package socket

import (
	"testing"
	"time"

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

func validStartPaper() *altv1.StartPaperTradingRequest {
	return &altv1.StartPaperTradingRequest{
		AccountId:    "paper-1",
		Spec:         &altv1.BacktestRunSpec{StrategyId: "strategy-v1"},
		StartingCash: &altv1.Price{Currency: altv1.Currency_CURRENCY_KRW, Amount: &altv1.Decimal{Value: "10000000"}},
	}
}

func TestHandleStartPaperTradingForwards(t *testing.T) {
	fake := &fakeWorkerClient{paperStartRes: &altv1.StartPaperTradingResponse{
		State: &altv1.PaperTradingState{AccountId: "paper-1"},
	}}

	resp, err := handleStartPaperTrading(fake, validStartPaper())
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
	if fake.paperStartReq == nil {
		t.Fatal("expected request to be forwarded to worker")
	}
	if resp.GetState().GetAccountId() != "paper-1" {
		t.Errorf("unexpected account id: %q", resp.GetState().GetAccountId())
	}
}

func TestHandleStartPaperTradingValidation(t *testing.T) {
	fake := &fakeWorkerClient{}

	cases := []*altv1.StartPaperTradingRequest{
		{Spec: &altv1.BacktestRunSpec{StrategyId: "x"}, StartingCash: &altv1.Price{}}, // missing account_id
		{AccountId: "paper-1", StartingCash: &altv1.Price{}},                          // missing spec
		{AccountId: "paper-1", Spec: &altv1.BacktestRunSpec{StrategyId: "x"}},         // missing starting_cash
	}
	for i, req := range cases {
		resp, err := handleStartPaperTrading(fake, req)
		if err != nil {
			t.Fatalf("case %d: expected typed validation response, got error: %v", i, err)
		}
		requireBacktestError(t, resp.GetError(), backtestErrorInvalidRequest)
	}
	if fake.paperStartReq != nil {
		t.Error("worker must not be called when validation fails")
	}
}

func TestHandleStartPaperTradingNilWorker(t *testing.T) {
	resp, err := handleStartPaperTrading(nil, validStartPaper())
	if err != nil {
		t.Fatalf("expected typed unavailable response, got error: %v", err)
	}
	requireBacktestError(t, resp.GetError(), backtestErrorUnavailable)
}

func TestHandleStartPaperTradingConnectFailure(t *testing.T) {
	fake := &fakeWorkerClient{connectErr: workerclient.ErrUnavailable}

	resp, err := handleStartPaperTrading(fake, validStartPaper())
	if err != nil {
		t.Fatalf("expected typed unavailable response, got error: %v", err)
	}
	requireBacktestError(t, resp.GetError(), backtestErrorUnavailable)
	if fake.paperStartReq != nil {
		t.Error("request must not be forwarded on connect failure")
	}
}

func TestHandleStartPaperTradingMapsTimeout(t *testing.T) {
	fake := &fakeWorkerClient{err: workerclient.ErrTimeout}

	resp, err := handleStartPaperTrading(fake, validStartPaper())
	if err != nil {
		t.Fatalf("expected typed timeout response, got error: %v", err)
	}
	requireBacktestError(t, resp.GetError(), backtestErrorTimeout)
}

func TestHandleStartPaperTradingNilWorkerResponse(t *testing.T) {
	fake := &fakeWorkerClient{}

	resp, err := handleStartPaperTrading(fake, validStartPaper())
	if err != nil {
		t.Fatalf("expected typed internal response, got error: %v", err)
	}
	requireBacktestError(t, resp.GetError(), backtestErrorInternal)
	if fake.paperStartReq == nil {
		t.Error("expected worker to be called before nil response was detected")
	}
}

func TestHandleGetPaperTradingStateForwards(t *testing.T) {
	fake := &fakeWorkerClient{paperStateRes: &altv1.GetPaperTradingStateResponse{
		State: &altv1.PaperTradingState{AccountId: "paper-1"},
	}}

	resp, err := handleGetPaperTradingState(fake, &altv1.GetPaperTradingStateRequest{AccountId: "paper-1"})
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
	if fake.paperStateReq.GetAccountId() != "paper-1" {
		t.Errorf("account id not forwarded unchanged, got %q", fake.paperStateReq.GetAccountId())
	}
	if resp.GetState().GetAccountId() != "paper-1" {
		t.Errorf("unexpected account id: %q", resp.GetState().GetAccountId())
	}
}

func TestHandleGetPaperTradingStateRequiresAccountID(t *testing.T) {
	fake := &fakeWorkerClient{}

	resp, err := handleGetPaperTradingState(fake, &altv1.GetPaperTradingStateRequest{})
	if err != nil {
		t.Fatalf("expected typed validation response, got error: %v", err)
	}
	requireBacktestError(t, resp.GetError(), backtestErrorInvalidRequest)
	if fake.paperStateReq != nil {
		t.Error("worker must not be called when validation fails")
	}
}

func TestHandleGetPaperTradingStateNilWorkerResponse(t *testing.T) {
	fake := &fakeWorkerClient{}

	resp, err := handleGetPaperTradingState(fake, &altv1.GetPaperTradingStateRequest{AccountId: "paper-1"})
	if err != nil {
		t.Fatalf("expected typed internal response, got error: %v", err)
	}
	requireBacktestError(t, resp.GetError(), backtestErrorInternal)
	if fake.paperStateReq == nil {
		t.Error("expected request to be forwarded before nil response was detected")
	}
}

func TestPaperHandlersRegisteredInSession(t *testing.T) {
	registered := make(map[string]bool)
	for _, h := range sessionHandlers(nil) {
		registered[h.requestType] = true
	}
	for _, req := range []string{
		protoSocket.TypeNameOf(&altv1.StartPaperTradingRequest{}),
		protoSocket.TypeNameOf(&altv1.GetPaperTradingStateRequest{}),
	} {
		if !registered[req] {
			t.Errorf("missing API handler registration for %q", req)
		}
	}
}

func TestPaperSocketWorkerUnavailableReturnsTypedError(t *testing.T) {
	fake := &fakeWorkerClient{err: workerclient.ErrUnavailable}
	client := startBacktestAPITestClient(t, fake)

	resp, err := protoSocket.SendRequestTyped[*altv1.StartPaperTradingRequest, *altv1.StartPaperTradingResponse](
		&client.Communicator,
		validStartPaper(),
		500*time.Millisecond,
	)
	if err != nil {
		t.Fatalf("request should return typed error response without timeout: %v", err)
	}
	requireBacktestError(t, resp.GetError(), backtestErrorUnavailable)
	if fake.paperStartReq == nil {
		t.Fatal("valid start request should be forwarded before worker error is mapped")
	}
}

func TestPaperSocketValidationReturnsTypedError(t *testing.T) {
	fake := &fakeWorkerClient{}
	client := startBacktestAPITestClient(t, fake)

	resp, err := protoSocket.SendRequestTyped[*altv1.GetPaperTradingStateRequest, *altv1.GetPaperTradingStateResponse](
		&client.Communicator,
		&altv1.GetPaperTradingStateRequest{},
		500*time.Millisecond,
	)
	if err != nil {
		t.Fatalf("request should return typed error response without timeout: %v", err)
	}
	requireBacktestError(t, resp.GetError(), backtestErrorInvalidRequest)
	if fake.paperStateReq != nil {
		t.Fatal("worker must not be called for socket-level validation failures")
	}
}