package main

import (
	"bytes"
	"errors"
	"text/template"

	"github.com/Masterminds/sprig"
)

const (
	// Errors to show when the template handling fails
	invalidTemplate   = "invalid template text"
	incorrectTemplate = "unable to create text based on template"
)

type textTemplate struct {
	Template string
	Context  interface{}
}

func (t *textTemplate) render() (string, error) {
	tmpl, err := template.New("title").Funcs(sprig.TxtFuncMap()).Parse(t.Template)
	if err != nil {
		return "", errors.New(invalidTemplate)
	}
	buffer := new(bytes.Buffer)
	defer buffer.Reset()
	err = tmpl.Execute(buffer, t.Context)
	if err != nil {
		return "", errors.New(incorrectTemplate)
	}
	return buffer.String(), nil
}