package virtualgameservice

import (
	"bytes"
	"context"
	"crypto/hmac"
	"crypto/sha256"
	"encoding/hex"
	"encoding/json"
	"errors"
	"fmt"
	"io"
	"log/slog"
	"math/rand/v2"
	"net/http"
	"sort"
	"strconv"
	"time"

	"github.com/SamuelTariku/FortuneBet-Backend/internal/config"
	"github.com/SamuelTariku/FortuneBet-Backend/internal/domain"
	"github.com/SamuelTariku/FortuneBet-Backend/internal/repository"
	"github.com/SamuelTariku/FortuneBet-Backend/internal/services/wallet"
	jwtutil "github.com/SamuelTariku/FortuneBet-Backend/internal/web_server/jwt"
)

type service struct {
	repo      repository.VirtualGameRepository
	walletSvc wallet.Service
	store     *repository.Store
	// virtualGameStore repository.VirtualGameRepository
	config *config.Config
	logger *slog.Logger
}

func New(repo repository.VirtualGameRepository, walletSvc wallet.Service, store *repository.Store, cfg *config.Config, logger *slog.Logger) VirtualGameService {
	return &service{
		repo:      repo,
		walletSvc: walletSvc,
		store:     store,
		config:    cfg,
		logger:    logger,
	}
}

func (s *service) GenerateGameLaunchURL(ctx context.Context, userID int64, gameID, currency, mode string) (string, error) {
	// 1. Fetch user
	user, err := s.store.GetUserByID(ctx, userID)
	if err != nil {
		s.logger.Error("Failed to get user", "userID", userID, "error", err)
		return "", err
	}

	// 2. Generate session and token
	sessionID := fmt.Sprintf("%d-%s-%d", userID, gameID, time.Now().UnixNano())
	token, err := jwtutil.CreatePopOKJwt(
		userID,
		user.CompanyID,
		user.PhoneNumber,
		currency,
		"en",
		mode,
		sessionID,
		s.config.PopOK.SecretKey,
		24*time.Hour,
	)
	if err != nil {
		s.logger.Error("Failed to create PopOK JWT", "userID", userID, "error", err)
		return "", err
	}

	// 3. Record virtual game history (optional but recommended)
	history := &domain.VirtualGameHistory{
		SessionID:             sessionID,
		UserID:                userID,
		CompanyID:             user.CompanyID.Value,
		Provider:              string(domain.PROVIDER_POPOK),
		GameID:                toInt64Ptr(gameID),
		TransactionType:       "LAUNCH",
		Amount:                0,
		Currency:              currency,
		ExternalTransactionID: sessionID,
		Status:                "COMPLETED",
		CreatedAt:             time.Now(),
		UpdatedAt:             time.Now(),
	}
	if err := s.repo.CreateVirtualGameHistory(ctx, history); err != nil {
		s.logger.Error("Failed to record game launch transaction", "error", err)
		// Non-fatal: log and continue
	}

	// 4. Prepare PopOK API request
	timestamp := time.Now().Format("02-01-2006 15:04:05")
	partnerID, err := strconv.Atoi(s.config.PopOK.ClientID)
	if err != nil {
		return "", fmt.Errorf("invalid PopOK ClientID: %v", err)
	}

	data := domain.PopokLaunchRequestData{
		GameMode: mode,
		GameID:   gameID,
		Lang:     "en",
		Token:    token,
		ExitURL:  "",
	}

	hash, err := generatePopOKHash(s.config.PopOK.SecretKey, timestamp, data)
	if err != nil {
		return "", fmt.Errorf("failed to generate PopOK hash: %w", err)
	}

	platformInt, err := strconv.Atoi(s.config.PopOK.Platform)
	if err != nil {
		return "", fmt.Errorf("invalid PopOK Platform: %v", err)
	}
	reqBody := domain.PopokLaunchRequest{
		Action:    "getLauncherURL",
		Platform:  platformInt,
		PartnerID: partnerID,
		Time:      timestamp,
		Hash:      hash,
		Data:      data,
	}

