package valuta

import (
	"encoding/json"
	"fmt"
	"github.com/PuerkitoBio/goquery"
	"log"
	"math/big"
	"net/http"
	"os"
	"strconv"
	"strings"
	"sync"
	"time"
)

var url = "https://chl.cn/?jinri"
var cMux sync.Mutex
var cacheDataAll = make(map[string]CurrencyRate)

//更新定时器
var upsetTicker *time.Ticker

type CurrencyRate struct {
	Country string  //目标地域
	Rate    float64 //汇率
}

func init() {
	//设置每天更新三次 即每8小时更新一次
	upsetTicker = time.NewTicker(time.Hour * 8)
	go func() {
		for {
			select {
			case <-upsetTicker.C:
				upset()
			}
		}
	}()
	//启动时更新
	upset()
}
func upset() {
	client := &http.Client{}
	req, err := http.NewRequest("GET", url, nil)
	req.Header.Set("Connection", "keep-alive") //设置请求头模拟浏览器登录
	req.Header.Set("Cache-Control", "max-age=0")
	req.Header.Set("sec-ch-ua-mobile", "?0")
	req.Header.Set("Upgrade-Insecure-Requests", "1")
	req.Header.Set("User-Agent", "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/96.0.4664.110 Safari/537.36")
	req.Header.Set("Accept", "text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.9")
	req.Header.Set("Sec-Fetch-Site", "same-origin")
	req.Header.Set("Sec-Fetch-Mode", "navigate")
	req.Header.Set("Sec-Fetch-User", "?1")
	req.Header.Set("Sec-Fetch-Dest", "document")
	req.Header.Set("Accept-Language", "zh-CN,zh;q=0.9")
	resp, err := client.Do(req)
	if err != nil {
		log.Fatalf("请求汇率站点发生错误：%s\n", err.Error())
	}
	defer resp.Body.Close()
	if resp.StatusCode != 200 {
		log.Fatalf("站点返回信息 status：%d，error:%s\n", resp.StatusCode, err.Error())
	}
	doc, err := goquery.NewDocumentFromReader(resp.Body)
	if err != nil {
		log.Fatalf("读取站点信息发生错误：%s\n", err.Error())
	}
	cacheData := make(map[string]CurrencyRate)
	//独立计算的币种
	doc.Find(".hlb_lt > table > tbody > tr").Each(func(i int, s *goquery.Selection) {
		if i == 0 {
			return
		}
		Country := s.Find("td").First().Text()
		//  CurrencyCode 货币代码 使用时需要阶段处理 [2:]
		CurrencyCode, _ := s.Find("td > a").Attr("href")

		case1, _ := strconv.ParseFloat(s.Find("td").First().Next().Text(), 10)
		case2, _ := strconv.ParseFloat(s.Find("td").First().Next().Next().Text(), 10)
		var rate float64
		if case1 > 0 {
			rate = 100 / case1
		} else {
			rate = 100 / case2
		}
		if Country == "卢布" {
			Country = "俄罗斯卢布"
		}
		cacheData[strings.ToLower(CurrencyCode[2:])] = CurrencyRate{Country: Country, Rate: rate}
	})
	doc.Find(".hblb3").Each(func(i int, s *goquery.Selection) {
		t, _ := s.Html()
		//fmt.Printf("%d\t%+v\n", i, t)
		tl := strings.Split(t, "<br/>")
		for k := range tl {
			if strings.Index(tl[k], "</a>") > 0 {
				temp := strings.Split(tl[k], "</a>")
				if len(temp) < 2 {
					continue
				}
				//fmt.Printf("%s\n", temp[0])
				//  CurrencyCode 货币代码 使用时不需要阶段处理
				var CurrencyCode string
				tempCodeArr := strings.Split(temp[0], "?")
				if len(tempCodeArr) >= 2 {
					tCode := strings.Split(tempCodeArr[1], "\"")
					if len(tCode) >= 2 {
						CurrencyCode = tCode[0]
					}
				}
				index := strings.Index(temp[1], "）")
				if index == -1 {
					continue
				}
				d := strings.Trim(temp[1], " ")
				Country := d[3:index]
				rate, _ := strconv.ParseFloat(string(d[index+3:]), 10)
				if CurrencyCode[len(CurrencyCode)-1:] == "0" {
					CurrencyCode = CurrencyCode[:len(CurrencyCode)-1]
				}
				cacheData[strings.ToLower(CurrencyCode)] = CurrencyRate{Country: Country, Rate: rate}
			}
		}
	})
	cacheData["cny"] = CurrencyRate{"中国人民币", 1}
	cMux.Lock()
	defer cMux.Unlock()
	cacheDataAll = cacheData
	fmt.Println("共", len(cacheData), "种货币", "更新完成")
}

