package socket

import (
	"context"
	"net"
	"testing"
	"time"

	altv1 "git.toki-labs.com/toki/alt/packages/contracts/gen/go/alt/v1"
	"git.toki-labs.com/toki/alt/services/api/internal/config"
	apiContracts "git.toki-labs.com/toki/alt/services/api/internal/contracts"
	"git.toki-labs.com/toki/alt/services/api/internal/workerclient"
	protoSocket "git.toki-labs.com/toki/proto-socket/go"
)

func TestServerRespondsToHelloRequest(t *testing.T) {
	ctx, cancel := context.WithCancel(context.Background())
	defer cancel()

	cfg := config.Config{
		Host:                 "127.0.0.1",
		Port:                 freeTCPPort(t),
		SocketPath:           "/socket",
		HeartbeatIntervalSec: 0,
		HeartbeatWaitSec:     0,
	}
	// Test with unavailable worker
	fakeWorker := &fakeWorkerClient{connectErr: workerclient.ErrUnavailable, isConnected: false}
	server := NewServerWithWorker(cfg, fakeWorker)
	if err := server.Start(ctx); err != nil {
		t.Fatalf("failed to start server: %v", err)
	}
	defer server.Stop()

	client, err := protoSocket.DialWsWithHeartbeat(ctx, cfg.Host, cfg.Port, cfg.SocketPath, 0, 0, apiContracts.ParserMap())
	if err != nil {
		t.Fatalf("failed to dial server: %v", err)
	}
	defer client.Close()

	res, err := protoSocket.SendRequestTyped[*altv1.HelloRequest, *altv1.HelloResponse](
		&client.Communicator,
		&altv1.HelloRequest{
			ClientName:         "alt-test",
			ClientVersion:      "test",
			AltProtocolVersion: "alt.v1",
		},
		2*time.Second,
	)
	if err != nil {
		t.Fatalf("failed to send hello request: %v", err)
	}

	if res.GetServerName() != serverName {
		t.Errorf("server name mismatch: expected %q, got %q", serverName, res.GetServerName())
	}
	if res.GetServerVersion() != serverVersion {
		t.Errorf("server version mismatch: expected %q, got %q", serverVersion, res.GetServerVersion())
	}
	if res.GetAltProtocolVersion() != "alt.v1" {
		t.Errorf("protocol version mismatch: expected %q, got %q", "alt.v1", res.GetAltProtocolVersion())
	}

	expectedCaps := map[string]bool{
		"hello":              true,
		"request-response":   true,
		"market-read":        true,
		"market-import":      true,
		"backtest-read":      true,
		"backtest-start":     true,
		"worker-execution":   true,
		"worker-unavailable": true,
	}
	for _, cap := range res.GetCapabilities() {
		if !expectedCaps[cap] {
			t.Errorf("unexpected capability: %q", cap)
		}
		delete(expectedCaps, cap)
	}
	if len(expectedCaps) > 0 {
		t.Errorf("missing expected capabilities: %v", expectedCaps)
	}
}

func TestServerRespondsToHelloRequest_WorkerAvailable(t *testing.T) {
	ctx, cancel := context.WithCancel(context.Background())
	defer cancel()

	cfg := config.Config{
		Host:                 "127.0.0.1",
		Port:                 freeTCPPort(t),
		SocketPath:           "/socket",
		HeartbeatIntervalSec: 0,
		HeartbeatWaitSec:     0,
	}
	// Test with available worker
	fakeWorker := &fakeWorkerClient{isConnected: true}
	server := NewServerWithWorker(cfg, fakeWorker)
	if err := server.Start(ctx); err != nil {
		t.Fatalf("failed to start server: %v", err)
	}
	defer server.Stop()

	client, err := protoSocket.DialWsWithHeartbeat(ctx, cfg.Host, cfg.Port, cfg.SocketPath, 0, 0, apiContracts.ParserMap())
	if err != nil {
		t.Fatalf("failed to dial server: %v", err)
	}
	defer client.Close()

