package checker

import (
	"fmt"

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

// directTLSServices enumerates SRV service names (the "service" part of
// _service._proto.domain) that by convention mean "direct TLS on connect",
// as opposed to STARTTLS or plaintext.
//
// Matching on the service name is more authoritative than matching on the
// port: port 636 could carry anything, but _ldaps._tcp unambiguously
// designates LDAP over TLS — even on a non-standard port. Conversely, a
// site may run HTTPS on a non-443 port and still want it probed.
//
// STARTTLS variants (_xmpp-client, _smtp, _submission, _imap, _pop3…) are
// intentionally excluded here; a dedicated endpoint type (e.g.
// "smtp-starttls") will be introduced when a TLS checker grows the
// capability to upgrade those protocols.
var directTLSServices = map[string]bool{
	"https":        true,
	"ftps":         true, // FTPS implicit
	"smtps":        true, // SMTP over TLS (legacy port 465 semantics)
	"submissions":  true, // RFC 8314: SMTP submission over TLS
	"imaps":        true,
	"pop3s":        true,
	"nntps":        true,
	"ircs":         true,
	"telnets":      true,
	"ldaps":        true,
	"sips":         true,
	"ipps":         true, // IPP over TLS (printing)
	"xmpps-client": true, // XMPP client over direct TLS
	"xmpps-server": true, // XMPP server-to-server over direct TLS
	"mqtts":        true,
	"coaps":        true,
	"stuns":        true,
	"turns":        true,
}

// DiscoverEndpoints is invoked right after Collect. It declares (host, port)
// pairs worth testing by other checkers — here: TLS endpoints whose SRV
// service name is a known direct-TLS protocol (see directTLSServices).
func (p *srvProvider) DiscoverEndpoints(data any) ([]sdk.DiscoveredEndpoint, error) {
	d, ok := data.(*SRVData)
	if !ok {
		return nil, fmt.Errorf("unexpected data type %T", data)
	}
	var out []sdk.DiscoveredEndpoint
	for _, r := range d.Records {
		if r.IsNullTarget || r.Target == "" {
			continue
		}
		if !directTLSServices[r.Service] {
			continue
		}
		out = append(out, sdk.DiscoveredEndpoint{
			Type: "tls",
			Host: r.Target,
			Port: r.Port,
			SNI:  r.Target,
		})
	}
	return out, nil
}