// ResetCache 主动刷新缓存
func ResetCache() {
	upset()
	//若城市地区被加载则更新缓存时，同步更新该数据
	if len(cacheCountryCurrency) > 0 {
		LoadCountryInfo("")
	}
}

// GetCurrencyExchangeRate 获取指定国家 货币与人民币的汇率
// 参考兑换比例  1元人命币，兑换该国家的货币 汇率
// code 该国家货币编码
func GetCurrencyExchangeRate(code string) CurrencyRate {
	code = strings.ToLower(code)
	return cacheDataAll[code]
}

// ExchangeCurrency 人民币转其他币种
// cny 人民币数额
// code 目标币种 编码
// 返回
// cur 目标币种数量
// country 目标币种名称
func ExchangeCurrency(cny float64, code string) (cur float64, country string) {
	c := GetCurrencyExchangeRate(code)
	country = c.Country + "|" + code
	cur = c.Rate * cny
	return
}

// ExchangeCurrencyTo 其他币种转人命币
// code 币种名称
// cur 币种数量
// 返回
// cny 人民币数量
// county 固定为CN之类表示中国的符号
func ExchangeCurrencyTo(code string, cur float64) (cny float64, country string) {
	c := GetCurrencyExchangeRate(code)
	country = "人民币|CNY"
	cny = cur / c.Rate
	return
}

// ExchangeCurrencyStrTo 其他币种转人命币
// code 币种名称
// cur 币种数量
// 返回
// cny 人民币数量
// county 固定为CN之类表示中国的符号
func ExchangeCurrencyStrTo(code, cur string, prec int) (cnyMoney string, country string) {
	c := GetCurrencyExchangeRate(code)
	country = "人民币|CNY"

	cnyRat := new(big.Rat).SetFloat64(c.Rate)
	curRat, _ := new(big.Rat).SetString(cur)
	quoRat := new(big.Rat).Quo(curRat, cnyRat)
	cnyMoney = quoRat.FloatString(prec)

	return
}

type CountryCurrency struct {
	ZhCountry      string  `json:"zh_country"`
	Code2          string  `json:"code2"`
	CurrencyCode   string  `json:"currency_code"`
	ZhCurrencyName string  `json:"zh_currency_name"`
	Rate           float64 `json:"rate"`
}

var mux sync.Mutex
var cacheCountryCurrency = make(map[string]CountryCurrency)

// LoadCountryInfo 加载国家信息
func LoadCountryInfo(path string) {
	if path == "" {
		path = "data/valuta/conuntryCurrency.json"
	}
	fc, err := os.Open(path)
	if err != nil {
		fmt.Printf("加载国家信息失败：%s\n", err.Error())
		return
	}
	defer fc.Close()
	tempCache := make(map[string]CountryCurrency)
	var cbuf []CountryCurrency
	temp := json.NewDecoder(fc)
	err = temp.Decode(&cbuf)
	if err != nil {
		log.Fatalf("读取国家信息出错：%s\n", err.Error())
	}
	for k := range cbuf {
		tmp := cbuf[k]
		tmp.Rate = cacheDataAll[strings.ToLower(cbuf[k].CurrencyCode)].Rate
		tempCache[strings.ToLower(cbuf[k].Code2)] = tmp
	}
	mux.Lock()
	defer mux.Unlock()
	cacheCountryCurrency = tempCache
}

// GetCountryExchangeRate 获取指定国家 货币与人民币的汇率
// 参考兑换比例  1元人命币，兑换该国家的货币 汇率
// code 该国家编码
func GetCountryExchangeRate(code string) CountryCurrency {
	code = strings.ToLower(code)
	return cacheCountryCurrency[code]
}

// ExchangeCountryValuta 人民办转目标地域货币
// cny 人民币数额
// code 目标地域编码 如MY 马来西亚
// 返回
// cur 目标币种数量 country 目标币种名称
func ExchangeCountryValuta(cny float64, code string) (cur float64, country string) {
	c := GetCountryExchangeRate(code)
	country = c.ZhCurrencyName + "|" + c.CurrencyCode
	cur = c.Rate * cny
	return
}

// ExchangeCountryValutaTo 目标地域货币转人民币
// cur 目标币种数量
// code 目标地域编码 如MY 马来西亚
// 返回
// cny 人民币数额 country 目标币种名称
func ExchangeCountryValutaTo(code string, cur float64) (cny float64, country string) {
	c := GetCountryExchangeRate(code)
	country = "人民币|CNY"
	cny = cur / c.Rate
	return
}