	// 5. Make API request
	bodyBytes, _ := json.Marshal(reqBody)
	resp, err := http.Post(s.config.PopOK.BaseURL+"/serviceApi.php", "application/json", bytes.NewReader(bodyBytes))
	if err != nil {
		return "", fmt.Errorf("PopOK POST failed: %w", err)
	}
	defer resp.Body.Close()

	var parsedResp domain.PopokLaunchResponse
	if err := json.NewDecoder(resp.Body).Decode(&parsedResp); err != nil {
		return "", fmt.Errorf("failed to parse PopOK response: %w", err)
	}
	if parsedResp.Code != 0 {
		return "", fmt.Errorf("PopOK error: %s", parsedResp.Message)
	}

	return parsedResp.Data.LauncherURL, nil
}

func (s *service) HandleCallback(ctx context.Context, callback *domain.PopOKCallback) error {
	s.logger.Info("Handling PopOK callback", "transactionID", callback.TransactionID, "type", callback.Type)

	if !s.verifySignature(callback) {
		s.logger.Error("Invalid callback signature", "transactionID", callback.TransactionID)
		return errors.New("invalid signature")
	}

	existingTx, err := s.repo.GetVirtualGameTransactionByExternalID(ctx, callback.TransactionID)
	if err != nil {
		s.logger.Error("Failed to check existing transaction", "transactionID", callback.TransactionID, "error", err)
		return err
	}
	if existingTx != nil {
		s.logger.Warn("Transaction already processed", "transactionID", callback.TransactionID)
		return nil // Idempotency
	}

	session, err := s.repo.GetVirtualGameSessionByToken(ctx, callback.SessionID)
	if err != nil || session == nil {
		s.logger.Error("Invalid or missing session", "sessionID", callback.SessionID, "error", err)
		return errors.New("invalid session")
	}

	wallets, err := s.walletSvc.GetWalletsByUser(ctx, session.UserID)
	if err != nil || len(wallets) == 0 {
		s.logger.Error("Failed to get wallets or no wallet found", "userID", session.UserID, "error", err)
		return errors.New("user has no wallet")
	}

	walletID := wallets[0].ID
	amount := int64(callback.Amount) // Convert to cents
	transactionType := callback.Type

	switch transactionType {
	case "BET":
		amount = -amount // Debit for bets
	case "WIN", "JACKPOT_WIN", "REFUND":
	default:
		s.logger.Error("Unknown transaction type", "transactionID", callback.TransactionID, "type", transactionType)
		return errors.New("unknown transaction type")
	}

	_, err = s.walletSvc.AddToWallet(ctx, walletID, domain.Currency(amount), domain.ValidInt64{}, domain.TRANSFER_DIRECT, domain.PaymentDetails{},
		fmt.Sprintf("Added %v to wallet for winning PopOkBet", amount),
	)
	if err != nil {
		s.logger.Error("Failed to update wallet", "walletID", walletID, "userID", session.UserID, "amount", amount, "error", err)
		return err
	}

	// Record transaction
	tx := &domain.VirtualGameTransaction{
		SessionID:             session.ID,
		UserID:                session.UserID,
		WalletID:              walletID,
		TransactionType:       transactionType,
		Amount:                amount,
		Currency:              callback.Currency,
		ExternalTransactionID: callback.TransactionID,
		Status:                "COMPLETED",
		CreatedAt:             time.Now(),
		UpdatedAt:             time.Now(),
	}

	if err := s.repo.CreateVirtualGameTransaction(ctx, tx); err != nil {
		s.logger.Error("Failed to create transaction", "transactionID", callback.TransactionID, "error", err)
		return err
	}

	s.logger.Info("Callback processed successfully", "transactionID", callback.TransactionID, "type", transactionType, "amount", callback.Amount)
	return nil
}

