package brevo

import (
	"bytes"
	"context"
	"enaklo-pos-be/internal/common/logger"
	"enaklo-pos-be/internal/entity"
	"go.uber.org/zap"
	"html/template"
	"io/ioutil"
	"log"

	brevo "github.com/getbrevo/brevo-go/lib"
)

type Config interface {
	GetApiKey() string
}

type ServiceImpl struct {
	brevoConn *brevo.APIClient
}

func (s ServiceImpl) SendEmailTransactional(ctx context.Context, param entity.SendEmailNotificationParam) error {
	templateFile, err := ioutil.ReadFile(param.TemplatePath)
	if err != nil {
		logger.ContextLogger(ctx).Error("error when reading file template", zap.Error(err))
		return err
	}

	tmpl := template.New(param.TemplateName).Funcs(template.FuncMap{
		"range": func(args ...interface{}) []interface{} {
			if len(args) == 0 {
				return nil
			}

			switch items := args[0].(type) {
			case []map[string]string:
				result := make([]interface{}, len(items))
				for i, item := range items {
					result[i] = item
				}
				return result
			case []interface{}:
				return items
			default:
				if slice, ok := args[0].([]interface{}); ok {
					return slice
				}
				return nil
			}
		},
	})

	renderedTemplate, err := tmpl.Parse(string(templateFile))
	if err != nil {
		log.Println(err)
		return err
	}

	return s.sendEmail(ctx, renderedTemplate, param)
}

func (s ServiceImpl) sendEmail(ctx context.Context, tmpl *template.Template, param entity.SendEmailNotificationParam) error {
	var body bytes.Buffer
	err := tmpl.Execute(&body, param.Data)
	if err != nil {
		log.Println(err)
		return err
	}

	payload := brevo.SendSmtpEmail{
		Sender: &brevo.SendSmtpEmailSender{
			Name:  "Enaklo",
			Email: param.Sender,
		},
		To: []brevo.SendSmtpEmailTo{
			{
				Email: param.Recipient,
			},
		},
		Subject:     param.Subject,
		HtmlContent: body.String(),
	}

	if len(param.CcEmails) != 0 {
		for _, email := range param.CcEmails {
			payload.Cc = append(payload.Cc, brevo.SendSmtpEmailCc{
				Email: email,
			})
		}
	}

	_, _, err = s.brevoConn.TransactionalEmailsApi.SendTransacEmail(ctx, payload)
	if err != nil {
		logger.ContextLogger(ctx).Error("error when sending email", zap.Error(err))
		return err
	}

	logger.ContextLogger(ctx).Info("sending email success")
	return nil
}

func New(conf Config) *ServiceImpl {
	cfg := brevo.NewConfiguration()
	cfg.AddDefaultHeader("api-key", conf.GetApiKey())
	client := brevo.NewAPIClient(cfg)
	return &ServiceImpl{brevoConn: client}
}