package connector

import (
	"context"
	"testing"

	flatbuffers "github.com/google/flatbuffers/go"
	"google.golang.org/grpc/codes"
	"google.golang.org/grpc/status"

	"scrabble/pkg/fbs/scrabblefb"
	telegramv1 "scrabble/pkg/proto/telegram/v1"
	"scrabble/platform/telegram/internal/initdata"
	"scrabble/platform/telegram/internal/loginwidget"
)

// stubValidator returns a fixed user / error from Validate.
type stubValidator struct {
	user initdata.User
	err  error
}

func (s stubValidator) Validate(string) (initdata.User, error) { return s.user, s.err }

// stubWidgetValidator returns a fixed user / error from the Login Widget Validate.
type stubWidgetValidator struct {
	user loginwidget.User
	err  error
}

func (s stubWidgetValidator) Validate(string) (loginwidget.User, error) { return s.user, s.err }

// fakeSender records the delivery calls the server makes.
type fakeSender struct {
	notify []notifyCall
	text   []textCall
	err    error
}

type notifyCall struct {
	chatID                       int64
	text, buttonText, startParam string
}
type textCall struct {
	chatID int64
	text   string
}

func (f *fakeSender) Notify(_ context.Context, chatID int64, text, buttonText, startParam string) error {
	f.notify = append(f.notify, notifyCall{chatID, text, buttonText, startParam})
	return f.err
}

func (f *fakeSender) SendText(_ context.Context, chatID int64, text string) error {
	f.text = append(f.text, textCall{chatID, text})
	return f.err
}

func yourTurnPayload(gameID string) []byte {
	b := flatbuffers.NewBuilder(0)
	gid := b.CreateString(gameID)
	scrabblefb.YourTurnEventStart(b)
	scrabblefb.YourTurnEventAddGameId(b, gid)
	b.Finish(scrabblefb.YourTurnEventEnd(b))
	return b.FinishedBytes()
}

func TestValidateInitData(t *testing.T) {
	want := initdata.User{ExternalID: "42", Username: "neo", FirstName: "Thomas", LanguageCode: "ru"}
	srv := NewServer(stubValidator{user: want}, stubWidgetValidator{}, &fakeSender{}, 0, nil)
	resp, err := srv.ValidateInitData(context.Background(), &telegramv1.ValidateInitDataRequest{InitData: "x"})
	if err != nil {
		t.Fatalf("validate: %v", err)
	}
	if resp.GetExternalId() != "42" || resp.GetUsername() != "neo" || resp.GetFirstName() != "Thomas" || resp.GetLanguageCode() != "ru" {
		t.Errorf("resp = %+v, want %+v", resp, want)
	}

	bad := NewServer(stubValidator{err: initdata.ErrInvalidInitData}, stubWidgetValidator{}, &fakeSender{}, 0, nil)
	if _, err := bad.ValidateInitData(context.Background(), &telegramv1.ValidateInitDataRequest{}); status.Code(err) != codes.InvalidArgument {
		t.Errorf("err code = %v, want InvalidArgument", status.Code(err))
	}
}

func TestValidateLoginWidget(t *testing.T) {
	want := loginwidget.User{ExternalID: "42", Username: "neo", FirstName: "Thomas"}
	srv := NewServer(stubValidator{}, stubWidgetValidator{user: want}, &fakeSender{}, 0, nil)
	resp, err := srv.ValidateLoginWidget(context.Background(), &telegramv1.ValidateLoginWidgetRequest{Data: "x"})
	if err != nil {
		t.Fatalf("validate: %v", err)
	}
	if resp.GetExternalId() != "42" || resp.GetUsername() != "neo" || resp.GetFirstName() != "Thomas" {
		t.Errorf("resp = %+v, want %+v", resp, want)
	}

	bad := NewServer(stubValidator{}, stubWidgetValidator{err: loginwidget.ErrInvalidLoginWidget}, &fakeSender{}, 0, nil)
	if _, err := bad.ValidateLoginWidget(context.Background(), &telegramv1.ValidateLoginWidgetRequest{}); status.Code(err) != codes.InvalidArgument {
		t.Errorf("err code = %v, want InvalidArgument", status.Code(err))
	}
}

