#!/bin/bash
set -euo pipefail

echo "[INFO] Starting proxy under supervisor..."

TEMPLATE="/etc/nginx/nginx.conf.template"
TARGET="/etc/nginx/nginx.conf"
DNS_CONF_PRIVATE="/private/argus/etc/dns.conf"
DNS_CONF_SYSTEM="/etc/resolv.conf"
DNS_DIR="/private/argus/etc"
DNS_SCRIPT="${DNS_DIR}/update-dns.sh"
RUNTIME_UID="${ARGUS_BUILD_UID:-2133}"
RUNTIME_GID="${ARGUS_BUILD_GID:-2015}"

mkdir -p "$DNS_DIR"
chown -R "$RUNTIME_UID:$RUNTIME_GID" "$DNS_DIR" 2>/dev/null || true

if [[ -x "$DNS_SCRIPT" ]]; then
  echo "[INFO] Running update-dns.sh before master starts"
  # 若脚本存在则执行，保证容器使用 bind 作为 DNS
  "$DNS_SCRIPT" || echo "[WARN] update-dns.sh execution failed"
else
  echo "[WARN] DNS update script not found or not executable: $DNS_SCRIPT"
fi

# ========== 读取 DNS ==========
RESOLVERS=""
# 优先等待 /private/argus/etc/dns.conf 生成并读取其中的 IP
for i in $(seq 1 10); do
  if [ -f "$DNS_CONF_PRIVATE" ]; then
    RESOLVERS=$(awk '/^[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+$/{print $1}' "$DNS_CONF_PRIVATE" | tr '\n' ' ')
  fi
  [ -n "$RESOLVERS" ] && break
  sleep 1
done

# 若仍为空则回退到系统 resolv.conf
if [ -z "$RESOLVERS" ]; then
  echo "未在 $DNS_CONF_PRIVATE 中找到有效 DNS，使用系统 /etc/resolv.conf"
  RESOLVERS=$(awk '/^nameserver/ {print $2}' "$DNS_CONF_SYSTEM" | tr '\n' ' ')
fi

# 最后兜底：若仍为空，使用公共 DNS
if [ -z "$RESOLVERS" ]; then
  echo "警告: 未找到任何 DNS，使用默认 8.8.8.8"
  RESOLVERS="8.8.8.8"
fi

echo "检测到 DNS 服务器列表: $RESOLVERS"

# ========== 生成 nginx.conf ==========
if [ -f "$TEMPLATE" ]; then
  echo "从模板生成 nginx.conf ..."
  # 合并 Docker 内置 DNS 以保障解析 Compose 服务名
  # 将 127.0.0.11 放在末尾，优先使用 /private/argus/etc/dns.conf 指向的 bind
  if ! echo " $RESOLVERS " | grep -q " 127.0.0.11 "; then
    RESOLVERS="${RESOLVERS} 127.0.0.11"
  fi
  sed "s|__RESOLVERS__|$RESOLVERS|" "$TEMPLATE" > "$TARGET"
else
  echo "错误: 找不到 nginx.conf.template ($TEMPLATE)"
  exit 1
fi

# 打印生成结果供排查
grep resolver "$TARGET" || true

# ========== 等待上游域名准备（避免启动即解析失败） ==========
UPSTREAM_DOMAINS=(
  web.argus.com
  grafana.metric.argus.com
  prom.metric.argus.com
  kibana.log.argus.com
  alertmanager.alert.argus.com
  master.argus.com
)
WAIT_MAX=15
WAITED=0
MISSING=()
while :; do
  MISSING=()
  for d in "${UPSTREAM_DOMAINS[@]}"; do
    if [ ! -s "/private/argus/etc/${d}" ]; then
      MISSING+=("$d")
    fi
  done
  if [ ${#MISSING[@]} -eq 0 ] || [ "$WAITED" -ge "$WAIT_MAX" ]; then
    break
  fi
  echo "[INFO] 等待上游域名记录生成(${WAITED}/${WAIT_MAX}) 缺失: ${MISSING[*]}"
  sleep 1
  WAITED=$((WAITED+1))
done

echo "[INFO] Launching nginx..."

# 启动 nginx 前台模式
exec /usr/sbin/nginx -g "daemon off;"