package geo

import (
	"bufio"
	"encoding/json"
	"fmt"
	"io"
	"net/http"
	"net/textproto"
	"proxy-server/client/env"
	"strings"
)

var (
	Ip   string
	Prov string
	City string
	Isp  string
)

func Query() (err error) {

	switch env.Mode {
	case "dev":
		err = dev()
	default:
		err = ipapi()
	}
	return err
}

func dev() (err error) {
	Prov = "河南省"
	City = "郑州市"
	Isp = "电信"
	return nil
}

func cip() (err error) {
	const endpoint = "http://cip.cc"

	req, err := http.NewRequest("GET", endpoint, nil)
	if err != nil {
		return fmt.Errorf("创建请求失败: %w", err)
	}
	req.Header.Set("User-Agent", "curl/8.9.1")
	req.Header.Set("Accept", "*/*")

	resp, err := http.DefaultClient.Do(req)
	if err != nil {
		return fmt.Errorf("执行请求失败: %w", err)
	}
	defer func(Body io.ReadCloser) {
		_ = Body.Close()
	}(resp.Body)
	if resp.StatusCode != http.StatusOK {
		return fmt.Errorf("状态码: %s", resp.Status)
	}

	reader := textproto.NewReader(bufio.NewReader(resp.Body))
	ipLine, err := reader.ReadLine()
	if err != nil {
		return fmt.Errorf("读取响应失败: %w", err)
	}
	Ip = strings.TrimSpace(strings.Split(ipLine, ":")[1])

	addrLine, err := reader.ReadLine()
	if err != nil {
		return fmt.Errorf("读取响应失败: %w", err)
	}
	addr := strings.Split(strings.Split(addrLine, ":")[1], " ")
	Prov = strings.TrimSpace(addr[1])
	City = strings.TrimSpace(addr[2])

	ispLine, err := reader.ReadLine()
	if err != nil {
		return fmt.Errorf("读取响应失败: %w", err)
	}
	Isp = strings.TrimSpace(strings.Split(ispLine, ":")[1])

	return nil
}

func ipapi() (err error) {
	const endpoint = "http://ip-api.com/json/?fields=regionName,city,as,query&lang=zh-CN"

	resp, err := http.Get(endpoint)
	if err != nil {
		return fmt.Errorf("执行请求失败: %w", err)
	}
	defer func(Body io.ReadCloser) {
		_ = Body.Close()
	}(resp.Body)

	if resp.StatusCode != http.StatusOK {
		return fmt.Errorf("状态码: %s", resp.Status)
	}

	var data struct {
		RegionName string `json:"regionName"`
		City       string `json:"city"`
		As         string `json:"as"`
		Query      string `json:"query"`
	}
	err = json.NewDecoder(resp.Body).Decode(&data)
	if err != nil {
		return fmt.Errorf("解析响应失败: %w", err)
	}

	Ip = data.Query
	Prov = data.RegionName
	City = data.City

	var telecom = []string{"AS4134", "AS4812", "AS134419", "AS140292"}
	var unicom = []string{"AS4837", "AS17621", "AS17816"}
	var mobile = []string{
		"AS9808", "AS24444", "AS24445", "AS24547", "AS38019",
		"AS56040", "AS56041", "AS56042", "AS56044", "AS56046", "AS56047",
		"AS132525", "AS134810",
	}
	var foreign = []string{
		"AS9299",
	}

	for _, telecomAsn := range telecom {
		if strings.HasPrefix(data.As, telecomAsn) {
			Isp = "电信"
			break
		}
	}
	if Isp == "" {
		for _, unicomAsn := range unicom {
			if strings.HasPrefix(data.As, unicomAsn) {
				Isp = "联通"
				break
			}
		}
	}
	if Isp == "" {
		for _, mobileAsn := range mobile {
			if strings.HasPrefix(data.As, mobileAsn) {
				Isp = "移动"
				break
			}
		}
	}
	if Isp == "" {
		for _, foreignAsn := range foreign {
			if strings.HasPrefix(data.As, foreignAsn) {
				Isp = "国外"
				break
			}
		}
	}

	return nil
}