package httpapi

import (
	"context"
	"errors"
	"io"
	"net"
	"net/http"
	"testing"
	"time"

	"cmroubao/backend-api/internal/config"
)

func TestNewServerAppliesAllSafetyLimits(t *testing.T) {
	cfg, err := config.Load(func(string) (string, bool) {
		return "", false
	})
	if err != nil {
		t.Fatalf("config.Load() error = %v", err)
	}
	handler := http.HandlerFunc(func(http.ResponseWriter, *http.Request) {})

	server := NewServer(cfg, handler)

	if server.Addr != cfg.HTTPAddress || server.Handler == nil {
		t.Fatalf("server = %+v", server)
	}
	if server.ReadHeaderTimeout != cfg.ReadHeaderTimeout ||
		server.ReadTimeout != cfg.ReadTimeout ||
		server.WriteTimeout != cfg.WriteTimeout ||
		server.IdleTimeout != cfg.IdleTimeout ||
		server.MaxHeaderBytes != cfg.MaxHeaderBytes {
		t.Fatal("server safety limits do not match config")
	}
}

func TestServerSupportsBoundedGracefulShutdown(t *testing.T) {
	cfg, err := config.Load(func(string) (string, bool) {
		return "", false
	})
	if err != nil {
		t.Fatalf("config.Load() error = %v", err)
	}
	server := NewServer(
		cfg,
		http.HandlerFunc(func(response http.ResponseWriter, _ *http.Request) {
			response.WriteHeader(http.StatusNoContent)
		}),
	)
	listener, err := net.Listen("tcp", "127.0.0.1:0")
	if err != nil {
		t.Fatalf("net.Listen() error = %v", err)
	}
	serverErrors := make(chan error, 1)
	go func() {
		serverErrors <- server.Serve(listener)
	}()

	client := http.Client{Timeout: time.Second}
	response, err := client.Get("http://" + listener.Addr().String())
	if err != nil {
		_ = listener.Close()
		t.Fatalf("GET server: %v", err)
	}
	_, _ = io.Copy(io.Discard, response.Body)
	_ = response.Body.Close()
	if response.StatusCode != http.StatusNoContent {
		t.Fatalf("status = %d", response.StatusCode)
	}

	shutdownContext, cancel := context.WithTimeout(
		context.Background(),
		time.Second,
	)
	defer cancel()
	if err := server.Shutdown(shutdownContext); err != nil {
		t.Fatalf("Shutdown() error = %v", err)
	}
	select {
	case err := <-serverErrors:
		if !errors.Is(err, http.ErrServerClosed) {
			t.Fatalf("Serve() error = %v", err)
		}
	case <-time.After(time.Second):
		t.Fatal("Serve() did not stop after Shutdown()")
	}
}