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package main
import (
"log"
"net/http"
"fmt"
"time"
"github.com/wcharczuk/go-chart/v2"
)
type ChartHandler struct {
building Building
}
func (h ChartHandler) 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
}
var series []chart.Series
for room, record := range h.building {
var x []time.Time
var y []float64
c := make(chan Entry[Humidity])
record.get <- c
for e := range c {
x = append(x, e.t)
y = append(y, float64(e.v))
}
series = append(series, chart.TimeSeries{
Name: string(room),
XValues: x,
YValues: y,
})
}
graph := chart.Chart{
Background: chart.Style{
Padding: chart.Box{Top: 20, Left: 20},
},
Series: series,
}
graph.Elements = []chart.Renderable{
chart.Legend(&graph),
}
w.Header().Set("Content-Type", "image/png")
if err := graph.Render(chart.PNG, w); err != nil {
log.Println(err)
}
}
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