package main

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

	_ "github.com/duckdb/duckdb-go/v2"
	"gopkg.in/ini.v1"

	"datasource/collector"
	"datasource/config"
	"datasource/controller"
	"datasource/store"
)

func main() {
	// todo (david): init logger

	var wg sync.WaitGroup
	defer wg.Wait()

	ctx, stop := signal.NotifyContext(context.Background(), os.Interrupt, syscall.SIGTERM)
	defer stop()

	cfg, err := ini.Load("./config.ini")
	if err != nil {
		log.Fatal(err)
	}

	dataSourceConfig, err := config.LoadDataSourceConfig(cfg)
	if err != nil {
		log.Fatal(err)
	}

	store, err := store.NewStore(dataSourceConfig.DBPath)
	if err != nil {
		log.Fatal(err)
	}
	defer store.Close()

	redisConfig, err := config.LoadRedisConfig(cfg)
	if err != nil {
		log.Fatal(err)
	}

	redisCollector := collector.NewRedisCollector(redisConfig, store)
	defer redisCollector.Close()

	collectors := []collector.Collector{redisCollector}

	for _, collector := range collectors {
		wg.Add(1)
		go func() {
			defer wg.Done()

			ticker := time.NewTicker(5 * time.Second)
			defer ticker.Stop()

			for {
				select {
				case <-ctx.Done():
					return
				case <-ticker.C:
					if err := collector.Collect(ctx); err != nil {
						log.Printf("failed to collect: %v", err)
					}
				}
			}
		}()
	}

	controller := controller.NewController(store)

	mux := http.NewServeMux()
	mux.HandleFunc("GET /api/v1/metrics", controller.GetMetrics)
	// todo (david)
	// mux.HandleFunc("DELETE /api/v1/metrics", controller.DeleteMetrics)

	srv := &http.Server{
		Addr:    fmt.Sprintf("0.0.0.0:%d", dataSourceConfig.Port),
		Handler: mux,
	}

	wg.Add(1)
	go func() {
		defer wg.Done()
		if err := srv.ListenAndServe(); err != nil && !errors.Is(err, http.ErrServerClosed) {
			log.Fatalf("http.ListenAndServe: %v\n", err)
		}
	}()

	<-ctx.Done()

	srv.Shutdown(context.Background())

	srvShutdownCtx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
	defer cancel()
	if err := srv.Shutdown(srvShutdownCtx); err != nil {
		log.Fatalf("srv.Shutdown: %v", err)
	}
}