package echo

import (
	"net/url"
	"path"

	"github.com/labstack/echo/v4"
)

// URLBuilder is used to build URLs with optional querystring arguments. This
// is used to build URLs to REST resources within handlers.
//
// This exists because the default Echo reversing logic requires handlers to
// hold references to other handlers to be able to build reverse URLs. This is
// a bad solution to an ugly problem but as the router currently stands there's
// not much that can be done about it. In the future this should go away and be
// replaced by something like named routes in echo.
type URLBuilder struct {
	c echo.Context
	u *url.URL
	q url.Values
}

func URLFor(c echo.Context, parts ...string) *URLBuilder {
	u := &url.URL{
		Scheme: "http",
		Host:   c.Request().Host,
		Path:   path.Join(parts...),
	}
	if c.Request().TLS != nil {
		u.Scheme = "https"
	}
	return &URLBuilder{c, u, nil}
}

func (b *URLBuilder) Query(k, v string) *URLBuilder {
	if b.q == nil {
		b.q = url.Values{}
	}
	b.q.Add(k, v)
	return b
}

func (b *URLBuilder) String() string {
	if b.q != nil {
		b.u.RawQuery = b.q.Encode()
	}
	return b.u.String()
}