package cryptostrategy

import (
	"bytes"
	"encoding/json"
	"fmt"
	"strings"
	"time"
)

type envelope struct {
	EventType     string          `json:"eventType"`
	CorrelationID string          `json:"correlationId"`
	Symbol        string          `json:"symbol"`
	Direction     string          `json:"direction"`
	Payload       json.RawMessage `json:"payload"`
	EventTime     int64           `json:"eventTime"`
}

type payload struct {
	StrategyCode    string  `json:"strategyCode"`
	Period          string  `json:"period"`
	Currency        string  `json:"currency"`
	IsSale          bool    `json:"isSale"`
	IsClose         bool    `json:"isClose"`
	IsGain          bool    `json:"isGain"`
	GainTarget      float64 `json:"gainTarget"`
	Price           float64 `json:"price"`
	LossPrice       float64 `json:"lossPrice"`
	GainPrices      string  `json:"gainPrices"`
	Remark          string  `json:"remark"`
	TotalGainTarget float64 `json:"totalGainTarget"`
	Leverage        int     `json:"leverage"`
}

type remark struct {
	OrderID string `json:"orderId"`
	Revenue string `json:"revenue"`
}

type Converter struct{}

func NewConverter() *Converter { return &Converter{} }

func (c *Converter) Convert(body []byte) (string, map[string]interface{}, error) {
	return Convert(body)
}

func Convert(body []byte) (string, map[string]interface{}, error) {
	var env envelope
	if err := json.Unmarshal(body, &env); err != nil {
		return "", nil, fmt.Errorf("invalid envelope: %w", err)
	}
	p, err := parsePayload(body, env.Payload)
	if err != nil {
		return "", nil, err
	}

	action := inferAction(p)
	event := "trade." + strings.ToLower(action)
	text := format(env, p, action)

	data := map[string]interface{}{
		"eventType":       env.EventType,
		"correlationId":   env.CorrelationID,
		"symbol":          firstNonEmpty(env.Symbol, p.Currency),
		"direction":       env.Direction,
		"side":            strings.ToUpper(env.Direction),
		"action":          action,
		"eventTime":       env.EventTime,
		"strategyCode":    p.StrategyCode,
		"period":          p.Period,
		"currency":        p.Currency,
		"isSale":          p.IsSale,
		"isClose":         p.IsClose,
		"isGain":          p.IsGain,
		"gainTarget":      p.GainTarget,
		"price":           p.Price,
		"lossPrice":       p.LossPrice,
		"gainPrices":      p.GainPrices,
		"leverage":        p.Leverage,
		"formatted":       text,
		"stopLossPrice":   p.LossPrice,
		"takeProfitPrice": takeProfitPrice(p),
		"totalAvgPx":      "",
	}
	if p.TotalGainTarget != 0 {
		data["totalGainTarget"] = p.TotalGainTarget
	}
	if r := parseRemark(p.Remark); r.OrderID != "" || r.Revenue != "" {
		if r.OrderID != "" {
			data["orderId"] = r.OrderID
		}
		if r.Revenue != "" {
			data["revenue"] = r.Revenue
		}
	}
	return event, data, nil
}

func parsePayload(body []byte, raw json.RawMessage) (payload, error) {
	var p payload
	raw = bytes.TrimSpace(raw)
	if len(raw) == 0 || string(raw) == "null" {
		if err := json.Unmarshal(body, &p); err != nil {
			return p, fmt.Errorf("invalid payload: %w", err)
		}
		return p, nil
	}
	var asString string
	if err := json.Unmarshal(raw, &asString); err == nil {
		asString = strings.TrimSpace(asString)
		if asString == "" {
			if err := json.Unmarshal(body, &p); err != nil {
				return p, fmt.Errorf("invalid payload: %w", err)
			}
			return p, nil
		}
		raw = []byte(asString)
	}
	if err := json.Unmarshal(raw, &p); err != nil {
		return p, fmt.Errorf("invalid payload: %w", err)
	}
	return p, nil
}

func inferAction(p payload) string {
	switch {
	case p.IsClose:
		return "CLOSE"
	case p.IsGain:
		return "GAIN"
	case p.IsSale:
		return "SELL"
	default:
		return "OPEN"
	}
}

func takeProfitPrice(p payload) interface{} {
	if gp := strings.TrimSpace(p.GainPrices); gp != "" {
		return gp
	}
	if p.IsGain && p.Price > 0 {
		return p.Price
	}
	return ""
}

func parseRemark(raw string) remark {
	raw = strings.TrimSpace(raw)
	if raw == "" {
		return remark{}
	}
	var r remark
	if err := json.Unmarshal([]byte(raw), &r); err != nil {
		return remark{}
	}
	return r
}

func format(env envelope, p payload, action string) string {
	symbol := firstNonEmpty(env.Symbol, p.Currency)
	lines := []string{actionTitle(env.Direction, action)}
	if symbol != "" {
		lines = append(lines, fmt.Sprintf("交易品种: %s", symbol))
	}
	if p.Period != "" {
		lines = append(lines, fmt.Sprintf("周期: %s", p.Period))
	}
	switch action {
	case "CLOSE":
		if p.Price > 0 {
			lines = append(lines, fmt.Sprintf("平仓价格: %.2f", p.Price))
		}
	case "GAIN":
		if p.Price > 0 {
			lines = append(lines, fmt.Sprintf("止盈价格: %.2f", p.Price))
		}
	case "SELL":
		if p.Price > 0 {
			lines = append(lines, fmt.Sprintf("卖出价格: %.2f", p.Price))
		}
	default:
		if p.Price > 0 {
			lines = append(lines, fmt.Sprintf("开仓价格: %.2f", p.Price))
		}
	}
	if p.LossPrice > 0 {
		lines = append(lines, fmt.Sprintf("止损价格: %.2f", p.LossPrice))
	}
	if gp := strings.TrimSpace(p.GainPrices); gp != "" && action != "GAIN" {
		lines = append(lines, fmt.Sprintf("止盈价格: %s", strings.Join(splitPrices(gp), ", ")))
	}
	if p.GainTarget != 0 {
		lines = append(lines, fmt.Sprintf("止盈目标: %g", p.GainTarget))
	}
	if p.Leverage > 0 {
		lines = append(lines, fmt.Sprintf("杠杆: %dx", p.Leverage))
	}
	if p.StrategyCode != "" {
		lines = append(lines, fmt.Sprintf("策略: %s", p.StrategyCode))
	}
	if env.EventTime > 0 {
		t := time.UnixMilli(env.EventTime).In(time.Local)
		lines = append(lines, fmt.Sprintf("Time: %s", t.Format("2006.01.02 15:04:05")))
	}
	return strings.Join(lines, "\n")
}

func actionTitle(direction, action string) string {
	var pos string
	switch strings.ToUpper(direction) {
	case "LONG":
		pos = "多单"
	case "SHORT":
		pos = "空单"
	default:
		pos = direction
	}
	var act string
	switch action {
	case "OPEN":
		act = "开仓"
	case "CLOSE":
		act = "平仓"
	case "GAIN":
		act = "止盈"
	case "SELL":
		act = "卖出"
	default:
		act = action
	}
	return pos + act
}

func splitPrices(s string) []string {
	parts := strings.Split(s, ",")
	out := make([]string, 0, len(parts))
	for _, p := range parts {
		p = strings.TrimSpace(p)
		if p != "" {
			out = append(out, p)
		}
	}
	return out
}

func firstNonEmpty(a, b string) string {
	if strings.TrimSpace(a) != "" {
		return a
	}
	return b
}