func (s *service) GetPlayerInfo(ctx context.Context, req *domain.PopOKPlayerInfoRequest) (*domain.PopOKPlayerInfoResponse, error) {
	claims, err := jwtutil.ParsePopOKJwt(req.ExternalToken, s.config.PopOK.SecretKey)
	fmt.Printf("\n\nClaims: %+v\n\n", claims)
	fmt.Printf("\n\nExternal token: %+v\n\n", req.ExternalToken)
	if err != nil {
		s.logger.Error("Failed to parse JWT", "error", err)
		return nil, fmt.Errorf("invalid token")
	}

	wallet, err := s.walletSvc.GetCustomerWallet(ctx, claims.UserID)
	if err != nil {
		s.logger.Error("No wallets found for user", "userID", claims.UserID)
		return nil, err
	}

	return &domain.PopOKPlayerInfoResponse{
		Country:  "ET",
		Currency: claims.Currency,
		Balance:  float64(wallet.RegularBalance.Float32()), // Convert cents to currency
		PlayerID: fmt.Sprintf("%d", claims.UserID),
	}, nil
}

func (s *service) ProcessBet(ctx context.Context, req *domain.PopOKBetRequest) (*domain.PopOKBetResponse, error) {
	// Validate external token and extract user context
	claims, err := jwtutil.ParsePopOKJwt(req.ExternalToken, s.config.PopOK.SecretKey)
	if err != nil {
		return nil, fmt.Errorf("invalid or expired token: %w", err)
	}

	// Validate required fields
	if req.Amount <= 0 {
		return nil, errors.New("invalid bet amount")
	}
	if req.TransactionID == "" {
		return nil, errors.New("missing transaction_id")
	}

	// Retrieve user's wallet
	wallet, err := s.walletSvc.GetCustomerWallet(ctx, claims.UserID)
	if err != nil {
		return nil, fmt.Errorf("failed to fetch wallet for user %d: %w", claims.UserID, err)
	}

	// Deduct amount from wallet
	_, err = s.walletSvc.DeductFromWallet(
		ctx,
		wallet.RegularID,
		domain.Currency(req.Amount),
		domain.ValidInt64{}, // optional linked transfer ID
		domain.TRANSFER_DIRECT,
		fmt.Sprintf("Virtual game bet placed (PopOK) - Txn: %s", req.TransactionID),
	)
	if err != nil {
		return nil, fmt.Errorf("failed to deduct from wallet (insufficient balance or wallet error): %w", err)
	}

	// Record the transaction
	tx := &domain.VirtualGameTransaction{
		UserID:                claims.UserID,
		CompanyID:             claims.CompanyID.Value,
		Provider:              string(domain.PROVIDER_POPOK),
		GameID:                req.GameID,
		TransactionType:       "BET",
		Amount:                -int64(req.Amount), // Represent bet as negative in accounting
		Currency:              req.Currency,
		ExternalTransactionID: req.TransactionID,
		Status:                "COMPLETED",
		CreatedAt:             time.Now(),
	}

	if err := s.repo.CreateVirtualGameTransaction(ctx, tx); err != nil {
		// Optionally rollback wallet deduction if transaction record fails
		_, addErr := s.walletSvc.AddToWallet(
			ctx,
			wallet.RegularID,
			domain.Currency(req.Amount),
			domain.ValidInt64{},
			domain.TRANSFER_DIRECT,
			domain.PaymentDetails{},
			fmt.Sprintf("Rollback refund for failed bet transaction (PopOK) - Txn: %s", req.TransactionID),
		)

		if addErr != nil {
			return nil, fmt.Errorf("failed to credit wallet: %w", addErr)
		}
		s.logger.Error("Failed to create bet transaction", "error", err, "txn_id", req.TransactionID, "user_id", claims.UserID)
		return nil, fmt.Errorf("failed to record bet transaction: %w", err)
	}

