// Package market adapts external market responses without floating point prices.
package market

import (
	"context"
	"encoding/json"
	"errors"
	"fmt"
	"git.sundynix.cn/Blizzard/Veyra/internal/model"
	"io"
	"net/http"
	"net/url"
	"sort"
	"strconv"
	"strings"
	"time"
)

type Client struct{ http *http.Client }

func New() *Client {
	return &Client{http: &http.Client{Timeout: 30 * time.Second, CheckRedirect: func(req *http.Request, via []*http.Request) error { return http.ErrUseLastResponse }}}
}
func (c *Client) get(ctx context.Context, base, path string, params url.Values, target any, timeout ...int) error {
	seconds := 4
	if len(timeout) > 0 && timeout[0] >= 1 && timeout[0] <= 30 {
		seconds = timeout[0]
	}
	ctx, cancel := context.WithTimeout(ctx, time.Duration(seconds)*time.Second)
	defer cancel()
	u, e := url.Parse(base)
	if e != nil || u.Scheme != "https" || u.Host == "" || u.User != nil || u.RawQuery != "" || u.Fragment != "" {
		return errors.New("invalid market endpoint")
	}
	u.Path = strings.TrimRight(u.Path, "/") + path
	u.RawQuery = params.Encode()
	req, e := http.NewRequestWithContext(ctx, http.MethodGet, u.String(), nil)
	if e != nil {
		return errors.New("invalid market request")
	}
	req.Header.Set("User-Agent", "Mozilla/5.0")
	referer := "https://finance.sina.com.cn/"
	if strings.HasSuffix(u.Hostname(), "eastmoney.com") {
		referer = "https://quote.eastmoney.com/"
	}
	req.Header.Set("Referer", referer)
	response, e := c.http.Do(req)
	if e != nil {
		return errors.New("market provider unavailable")
	}
	defer response.Body.Close()
	if response.StatusCode != 200 {
		return errors.New("market provider rejected request")
	}
	data, e := io.ReadAll(io.LimitReader(response.Body, (4<<20)+1))
	if e != nil || len(data) > 4<<20 {
		return errors.New("invalid market response size")
	}
	if json.Unmarshal(data, target) != nil {
		return errors.New("invalid market response")
	}
	return nil
}
func (c *Client) Snapshot(ctx context.Context, config model.ProviderConfig) ([]model.Instrument, error) {
	if config.MarketAdapter == "sina_public" {
		return c.sinaSnapshot(ctx, config)
	}
	list := make([]model.Instrument, 0)
	seen := map[string]bool{}
	for page := 1; page <= 120; page++ {
		var response struct {
			RC   int `json:"rc"`
			Data *struct {
				Total int `json:"total"`
				Diff  map[string]struct {
					Symbol   string          `json:"f12"`
					Market   int             `json:"f13"`
					Name     string          `json:"f14"`
					Price    json.RawMessage `json:"f2"`
					Observed int64           `json:"f124"`
					Decimals int             `json:"f152"`
				} `json:"diff"`
			} `json:"data"`
		}
		p := url.Values{"pn": {strconv.Itoa(page)}, "pz": {"100"}, "fs": {"m:0+t:6,m:0+t:80,m:1+t:2,m:1+t:23"}, "fields": {"f12,f13,f14,f2,f124,f152"}, "fid": {"f12"}, "po": {"0"}}
		if e := c.get(ctx, config.BaseURL, "/api/qt/clist/get", p, &response, config.TimeoutSeconds); e != nil {
			return nil, e
		}
		if response.RC != 0 || response.Data == nil || response.Data.Total < 1 || response.Data.Total > 12000 || len(response.Data.Diff) == 0 {
			return nil, errors.New("invalid market universe")
		}
		for _, row := range response.Data.Diff {
			if len(row.Symbol) != 6 || row.Name == "" || (row.Market != 0 && row.Market != 1) || row.Decimals != 2 {
