────────────────────────────────────────────────────────────
log() {
  local ts
  ts="$(date '+%Y-%m-%d %H:%M:%S')"
  echo "[$ts] $*" | tee -a "$WATCHDOG_LOG"
}

# ─── Discord messaging ───────────────────────────────────────────────────────
discord_send() {
  local msg="$1"
  [[ -z "$DISCORD_CHANNEL_ID" ]] && return 0
  [[ -z "$DISCORD_BOT_TOKEN" ]] && return 0

  curl -sf -X POST \
    "https://discord.com/api/v10/channels/${DISCORD_CHANNEL_ID}/messages" \
    -H "Authorization: Bot ${DISCORD_BOT_TOKEN}" \
    -H "Content-Type: application/json" \
    -d "{\"content\": $(printf '%s' "$msg" | jq -Rs .)}" \
    >/dev/null 2>&1 || log "WARN: Failed to send Discord message"
}

# ─── Telegram messaging ──────────────────────────────────────────────────────
telegram_send() {
  local msg="$1"
  [[ -z "$TELEGRAM_BOT_TOKEN" ]] && return 0
  [[ -z "$TELEGRAM_CHAT" ]] && return 0

  curl -sf -X POST \
    "https://api.telegram.org/bot${TELEGRAM_BOT_TOKEN}/sendMessage" \
    -H "Content-Type: application/json" \
    -d "{\"chat_id\": \"$TELEGRAM_CHAT\", \"text\": $(printf '%s' "$msg" | jq -Rs .), \"parse_mode\": \"Markdown\"}" \
    >/dev/null 2>&1 || log "WARN: Failed to send Telegram message"
}

# ─── ntfy messaging ─────────────────────────────────────────────────────────
ntfy_send() {
  local title="$1"
  local msg="$2"
  local priority="${3:-4}"  # 1-5 or low|default|high|urgent
  local sound="${4:-default}"

  [[ -z "$NTFY_URL" ]] && return 0
  [[ -z "$NTFY_TOPIC" ]] && return 0

  # Enforce minimum priority (default 4)
  local minp="${NTFY_MIN_PRIORITY:-4}"
  if [[ "$priority" =~ ^[0-9]+$ ]] && [[ "$minp" =~ ^[0-9]+$ ]]; then
    if (( priority < minp )); then
      priority="$minp"
    fi
  fi

  curl -sf -X POST \
    "${NTFY_URL%/}/${NTFY_TOPIC}" \
    -H "Title: $title" \
    -H "Priority: $priority" \
    -H "Sound: $sound" \
    -d "$msg" \
    >/dev/null 2>&1 || log "WARN: Failed to send ntfy message"
}

# ─── Send to all configured channels ─────────────────────────────────────────
send_notification() {
  local title="$1"
  local msg="$2"
  local priority="${3:-5}"
  
  discord_send "$msg"
  telegram_send "$msg"
  ntfy_send "$title" "$msg" "4" "default"
}

# ─── Health check ─────────────────────────────────────────────────────────────
check_health() {
  curl -sf --max-time 10 "$HEALTH_URL" >/dev/null 2>&1
}

# ─── Save last-known-good config ─────────────────────────────────────────────
save_good_config() {
  if [[ -f "$OPENCLAW_CONFIG_PATH" ]]; then
    cp "$OPENCLAW_CONFIG_PATH" "$GOOD_CONFIG_PATH"
  fi
}

# ─── Revert to last-known-good config ────────────────────────────────────────
revert_config() {
  if [[ -f "$GOOD_CONFIG_PATH" ]]; then
    log "Reverting config to last-known-good snapshot"
    cp "$GOOD_CONFIG_PATH" "$OPENCLAW_CONFIG_PATH"
    return 0
  else
    log "WARN: No good config snapshot available to revert"
    return 1
  fi
}

# ─── Restart gateway ─────────────────────────────────────────────────────────
restart_gateway() {
  log "Restarting OpenClaw gateway..."
  openclaw gateway restart >/dev/null 2>&1 || true
  sleep 5
}

# ─── SOS alert ────────────────────────────────────────────────────────────────
send_sos() {
  local hostname
  hostname="$(hostname 2>/dev/null || echo 'unknown')"
  local title="🚨 OpenClaw Gateway DOWN"
  local msg="🚨 **OpenClaw Gateway DOWN** on \`${hostname}\`

Watchdog tried:
1. ✅ Simple restart
2. ✅ Config rollback + restart
3. ❌ Still unreachable after ${FAIL_THRESHOLD}+ failures

**Manual intervention needed:**
\`\`\`
ssh ${USER}@${hostname}
openclaw gateway status
journalctl -u openclaw-gateway --since '10 min ago'
\`\`\`"

  log "CRITICAL: Sending SOS alert"
  send_notification "$title" "$msg" 10
  alerted=true
}

# ─── Recovery notification ────────────────────────────────────────────────────
send_recovery() {
  local hostname
  hostname="$(hostname 2>/dev/null || echo 'unknown')"
  local title="✅ OpenClaw Gateway Recovered"
  local msg="✅ **OpenClaw Gateway recovered** on \`${hostname}\` — back online!"
  log "Gateway recovered"
  send_notification "$title" "$msg" 5
}

# ─── Main loop ────────────────────────────────────────────────────────────────
main() {
  log "Watchdog started (interval=${CHECK_INTERVAL}s, threshold=${FAIL_THRESHOLD}, health=${HEALTH_URL})"
  log "Notifications: Telegram=${TELEGRAM_CHAT:+enabled}, ntfy=${NTFY_TOPIC:+enabled}, Discord=${DISCORD_CHANNEL_ID:+enabled}"

  while true; do
    if check_health; then
      # ── Healthy ──
      if [[ "$was_down" == true ]]; then
        send_recovery
        was_down=false
        alerted=false
      fi
      fail_count=0
      save_good_config
    else
      # ── Unhealthy ──
      fail_count=$((fail_count + 1))
      log "Health check failed (${fail_count}/${FAIL_THRESHOLD})"

      if [[ $fail_count -eq 1 ]]; then
        # Stage 1: simple restart
        was_down=true
        restart_gateway
      elif [[ $fail_count -eq 2 ]]; then
        # Stage 2: config revert + restart
        revert_config && restart_gateway
      elif [[ $fail_count -ge $FAIL_THRESHOLD && "$alerted" == false ]]; then
        # Stage 3: SOS (once)
        send_sos
      fi
    fi

    sleep "$CHECK_INTERVAL"
  done
}

main "$@"