package chaos_test

import (
	"net"
	"net/http"
	"os"
	"os/exec"
	"path/filepath"
	"strings"
	"testing"
	"time"

	"git.asio.asia/nixevol/NixMsg/test/accept"
	"git.asio.asia/nixevol/NixMsg/test/chaos"
	"git.asio.asia/nixevol/NixMsg/test/harness"
)

const (
	q3ComposeProject = "q3-chaos"
	q3ProxyName      = "q3-nixmsg"
	epPassword       = "password1234"
)

// TestQ3ToxiproxyOfflineKeepDelivered：延迟 + 断开后，离线保留期内消息最终送达。
func TestQ3ToxiproxyOfflineKeepDelivered(t *testing.T) {
	if _, err := exec.LookPath("docker"); err != nil {
		t.Skip("docker 不可用，跳过 toxiproxy 弱网")
	}

	composeFile := filepath.Join(moduleRoot(t), "test", "chaos", "compose.yml")
	down := func() {
		cmd := exec.Command("docker", "compose", "-p", q3ComposeProject, "-f", composeFile, "down", "-v", "--remove-orphans")
		_ = cmd.Run()
	}
	down()
	t.Cleanup(down)

	up := exec.Command("docker", "compose", "-p", q3ComposeProject, "-f", composeFile, "up", "-d")
	if out, err := up.CombinedOutput(); err != nil {
		t.Fatalf("compose up: %v\n%s", err, out)
	}

	apiHostPort := waitComposePort(t, composeFile, "8474", 90*time.Second)
	listenHostPort := waitComposePort(t, composeFile, "8475", 90*time.Second)
	apiURL := "http://127.0.0.1:" + apiHostPort
	waitHTTP(t, apiURL+"/version", 90*time.Second)

	srv, err := harness.Start(harness.Options{})
	if err != nil {
		t.Fatal(err)
	}
	defer func() { _ = srv.Stop() }()

	_, nixPort, err := net.SplitHostPort(srv.Addr)
	if err != nil {
		t.Fatal(err)
	}

	c := chaos.NewClient(apiURL)
	_ = c.DeleteProxy(q3ProxyName)
	if _, err := c.CreateProxy(q3ProxyName, "0.0.0.0:8475", "host.docker.internal:"+nixPort); err != nil {
		t.Fatalf("CreateProxy: %v", err)
	}
	t.Cleanup(func() { _ = c.DeleteProxy(q3ProxyName) })

	proxyBase := "http://127.0.0.1:" + listenHostPort
	if _, err := c.AddLatency(q3ProxyName, "q3-lag", 150, 50, ""); err != nil {
		t.Fatalf("AddLatency: %v", err)
	}

	ac := accept.AdminLogin(t, srv)
	accept.CreateEndpoint(t, ac, "q3alice01", epPassword)
	accept.CreateEndpoint(t, ac, "q3bob0001", epPassword)

	alice := accept.MQTTLogin(t, proxyBase, "q3alice01", epPassword)
	defer alice.Close()

	sendOff := alice.Request(t, map[string]any{
		"v": 1, "type": "send", "rid": "q3s1", "id": "q3-off-keep",
		"to":       map[string]any{"kind": "endpoint", "id": "q3bob0001"},
		"body":     map[string]any{"enc": "utf8", "data": "keep-me"},
		"delay_ms": int64(0),
		"offline":  map[string]any{"keep": true, "ttl_seconds": int64(86400)},
	})
	if !sendOff.OK {
		t.Fatalf("send offline keep: %+v", sendOff)
	}

	if _, err := c.AddResetPeer(q3ProxyName, "q3-rst", 0, ""); err != nil {
		t.Fatalf("AddResetPeer: %v", err)
	}
	time.Sleep(400 * time.Millisecond)
	_ = c.RemoveToxic(q3ProxyName, "q3-rst")
	_ = c.RemoveToxic(q3ProxyName, "q3-lag")

	bob := accept.MQTTLogin(t, proxyBase, "q3bob0001", epPassword)
	defer bob.Close()
	msg := bob.WaitType(t, "msg", 20*time.Second)
	if msg["id"] != "q3-off-keep" {
		t.Fatalf("want q3-off-keep got %v", msg)
	}
	bob.Request(t, map[string]any{"v": 1, "type": "ack", "rid": "q3a1", "from": "q3alice01", "id": "q3-off-keep"})
}

// TestQ3NetemUntested 记录本机 Windows 上 netem 20% 丢包未测原因。
func TestQ3NetemUntested(t *testing.T) {
	t.Log("未测：Linux netem 20% 丢包。本机为 Windows；无法在宿主直接用 tc/netem。" +
		"若只对 toxiproxy 容器网卡挂 netshoot，不等于 NixMsg 业务端到端丢包验收。" +
		"本波用 toxiproxy 延迟/断开覆盖弱网；netem 需 Linux 宿主或把服务放进同网络 Linux 容器后再测。")
}

func moduleRoot(t *testing.T) string {
	t.Helper()
	dir, err := os.Getwd()
	if err != nil {
		t.Fatal(err)
	}
	for {
		if _, err := os.Stat(filepath.Join(dir, "go.mod")); err == nil {
			return dir
		}
		parent := filepath.Dir(dir)
		if parent == dir {
			t.Fatal("go.mod not found")
		}
		dir = parent
	}
}

func waitComposePort(t *testing.T, composeFile, containerPort string, timeout time.Duration) string {
	t.Helper()
	deadline := time.Now().Add(timeout)
	var last string
	for time.Now().Before(deadline) {
		cmd := exec.Command("docker", "compose", "-p", q3ComposeProject, "-f", composeFile, "port", "toxiproxy", containerPort)
		out, err := cmd.CombinedOutput()
		last = strings.TrimSpace(string(out))
		if err == nil && last != "" {
			_, port, perr := net.SplitHostPort(normalizeComposeAddr(last))
			if perr == nil && port != "" {
				return port
			}
		}
		time.Sleep(400 * time.Millisecond)
	}
	t.Fatalf("compose port %s timeout, last=%q", containerPort, last)
	return ""
}

func normalizeComposeAddr(s string) string {
	s = strings.TrimSpace(s)
	if strings.HasPrefix(s, "[::]") {
		return "127.0.0.1" + s[len("[::]"):]
	}
	if strings.HasPrefix(s, "0.0.0.0:") {
		return "127.0.0.1" + s[len("0.0.0.0"):]
	}
	return s
}

func waitHTTP(t *testing.T, url string, timeout time.Duration) {
	t.Helper()
	client := &http.Client{Timeout: 2 * time.Second}
	deadline := time.Now().Add(timeout)
	var last error
	for time.Now().Before(deadline) {
		resp, err := client.Get(url)
		if err == nil {
			_ = resp.Body.Close()
			if resp.StatusCode < 500 {
				return
			}
			last = err
		} else {
			last = err
		}
		time.Sleep(400 * time.Millisecond)
	}
	t.Fatalf("wait HTTP %s: %v", url, last)
}