package okx

import (
	"context"
	"errors"
	"fmt"
	"net/http"
	"net/url"
	"sig-pub/pkg/types"
	"strings"
	"time"

	"github.com/go-resty/resty/v2"
	"golang.org/x/time/rate"
)

const (
	HttpBaseUrl        = "https://www.okx.com"
	KlineBefore0 int64 = 1672502400000 // k线开始数据 2023-01-01 00:00:00 GMT+8
)

type OkxFetcher struct {
	client              *resty.Client
	httpProxy           string
	historyKlineLimiter *rate.Limiter
}

func NewOkxFetcher(httpProxy string) (f *OkxFetcher) {
	client := resty.New()
	client.SetTimeout(30 * time.Second)
	client.SetTransport(&http.Transport{
		MaxIdleConns:        100,
		MaxConnsPerHost:     10,
		IdleConnTimeout:     90 * time.Second,
		TLSHandshakeTimeout: 10 * time.Second,
	})
	if httpProxy != "" {
		client.SetProxy(httpProxy)
	}

	f = &OkxFetcher{
		client:              client,
		httpProxy:           httpProxy,
		historyKlineLimiter: rate.NewLimiter(rate.Every(100*time.Millisecond), 20), // rate: 20次/2s
	}
	return
}

// FetchHistoryKlines 获取交易产品历史K线数据
// https://my.okx.com/docs-v5/zh/#order-book-trading-market-data-get-candlesticks-history
// 周期区间 after > before, (after, before)
func (f *OkxFetcher) FetchHistoryKlines(ctx context.Context, okxInstId string, interval types.Interval, after, before int64) (klines []*types.Kline, err error) {
	if okxInstId == "" {
		err = errors.New("instid is empty")
		return
	}
	if after <= 0 && before <= 0 {
		err = errors.New("time range zero")
		return
	}
	if err = f.historyKlineLimiter.Wait(ctx); err != nil {
		return
	}

	var params []string
	params = append(params, fmt.Sprintf("instId=%s", url.QueryEscape(okxInstId)))
	params = append(params, "limit=100") // 最大为100
	if v, ok := subscribeCandles[interval]; ok {
		params = append(params, "bar="+v)
	}
	if after > 0 {
		params = append(params, fmt.Sprintf("after=%d", after))
	}
	if before > 0 {
		params = append(params, fmt.Sprintf("before=%d", before))
	}
	url := fmt.Sprintf("%s/api/v5/market/history-candles?%s", HttpBaseUrl, strings.Join(params, "&"))

	resp, err := f.client.R().Get(url)
	if err != nil {
		return
	}

	status := resp.StatusCode()
	if status != 200 {
		err = fmt.Errorf("request history klines status error: %s, %s", url, resp.Status())
		return
	}

	fmt.Println(string(resp.Body()))
	return
}