	// Return updated wallet balance
	updatedWallet, err := s.walletSvc.GetCustomerWallet(ctx, claims.UserID)
	if err != nil {
		return nil, fmt.Errorf("failed to refresh wallet balance: %w", err)
	}

	return &domain.PopOKBetResponse{
		TransactionID: req.TransactionID,
		ExternalTrxID: fmt.Sprintf("%v", tx.ID), // internal reference
		Balance:       float64(updatedWallet.RegularBalance.Float32()),
	}, nil
}

func (s *service) ProcessWin(ctx context.Context, req *domain.PopOKWinRequest) (*domain.PopOKWinResponse, error) {
	// 1. Validate token and get user ID
	claims, err := jwtutil.ParsePopOKJwt(req.ExternalToken, s.config.PopOK.SecretKey)
	if err != nil {
		s.logger.Error("Invalid token in win request", "error", err)
		return nil, fmt.Errorf("invalid token")
	}

	fmt.Printf("\n\nClaims: %+v\n\n", claims)

	// 2. Check for duplicate transaction (idempotency)
	existingTx, err := s.repo.GetVirtualGameTransactionByExternalID(ctx, req.TransactionID)
	if err != nil {
		s.logger.Error("Failed to check existing transaction", "error", err)
		return nil, fmt.Errorf("transaction check failed")
	}

	if existingTx != nil && existingTx.TransactionType == "WIN" {
		s.logger.Warn("Duplicate win transaction", "transactionID", req.TransactionID)
		wallet, _ := s.walletSvc.GetCustomerWallet(ctx, claims.UserID)
		// balance := 0.0
		// if len(wallets) > 0 {
		// 	balance = float64(wallets[0].Balance)
		// }
		return &domain.PopOKWinResponse{
			TransactionID: req.TransactionID,
			ExternalTrxID: fmt.Sprintf("%d", existingTx.ID),
			Balance:       float64(wallet.RegularBalance.Float32()),
		}, nil
	}

	// 3. Convert amount to cents
	// amountCents := int64(req.Amount)

	wallet, err := s.walletSvc.GetCustomerWallet(ctx, claims.UserID)
	if err != nil {
		return nil, fmt.Errorf("failed to read user wallets")
	}

	// 4. Credit to wallet
	_, err = s.walletSvc.AddToWallet(ctx, wallet.RegularID, domain.Currency(req.Amount), domain.ValidInt64{},
		domain.TRANSFER_DIRECT, domain.PaymentDetails{},
		fmt.Sprintf("Added %v to wallet for winning PopOkBet", req.Amount),
	)
	if err != nil {
		s.logger.Error("Failed to credit wallet", "userID", claims.UserID, "error", err)
		return nil, fmt.Errorf("wallet credit failed")
	}

	// userWallets, err := s.walletSvc.GetWalletsByUser(ctx, claims.UserID)
	// if err != nil {
	// 	return &domain.PopOKWinResponse{}, fmt.Errorf("Failed to read user wallets")
	// }
	// 5. Create transaction record
	tx := &domain.VirtualGameTransaction{
		UserID:                claims.UserID,
		CompanyID:             claims.CompanyID.Value,
		Provider:              string(domain.PROVIDER_POPOK),
		GameID:                req.GameID,
		TransactionType:       "WIN",
		Amount:                int64(req.Amount),
		Currency:              req.Currency,
		ExternalTransactionID: req.TransactionID,
		Status:                "COMPLETED",
		CreatedAt:             time.Now(),
	}

	if err := s.repo.CreateVirtualGameTransaction(ctx, tx); err != nil {
		s.logger.Error("Failed to create win transaction", "error", err)
		return nil, fmt.Errorf("transaction recording failed")
	}

	fmt.Printf("\n\n Win balance is:%v\n\n", float64(wallet.RegularBalance.Float32()))

	return &domain.PopOKWinResponse{
		TransactionID: req.TransactionID,
		ExternalTrxID: fmt.Sprintf("%v", tx.ID),
		Balance:       float64(wallet.RegularBalance.Float32()),
	}, nil
}

func (s *service) ProcessTournamentWin(ctx context.Context, req *domain.PopOKWinRequest) (*domain.PopOKWinResponse, error) {
	// --- 1. Validate token and get user ID ---
	claims, err := jwtutil.ParsePopOKJwt(req.ExternalToken, s.config.PopOK.SecretKey)
	if err != nil {
		s.logger.Error("Invalid token in tournament win request", "error", err)
		return nil, fmt.Errorf("invalid token")
	}

