package main

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

	"calllinesystem/server/internal/config"
	"calllinesystem/server/internal/database"
	"calllinesystem/server/internal/httpapi"
)

func main() {
	logger := slog.New(slog.NewJSONHandler(os.Stdout, &slog.HandlerOptions{Level: slog.LevelInfo}))
	slog.SetDefault(logger)
	cfg, err := config.Load()
	if err != nil {
		logger.Error("invalid configuration", "error", err)
		os.Exit(1)
	}

	ctx, stop := signal.NotifyContext(context.Background(), syscall.SIGINT, syscall.SIGTERM)
	defer stop()
	db, err := database.Open(ctx, cfg.DatabaseURL, logger, database.OpenOptions{
		MaxOpenConns: cfg.DBMaxOpenConns, MaxIdleConns: cfg.DBMaxIdleConns,
		ConnMaxIdleTime: cfg.DBConnMaxIdleTime, ConnMaxLifetime: cfg.DBConnMaxLifetime,
	})
	if err != nil {
		logger.Error("database startup failed", "error", err)
		os.Exit(1)
	}
	defer database.Close(db)
	sqlDB, err := database.SQLDB(db)
	if err != nil {
		logger.Error("database handle failed", "error", err)
		os.Exit(1)
	}
	if cfg.MigrateOnStart {
		if err := database.Migrate(ctx, sqlDB, logger); err != nil {
			logger.Error("database migration failed", "error", err)
			os.Exit(1)
		}
	}
	database.StartMaintenance(ctx, sqlDB, logger, cfg.MaintenanceInterval, cfg.MaintenanceBatchSize)

	api, err := httpapi.New(db, cfg, logger)
	if err != nil {
		logger.Error("api startup failed", "error", err)
		os.Exit(1)
	}
	httpServer := &http.Server{
		Addr:              cfg.HTTPAddr,
		Handler:           api.Handler(),
		ReadHeaderTimeout: 5 * time.Second,
		ReadTimeout:       15 * time.Second,
		IdleTimeout:       60 * time.Second,
		MaxHeaderBytes:    1 << 20,
	}

	serveErr := make(chan error, 1)
	go func() {
		logger.Info("api listening", "addr", cfg.HTTPAddr, "environment", cfg.Environment)
		serveErr <- httpServer.ListenAndServe()
	}()

	select {
	case err := <-serveErr:
		if !errors.Is(err, http.ErrServerClosed) {
			logger.Error("http server failed", "error", err)
			os.Exit(1)
		}
	case <-ctx.Done():
		logger.Info("shutdown requested")
	}

	shutdownCtx, cancel := context.WithTimeout(context.Background(), cfg.ShutdownTimeout)
	defer cancel()
	if err := httpServer.Shutdown(shutdownCtx); err != nil {
		logger.Error("graceful shutdown failed", "error", err)
		_ = httpServer.Close()
	}
}