	res, err := protoSocket.SendRequestTyped[*altv1.HelloRequest, *altv1.HelloResponse](
		&client.Communicator,
		&altv1.HelloRequest{
			ClientName:         "alt-test",
			ClientVersion:      "test",
			AltProtocolVersion: "alt.v1",
		},
		2*time.Second,
	)
	if err != nil {
		t.Fatalf("failed to send hello request: %v", err)
	}

	expectedCaps := map[string]bool{
		"hello":            true,
		"request-response": true,
		"market-read":      true,
		"market-import":    true,
		"backtest-read":    true,
		"backtest-start":   true,
		"worker-execution": true,
		"worker-available": true,
	}
	for _, cap := range res.GetCapabilities() {
		if !expectedCaps[cap] {
			t.Errorf("unexpected capability: %q", cap)
		}
		delete(expectedCaps, cap)
	}
	if len(expectedCaps) > 0 {
		t.Errorf("missing expected capabilities: %v", expectedCaps)
	}
}

func TestTwoServersIsolation(t *testing.T) {
	ctx, cancel := context.WithCancel(context.Background())
	defer cancel()

	cfg1 := config.Config{
		Host:                 "127.0.0.1",
		Port:                 freeTCPPort(t),
		SocketPath:           "/socket",
		HeartbeatIntervalSec: 0,
		HeartbeatWaitSec:     0,
	}
	fakeWorker1 := &fakeWorkerClient{isConnected: true}
	server1 := NewServerWithWorker(cfg1, fakeWorker1)
	if err := server1.Start(ctx); err != nil {
		t.Fatalf("failed to start server 1: %v", err)
	}
	defer server1.Stop()

	cfg2 := config.Config{
		Host:                 "127.0.0.1",
		Port:                 freeTCPPort(t),
		SocketPath:           "/socket",
		HeartbeatIntervalSec: 0,
		HeartbeatWaitSec:     0,
	}
	fakeWorker2 := &fakeWorkerClient{connectErr: workerclient.ErrUnavailable, isConnected: false}
	server2 := NewServerWithWorker(cfg2, fakeWorker2)
	if err := server2.Start(ctx); err != nil {
		t.Fatalf("failed to start server 2: %v", err)
	}
	defer server2.Stop()

	// Check server 1 capabilities
	client1, err := protoSocket.DialWsWithHeartbeat(ctx, cfg1.Host, cfg1.Port, cfg1.SocketPath, 0, 0, apiContracts.ParserMap())
	if err != nil {
		t.Fatalf("failed to dial server 1: %v", err)
	}
	defer client1.Close()

	res1, err := protoSocket.SendRequestTyped[*altv1.HelloRequest, *altv1.HelloResponse](
		&client1.Communicator,
		&altv1.HelloRequest{AltProtocolVersion: "alt.v1"},
		2*time.Second,
	)
	if err != nil {
		t.Fatalf("failed to send hello request to server 1: %v", err)
	}

	hasWorkerAvailable := false
	for _, cap := range res1.GetCapabilities() {
		if cap == "worker-available" {
			hasWorkerAvailable = true
		}
	}
	if !hasWorkerAvailable {
		t.Error("expected server 1 to advertise worker-available")
	}

	// Check server 2 capabilities
	client2, err := protoSocket.DialWsWithHeartbeat(ctx, cfg2.Host, cfg2.Port, cfg2.SocketPath, 0, 0, apiContracts.ParserMap())
	if err != nil {
		t.Fatalf("failed to dial server 2: %v", err)
	}
	defer client2.Close()

	res2, err := protoSocket.SendRequestTyped[*altv1.HelloRequest, *altv1.HelloResponse](
		&client2.Communicator,
		&altv1.HelloRequest{AltProtocolVersion: "alt.v1"},
		2*time.Second,
	)
	if err != nil {
		t.Fatalf("failed to send hello request to server 2: %v", err)
	}

	hasWorkerUnavailable := false
	for _, cap := range res2.GetCapabilities() {
		if cap == "worker-unavailable" {
			hasWorkerUnavailable = true
		}
	}
	if !hasWorkerUnavailable {
		t.Error("expected server 2 to advertise worker-unavailable")
	}
}

func TestSessionHandlersHaveUniqueRequestTypes(t *testing.T) {
	seen := make(map[string]int)
	for _, handler := range sessionHandlers(nil) {
		if handler.requestType == "" {
			t.Errorf("session handler has empty request type")
			continue
		}
		seen[handler.requestType]++
	}

