package pwreset

import (
	"bytes"
	"html/template"
)

//TemplateRepository is responsible for retrieving and executing template files
type TemplateRepository interface {
	Template(username, fromEmail, toEmail, code string) ([]byte, error)
}

//NewFSTemplateRepository returns a file system backed template repository.
func NewFSTemplateRepository(templateFilePath string) TemplateRepository {
	return &templateRepository{templateFilePath}
}

type templateRepository struct {
	templateFilePath string
}

type templateData struct {
	Username  string
	FromMail  string
	ToEmail   string
	ResetCode string
}

//Template finds and executes a template and returns the resulting []byte.
func (tr *templateRepository) Template(username, fromEmail, toEmail, code string) ([]byte, error) {
	tmpl, err := template.ParseFiles(tr.templateFilePath)
	if err != nil {
		return nil, err
	}

	var b bytes.Buffer
	err = tmpl.Execute(&b, templateData{username, fromEmail, toEmail, code})
	if err != nil {
		return nil, err
	}

	return b.Bytes(), nil
}