	// --- 2. Check for duplicate tournament win transaction (idempotency) ---
	existingTx, err := s.repo.GetVirtualGameTransactionByExternalID(ctx, req.TransactionID)
	if err != nil {
		s.logger.Error("Failed to check existing tournament transaction", "error", err)
		return nil, fmt.Errorf("transaction check failed")
	}
	if existingTx != nil && existingTx.TransactionType == "TOURNAMENT_WIN" {
		s.logger.Warn("Duplicate tournament win", "transactionID", req.TransactionID)
		wallet, _ := s.walletSvc.GetCustomerWallet(ctx, claims.UserID)
		return &domain.PopOKWinResponse{
			TransactionID: req.TransactionID,
			ExternalTrxID: fmt.Sprintf("%v", existingTx.ID),
			Balance:       float64(wallet.RegularBalance.Float32()),
		}, nil
	}

	// --- 3. Fetch wallet ---
	wallet, err := s.walletSvc.GetCustomerWallet(ctx, claims.UserID)
	if err != nil {
		return nil, fmt.Errorf("failed to fetch wallet for user %d: %w", claims.UserID, err)
	}

	// --- 4. Credit user wallet ---
	_, err = s.walletSvc.AddToWallet(
		ctx,
		wallet.RegularID,
		domain.Currency(req.Amount),
		domain.ValidInt64{},
		domain.TRANSFER_DIRECT,
		domain.PaymentDetails{
			ReferenceNumber: domain.ValidString{
				Value: req.TransactionID,
				Valid: true,
			},
		},
		fmt.Sprintf("Added %v to wallet for winning PopOK Tournament", req.Amount),
	)
	if err != nil {
		s.logger.Error("Failed to credit wallet for tournament", "userID", claims.UserID, "error", err)
		return nil, fmt.Errorf("wallet credit failed")
	}

	// --- 5. Record tournament win transaction ---
	tx := &domain.VirtualGameTransaction{
		UserID:                claims.UserID,
		CompanyID:             claims.CompanyID.Value,
		Provider:              string(domain.PROVIDER_POPOK),
		GameID:                req.GameID,
		TransactionType:       "TOURNAMENT_WIN",
		Amount:                int64(req.Amount),
		Currency:              req.Currency,
		ExternalTransactionID: req.TransactionID,
		Status:                "COMPLETED",
		CreatedAt:             time.Now(),
	}

	if err := s.repo.CreateVirtualGameTransaction(ctx, tx); err != nil {
		s.logger.Error("Failed to record tournament win transaction", "error", err)
		return nil, fmt.Errorf("transaction recording failed")
	}

	// --- 6. Return response with updated balance ---
	return &domain.PopOKWinResponse{
		TransactionID: req.TransactionID,
		ExternalTrxID: fmt.Sprintf("%v", tx.ID),
		Balance:       float64(wallet.RegularBalance.Float32()),
	}, nil
}

func (s *service) ProcessPromoWin(ctx context.Context, req *domain.PopOKWinRequest) (*domain.PopOKWinResponse, error) {
	// --- 1. Validate token and get user ID ---
	claims, err := jwtutil.ParsePopOKJwt(req.ExternalToken, s.config.PopOK.SecretKey)
	if err != nil {
		s.logger.Error("Invalid token in promo win request", "error", err)
		return nil, fmt.Errorf("invalid token")
	}

