package checker

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

func Provider() sdk.ObservationProvider {
	return &sipProvider{}
}

type sipProvider struct{}

func (p *sipProvider) Key() sdk.ObservationKey {
	return ObservationKeySIP
}

// Definition implements sdk.CheckerDefinitionProvider.
func (p *sipProvider) Definition() *sdk.CheckerDefinition {
	return Definition()
}

// DiscoverEndpoints implements sdk.EndpointDiscoverer.
//
// It publishes every _sips._tcp SRV target as a "tls" discovery
// endpoint so the downstream TLS checker can verify certificate chain,
// SAN and expiry without re-doing the SRV lookup. SNI is set to the
// SRV target — SIPS certificates are expected to cover the server
// hostname (unlike XMPP where it's the bare JID domain).
//
// _sip._udp and _sip._tcp are plaintext with no historical STARTTLS
// convention, so nothing is emitted for them.
func (p *sipProvider) DiscoverEndpoints(data any) ([]sdk.DiscoveredEndpoint, error) {
	d, ok := data.(*SIPData)
	if !ok || d == nil {
		return nil, nil
	}
	var out []sdk.DiscoveredEndpoint
	for _, r := range d.SRV.SIPS {
		out = append(out, sdk.DiscoveredEndpoint{
			Type: "tls",
			Host: r.Target,
			Port: r.Port,
			SNI:  r.Target,
		})
	}
	return out, nil
}