package products

import (
	"net/url"
	"regexp"
	"strings"

	"git.t5de.dev/t5de/t5de-proxy/internal/proxy"
)

// Guard is the last check before a request goes to IMVU: one that still names a community product (a local ID the
// proxy gave out, in its query or body, as an integer or a float) is refused, not sent. The interceptors take
// community products out of every request known to carry them; Guard stops the ones not known yet, and logs them
// so they can be handled.
type Guard struct{ Products *Products }

var localIDPattern = regexp.MustCompile(`(?:^|[^0-9.])(2[0-9]{9})(?:\.0+)?(?:[^0-9.]|$)`)

func (g Guard) Intercept(x *proxy.Exchange) error {
	if x.Response != nil || !strings.HasSuffix(strings.ToLower(x.URL.Hostname()), ".imvu.com") {
		return nil
	}
	query, _ := url.QueryUnescape(x.URL.RawQuery)
	for _, text := range []string{query, x.URL.Path, string(x.Body)} {
		for _, m := range localIDPattern.FindAllStringSubmatch(text, -1) {
			id, ok := parseID(m[1])
			if ok && IsCommunity(id) && g.Products.given(id) {
				g.Products.logf("products: refused a request to %s%s: it names community product %d", x.URL.Host, x.URL.Path, id)
				x.Response = localResponse(403, "application/json", []byte(`{"error":"t5de: community products stay off IMVU"}`))
				return nil
			}
		}
	}
	return nil
}

// given reports whether a local ID was given to a product.
func (p *Products) given(local int64) bool {
	_, ok := p.state.productID(local)
	return ok
}