	// --- 2. Check for duplicate promo win transaction (idempotency) ---
	existingTx, err := s.repo.GetVirtualGameTransactionByExternalID(ctx, req.TransactionID)
	if err != nil {
		s.logger.Error("Failed to check existing promo transaction", "error", err)
		return nil, fmt.Errorf("transaction check failed")
	}
	if existingTx != nil && existingTx.TransactionType == "PROMO_WIN" {
		s.logger.Warn("Duplicate promo win", "transactionID", req.TransactionID)
		wallet, _ := s.walletSvc.GetCustomerWallet(ctx, claims.UserID)
		return &domain.PopOKWinResponse{
			TransactionID: req.TransactionID,
			ExternalTrxID: fmt.Sprintf("%v", existingTx.ID),
			Balance:       float64(wallet.RegularBalance.Float32()),
		}, nil
	}

	// --- 3. Fetch wallet ---
	wallet, err := s.walletSvc.GetCustomerWallet(ctx, claims.UserID)
	if err != nil {
		return nil, fmt.Errorf("failed to fetch wallet for user %d: %w", claims.UserID, err)
	}

	// --- 4. Credit user wallet ---
	_, err = s.walletSvc.AddToWallet(
		ctx,
		wallet.RegularID,
		domain.Currency(req.Amount),
		domain.ValidInt64{},
		domain.TRANSFER_DIRECT,
		domain.PaymentDetails{
			ReferenceNumber: domain.ValidString{
				Value: req.TransactionID,
				Valid: true,
			},
		},
		fmt.Sprintf("Added %v to wallet for winning PopOK Promo Win", req.Amount),
	)
	if err != nil {
		s.logger.Error("Failed to credit wallet for promo", "userID", claims.UserID, "error", err)
		return nil, fmt.Errorf("wallet credit failed")
	}

	// --- 5. Record promo win transaction ---
	tx := &domain.VirtualGameTransaction{
		UserID:                claims.UserID,
		CompanyID:             claims.CompanyID.Value,
		Provider:              string(domain.PROVIDER_POPOK),
		GameID:                req.GameID,
		TransactionType:       "PROMO_WIN",
		Amount:                int64(req.Amount),
		Currency:              req.Currency,
		ExternalTransactionID: req.TransactionID,
		Status:                "COMPLETED",
		CreatedAt:             time.Now(),
	}

	if err := s.repo.CreateVirtualGameTransaction(ctx, tx); err != nil {
		s.logger.Error("Failed to record promo win transaction", "error", err)
		return nil, fmt.Errorf("transaction recording failed")
	}

	// --- 6. Return response with updated balance ---
	return &domain.PopOKWinResponse{
		TransactionID: req.TransactionID,
		ExternalTrxID: fmt.Sprintf("%v", tx.ID),
		Balance:       float64(wallet.RegularBalance.Float32()),
	}, nil
}

func (s *service) ProcessCancel(ctx context.Context, req *domain.PopOKCancelRequest) (*domain.PopOKCancelResponse, error) {
	// --- 1. Validate token and get user ID ---
	claims, err := jwtutil.ParsePopOKJwt(req.ExternalToken, s.config.PopOK.SecretKey)
	if err != nil {
		s.logger.Error("Invalid token in cancel request", "error", err)
		return nil, fmt.Errorf("invalid token")
	}

	// --- 2. Fetch wallet ---
	wallet, err := s.walletSvc.GetCustomerWallet(ctx, claims.UserID)
	if err != nil {
		return nil, fmt.Errorf("failed to fetch wallet for user %d: %w", claims.UserID, err)
	}

	// --- 3. Find the original bet transaction ---
	originalBet, err := s.repo.GetVirtualGameTransactionByExternalID(ctx, req.TransactionID)
	if err != nil {
		s.logger.Error("Failed to find original bet", "transactionID", req.TransactionID, "error", err)
		return nil, fmt.Errorf("original bet not found")
	}

