package workerclient

import (
	"context"
	"errors"
	"fmt"
	"net"
	"testing"
	"time"

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

func TestWorkerClient_Connect_Unavailable(t *testing.T) {
	// Port that is highly unlikely to have anything listening
	client := New("ws://127.0.0.1:54321/socket")
	ctx, cancel := context.WithTimeout(context.Background(), 100*time.Millisecond)
	defer cancel()

	err := client.Connect(ctx)
	if err == nil {
		t.Fatalf("expected error on unavailable worker, got nil")
	}
	if !errors.Is(err, ErrUnavailable) {
		t.Errorf("expected ErrUnavailable, got %v", err)
	}
}

func startFakeWorker(t *testing.T, handler func(*protoSocket.WsClient)) (int, func()) {
	l, err := net.Listen("tcp", "127.0.0.1:0")
	if err != nil {
		t.Fatalf("failed to listen on temporary port: %v", err)
	}
	port := l.Addr().(*net.TCPAddr).Port
	l.Close()

	wsServer := protoSocket.NewWsServer("127.0.0.1", port, "/socket", func(conn *websocket.Conn) *protoSocket.WsClient {
		return protoSocket.NewWsClient(conn, 30, 10, apiContracts.ParserMap())
	})
	wsServer.OnClientConnected = handler

	ctx, cancel := context.WithCancel(context.Background())
	if err := wsServer.Start(ctx); err != nil {
		t.Fatalf("failed to start fake worker server: %v", err)
	}

	cleanup := func() {
		cancel()
		_ = wsServer.Stop()
	}

	return port, cleanup
}

func TestWorkerClient_Hello_Success(t *testing.T) {
	port, cleanup := startFakeWorker(t, func(client *protoSocket.WsClient) {
		protoSocket.AddRequestListenerTyped[*altv1.HelloRequest, *altv1.HelloResponse](&client.Communicator, func(req *altv1.HelloRequest) (*altv1.HelloResponse, error) {
			return &altv1.HelloResponse{
				ServerName:         "alt-worker-fake",
				ServerVersion:      "test",
				AltProtocolVersion: req.GetAltProtocolVersion(),
			}, nil
		})
	})
	defer cleanup()

	client := New(fmt.Sprintf("ws://127.0.0.1:%d/socket", port))
	ctx := context.Background()

	if err := client.Connect(ctx); err != nil {
		t.Fatalf("failed to connect: %v", err)
	}
	defer client.Close()

	res, err := client.Hello(ctx, &altv1.HelloRequest{
		AltProtocolVersion: "alt.v1",
	})
	if err != nil {
		t.Fatalf("Hello request failed: %v", err)
	}

	if res.ServerName != "alt-worker-fake" {
		t.Errorf("expected ServerName to be alt-worker-fake, got %q", res.ServerName)
	}
}

func TestWorkerClient_Hello_Timeout(t *testing.T) {
	port, cleanup := startFakeWorker(t, func(client *protoSocket.WsClient) {
		protoSocket.AddRequestListenerTyped[*altv1.HelloRequest, *altv1.HelloResponse](&client.Communicator, func(req *altv1.HelloRequest) (*altv1.HelloResponse, error) {
			// Deliberately delay response to trigger timeout
			time.Sleep(200 * time.Millisecond)
			return &altv1.HelloResponse{
				ServerName: "alt-worker-fake",
			}, nil
		})
	})
	defer cleanup()

	client := New(fmt.Sprintf("ws://127.0.0.1:%d/socket", port))
	ctx := context.Background()

	if err := client.Connect(ctx); err != nil {
		t.Fatalf("failed to connect: %v", err)
	}
	defer client.Close()

	// Short deadline context
	timeoutCtx, cancel := context.WithTimeout(context.Background(), 50*time.Millisecond)
	defer cancel()

	_, err := client.Hello(timeoutCtx, &altv1.HelloRequest{
		AltProtocolVersion: "alt.v1",
	})
	if err == nil {
		t.Fatalf("expected timeout error, got nil")
	}
	if !errors.Is(err, ErrTimeout) {
		t.Errorf("expected ErrTimeout, got %v", err)
	}
}

func TestWorkerClient_Hello_ContextCanceled(t *testing.T) {
	port, cleanup := startFakeWorker(t, func(client *protoSocket.WsClient) {})
	defer cleanup()

	client := New(fmt.Sprintf("ws://127.0.0.1:%d/socket", port))
	ctx, cancel := context.WithCancel(context.Background())
	cancel()

	if err := client.Connect(context.Background()); err != nil {
		t.Fatalf("failed to connect: %v", err)
	}
	defer client.Close()

	_, err := client.Hello(ctx, &altv1.HelloRequest{AltProtocolVersion: "alt.v1"})
	if err == nil {
		t.Fatalf("expected error on canceled context, got nil")
	}
	if !errors.Is(err, context.Canceled) {
		t.Errorf("expected context.Canceled, got %v", err)
	}
}

func TestWorkerClient_Hello_ContextCanceled_Midflight(t *testing.T) {
	port, cleanup := startFakeWorker(t, func(client *protoSocket.WsClient) {
		protoSocket.AddRequestListenerTyped[*altv1.HelloRequest, *altv1.HelloResponse](&client.Communicator, func(req *altv1.HelloRequest) (*altv1.HelloResponse, error) {
			time.Sleep(200 * time.Millisecond)
			return &altv1.HelloResponse{ServerName: "alt-worker-fake"}, nil
		})
	})
	defer cleanup()

	client := New(fmt.Sprintf("ws://127.0.0.1:%d/socket", port))
	if err := client.Connect(context.Background()); err != nil {
		t.Fatalf("failed to connect: %v", err)
	}
	defer client.Close()

	ctx, cancel := context.WithCancel(context.Background())
	
	go func() {
		time.Sleep(50 * time.Millisecond)
		cancel()
	}()

	_, err := client.Hello(ctx, &altv1.HelloRequest{AltProtocolVersion: "alt.v1"})
	if err == nil {
		t.Fatalf("expected error on canceled context mid-flight, got nil")
	}
	if !errors.Is(err, context.Canceled) {
		t.Errorf("expected context.Canceled, got %v", err)
	}
}

func TestWorkerClient_Hello_DeadlineExceeded(t *testing.T) {
	port, cleanup := startFakeWorker(t, func(client *protoSocket.WsClient) {})
	defer cleanup()

	client := New(fmt.Sprintf("ws://127.0.0.1:%d/socket", port))
	ctx, cancel := context.WithDeadline(context.Background(), time.Now().Add(-1*time.Second))
	defer cancel()

	if err := client.Connect(context.Background()); err != nil {
		t.Fatalf("failed to connect: %v", err)
	}
	defer client.Close()

	_, err := client.Hello(ctx, &altv1.HelloRequest{AltProtocolVersion: "alt.v1"})
	if err == nil {
		t.Fatalf("expected error on exceeded deadline, got nil")
	}
	if !errors.Is(err, ErrTimeout) {
		t.Errorf("expected ErrTimeout, got %v", err)
	}
}