package clientapi

import (
	"net/http"
	"strings"

	"github.com/dariuszjaniak/warp/server/internal/httputil"
	"github.com/dariuszjaniak/warp/server/internal/userapi"
)

// rtcTransportsPath is MSC4143's endpoint for the group call backends a
// client may use: the same list /.well-known/matrix/client carries as
// org.matrix.msc4143.rtc_foci, behind authentication and without needing
// the discovery document.
const rtcTransportsPath = "/_matrix/client/unstable/org.matrix.msc4143/rtc/transports"

// RTCTransport is one group call backend: a LiveKit SFU, named by the JWT
// service that hands out tokens for it.
type RTCTransport struct {
	Type              string `json:"type"`
	LiveKitServiceURL string `json:"livekit_service_url"`
}

// RTCTransports lists the configured group call backends, or nil for none.
func RTCTransports(liveKitServiceURL string) []RTCTransport {
	if liveKitServiceURL == "" {
		return nil
	}
	return []RTCTransport{{Type: "livekit", LiveKitServiceURL: strings.TrimRight(liveKitServiceURL, "/")}}
}

type rtcTransportsResponse struct {
	Transports []RTCTransport `json:"rtc_transports"`
}

// registerRTCRoutes adds the MSC4143 endpoint, if a backend is configured.
// Without one it is left unregistered: the 404 is how a client learns there
// is none.
func (c *ClientAPI) registerRTCRoutes(r *httputil.Router) {
	if len(c.rtcTransports) == 0 {
		return
	}
	c.authed(r, "GET "+rtcTransportsPath, c.limitDefault, c.handleRTCTransports)
}

// handleRTCTransports implements
// GET /_matrix/client/unstable/org.matrix.msc4143/rtc/transports.
func (c *ClientAPI) handleRTCTransports(w http.ResponseWriter, _ *http.Request, _ userapi.Authenticated) error {
	httputil.WriteJSON(w, http.StatusOK, rtcTransportsResponse{Transports: c.rtcTransports})
	return nil
}