	// --- 4. Validate original transaction ---
	if originalBet == nil || originalBet.TransactionType != "BET" {
		s.logger.Error("Invalid original transaction for cancel", "transactionID", req.TransactionID)
		return nil, fmt.Errorf("invalid original transaction")
	}

	// --- 5. Check for duplicate cancellation ---
	if originalBet.Status == "CANCELLED" {
		s.logger.Warn("Transaction already cancelled", "transactionID", req.TransactionID)
		return &domain.PopOKCancelResponse{
			TransactionID: req.TransactionID,
			ExternalTrxID: fmt.Sprintf("%v", originalBet.ID),
			Balance:       float64(wallet.RegularBalance.Float32()),
		}, nil
	}

	// --- 6. Refund the bet amount ---
	refundAmount := -originalBet.Amount // Bet amounts are negative
	_, err = s.walletSvc.AddToWallet(
		ctx,
		wallet.RegularID,
		domain.Currency(refundAmount),
		domain.ValidInt64{},
		domain.TRANSFER_DIRECT,
		domain.PaymentDetails{
			ReferenceNumber: domain.ValidString{
				Value: req.TransactionID,
				Valid: true,
			},
		},
		fmt.Sprintf("Refunded %v to wallet for cancelling PopOK bet", refundAmount),
	)
	if err != nil {
		s.logger.Error("Failed to refund bet", "userID", claims.UserID, "error", err)
		return nil, fmt.Errorf("refund failed")
	}

	// --- 7. Mark original bet as cancelled and create cancel record ---
	cancelTx := &domain.VirtualGameTransaction{
		UserID:                 claims.UserID,
		TransactionType:        "CANCEL",
		Amount:                 refundAmount,
		Currency:               originalBet.Currency,
		ExternalTransactionID:  req.TransactionID,
		ReferenceTransactionID: fmt.Sprintf("%v", originalBet.ID),
		Status:                 "COMPLETED",
		CreatedAt:              time.Now(),
	}

	// Update original transaction status
	if err := s.repo.UpdateVirtualGameTransactionStatus(ctx, originalBet.ID, "CANCELLED"); err != nil {
		s.logger.Error("Failed to update transaction status", "error", err)
		return nil, fmt.Errorf("update failed")
	}

	// Create cancel transaction
	if err := s.repo.CreateVirtualGameTransaction(ctx, cancelTx); err != nil {
		s.logger.Error("Failed to create cancel transaction", "error", err)
		// Attempt to revert original transaction status
		if revertErr := s.repo.UpdateVirtualGameTransactionStatus(ctx, originalBet.ID, originalBet.Status); revertErr != nil {
			s.logger.Error("Failed to revert transaction status", "error", revertErr)
		}
		return nil, fmt.Errorf("create cancel transaction failed")
	}

	// --- 8. Return response with updated balance ---
	return &domain.PopOKCancelResponse{
		TransactionID: req.TransactionID,
		ExternalTrxID: fmt.Sprintf("%v", cancelTx.ID),
		Balance:       float64(wallet.RegularBalance.Float32()),
	}, nil
}

func generatePopOKHash(privateKey, timestamp string, data domain.PopokLaunchRequestData) (string, error) {
	// Marshal data to JSON (compact format, like json_encode in PHP)
	dataBytes, err := json.Marshal(data)
	if err != nil {
		return "", err
	}

	// Concatenate: privateKey + time + json_encoded(data)
	hashInput := fmt.Sprintf("%s%s%s", privateKey, timestamp, string(dataBytes))

