package senders

import (
	"bytes"
	_ "embed"
	"fmt"
	"html/template"
	"penahub.gitlab.yandexcloud.net/backend/quiz/common.git/clients"
	"penahub.gitlab.yandexcloud.net/backend/quiz/common.git/model"
)

type LeadSender interface {
	SendLead(leadData LeadData) error
	Name() string
}

type LeadData struct {
	To           interface{}
	Subject      string
	Template     string
	TemplateData TemplateData
}

type TemplateData struct {
	QuizConfig    model.ResultInfo
	AnswerContent model.ResultContent
	AllAnswers    []model.ResultAnswer
	QuestionsMap  map[uint64]string
	AnswerTime    string
}

type MailLeadSender struct {
	client *clients.SmtpClient
}

func NewMailLeadSender(client *clients.SmtpClient) *MailLeadSender {
	return &MailLeadSender{client: client}
}

func (m *MailLeadSender) SendLead(data LeadData) error {
	err := m.SendMailWithAttachment(data.To.(string), data.Subject, data.Template, data.TemplateData, nil)
	if err != nil {
		return err
	}

	return nil
}

func (m *MailLeadSender) Name() string {
	return "mail"
}

func (m *MailLeadSender) SendMailWithAttachment(recipient, subject string, emailTemplate string, data TemplateData, attachments []clients.Attachment) error {
	text, err := m.generateTextFromTemplate(data, emailTemplate)
	if err != nil {
		return err
	}

	msg := clients.Message{
		To:          recipient,
		Subject:     subject,
		HtmlBody:    text,
		Attachments: attachments,
	}

	return m.client.MailSender(msg)
}

func (m *MailLeadSender) generateTextFromTemplate(data TemplateData, tpl string) (string, error) {
	t, err := template.New("email").Parse(tpl)
	if err != nil {
		return "", fmt.Errorf("error parsing template: %w", err)
	}

	var text bytes.Buffer
	if err := t.Execute(&text, TemplateData{
		QuizConfig:    data.QuizConfig,
		AnswerContent: data.AnswerContent,
		AllAnswers:    data.AllAnswers,
		QuestionsMap:  data.QuestionsMap,
		AnswerTime:    data.AnswerTime,
	}); err != nil {
		return "", fmt.Errorf("error executing template: %w", err)
	}

	return text.String(), nil
}