package middleware

import (
	"context"
	"net/http"
	"strings"
)

func ReqHeaderCtxMiddleware(next http.HandlerFunc) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		brand := r.Header.Get("X-Brand")
		platform := r.Header.Get("X-Platform")
		promoteValue := r.Header.Get("X-Promote-Key")
		clientIP := getClientIP(r)
		ctx := r.Context()
		if brand != "" {
			ctx = context.WithValue(ctx, "brand", brand)
		}
		if platform != "" {
			ctx = context.WithValue(ctx, "platform", platform)
		}
		if promoteValue != "" {
			ctx = context.WithValue(ctx, "promoteKey", promoteValue)
		}
		if clientIP != "" {
			ctx = context.WithValue(ctx, "client_ip", clientIP)
		}
		r = r.WithContext(ctx)
		next(w, r)
	}
}

// getClientIP 获取客户端真实IP
func getClientIP(r *http.Request) string {
	// 检查代理头
	if ip := r.Header.Get("X-Forwarded-For"); ip != "" {
		// 取第一个IP（最原始的客户端IP）
		if commaIndex := strings.Index(ip, ","); commaIndex != -1 {
			return strings.TrimSpace(ip[:commaIndex])
		}
		return strings.TrimSpace(ip)
	}

	if ip := r.Header.Get("X-Real-IP"); ip != "" {
		return strings.TrimSpace(ip)
	}

	if ip := r.Header.Get("X-Client-IP"); ip != "" {
		return strings.TrimSpace(ip)
	}

	// 直接连接
	if r.RemoteAddr != "" {
		if colonIndex := strings.LastIndex(r.RemoteAddr, ":"); colonIndex != -1 {
			return r.RemoteAddr[:colonIndex]
		}
		return r.RemoteAddr
	}

	return "unknown"
}