package server

import (
	"fmt"
	"io"
	"net/http"
	"net/http/httputil"
	"net/url"
	"strings"

	"git.magicany.cc/black1552/gf-common/log"
	"github.com/gogf/gf/v2/net/gclient"
	"github.com/gogf/gf/v2/net/ghttp"
	"github.com/gogf/gf/v2/os/gctx"
	"github.com/gogf/gf/v2/text/gstr"
)

// hasProtocol 检查字符串是否包含协议前缀
func hasProtocol(s string) bool {
	return strings.HasPrefix(s, "http://") ||
		strings.HasPrefix(s, "https://") ||
		strings.HasPrefix(s, "ws://") ||
		strings.HasPrefix(s, "wss://")
}

// BuildRequest 反向代理请求到指定主机
// 自动支持所有 HTTP 方法及 WebSocket 连接
func BuildRequest(r *ghttp.Request, host string) {
	if gstr.Contains(r.RequestURI, "/ws") {
		proxyWebSocket(r, host)
		return
	}
	client := gclient.New()
	// 构建目标URL而不是直接复制RequestURI
	targetURL := host + r.URL.Path
	if r.URL.RawQuery != "" {
		targetURL += "?" + r.URL.RawQuery
	}
	// 复制请求头
	for key, values := range r.Header {
		for _, value := range values {
			client.SetHeader(key, value)
		}
	}
	response, err := client.DoRequest(gctx.New(), r.Method, targetURL, r.GetBody())
	if err != nil {
		log.Error(gctx.New(), "request error:", err)
		panic(fmt.Sprintf("request error: %v", err))
	}
	defer response.Body.Close()
	// 读取响应体
	respBody, err := io.ReadAll(response.Body)
	if err != nil {
		log.Error(gctx.New(), "read response body error:", err)
		panic(fmt.Sprintf("read response body error: %v", err))
	}

	// 复制响应头
	for key, values := range response.Header {
		for _, value := range values {
			r.Response.Header().Add(key, value)
		}
	}
	// 设置响应状态码并写入响应体
	r.Response.Status = response.StatusCode
	r.Response.Write(respBody)
}

// proxyWebSocket 处理 WebSocket 连接的代理
func proxyWebSocket(r *ghttp.Request, targetHost string) {
	// 解析目标主机 URL
	targetURL, err := url.Parse(targetHost)
	if err != nil {
		log.Error(gctx.New(), "parse target host error:", err)
		r.Response.WriteStatus(http.StatusInternalServerError)
		r.Response.Write([]byte("Invalid target host"))
		return
	}

	// 创建反向代理
	proxy := httputil.NewSingleHostReverseProxy(targetURL)

	// 修改请求 URL，保留原始路径和查询参数
	r.URL.Scheme = targetURL.Scheme
	r.URL.Host = targetURL.Host
	log.Info(gctx.New(), r.GetBodyString())
	// 处理 WebSocket 连接
	proxy.ServeHTTP(r.Response.Writer, r.Request)
}