package okx

import (
	"encoding/csv"
	"encoding/json"
	"fmt"
	"strconv"
	"strings"
	"time"
)

// formatTimestamp 将毫秒时间戳字符串转换为可读格式
func formatTimestamp(ts string) (string, error) {
	millis, err := strconv.ParseInt(ts, 10, 64)
	if err != nil {
		return "", err
	}
	return time.UnixMilli(millis).Format("2006-01-02 15:04:05"), nil
}

// CandleList 封装Candle数组并提供序列化方法
type CandleList struct {
	Candles []*Candle
}

func MakeCandleList(instId string, period string, startTime time.Time, endTime time.Time, blockSize int) (*CandleList, error) {
	service := NewOkxPublicDataService()
	var allCandles []*Candle
	currentTime := endTime

	for currentTime.After(startTime) || currentTime.Equal(startTime) {
		req := CandlesRequest{
			InstID: instId,
			Bar:    period,
			After:  strconv.FormatInt(currentTime.UnixMilli(), 10),
			Limit:  strconv.Itoa(blockSize),
		}
		candles, err := service.GetCandles(req)
		if err != nil {
			return nil, err
		}
		if len(candles) == 0 {
			break
		}
		allCandles = append(allCandles, candles...)
		// 更新currentTime为最后一条数据的时间戳
		lastCandleTime, _ := strconv.ParseInt(candles[len(candles)-1].Timestamp, 10, 64)
		newCurrentTime := time.UnixMilli(lastCandleTime).Add(time.Millisecond)
		currentTime = newCurrentTime
	}
	fmt.Println("lens of allCandles: ", len(allCandles))
	cl := &CandleList{Candles: allCandles}
	return cl, nil
}

// ToJson 将Candle数组序列化为JSON字符串
func (cl *CandleList) ToJson() (string, error) {
	// 创建临时结构体用于格式化时间戳
	type FormattedCandle struct {
		Timestamp string `json:"timestamp"`
		Open      string `json:"open"`
		High      string `json:"high"`
		Low       string `json:"low"`
		Close     string `json:"close"`
		Volume    string `json:"volume"`
		VolumeCcy string `json:"volumeCcy"`
	}

	var formattedCandles []FormattedCandle
	for _, candle := range cl.Candles {
		formattedTs, err := formatTimestamp(candle.Timestamp)
		if err != nil {
			return "", err
		}
		formattedCandles = append(formattedCandles, FormattedCandle{
			Timestamp: formattedTs,
			Open:      candle.Open,
			High:      candle.High,
			Low:       candle.Low,
			Close:     candle.Close,
			Volume:    candle.Volume,
			VolumeCcy: candle.VolumeCcy,
		})
	}

	jsonData, err := json.Marshal(formattedCandles)
	if err != nil {
		return "", err
	}
	return string(jsonData), nil
}

// ToCsv 将Candle数组序列化为CSV字符串
func (cl *CandleList) ToCsv() (string, error) {
	var sb strings.Builder
	writer := csv.NewWriter(&sb)

	// 写入CSV头
	header := []string{"Timestamp", "Open", "High", "Low", "Close", "Volume", "VolumeCcy"}
	if err := writer.Write(header); err != nil {
		return "", err
	}

	// 调试信息
	fmt.Printf("Number of candles: %d\n", len(cl.Candles))

	for _, candle := range cl.Candles {
		formattedTs, err := formatTimestamp(candle.Timestamp)
		if err != nil {
			return "", err
		}
		record := []string{
			formattedTs,
			candle.Open,
			candle.High,
			candle.Low,
			candle.Close,
			candle.Volume,
			candle.VolumeCcy,
		}
		if err := writer.Write(record); err != nil {
			return "", err
		}
	}

	writer.Flush()
	if err := writer.Error(); err != nil {
		return "", err
	}

	return sb.String(), nil
}