package main

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

	"ts3monolith/internal/config"
	"ts3monolith/internal/rrd"
	"ts3monolith/internal/ts3"
	webapp "ts3monolith/internal/web"
)

func main() {
	log.SetFlags(log.LstdFlags | log.LUTC)
	cfg, err := config.Load()
	if err != nil {
		log.Fatal(err)
	}
	tq := &ts3.Query{Addr: cfg.TSQueryHost + ":" + strconv.Itoa(cfg.TSQueryPort), User: cfg.TSQueryUser, Password: cfg.TSQueryPassword, VoicePort: cfg.TSVoicePort, Timeout: cfg.TSQueryTimeout}
	rm := &rrd.Manager{Tool: cfg.RRDTool, Path: cfg.RRDPath, GraphDir: cfg.GraphDir}
	if err := rm.Validate(); err != nil {
		log.Fatal(err)
	}
	app, err := webapp.New(cfg, tq, rm)
	if err != nil {
		log.Fatal(err)
	}

	srv := &http.Server{Addr: cfg.ListenAddr, Handler: app.Handler(), ReadHeaderTimeout: 5 * time.Second, ReadTimeout: 10 * time.Second, WriteTimeout: 15 * time.Second, IdleTimeout: 60 * time.Second, MaxHeaderBytes: 16 << 10}
	ctx, stop := signal.NotifyContext(context.Background(), os.Interrupt, syscall.SIGTERM)
	defer stop()
	go collect(ctx, cfg, tq, rm)
	go func() {
		<-ctx.Done()
		c, cancel := context.WithTimeout(context.Background(), 8*time.Second)
		defer cancel()
		_ = srv.Shutdown(c)
	}()
	log.Printf("listening on %s", cfg.ListenAddr)
	if err := srv.ListenAndServe(); err != nil && !errors.Is(err, http.ErrServerClosed) {
		log.Fatal(err)
	}
}

func collect(ctx context.Context, cfg config.Config, tq *ts3.Query, rm *rrd.Manager) {
	run := func() {
		c, cancel := context.WithTimeout(ctx, cfg.TSQueryTimeout)
		defer cancel()
		n, err := tq.CountOnline(c)
		if err != nil {
			log.Printf("stats query failed: %v", err)
			return
		}
		c2, cancel2 := context.WithTimeout(ctx, 5*time.Second)
		defer cancel2()
		if err := rm.Update(c2, n); err != nil {
			log.Printf("rrd update failed: %v", err)
		}
	}
	run()
	t := time.NewTicker(cfg.StatsInterval)
	defer t.Stop()
	for {
		select {
		case <-ctx.Done():
			return
		case <-t.C:
			run()
		}
	}
}