				return nil, errors.New("unsupported market precision")
			}
			price, e := strconv.ParseInt(string(row.Price), 10, 64)
			if e != nil || price < 0 || price > 100000000 {
				continue
			}
			when := time.Unix(row.Observed, 0).UTC()
			if row.Observed <= 0 || when.After(time.Now().Add(time.Minute)) {
				continue
			}
			exchange := "SZSE"
			if row.Market == 1 {
				exchange = "SSE"
			}
			key := exchange + row.Symbol
			if seen[key] {
				return nil, errors.New("duplicate market page")
			}
			seen[key] = true
			list = append(list, model.Instrument{Symbol: row.Symbol, Exchange: exchange, Name: row.Name, PriceCents: price, Price: model.FormatMoney(price), ObservedAt: when, SourceID: config.ID, SourceVersion: config.Version})
		}
		if page*100 >= response.Data.Total {
			sort.Slice(list, func(i, j int) bool { return list[i].Symbol < list[j].Symbol })
			return list, nil
		}
		select {
		case <-ctx.Done():
			return nil, ctx.Err()
		case <-time.After(150 * time.Millisecond):
		}
	}
	return nil, errors.New("market pagination limit exceeded")
}
func (c *Client) History(ctx context.Context, config model.ProviderConfig, symbol, exchange, start, end string) (model.MarketHistory, error) {
	if config.MarketAdapter == "sina_public" {
		return c.sinaHistory(ctx, config, symbol, exchange, start, end)
	}
	var response struct {
		RC   int `json:"rc"`
		Data *struct {
			Code, Name string
			Klines     []string `json:"klines"`
		} `json:"data"`
	}
	secid := "0." + symbol
	if exchange == "SSE" {
		secid = "1." + symbol
	}
	params := url.Values{"secid": {secid}, "klt": {"101"}, "fqt": {"0"}, "beg": {strings.ReplaceAll(start, "-", "")}, "end": {strings.ReplaceAll(end, "-", "")}, "fields1": {"f1,f2,f3,f4,f5,f6"}, "fields2": {"f51,f52,f53,f54,f55,f56,f57"}}
	result := model.MarketHistory{Symbol: symbol, Exchange: exchange, Source: "eastmoney_public", SourceVersion: config.Version, Adjustment: "unadjusted", ReceivedAt: time.Now().UTC(), Bars: make([]model.HistoricalBar, 0)}
	if e := c.get(ctx, config.HistoryBaseURL, "/api/qt/stock/kline/get", params, &response, config.TimeoutSeconds); e != nil {
		return result, e
	}
	if response.RC != 0 || response.Data == nil || response.Data.Code != symbol || len(response.Data.Klines) > 1000 {
		return result, errors.New("invalid market history")
	}
	result.Name = response.Data.Name
	previous := ""
	for _, line := range response.Data.Klines {
		parts := strings.Split(line, ",")
		if len(parts) < 5 {
			return result, errors.New("invalid historical bar")
		}
		date, e := time.Parse("2006-01-02", parts[0])
		if e != nil || parts[0] <= previous || parts[0] < start || parts[0] > end || date.After(time.Now()) {
			return result, errors.New("invalid historical date")
		}
		previous = parts[0]
		o, e1 := model.ParseMoney(parts[1])
		close, e2 := model.ParseMoney(parts[2])
		high, e3 := model.ParseMoney(parts[3])
		low, e4 := model.ParseMoney(parts[4])
		if e1 != nil || e2 != nil || e3 != nil || e4 != nil || low <= 0 || high > 100000000 || low > o || low > close || high < o || high < close {
			return result, fmt.Errorf("invalid historical OHLC")
		}
		result.Bars = append(result.Bars, model.HistoricalBar{Date: parts[0], Open: model.FormatMoney(o), High: model.FormatMoney(high), Low: model.FormatMoney(low), Close: model.FormatMoney(close)})
	}
	return result, nil
}