/* SPDX-License-Identifier: MIT */
/*
 * Author: Jianhui Zhao <zhaojh329@gmail.com>
 */

package main

import (
	"context"
	"flag"
	"fmt"
	"io"
	"net/http"
	"net/http/cookiejar"
	"net/url"
	"strings"
	"sync"
	"testing"
	"time"

	"github.com/gorilla/websocket"
	"github.com/rs/zerolog/log"
)

const (
	testAckBlkSize = 4 * 1024
	testTermPerDev = 7
	testHttp       = true
)

// Run rtty clients with "-f username"
func TestRttysStress(t *testing.T) {
	duration := 10 * time.Minute

	timeoutFlag := flag.Lookup("test.timeout")
	if timeoutFlag != nil {
		duration = timeoutFlag.Value.(flag.Getter).Get().(time.Duration)
	}

	cfg := Config{
		AddrDev:  ":5912",
		AddrUser: ":5913",
	}

	srv := &RttyServer{cfg: cfg}

	go func() {
		err := srv.Run()
		if err != nil {
			log.Fatal().Msg(err.Error())
		}
	}()

	ctx, cancel := context.WithTimeout(context.Background(), duration-time.Second*2)
	defer cancel()

	time.Sleep(time.Millisecond * 100)

	log.Info().Msg("Waiting for devices to connect for testing...")

	devices := &sync.Map{}

	for {
		select {
		case <-ctx.Done():
			log.Info().Msg("Test timeout, exiting...")
			return
		default:
			time.Sleep(time.Second * 1)

			srv.groups.Range(func(key, value any) bool {
				group := key.(string)
				g := value.(*DeviceGroup)
				g.devices.Range(func(key, value any) bool {
					dev := value.(*Device)
					if _, loaded := devices.LoadOrStore(dev.id, group+dev.id); !loaded {
						go runDeviceTest(ctx, devices, group, dev.id)
					}
					return true
				})
				return true
			})
		}
	}
}

func runDeviceTest(ctx context.Context, devices *sync.Map, group, devID string) {
	ctx, cancel := context.WithCancel(ctx)

	defer func() {
		time.Sleep(time.Second)
		cancel()
		devices.Delete(group + devID)
	}()

	if testHttp {
		go runHttpTest(ctx, group, devID)
	}

	wg := &sync.WaitGroup{}

	for range testTermPerDev {
		wg.Add(1)
		go runWebSocketTest(ctx, group, devID, wg)
	}

	wg.Wait()
}

func runWebSocketTest(ctx context.Context, group, devID string, wg *sync.WaitGroup) {
	conn, _, err := websocket.DefaultDialer.Dial("ws://127.0.0.1:5913/connect/"+devID+"?group="+group, nil)
	if err != nil {
		log.Fatal().Msg(err.Error())
	}
	defer conn.Close()
	defer wg.Done()

	go func() {
		<-ctx.Done()
		conn.Close()
	}()

	ml := &sync.Mutex{}

	go func() {
		msg := []byte{0}
		msg = append(msg, []byte("cat /proc/cpuinfo\n")...)
		for {
			ml.Lock()
			err = conn.WriteMessage(websocket.BinaryMessage, msg)
			ml.Unlock()
			if err != nil {
				return
			}

			time.Sleep(time.Millisecond * 20)
		}
	}()

	unack := 0

	for {
		msgType, data, err := conn.ReadMessage()
		if err != nil {
			return
		}

		if msgType == websocket.BinaryMessage {
			if data[0] == 0 {
				unack += len(data) - 1

				if unack > testAckBlkSize {
					msg := fmt.Sprintf(`{"type":"ack","ack":%d}`, unack)
					ml.Lock()
					conn.WriteMessage(websocket.TextMessage, []byte(msg))
					ml.Unlock()
					unack = 0
				}
			}
		}
	}
}

func runHttpTest(ctx context.Context, group, devID string) {
	for {
		select {
		case <-ctx.Done():
			return
		default:
			runHttpTestOnce(ctx, group, devID)
		}
	}
}

func runHttpTestOnce(ctx context.Context, group, devID string) {
	addr := ""

	if group == "" {
		addr = "http://127.0.0.1:5913/web/"
	} else {
		addr = "http://127.0.0.1:5913/web2/" + group + "/"
	}

	addr += devID + "/http/" + encodeURIComponent("127.0.0.1:80/")

	jar, _ := cookiejar.New(nil)
	client := &http.Client{
		Jar: jar,
	}

	request, _ := http.NewRequestWithContext(ctx, "GET", addr, nil)

	for range 10 {
		res, err := client.Do(request)
		if err != nil {
			log.Info().Msg(err.Error())
			return
		}
		defer res.Body.Close()

		io.ReadAll(res.Body)

		time.Sleep(10 * time.Millisecond)
	}
}

func encodeURIComponent(str string) string {
	r := url.QueryEscape(str)
	r = strings.ReplaceAll(r, "+", "%20")
	return r
}