package main

import (
	"database/sql"
	"encoding/json"
	"fmt"
	"log"
	"math"
	"strconv"
	"sync"
)

// KlineHandler handles Bybit kline streams for multiple intervals (e.g., 5, 15, 60).
type KlineHandler struct {
	cfg     Config
	storage *StreamStorage
	dbs     map[string]*sql.DB // interval -> kline_<interval>.db handle
	featDB  *sql.DB
	mu      sync.Mutex
}

func NewKlineHandler(cfg Config, sm *StorageManager) (*KlineHandler, error) {
	ss := sm.GetStreamStorage("klines")
	if ss == nil {
		return nil, fmt.Errorf("klines stream storage not found")
	}

	dbs := make(map[string]*sql.DB)
	for _, interval := range cfg.Streams.Klines.Intervals {
		dbName := fmt.Sprintf("kline_%s.db", interval)
		db, err := OpenDBWithAutoVacuum(ss.DBPath(dbName))
		if err != nil {
			for _, d := range dbs {
				d.Close()
			}
			return nil, fmt.Errorf("open kline_%s db: %w", interval, err)
		}
		dbs[interval] = db
	}

	featDB, err := OpenDBWithAutoVacuum(ss.DBPath("features.db"))
	if err != nil {
		for _, d := range dbs {
			d.Close()
		}
		return nil, fmt.Errorf("open kline features db: %w", err)
	}

	return &KlineHandler{
		cfg:     cfg,
		storage: ss,
		dbs:     dbs,
		featDB:  featDB,
	}, nil
}

func (kh *KlineHandler) Topics() []string {
	var topics []string
	for _, interval := range kh.cfg.Streams.Klines.Intervals {
		topics = append(topics, fmt.Sprintf("kline.%s.%s", interval, kh.cfg.Symbol))
	}
	return topics
}

func (kh *KlineHandler) HandleMessage(data []byte) {
	var msg BybitKlineMessage
	if err := json.Unmarshal(data, &msg); err != nil {
		return
	}

	if len(msg.Data) == 0 {
		return
	}

	kh.mu.Lock()
	defer kh.mu.Unlock()

	for _, raw := range msg.Data {
		open, _ := strconv.ParseFloat(raw.Open, 64)
		closeP, _ := strconv.ParseFloat(raw.Close, 64)
		high, _ := strconv.ParseFloat(raw.High, 64)
		low, _ := strconv.ParseFloat(raw.Low, 64)
		vol, _ := strconv.ParseFloat(raw.Volume, 64)
		turnover, _ := strconv.ParseFloat(raw.Turnover, 64)

		confirmInt := 0
		if raw.Confirm {
			confirmInt = 1
		}

		db, ok := kh.dbs[raw.Interval]
		if !ok {
			continue
		}

		// Insert or replace kline in hot DB
		_, err := db.Exec(`
			INSERT INTO klines (start_time, end_time, interval, open, high, low, close, volume, turnover, confirmed)
			VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?)
			ON CONFLICT(start_time) DO UPDATE SET
				end_time=excluded.end_time,
				open=excluded.open,
				high=excluded.high,
				low=excluded.low,
				close=excluded.close,
				volume=excluded.volume,
				turnover=excluded.turnover,
				confirmed=excluded.confirmed
		`, raw.Start, raw.End, raw.Interval, open, high, low, closeP, vol, turnover, confirmInt)
		if err != nil {
			log.Printf("[kline_handler] insert kline error: %v", err)
		}

		// Calculate features if confirmed or on updates
		if raw.Confirm {
			highLow := high - low
			bodyRatio := 0.0
			upperWick := 0.0
			lowerWick := 0.0

			if highLow > 0 {
				bodyRatio = math.Abs(closeP-open) / highLow
				maxBody := math.Max(open, closeP)
				minBody := math.Min(open, closeP)
				upperWick = (high - maxBody) / highLow
				lowerWick = (minBody - low) / highLow
			}

			logRet := 0.0
			if open > 0 {
				logRet = math.Log(closeP / open)
			}

			_, err = kh.featDB.Exec(`
				INSERT INTO kline_features (timestamp, interval, body_ratio, upper_wick, lower_wick, log_return, volume, turnover)
				VALUES (?, ?, ?, ?, ?, ?, ?, ?)
				ON CONFLICT(interval, timestamp) DO UPDATE SET
					body_ratio=excluded.body_ratio,
					upper_wick=excluded.upper_wick,
					lower_wick=excluded.lower_wick,
					log_return=excluded.log_return,
					volume=excluded.volume,
					turnover=excluded.turnover
			`, raw.Start, raw.Interval, bodyRatio, upperWick, lowerWick, logRet, vol, turnover)
			if err != nil {
				log.Printf("[kline_handler] insert kline features error: %v", err)
			}
		}
	}
}

func (kh *KlineHandler) Close() {
	kh.mu.Lock()
	defer kh.mu.Unlock()
	for _, db := range kh.dbs {
		db.Close()
	}
	if kh.featDB != nil {
		kh.featDB.Close()
	}
}