templating/parser/name.go

package parser

import (
	"context"
	"path"
	"strings"

	"gitoa.ru/go-4devs/mime"
	"gitoa.ru/go-4devs/templating/render"
)

const (
	nameWithExt    = 2
	nameWithEngine = 3
	countOption    = 2
)

// Name parse name by <tpl name>.<format>.<engine> or <tpl name>.<format>.
func Name(_ context.Context, name string, opts ...render.Option) (render.Reference, error) {
	options := make([]render.Option, 0, countOption)
	tplName := strings.ToLower(name)

	base := path.Base(tplName)
	el := strings.SplitN(base, ".", nameWithEngine)

	var ext mime.Ext

	switch len(el) {
	case nameWithEngine:
		ext = mime.ExtFromString(el[1])
		options = append(options, render.WithEngine(el[2]))
		tplName = strings.TrimRight(tplName, "."+el[1]+"."+el[2])
	case nameWithExt:
		ext = mime.ExtFromString(el[1])
		tplName = strings.TrimRight(tplName, "."+el[1])
	}

	if !ext.Is(mime.ExtUnrecognized) {
		options = append(options, render.WithFormat(ext))
	}

	return render.NewReference(tplName, append(options, opts...)...), nil
}