package services

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

var LBTelegram *LBTelegramService

type LBTelegramService struct {
	gatewayURL   string
	Bot1Username string
	Bot2Username string
	client       *http.Client
}

func NewLBTelegramService() *LBTelegramService {
	url := os.Getenv("LBTELEGRAM_URL")
	if url == "" {
		url = "http://lbtelegram:8081"
	}
	svc := &LBTelegramService{
		gatewayURL:   url,
		Bot1Username: os.Getenv("LBTELEGRAM_BOT1_USERNAME"),
		Bot2Username: os.Getenv("LBTELEGRAM_BOT2_USERNAME"),
		client:       &http.Client{Timeout: 10 * time.Second},
	}
	LBTelegram = svc
	return svc
}

func (s *LBTelegramService) IsConfigured() bool {
	return os.Getenv("LBTELEGRAM_URL") != ""
}

// EnrollUser enrôle un utilisateur auprès de LBTelegram après liaison du compte.
// LBTelegram envoie lui-même le message de confirmation (chaîne Bot1→Bot2→Bot3).
func (s *LBTelegramService) EnrollUser(chatID int64, username, role string) error {
	payload := map[string]interface{}{
		"user_id":  chatID,
		"username": username,
		"role":     role,
		"chat_id":  chatID,
	}

	body, _ := json.Marshal(payload)
	resp, err := s.client.Post(s.gatewayURL+"/enrollment/begin", "application/json", bytes.NewReader(body))
	if err != nil {
		return fmt.Errorf("enrollment: %w", err)
	}
	defer resp.Body.Close()

	if resp.StatusCode != http.StatusOK {
		b, _ := io.ReadAll(resp.Body)
		return fmt.Errorf("enrollment HTTP %d: %s", resp.StatusCode, string(b))
	}

	log.Printf("✅ [LB] Enrollment OK pour %s (%s)", username, role)
	return nil
}

// SendNotification envoie un message via la gateway LBTelegram.
// Le bot est choisi automatiquement selon la stratégie configurée (failover/roundrobin/leastconn).
func (s *LBTelegramService) SendNotification(userID int64, message string) error {
	payload := map[string]interface{}{
		"user_id": userID,
		"message": message,
	}

	body, _ := json.Marshal(payload)
	resp, err := s.client.Post(s.gatewayURL+"/notify", "application/json", bytes.NewReader(body))
	if err != nil {
		return fmt.Errorf("notify: %w", err)
	}
	defer resp.Body.Close()

	if resp.StatusCode != http.StatusOK {
		b, _ := io.ReadAll(resp.Body)
		return fmt.Errorf("notify HTTP %d: %s", resp.StatusCode, string(b))
	}

	return nil
}