#!/usr/bin/env bash

# mihomo-guard.sh
# 自动保活 + 自动刷新订阅 + 自动切换可用线路
#
# 目标：
# - 定期通过 mihomo 代理探测 Telegram 官方入口连通性
# - 连续失败后，自动刷新订阅并切换到候选节点
# - 若切换后仍失败，再 fallback 重启 mihomo
#
# 说明：
# - 依赖 mihomo external-controller API (9090)
# - 当前按你的环境写死了 controller / secret / provider / group 名称

# ===== 可调参数 =====

PROBE_URL="https://api.telegram.org"
PROXY_ADDR="http://127.0.0.1:7897"
PROBE_TIMEOUT=4
SLEEP_INTERVAL=15
MAX_FAIL_COUNT=5

MIHOMO_BIN="/usr/local/opt/mihomo/bin/mihomo"
MIHOMO_DIR="/usr/local/etc/mihomo"
LOG_FILE="/usr/local/var/mihomo-guard.log"

# Mihomo controller API
CONTROLLER_URL="http://127.0.0.1:9090"
CONTROLLER_SECRET="123456"
SUB_PROVIDER="my_sub"

# 代理组名称（基于你当前 API 返回）
MANUAL_GROUP="手动选择"
AI_GROUP="🤖 AI服务"
DEV_GROUP="💻 开发服务"

# 故障恢复时优先尝试的候选节点（亚洲优先）
CANDIDATE_PROXIES=(
  "🇭🇰香港01-IPv6|AI"
  "🇭🇰香港03-IPv6|AI"
  "🇭🇰香港05-流媒体解锁|AI"
  "🇸🇬新加坡01-流媒体解锁|AI"
  "🇸🇬新加坡02-流媒体解锁|AI"
  "🇨🇳台湾03-流媒体解锁|AI"
  "🇨🇳台湾04-流媒体解锁|AI"
  "🇯🇵日本03"
  "🇯🇵日本01"
)

FAIL_COUNT=0
LAST_SWITCH_INDEX=-1

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

api_call() {
  local method="$1"
  local path="$2"
  local data="${3:-}"

  if [ -n "$data" ]; then
    curl -sS -X "$method" \
      -H "Authorization: Bearer $CONTROLLER_SECRET" \
      -H "Content-Type: application/json" \
      -d "$data" \
      "$CONTROLLER_URL$path"
  else
    curl -sS -X "$method" \
      -H "Authorization: Bearer $CONTROLLER_SECRET" \
      "$CONTROLLER_URL$path"
  fi
}

probe_once() {
  curl -x "$PROXY_ADDR" -m "$PROBE_TIMEOUT" -sS "$PROBE_URL" >/dev/null
}

refresh_subscription() {
  log "[ACTION] Refreshing provider: $SUB_PROVIDER"
  api_call PUT "/providers/proxies/$SUB_PROVIDER" >/dev/null 2>&1
}

switch_group_to() {
  local group_name="$1"
  local target_proxy="$2"

  log "[ACTION] Switching group [$group_name] -> [$target_proxy]"
  api_call PUT "/proxies/$group_name" "{\"name\":\"$target_proxy\"}" >/dev/null 2>&1
}

try_switch_routes() {
  log "[ACTION] Starting provider refresh + route switching workflow"

  refresh_subscription
  sleep 3

  local total=${#CANDIDATE_PROXIES[@]}
  local i
  for ((i=1; i<=total; i++)); do
    local idx=$(((LAST_SWITCH_INDEX + i) % total))
    local candidate="${CANDIDATE_PROXIES[$idx]}"

    log "[INFO] Trying candidate proxy: $candidate"

    # 1) 手动选择 -> 指定节点
    switch_group_to "$MANUAL_GROUP" "$candidate"
    sleep 1

    # 2) 关键业务组切到手动选择，避免继续受 URLTest 组影响
    switch_group_to "$AI_GROUP" "$MANUAL_GROUP"
    sleep 1
    switch_group_to "$DEV_GROUP" "$MANUAL_GROUP"
    sleep 1

    # 给 mihomo 一点时间收敛
    sleep 3

    if probe_once; then
      LAST_SWITCH_INDEX=$idx
      log "[OK] Probe success after switching to [$candidate]"
      log "[RECOVERED] 当前恢复到线路: [$candidate]"
      return 0
    else
      log "[WARN] Probe still failed after switching to [$candidate]"
    fi
  done

  log "[ERROR] All candidate proxies failed after refresh + switching"
  return 1
}

restart_mihomo() {
  log "[ACTION] Restarting mihomo..."

  if pgrep -f "$MIHOMO_BIN" >/dev/null 2>&1; then
    log "[INFO] Existing mihomo process found, sending TERM"
    pkill -f "$MIHOMO_BIN" || log "[WARN] pkill mihomo returned non-zero"
    sleep 3
  else
    log "[INFO] No existing mihomo process found"
  fi

  if [ ! -x "$MIHOMO_BIN" ]; then
    log "[ERROR] mihomo binary not found or not executable: $MIHOMO_BIN"
    return 1
  fi

  if [ ! -d "$MIHOMO_DIR" ]; then
    log "[ERROR] mihomo directory not found: $MIHOMO_DIR"
    return 1
  fi

  log "[INFO] Starting mihomo with: $MIHOMO_BIN -d $MIHOMO_DIR"
  nohup "$MIHOMO_BIN" -d "$MIHOMO_DIR" >>"$LOG_FILE" 2>&1 &
  sleep 3

  if pgrep -f "$MIHOMO_BIN" >/dev/null 2>&1; then
    log "[INFO] mihomo started successfully (pid: $(pgrep -f "$MIHOMO_BIN" | tr '\n' ' '))"
  else
    log "[ERROR] Failed to start mihomo"
    return 1
  fi

  sleep 5

  if probe_once; then
    log "[OK] Probe success after mihomo restart"
    log "[RECOVERED] 当前恢复到线路: [mihomo重启后默认线路]"
    return 0
  else
    log "[WARN] Probe still failed after mihomo restart"
    return 1
  fi
}

log "=== mihomo-guard started (PROXY=$PROXY_ADDR, URL=$PROBE_URL, INTERVAL=${SLEEP_INTERVAL}s, MAX_FAIL=$MAX_FAIL_COUNT) ==="
log "=== controller=$CONTROLLER_URL provider=$SUB_PROVIDER manual_group=$MANUAL_GROUP ==="

while true; do
  if probe_once; then
    if [ "$FAIL_COUNT" -gt 0 ]; then
      log "[OK] Probe success after $FAIL_COUNT failure(s)"
    fi
    FAIL_COUNT=0
  else
    FAIL_COUNT=$((FAIL_COUNT + 1))
    log "[WARN] Probe failed ($FAIL_COUNT/$MAX_FAIL_COUNT)"

    if [ "$FAIL_COUNT" -ge "$MAX_FAIL_COUNT" ]; then
      log "[WARN] Consecutive probe failures reached $FAIL_COUNT, trying refresh + route switch"

      if try_switch_routes; then
        FAIL_COUNT=0
      else
        log "[WARN] Refresh + route switch failed, falling back to mihomo restart"
        restart_mihomo || log "[ERROR] Restart fallback did not recover probe"
        FAIL_COUNT=0
      fi
    fi
  fi

  sleep "$SLEEP_INTERVAL"
done