package main
import (
"fmt"
"html/template"
"log"
"net/http"
)
const dashboardHtml = `
HVAC Dashboard
Average humidity:
{{- if ge .Average 0.0 -}}
{{ printf "%.1f%%" .Average }}
{{- else -}}
unknown
{{- end }}
| Room | Humidity |
|---|
{{ range $id, $humidity := .Rooms }}
| {{ $id }} |
{{- if ge $humidity 0.0 -}}
{{ printf "%.1f%%" $humidity }}
{{- else -}}
unknown
{{- end -}}
|
{{ end }}
`
var dashboard = template.Must(template.New("dashboard").Parse(dashboardHtml))
type Dashboard struct {
Average Humidity
Rooms map[RoomID]Humidity
}
type DashboardHandler struct {
Building
}
func (h DashboardHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
log.Println(r.Method, r.URL)
if r.Method != http.MethodGet {
w.WriteHeader(http.StatusMethodNotAllowed)
fmt.Fprintf(w, "invalid method: '%s'", r.Method)
return
}
db := newDashboard(h.Building)
err := dashboard.Execute(w, db)
if err != nil {
log.Println(err)
}
}
func newDashboard(b Building) Dashboard {
average, ok := b.average()
if !ok {
average = -1
}
rooms := make(map[RoomID]Humidity)
for id, record := range b {
c := make(chan Humidity)
record.getRecent <- c
humidity, ok := <-c
if !ok {
humidity = -1
}
rooms[id] = humidity
}
return Dashboard{average, rooms}
}