	for requestType, count := range seen {
		if count > 1 {
			t.Errorf("request type %q registered %d times; duplicate handlers would panic the communicator", requestType, count)
		}
	}
}

func TestSessionHandlersCoverRequiredRequests(t *testing.T) {
	registered := make(map[string]bool)
	for _, handler := range sessionHandlers(nil) {
		registered[handler.requestType] = true
	}

	required := []string{
		protoSocket.TypeNameOf(&altv1.HelloRequest{}),
	}
	for _, requestType := range required {
		if !registered[requestType] {
			t.Errorf("required handler for %q is not registered", requestType)
		}
	}
}

func TestRegisterHandlersSkipsNilRegistrar(t *testing.T) {
	// registerHandlers must tolerate a malformed registry entry instead of
	// panicking during connection setup. A nil registrar is skipped without
	// dereferencing the client.
	defer func() {
		if r := recover(); r != nil {
			t.Fatalf("registerHandlers panicked on nil registrar: %v", r)
		}
	}()

	called := false
	handlers := []sessionHandler{
		{requestType: "alt.v1.NilRegistrarProbe", register: nil},
		{requestType: "alt.v1.LiveRegistrarProbe", register: func(*protoSocket.WsClient) { called = true }},
	}
	registerHandlers(nil, handlers)

	if !called {
		t.Fatal("expected non-nil registrar to run after nil registrar was skipped")
	}
}

func freeTCPPort(t *testing.T) int {
	t.Helper()

	listener, err := net.Listen("tcp", "127.0.0.1:0")
	if err != nil {
		t.Fatalf("failed to reserve TCP port: %v", err)
	}
	defer listener.Close()

	addr, ok := listener.Addr().(*net.TCPAddr)
	if !ok {
		t.Fatalf("unexpected listener address type %T", listener.Addr())
	}
	return addr.Port
}

func TestCapabilitiesAndHandlersSync(t *testing.T) {
	handlers := sessionHandlers(nil)
	registered := make(map[string]bool)
	for _, h := range handlers {
		registered[h.requestType] = true
	}

	caps := capabilitiesForSession(nil)
	capSet := make(map[string]bool)
	for _, c := range caps {
		capSet[c] = true
	}

	// 1. Check ListInstruments/ListBars -> market-read
	hasMarketRequest := registered[protoSocket.TypeNameOf(&altv1.ListInstrumentsRequest{})] &&
		registered[protoSocket.TypeNameOf(&altv1.ListBarsRequest{})]
	if hasMarketRequest && !capSet["market-read"] {
		t.Error("market-read capability missing although ListInstruments/ListBars handlers are registered")
	}

	// 1b. Check ImportDailyBars -> market-import
	if registered[protoSocket.TypeNameOf(&altv1.ImportDailyBarsRequest{})] && !capSet["market-import"] {
		t.Error("market-import capability missing although ImportDailyBars handler is registered")
	}

	// 2. Check backtest queries -> backtest-read
	hasBacktestReadRequest := registered[protoSocket.TypeNameOf(&altv1.ListBacktestRunsRequest{})] &&
		registered[protoSocket.TypeNameOf(&altv1.GetBacktestRunDetailRequest{})] &&
		registered[protoSocket.TypeNameOf(&altv1.GetBacktestResultRequest{})] &&
		registered[protoSocket.TypeNameOf(&altv1.CompareBacktestRunsRequest{})]
	if hasBacktestReadRequest && !capSet["backtest-read"] {
		t.Error("backtest-read capability missing although backtest query handlers are registered")
	}

	// 3. Check StartBacktest -> backtest-start, worker-execution
	hasBacktestStartRequest := registered[protoSocket.TypeNameOf(&altv1.StartBacktestRequest{})]
	if hasBacktestStartRequest {
		if !capSet["backtest-start"] {
			t.Error("backtest-start capability missing although StartBacktest handler is registered")
		}
		if !capSet["worker-execution"] {
			t.Error("worker-execution capability missing although StartBacktest handler is registered")
		}
	}
}