package main

import (
	"bytes"
	"encoding/json"
	"fmt"
	"log"
	"net/http"
	"time"
)

type Notifier struct {
	BotToken string
	ChatID   string
	client   *http.Client
}

func NewNotifier(botToken, chatID string) *Notifier {
	return &Notifier{
		BotToken: botToken,
		ChatID:   chatID,
		client:   &http.Client{Timeout: 10 * time.Second},
	}
}

// Send sends a text message to Telegram.
func (n *Notifier) Send(text string) error {
	if n.BotToken == "" || n.ChatID == "" {
		log.Printf("[Notifier] Skipped (not configured): %.80s", text)
		return nil
	}

	url := fmt.Sprintf("https://api.telegram.org/bot%s/sendMessage", n.BotToken)
	payload := map[string]string{
		"chat_id":    n.ChatID,
		"text":       text,
		"parse_mode": "HTML",
	}

	body, _ := json.Marshal(payload)
	resp, err := n.client.Post(url, "application/json", bytes.NewReader(body))
	if err != nil {
		return fmt.Errorf("telegram send error: %w", err)
	}
	defer resp.Body.Close()

	if resp.StatusCode != 200 {
		return fmt.Errorf("telegram status %d", resp.StatusCode)
	}

	log.Printf("[Notifier] Sent (%d bytes)", len(text))
	return nil
}

// SendAlert sends an arbitrage alert notification.
func (n *Notifier) SendAlert(opp *ArbOpportunity) {
	msg := fmt.Sprintf(
		"<b>[套利信号]</b>  %s/USDT\n"+
			"  %s  %.4f  ->  %s  %.4f\n"+
			"  净利: <b>%+.4f%%</b>\n",
		opp.Coin,
		opp.BuyEx, opp.BuyPrice,
		opp.SellEx, opp.SellPrice,
		opp.NetProfit,
	)
	if opp.NetProfit > 0.10 {
		msg += "  高价值机会!\n"
	}

	if err := n.Send(msg); err != nil {
		log.Printf("[Notifier] Alert error: %v", err)
	}
}

// SendTradeSummary sends a summary of open positions at each hour.
func (n *Notifier) SendTradeSummary(positions []ArbPosition, timeStr string) {
	if n.BotToken == "" || n.ChatID == "" {
		return
	}
	lines := fmt.Sprintf("=== 持仓汇总 ===  %s\n", timeStr)
	if len(positions) == 0 {
		lines += "  当前无持仓\n"
	} else {
		for i, p := range positions {
			dur := time.Since(p.StartedAt).Round(time.Second).String()
			lines += fmt.Sprintf("%d. %s %s  %.0f  %s\n", i+1, p.Coin, p.Direction, p.AmountUSD, dur)
		}
	}
	if err := n.Send(lines); err != nil {
		log.Printf("[Notifier] Hourly error: %v", err)
	}
}