func TestNotifyDelivers(t *testing.T) {
	const gameID = "7c9e6679-7425-40de-944b-e07fc1f90ae7"
	sender := &fakeSender{}
	srv := NewServer(stubValidator{}, stubWidgetValidator{}, sender, 0, nil)
	resp, err := srv.Notify(context.Background(), &telegramv1.NotifyRequest{
		ExternalId: "12345", Kind: "your_turn", Payload: yourTurnPayload(gameID), Language: "en",
	})
	if err != nil {
		t.Fatalf("notify: %v", err)
	}
	if !resp.GetDelivered() {
		t.Fatal("expected delivered=true")
	}
	if len(sender.notify) != 1 {
		t.Fatalf("notify calls = %d, want 1", len(sender.notify))
	}
	if got := sender.notify[0]; got.chatID != 12345 || got.startParam != "g"+gameID {
		t.Errorf("notify call = %+v, want chatID 12345 startParam g%s", got, gameID)
	}
}

func TestNotifySkipsUnrenderedKind(t *testing.T) {
	sender := &fakeSender{}
	srv := NewServer(stubValidator{}, stubWidgetValidator{}, sender, 0, nil)
	resp, err := srv.Notify(context.Background(), &telegramv1.NotifyRequest{
		ExternalId: "12345", Kind: "opponent_moved", Language: "en",
	})
	if err != nil {
		t.Fatalf("notify: %v", err)
	}
	if resp.GetDelivered() {
		t.Error("expected delivered=false for an unrendered kind")
	}
	if len(sender.notify) != 0 {
		t.Errorf("sender called %d times, want 0", len(sender.notify))
	}
}

func TestNotifyInvalidExternalID(t *testing.T) {
	srv := NewServer(stubValidator{}, stubWidgetValidator{}, &fakeSender{}, 0, nil)
	_, err := srv.Notify(context.Background(), &telegramv1.NotifyRequest{
		ExternalId: "not-a-number", Kind: "your_turn", Payload: yourTurnPayload("g"), Language: "en",
	})
	if status.Code(err) != codes.InvalidArgument {
		t.Errorf("err code = %v, want InvalidArgument", status.Code(err))
	}
}

func TestSendToUser(t *testing.T) {
	sender := &fakeSender{}
	srv := NewServer(stubValidator{}, stubWidgetValidator{}, sender, 0, nil)
	resp, err := srv.SendToUser(context.Background(), &telegramv1.SendToUserRequest{ExternalId: "999", Text: "hi"})
	if err != nil {
		t.Fatalf("send to user: %v", err)
	}
	if !resp.GetDelivered() || len(sender.text) != 1 || sender.text[0].chatID != 999 || sender.text[0].text != "hi" {
		t.Errorf("send to user = %v / calls %+v", resp.GetDelivered(), sender.text)
	}
}

func TestSendToGameChannel(t *testing.T) {
	t.Run("unconfigured", func(t *testing.T) {
		srv := NewServer(stubValidator{}, stubWidgetValidator{}, &fakeSender{}, 0, nil)
		_, err := srv.SendToGameChannel(context.Background(), &telegramv1.SendToGameChannelRequest{Text: "x"})
		if status.Code(err) != codes.FailedPrecondition {
			t.Errorf("err code = %v, want FailedPrecondition", status.Code(err))
		}
	})
	t.Run("configured", func(t *testing.T) {
		sender := &fakeSender{}
		srv := NewServer(stubValidator{}, stubWidgetValidator{}, sender, 555, nil)
		resp, err := srv.SendToGameChannel(context.Background(), &telegramv1.SendToGameChannelRequest{Text: "news"})
		if err != nil {
			t.Fatalf("send to channel: %v", err)
		}
		if !resp.GetDelivered() || len(sender.text) != 1 || sender.text[0].chatID != 555 {
			t.Errorf("send to channel calls = %+v", sender.text)
		}
	})
}