//go:build standalone

package checker

import (
	"errors"
	"net"
	"net/http"
	"strings"

	"github.com/miekg/dns"

	sdk "git.happydns.org/checker-sdk-go/checker"
)

// RenderForm exposes a minimal form accepting either an IP address or a
// reverse-arpa owner, plus an optional expected hostname (for FCrDNS).
func (p *ptrProvider) RenderForm() []sdk.CheckerOptionField {
	return []sdk.CheckerOptionField{
		{
			Id:          "ip",
			Type:        "string",
			Label:       "IP address or reverse name",
			Placeholder: "2001:db8::1  or  4.3.2.1.in-addr.arpa",
			Required:    true,
			Description: "IPv4, IPv6 or fully-qualified reverse name. The checker derives one from the other automatically.",
		},
		{
			Id:          "expected",
			Type:        "string",
			Label:       "Expected hostname",
			Placeholder: "mail.example.com",
			Description: "Optional. When set, the checker compares it to the PTR served by the reverse zone.",
		},
	}
}

// ParseForm turns the submitted input into a minimal CheckerOptions set
// suitable for the Collect pipeline. We encode the inputs as a synthetic
// svcs.PTR service so Collect's existing unmarshaller picks it up.
func (p *ptrProvider) ParseForm(r *http.Request) (sdk.CheckerOptions, error) {
	raw := strings.TrimSpace(r.FormValue("ip"))
	if raw == "" {
		return nil, errors.New("IP address or reverse name is required")
	}

	var owner string
	if ip := net.ParseIP(raw); ip != nil {
		rev, err := dns.ReverseAddr(ip.String())
		if err != nil {
			return nil, err
		}
		owner = rev
	} else {
		owner = dns.Fqdn(raw)
	}

	expected := strings.TrimSpace(r.FormValue("expected"))
	if expected == "" {
		// Build a service payload with no declared target: the checker will
		// still do existence + FCrDNS.
		return sdk.CheckerOptions{
			"domain_name": strings.TrimSuffix(owner, "."),
			"subdomain":   "@",
		}, nil
	}

	return sdk.CheckerOptions{
		"domain_name":     strings.TrimSuffix(owner, "."),
		"subdomain":       "@",
		"expected_target": expected,
	}, nil
}