package http_internal

import (
	"encoding/json"
	"fmt"
	"log"
	"net/http"
	loadaverage "rpi5-health/internal/load_average"
	"rpi5-health/internal/memory"
	"rpi5-health/internal/processor"
	"rpi5-health/internal/temperature"
	"rpi5-health/internal/uptime"
	"time"
)

func SSEHandler(w http.ResponseWriter, r *http.Request) {
	w.Header().Set("Content-Type", "text/event-stream")
	w.Header().Set("Cache-Control", "no-cache")
	w.Header().Set("Connection", "keep-alive")

	// For CORS requests
	w.Header().Set("Access-Control-Allow-Origin", "*")

	clientGone := r.Context().Done() // Channel to signal client disconnection

	rc := http.NewResponseController(w)
	t := time.NewTicker(time.Millisecond * 1000)
	defer t.Stop()
	for {
		select {
		case <-clientGone:
			log.Println("Client disconnected")
			return
		case <-t.C:
			resp := buildDashboardResponse()
			_, err := fmt.Fprintf(w, "data: %s\n\n", resp)
			if err != nil {
				return
			}
			err = rc.Flush()
			if err != nil {
				return
			}
		}
	}
}

func buildDashboardResponse() []byte {
	// TODO: proper error handling
	loadavg, _ := loadaverage.GetLoadAverage()
	memoryInfo, _ := memory.GetRamInformation()
	processorInfo := processor.GetCPUInformation()
	temperatureInfo, _ := temperature.GetTemperatureInformation()
	uptimeInfo, _ := uptime.GetUptimeInformation()

	stats := ServerStatistics{
		LoadAvgInfo:     loadavg,
		MemoryInfo:      memoryInfo,
		ProcessorInfo:   processorInfo,
		TemperatureInfo: temperatureInfo,
		UptimeInfo:      uptimeInfo,
	}

	payload, _ := json.Marshal(stats)

	return payload
}