package service

import (
	"encoding/json"
	"fmt"
	"log"

	"accounting-app/internal/config"

	"github.com/aliyun/alibaba-cloud-sdk-go/services/dysmsapi"
)

// SmsService handles SMS notifications
type SmsService struct {
	client       *dysmsapi.Client
	signName     string
	templateCode string
	enabled      bool
}

// NewSmsService creates a new SmsService instance
func NewSmsService(cfg *config.Config) *SmsService {
	if cfg.AliyunAccessKeyID == "" || cfg.AliyunAccessKeySecret == "" {
		log.Println("Aliyun SMS configuration missing, SMS service disabled")
		return &SmsService{enabled: false}
	}

	client, err := dysmsapi.NewClientWithAccessKey("cn-hangzhou", cfg.AliyunAccessKeyID, cfg.AliyunAccessKeySecret)
	if err != nil {
		log.Printf("Failed to initialize Aliyun SMS client: %v", err)
		return &SmsService{enabled: false}
	}

	return &SmsService{
		client:       client,
		signName:     cfg.AliyunSignName,
		templateCode: cfg.AliyunTemplateCode,
		enabled:      true,
	}
}

// SendAllocationNotification sends an SMS notification for auto allocation
func (s *SmsService) SendAllocationNotification(phoneNumber string, totalAmount float64, ruleName string) error {
	if !s.enabled || phoneNumber == "" {
		return nil
	}

	request := dysmsapi.CreateSendSmsRequest()
	request.Scheme = "https"
	request.PhoneNumbers = phoneNumber
	request.SignName = s.signName
	request.TemplateCode = s.templateCode

	// Template params: {"amount": "1000", "rule": "Salary Allocation"}
	// You might need to adjust parameters based on your actual Aliyun template
	params := map[string]string{
		"amount": fmt.Sprintf("%.2f", totalAmount),
		"rule":   ruleName,
	}
	paramBytes, _ := json.Marshal(params)
	request.TemplateParam = string(paramBytes)

	response, err := s.client.SendSms(request)
	if err != nil {
		return fmt.Errorf("failed to send SMS: %w", err)
	}

	if response.Code != "OK" {
		return fmt.Errorf("aliyun SMS error: %s - %s", response.Code, response.Message)
	}

	log.Printf("SMS sent successfully to %s", phoneNumber)
	return nil
}