package main

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

	"nfeeder/internal/db"
	"nfeeder/internal/web"

	"github.com/jackc/pgx/v5/pgxpool"
)

func main() {

	// @Logger
	// ------------------------------------------------------------
	var handler slog.Handler
	if os.Getenv("ENV") == "production" {
		handler = slog.NewJSONHandler(os.Stdout, nil)
	} else {
		handler = slog.NewTextHandler(os.Stdout, &slog.HandlerOptions{Level: slog.LevelDebug})
	}
	logger := slog.New(handler)

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

	// @DB
	// ------------------------------------------------------------
	connStr := os.Getenv("DATABASE_URL")
	if connStr == "" {
		log.Fatal("DATABASE_URL environment variable is not set")
	}

	poolConfig, err := pgxpool.ParseConfig(connStr)
	if err != nil {
		log.Fatalf("Unable to parse DATABASE_URL: %v", err)
	}

	poolConfig.MaxConns = 25
	poolConfig.MinConns = 5
	poolConfig.MaxConnLifetime = 5 * time.Minute
	poolConfig.MaxConnIdleTime = 30 * time.Second

	pool, err := pgxpool.NewWithConfig(ctx, poolConfig)
	if err != nil {
		log.Fatalf("Unable to create connection pool: %v", err)
	}

	// Verify the connection is alive before proceeding
	if err := pool.Ping(ctx); err != nil {
		log.Fatalf("Unable to reach database: %v", err)
	}
	logger.Info("database connection established", "max_conns", poolConfig.MaxConns, "min_conns", poolConfig.MinConns)

	defer func() {
		pool.Close()
		logger.Info("database pool closed")
	}()

	// Create Store sqlc wrapper
	store := db.NewStore(pool)

	// @Server
	// ------------------------------------------------------------
	jwtSecret := os.Getenv("JWT_SECRET")
	if jwtSecret == "" {
		log.Fatal("JWT_SECRET environment variable is required")
	}
	server := web.NewServer(store, logger, jwtSecret)

	// We run it in a goroutine so it doesn't block main from reaching the signal listener.
	go func() {
		addr := os.Getenv("SERVER_PORT")
		if connStr == "" {
			log.Fatal("SERVER_PORT environment variable is not set")
		}

		if err := server.Start(addr); err != nil && err != http.ErrServerClosed {
			log.Fatalf("Server failed: %v", err)
		}
	}()

	// @GracefulShutdown
	// ------------------------------------------------------------
	<-ctx.Done()
	logger.Warn("shutdown signal received", "signal", "SIGTERM/Interrupt")

	shutdownCtx, shutdownCtxCancel := context.WithTimeout(context.Background(), 10*time.Second)
	defer shutdownCtxCancel()

	if err := server.Shutdown(shutdownCtx); err != nil {
		log.Fatalf("Graceful shutdown failed: %v", err)
	}

	logger.Info("Server shutdown successful")
}