// Command smartrund is smartrun's backend server: syncs runs from Garmin,
// classifies them into workout kinds, and serves the REST API the frontend
// talks to.
package main

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

	"smartrun/backend/internal/api"
	"smartrun/backend/internal/config"
	"smartrun/backend/internal/garmin"
	"smartrun/backend/internal/store"
	appsync "smartrun/backend/internal/sync"
)

func main() {
	cfg, err := config.Load()
	if err != nil {
		log.Fatalf("config: %v", err)
	}

	db, err := store.Open(cfg.DBPath)
	if err != nil {
		log.Fatalf("open database: %v", err)
	}
	defer db.Close()

	profile, err := db.GetProfile(context.Background())
	if err != nil {
		log.Fatalf("load profile: %v", err)
	}

	garminClient := garmin.NewClient(garmin.Config{
		PythonPath:     cfg.GarminPythonPath,
		ServerPath:     cfg.GarminServerPath,
		GarminEmail:    profile.GarminEmail,
		GarminPassword: profile.GarminPassword,
		TokenStorePath: cfg.GarminTokenStore,
	})
	defer garminClient.Close()

	syncSvc := appsync.NewService(garminClient, db, appsync.Config{
		MinConfidence: cfg.MinConfidence,
	}, nil)

	server := api.NewServer(db, garminClient, syncSvc)

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

	go runIncrementalSyncLoop(ctx, syncSvc, cfg.IncrementalSyncEvery)

	httpServer := &http.Server{Addr: cfg.Addr, Handler: server.Router()}
	go func() {
		log.Printf("smartrund listening on %s", cfg.Addr)
		if err := httpServer.ListenAndServe(); err != nil && err != http.ErrServerClosed {
			log.Fatalf("http server: %v", err)
		}
	}()

	<-ctx.Done()
	log.Println("shutting down...")
	shutdownCtx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
	defer cancel()
	if err := httpServer.Shutdown(shutdownCtx); err != nil {
		log.Printf("http server shutdown: %v", err)
	}
}

// runIncrementalSyncLoop periodically syncs new activities in the
// background so the frontend doesn't need to trigger every sync manually.
func runIncrementalSyncLoop(ctx context.Context, svc *appsync.Service, every time.Duration) {
	ticker := time.NewTicker(every)
	defer ticker.Stop()
	for {
		select {
		case <-ctx.Done():
			return
		case <-ticker.C:
			if err := svc.IncrementalSync(ctx); err != nil {
				log.Printf("incremental sync: %v", err)
				continue
			}
			if err := svc.FillPendingDetails(ctx, 50); err != nil {
				log.Printf("fill pending details: %v", err)
			}
		}
	}
}