package main

import (
	"errors"
	"fmt"
	"spend-sparrow/db"
	"spend-sparrow/handler"
	"spend-sparrow/handler/middleware"
	"spend-sparrow/log"
	"spend-sparrow/service"
	"spend-sparrow/types"

	"context"
	"net/http"
	"os"
	"os/signal"
	"sync"
	"syscall"
	"time"

	"github.com/jmoiron/sqlx"
	"github.com/joho/godotenv"
	_ "github.com/mattn/go-sqlite3"
	"github.com/prometheus/client_golang/prometheus/promhttp"
)

func main() {
	err := godotenv.Load()
	if err != nil {
		log.Fatal("Error loading .env file")
	}

	db, err := sqlx.Open("sqlite3", "./data/spend-sparrow.db")
	if err != nil {
		log.Fatal("Could not open Database data.db: %v", err)
	}
	defer func() {
		err := db.Close()
		log.Fatal("Could not close Database data.db: %v", err)
	}()

	err = run(context.Background(), db, os.Getenv)
	if err != nil {
		log.Error("Error running server: %v", err)
		return
	}
}

func run(ctx context.Context, database *sqlx.DB, env func(string) string) error {
	ctx, cancel := signal.NotifyContext(ctx, syscall.SIGINT, syscall.SIGTERM)
	defer cancel()

	log.Info("Starting server...")

	// init server settings
	serverSettings := types.NewSettingsFromEnv(env)

	// init db
	err := db.RunMigrations(database, "")
	if err != nil {
		return fmt.Errorf("could not run migrations: %w", err)
	}

	// init servers
	var prometheusServer *http.Server
	if serverSettings.PrometheusEnabled {
		prometheusServer := &http.Server{
			Addr:              ":8081",
			Handler:           promhttp.Handler(),
			ReadHeaderTimeout: 10 * time.Second,
		}
		go startServer(prometheusServer)
	}

	httpServer := &http.Server{
		Addr:              ":" + serverSettings.Port,
		Handler:           createHandler(database, serverSettings),
		ReadHeaderTimeout: 10 * time.Second,
	}
	go startServer(httpServer)

	// graceful shutdown
	var wg sync.WaitGroup
	wg.Add(2)
	go shutdownServer(httpServer, ctx, &wg)
	go shutdownServer(prometheusServer, ctx, &wg)
	wg.Wait()

	return nil
}

func startServer(s *http.Server) {
	log.Info("Starting server on %q", s.Addr)
	if err := s.ListenAndServe(); err != nil && !errors.Is(err, http.ErrServerClosed) {
		log.Error("error listening and serving: %v", err)
	}
}

func shutdownServer(s *http.Server, ctx context.Context, wg *sync.WaitGroup) {
	defer wg.Done()
	if s == nil {
		return
	}

	<-ctx.Done()
	shutdownCtx := context.Background()
	shutdownCtx, cancel := context.WithTimeout(shutdownCtx, 10*time.Second)
	defer cancel()
	if err := s.Shutdown(shutdownCtx); err != nil {
		log.Error("error shutting down http server: %v", err)
	} else {
		log.Info("Gracefully stopped http server on %v", s.Addr)
	}
}

func createHandler(d *sqlx.DB, serverSettings *types.Settings) http.Handler {
	var router = http.NewServeMux()

	authDb := db.NewAuthSqlite(d)

	randomService := service.NewRandom()
	clockService := service.NewClock()
	mailService := service.NewMail(serverSettings)

	authService := service.NewAuth(authDb, randomService, clockService, mailService, serverSettings)
	accountService := service.NewAccount(d, randomService, clockService, serverSettings)
	treasureChestService := service.NewTreasureChest(d, randomService, clockService, serverSettings)
	transactionService := service.NewTransaction(d, randomService, clockService, serverSettings)
	transactionRecurringService := service.NewTransactionRecurring(d, randomService, clockService, serverSettings)

	render := handler.NewRender()
	indexHandler := handler.NewIndex(render)
	authHandler := handler.NewAuth(authService, render)
	accountHandler := handler.NewAccount(accountService, render)
	treasureChestHandler := handler.NewTreasureChest(treasureChestService, transactionRecurringService, render)
	transactionHandler := handler.NewTransaction(transactionService, accountService, treasureChestService, render)
	transactionRecurringHandler := handler.NewTransactionRecurring(transactionRecurringService, render)

	indexHandler.Handle(router)
	accountHandler.Handle(router)
	treasureChestHandler.Handle(router)
	authHandler.Handle(router)
	transactionHandler.Handle(router)
	transactionRecurringHandler.Handle(router)

	// Serve static files (CSS, JS and images)
	router.Handle("/static/", http.StripPrefix("/static/", http.FileServer(http.Dir("./static/"))))

	return middleware.Wrapper(
		router,
		middleware.SecurityHeaders(serverSettings),
		middleware.CacheControl,
		middleware.CrossSiteRequestForgery(authService),
		middleware.Authenticate(authService),
		middleware.Gzip,
		middleware.Log,
	)
}