package main

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

	apiv1 "git.ar21.de/yolokube/country-geo-locations/api/v1"
	"git.ar21.de/yolokube/country-geo-locations/internal/cache"
	"git.ar21.de/yolokube/country-geo-locations/internal/cmd"
	csvimporter "git.ar21.de/yolokube/country-geo-locations/internal/csv_importer"
	"git.ar21.de/yolokube/country-geo-locations/internal/database"
	"git.ar21.de/yolokube/country-geo-locations/internal/downloader"
	"git.ar21.de/yolokube/country-geo-locations/internal/exporter"
	"github.com/go-chi/chi/v5"
	"github.com/go-chi/chi/v5/middleware"
	"github.com/go-chi/render"
)

func main() {
	cli := cmd.CLI{}
	config, err := cli.Parse()
	if err != nil {
		log.Fatal(err)
	}

	handleGracefulShutdown()

	r := chi.NewRouter()
	r.Use(middleware.RequestID)
	r.Use(middleware.Logger)
	r.Use(middleware.Recoverer)
	r.Use(render.SetContentType(render.ContentTypeJSON))

	ctx := downloader.NewContext(config.DataFile, config.DataURL)
	if !ctx.FileExists() {
		if downloadErr := ctx.Download(); downloadErr != nil {
			log.Fatal(downloadErr)
		}
		log.Printf("saved file to %s\n", ctx.Filename)
	}

	cache := cache.NewCache(config.CacheTTL)
	db, err := database.NewDatabase(config)
	if err != nil {
		log.Fatal("database creation failed", err)
	}

	if config.EnableExporter {
		exporter := exporter.NewExporter(config, cache, db)
		r.Use(exporter.Middleware())

		ticker := time.NewTicker(config.ExporterInterval)
		exit := make(chan struct{})
		go func() {
			for {
				select {
				case <-ticker.C:
					exporter.Collect()
				case <-exit:
					ticker.Stop()
					return
				}
			}
		}()
		log.Println("prometheus exporter refreshes metric data every", config.ExporterInterval)

		go func() {
			err = exporter.Start()
			if err != nil {
				log.Panic(err)
			}
		}()
		log.Println("prometheus exporter started at", config.ExporterAddress)
	}

	log.Println("importing data from file", config.DataFile)
	err = csvimporter.ImportCSV(config.DataFile, db)
	if err != nil {
		log.Fatal("data Import from file failed", err)
	}
	log.Println("imported data from file successful")

	lh := apiv1.NewLocationHandler(cache, db)
	r.Mount("/api/v1", apiv1.NewRouter(lh))

	server := &http.Server{
		Addr:              config.ServerAddress,
		Handler:           r,
		ReadHeaderTimeout: config.ReadHeaderTimeout,
	}

	log.Println("starting server at", server.Addr)
	if err = server.ListenAndServe(); err != nil {
		log.Panic(err)
	}
}

func handleGracefulShutdown() {
	var signals = make(chan os.Signal, 1)

	signal.Notify(signals, syscall.SIGTERM, syscall.SIGINT)

	go func() {
		sig := <-signals
		log.Printf("caught signal: %+v", sig)
		os.Exit(0)
	}()
}