package sms

import (
	"context"
	"encoding/json"
	"fmt"
	"strings"

	openapi "github.com/alibabacloud-go/darabonba-openapi/v2/utils"
	dysms "github.com/alibabacloud-go/dysmsapi-20170525/v5/client"
	"github.com/alibabacloud-go/tea/dara"
	"go.uber.org/zap"
)

type AliyunConfig struct {
	AccessKeyID       string
	AccessKeySecret   string
	Endpoint          string
	SignName          string
	LoginTemplateCode string
}

type AliyunProvider struct {
	client            *dysms.Client
	signName          string
	loginTemplateCode string
	log               *zap.Logger
}

func NewAliyunProvider(cfg AliyunConfig, log *zap.Logger) (*AliyunProvider, error) {
	cfg.Endpoint = strings.TrimSpace(cfg.Endpoint)
	if cfg.Endpoint == "" {
		cfg.Endpoint = "dysmsapi.aliyuncs.com"
	}
	if strings.TrimSpace(cfg.AccessKeyID) == "" ||
		strings.TrimSpace(cfg.AccessKeySecret) == "" ||
		strings.TrimSpace(cfg.SignName) == "" ||
		strings.TrimSpace(cfg.LoginTemplateCode) == "" {
		return nil, ErrProviderConfigInvalid
	}

	client, err := dysms.NewClient(&openapi.Config{
		AccessKeyId:     dara.String(strings.TrimSpace(cfg.AccessKeyID)),
		AccessKeySecret: dara.String(strings.TrimSpace(cfg.AccessKeySecret)),
		Endpoint:        dara.String(cfg.Endpoint),
	})
	if err != nil {
		return nil, err
	}

	return &AliyunProvider{
		client:            client,
		signName:          strings.TrimSpace(cfg.SignName),
		loginTemplateCode: strings.TrimSpace(cfg.LoginTemplateCode),
		log:               log,
	}, nil
}

func (p *AliyunProvider) SendLoginCode(ctx context.Context, phone string, code string) error {
	return p.SendTemplate(ctx, TemplateRequest{
		Phone:        phone,
		TemplateCode: p.loginTemplateCode,
		Params:       map[string]string{"code": code},
	})
}

// SendTemplate 发送已报备的模板短信。req.SignName 为空时回退到 Provider 默认签名。
// 模板无变量时按阿里云要求传空 JSON，避免拼接文案导致模板不匹配。
func (p *AliyunProvider) SendTemplate(ctx context.Context, req TemplateRequest) error {
	phone := strings.TrimSpace(req.Phone)
	if phone == "" {
		return ErrProviderConfigInvalid
	}
	signName := strings.TrimSpace(req.SignName)
	if signName == "" {
		signName = p.signName
	}
	templateCode := strings.TrimSpace(req.TemplateCode)
	if templateCode == "" {
		return ErrProviderConfigInvalid
	}

	params := "{}"
	if len(req.Params) > 0 {
		raw, err := json.Marshal(req.Params)
		if err != nil {
			return err
		}
		params = string(raw)
	}

	apiReq := &dysms.SendSmsRequest{}
	apiReq.SetPhoneNumbers(phone)
	apiReq.SetSignName(signName)
	apiReq.SetTemplateCode(templateCode)
	apiReq.SetTemplateParam(params)

	resp, err := p.client.SendSmsWithContext(ctx, apiReq, &dara.RuntimeOptions{})
	if err != nil {
		return fmt.Errorf("aliyun sms send failed: %w", err)
	}
	if resp == nil || resp.Body == nil {
		return fmt.Errorf("aliyun sms empty response")
	}

	resultCode := dara.StringValue(resp.Body.Code)
	if resultCode != "OK" {
		resultMessage := dara.StringValue(resp.Body.Message)
		providerErr := &ProviderError{Code: resultCode, Message: resultMessage}
		if resultCode == "isv.BUSINESS_LIMIT_CONTROL" {
			providerErr.Err = ErrProviderRateLimited
		}
		return providerErr
	}

	if p.log != nil {
		p.log.Debug(
			"短信发送成功",
			zap.String("phone", maskPhone(phone)),
			zap.String("template_code", templateCode),
			zap.String("provider_request_id", dara.StringValue(resp.Body.RequestId)),
		)
	}
	return nil
}

func maskPhone(phone string) string {
	if len(phone) < 7 {
		return phone
	}
	return phone[:3] + "****" + phone[len(phone)-4:]
}