package browser

import (
	"context"
	"errors"
	"net"
	"net/http"
	"net/http/httptest"
	"net/url"
	"os"
	"path/filepath"
	"strconv"
	"strings"
	"testing"

	"chub/internal/domain"
)

func TestCDPInspectorValidatesEndpointFromProfileFile(t *testing.T) {
	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if r.URL.Path != "/json/version" {
			t.Fatalf("path = %q", r.URL.Path)
		}
		_, _ = w.Write([]byte(`{"Browser":"Chrome/136.0.0.0"}`))
	}))
	defer server.Close()
	parsed, err := url.Parse(server.URL)
	if err != nil {
		t.Fatal(err)
	}
	_, portText, err := net.SplitHostPort(parsed.Host)
	if err != nil {
		t.Fatal(err)
	}
	profile := t.TempDir()
	if err := os.WriteFile(filepath.Join(profile, "DevToolsActivePort"), []byte(portText+"\n/devtools/browser/test\n"), 0o600); err != nil {
		t.Fatal(err)
	}
	endpoint, err := NewCDPInspector().InspectRemoteDebugEndpoint(context.Background(), domain.BrowserChrome, profile)
	if err != nil {
		t.Fatalf("InspectRemoteDebugEndpoint() error = %v", err)
	}
	port, _ := strconv.Atoi(portText)
	if endpoint.Port != port || endpoint.Browser != "Chrome/136.0.0.0" {
		t.Fatalf("endpoint = %#v", endpoint)
	}
	direct, err := NewCDPInspector().InspectRemoteDebugPort(context.Background(), domain.BrowserChrome, port)
	if err != nil || direct.Port != port {
		t.Fatalf("InspectRemoteDebugPort() = %#v, %v", direct, err)
	}
}

func TestCDPInspectorRejectsMismatchedAndMalformedEndpoints(t *testing.T) {
	profile := t.TempDir()
	if err := os.WriteFile(filepath.Join(profile, "DevToolsActivePort"), []byte("not-a-port\n/devtools/browser/test\n"), 0o600); err != nil {
		t.Fatal(err)
	}
	if _, err := NewCDPInspector().InspectRemoteDebugEndpoint(context.Background(), domain.BrowserChrome, profile); !errors.Is(err, ErrRemoteDebugEndpointUnavailable) {
		t.Fatalf("malformed endpoint error = %v", err)
	}

	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
		_, _ = w.Write([]byte(`{"Browser":"Edg/136.0.0.0"}`))
	}))
	defer server.Close()
	parsed, err := url.Parse(server.URL)
	if err != nil {
		t.Fatal(err)
	}
	_, portText, err := net.SplitHostPort(parsed.Host)
	if err != nil {
		t.Fatal(err)
	}
	if err := os.WriteFile(filepath.Join(profile, "DevToolsActivePort"), []byte(portText+"\n/devtools/browser/test\n"), 0o600); err != nil {
		t.Fatal(err)
	}
	if _, err := NewCDPInspector().InspectRemoteDebugEndpoint(context.Background(), domain.BrowserChrome, profile); !errors.Is(err, ErrRemoteDebugEndpointUnavailable) {
		t.Fatalf("mismatched endpoint error = %v", err)
	}
}

func TestCDPInspectorFindsNextAvailablePort(t *testing.T) {
	listener, err := net.Listen("tcp4", "127.0.0.1:0")
	if err != nil {
		t.Fatal(err)
	}
	defer listener.Close()
	start := listener.Addr().(*net.TCPAddr).Port
	port, err := NewCDPInspector().FindAvailableRemoteDebugPort(context.Background(), start)
	if err != nil {
		t.Fatal(err)
	}
	if port != start+1 {
		t.Fatalf("port = %d, want %d", port, start+1)
	}
}

func TestCDPInspectorListsVerifiedTargetsWithoutControlEndpoints(t *testing.T) {
	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		switch r.URL.Path {
		case "/json/version":
			_, _ = w.Write([]byte(`{"Browser":"Chrome/136.0.0.0"}`))
		case "/json/list":
			_, _ = w.Write([]byte(`[
				{"id":"page-1","type":"page","title":"运营后台","url":"https://user:secret@example.com/orders?token=hidden#section","webSocketDebuggerUrl":"ws://127.0.0.1/devtools/page/page-1"},
				{"id":"worker-1","type":"service_worker","title":"","url":"chrome-extension://example/worker.js?key=hidden"}
			]`))
		default:
			t.Fatalf("path = %q", r.URL.Path)
		}
	}))
	defer server.Close()
	parsed, err := url.Parse(server.URL)
	if err != nil {
		t.Fatal(err)
	}
	_, portText, err := net.SplitHostPort(parsed.Host)
	if err != nil {
		t.Fatal(err)
	}
	port, _ := strconv.Atoi(portText)

	targets, err := NewCDPInspector().ListRemoteDebugTargets(context.Background(), domain.BrowserChrome, port)
	if err != nil || len(targets) != 2 {
		t.Fatalf("ListRemoteDebugTargets() = %#v, %v", targets, err)
	}
	if targets[0].ID != "page-1" || targets[0].Type != "page" || targets[0].Title != "运营后台" || targets[0].URL != "https://example.com/orders" {
		t.Fatalf("first target = %#v", targets[0])
	}
	if targets[1].URL != "chrome-extension://example/worker.js" {
		t.Fatalf("second target URL = %q", targets[1].URL)
	}
}

func TestCDPInspectorRejectsMalformedOrOversizedTargetList(t *testing.T) {
	for _, test := range []struct {
		name     string
		status   int
		response string
	}{
		{name: "malformed JSON", status: http.StatusOK, response: `not-json`},
		{name: "too many targets", status: http.StatusOK, response: `[` + strings.Repeat(`{"id":"page","type":"page"},`, remoteDebugTargetsMaxCount) + `{"id":"last","type":"page"}]`},
		{name: "non-success status", status: http.StatusServiceUnavailable, response: `temporarily unavailable`},
	} {
		t.Run(test.name, func(t *testing.T) {
			server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
				if r.URL.Path == "/json/version" {
					_, _ = w.Write([]byte(`{"Browser":"Chrome/136.0.0.0"}`))
					return
				}
				w.WriteHeader(test.status)
				_, _ = w.Write([]byte(test.response))
			}))
			defer server.Close()
			parsed, err := url.Parse(server.URL)
			if err != nil {
				t.Fatal(err)
			}
			_, portText, err := net.SplitHostPort(parsed.Host)
			if err != nil {
				t.Fatal(err)
			}
			port, _ := strconv.Atoi(portText)
			if _, err := NewCDPInspector().ListRemoteDebugTargets(context.Background(), domain.BrowserChrome, port); !errors.Is(err, ErrRemoteDebugEndpointUnavailable) {
				t.Fatalf("ListRemoteDebugTargets() error = %v", err)
			}
		})
	}
}