monitor.go

package www

import (
	"encoding/json"
	"io"
	"io/ioutil"
	"net/http"
	"time"

	"github.com/gorilla/mux"
	"github.com/markdaws/gohome/pkg/gohome"
)

// RegisterMonitorHandlers registers all of the monitor specific REST API routes
func RegisterMonitorHandlers(r *mux.Router, s *Server) {
	//TODO: Need a way to check the SID used for the user against the current valid
	//SIDs and make sure it has not expired, otherwise someone can listen forever
	wsHelper := NewWSHelper(s.system.Services.Monitor, s.system.Services.EvtBus)

	// Clients call to subscribe to items, api returns a monitorID that can then be used
	// to subscribe and unsubscribe to notifications
	r.HandleFunc("/v1/monitor/groups", apiSubscribeHandler(s.system, wsHelper)).Methods("POST")

	// extends the timeout period for a monitor groups
	r.HandleFunc("/v1/monitor/groups/{monitorID}", apiRefreshSubscribeHandler(s.system, wsHelper)).Methods("PUT")

	// deletes a monitor group
	r.HandleFunc("/v1/monitor/groups/{monitorID}", apiUnsubscribeHandler(s.system, wsHelper)).Methods("DELETE")

	// web socket for receiving new events
	r.HandleFunc("/v1/monitor/groups/{monitorID}", wsHelper.HTTPHandler())

}

func apiUnsubscribeHandler(system *gohome.System, wsHelper *WSHelper) func(http.ResponseWriter, *http.Request) {
	return func(w http.ResponseWriter, r *http.Request) {
		monitorID := mux.Vars(r)["monitorID"]
		if _, ok := system.Services.Monitor.Group(monitorID); !ok {
			respBadRequest("monitorID is invalid", w)
			return
		}

		system.Services.Monitor.Unsubscribe(monitorID)
		w.WriteHeader(http.StatusOK)
	}
}

func apiRefreshSubscribeHandler(system *gohome.System, wsHelper *WSHelper) func(http.ResponseWriter, *http.Request) {
	return func(w http.ResponseWriter, r *http.Request) {
		monitorID := mux.Vars(r)["monitorID"]
		if _, ok := system.Services.Monitor.Group(monitorID); !ok {
			respBadRequest("monitorID is invalid", w)
			return
		}
		system.Services.Monitor.SubscribeRenew(monitorID)
		w.WriteHeader(http.StatusOK)
	}
}

func apiSubscribeHandler(system *gohome.System, wsHelper *WSHelper) func(http.ResponseWriter, *http.Request) {
	return func(w http.ResponseWriter, r *http.Request) {
		body, err := ioutil.ReadAll(io.LimitReader(r.Body, 1024*1024))
		if err != nil {
			respBadRequest("Content length too long, max length 1024 bytes", w)
			return
		}

		var groupJSON jsonMonitorGroup
		if err = json.Unmarshal(body, &groupJSON); err != nil {
			respBadRequest("Content is not valid JSON", w)
			return
		}

		group := &gohome.MonitorGroup{
			Timeout:  time.Duration(groupJSON.TimeoutInSeconds) * time.Second,
			Features: make(map[string]bool),
			Handler:  wsHelper,
		}
		for _, featureID := range groupJSON.FeatureIDs {
			group.Features[featureID] = true
		}

		mID, err := system.Services.Monitor.Subscribe(group, false)
		if err != nil {
			respBadRequest("Invalid input, unable to subscribe", w)
			return
		}

		resp(apiResponse{
			Data: &struct {
				MonitorID string `json:"monitorId"`
			}{MonitorID: mID},
		}, w)
	}
}