// Command emulator serves a small web UI that stands in for an ESP32
// growbox controller: a sensor slot (publishes temperature/humidity
// telemetry) and three actuator slots (fan/light/pump — react live to
// commands the platform sends over MQTT). See README.md for the protocol
// this speaks and why it exists as a standalone tool.
package main

import (
	"context"
	"log/slog"
	"net/http"
	"os"
	"os/signal"
	"syscall"
	"time"

	"git.cactoz.su/cacto/home_automation_emulator/internal/httpserver"
	"git.cactoz.su/cacto/home_automation_emulator/internal/mqttclient"
	"git.cactoz.su/cacto/home_automation_emulator/internal/state"
)

func main() {
	logger := slog.New(slog.NewTextHandler(os.Stdout, nil))

	brokerURL := getEnv("MQTT_BROKER_URL", "tcp://localhost:1883")
	httpAddr := ":" + getEnv("HTTP_PORT", "8091")

	store := state.NewStore()

	mqttClient, err := mqttclient.Connect(mqttclient.Config{
		BrokerURL: brokerURL,
		ClientID:  "esp32-emulator",
	}, logger)
	if err != nil {
		logger.Error("mqtt connect failed", "broker", brokerURL, "error", err)
		os.Exit(1)
	}
	defer mqttClient.Close()

	if err := mqttClient.SubscribeCommands(func(externalID, action string, level float64, hasLevel bool) {
		reported, ok := store.ApplyCommand(externalID, action, level, hasLevel)
		if !ok {
			logger.Warn("command for unknown device ignored", "device_id", externalID, "action", action)
			return
		}
		logger.Info("command applied", "device_id", externalID, "action", action)
		if err := mqttClient.PublishAck(externalID, reported); err != nil {
			logger.Error("publish ack failed", "device_id", externalID, "error", err)
		}
	}); err != nil {
		logger.Error("mqtt subscribe failed", "error", err)
		os.Exit(1)
	}

	srv := &http.Server{
		Addr:    httpAddr,
		Handler: httpserver.New(store, mqttClient, logger),
	}

	go func() {
		logger.Info("http server listening", "addr", httpAddr, "mqtt_broker", brokerURL)
		if err := srv.ListenAndServe(); err != nil && err != http.ErrServerClosed {
			logger.Error("http server failed", "error", err)
			os.Exit(1)
		}
	}()

	ctx, stop := signal.NotifyContext(context.Background(), syscall.SIGINT, syscall.SIGTERM)
	defer stop()
	<-ctx.Done()

	logger.Info("shutting down")
	shutdownCtx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
	defer cancel()
	_ = srv.Shutdown(shutdownCtx)
}

func getEnv(key, fallback string) string {
	if v := os.Getenv(key); v != "" {
		return v
	}
	return fallback
}