	// SHA-256 hash
	hash := sha256.Sum256([]byte(hashInput))
	return hex.EncodeToString(hash[:]), nil
}

func (s *service) verifySignature(callback *domain.PopOKCallback) bool {
	data, _ := json.Marshal(struct {
		TransactionID string  `json:"transaction_id"`
		SessionID     string  `json:"session_id"`
		Type          string  `json:"type"`
		Amount        float64 `json:"amount"`
		Currency      string  `json:"currency"`
		Timestamp     int64   `json:"timestamp"`
	}{
		TransactionID: callback.TransactionID,
		SessionID:     callback.SessionID,
		Type:          callback.Type,
		Amount:        callback.Amount,
		Currency:      callback.Currency,
		Timestamp:     callback.Timestamp,
	})

	h := hmac.New(sha256.New, []byte(s.config.PopOK.SecretKey))
	h.Write(data)
	expected := hex.EncodeToString(h.Sum(nil))
	return expected == callback.Signature
}

func (s *service) ListGames(ctx context.Context, currency string) ([]domain.PopOKGame, error) {
	now := time.Now().Format("02-01-2006 15:04:05") // dd-mm-yyyy hh:mm:ss

	// Step 1: Construct payload without the hash
	data := map[string]interface{}{
		"action":    "gameList",
		"platform":  s.config.PopOK.Platform,
		"partnerId": s.config.PopOK.ClientID,
		"currency":  currency,
		"time":      now,
	}

	// Step 2: Marshal data to JSON for hash calculation
	// dataBytes, err := json.Marshal(data)
	// if err != nil {
	// 	s.logger.Error("Failed to marshal data for hash generation", "error", err)
	// 	return nil, err
	// }

	// Step 3: Calculate hash: sha256(privateKey + time + json(data))
	rawHash := s.config.PopOK.SecretKey + now
	hash := fmt.Sprintf("%x", sha256.Sum256([]byte(rawHash)))

	// Step 4: Add the hash to the payload
	data["hash"] = hash

	// Step 5: Marshal full payload with hash
	bodyBytes, err := json.Marshal(data)
	if err != nil {
		s.logger.Error("Failed to marshal final payload with hash", "error", err)
		return nil, err
	}

	// Step 6: Create and send the request
	req, err := http.NewRequestWithContext(ctx, "POST", s.config.PopOK.BaseURL+"/serviceApi.php", bytes.NewReader(bodyBytes))
	if err != nil {
		s.logger.Error("Failed to create game list request", "error", err)
		return nil, err
	}
	req.Header.Set("Content-Type", "application/json")
	req.Header.Set("User-Agent", "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/114.0.0.0 Safari/537.36")
	req.Header.Set("Accept", "application/json, text/plain, */*")
	req.Header.Set("Accept-Language", "en-US,en;q=0.9")

	client := &http.Client{Timeout: 10 * time.Second}
	resp, err := client.Do(req)
	if err != nil {
		s.logger.Error("Failed to send game list request", "error", err)
		return nil, err
	}
	defer resp.Body.Close()

	// Step 7: Handle response
	if resp.StatusCode != http.StatusOK {
		b, _ := io.ReadAll(resp.Body)
		return nil, fmt.Errorf("PopOK game list failed with status %d: %s", resp.StatusCode, string(b))
	}

	var gameList domain.PopOKGameListResponse
	if err := json.NewDecoder(resp.Body).Decode(&gameList); err != nil {
		s.logger.Error("Failed to decode game list response", "error", err)
		return nil, err
	}

	if gameList.Code != 0 {
		return nil, fmt.Errorf("PopOK error: %s", gameList.Message)
	}

	return gameList.Data.Slots, nil
}

func (s *service) RecommendGames(ctx context.Context, userID int64) ([]domain.GameRecommendation, error) {
	// Fetch all available games
	games, err := s.ListGames(ctx, "ETB")
	if err != nil || len(games) == 0 {
		return nil, fmt.Errorf("could not fetch games")
	}

	// Check if user has existing interaction
	history, err := s.repo.GetUserGameHistory(ctx, userID)
	if err != nil {
		s.logger.Warn("No previous game history", "userID", userID)
	}

	recommendations := []domain.GameRecommendation{}

	if len(history) > 0 {
		// Score games based on interaction frequency
		gameScores := map[int64]int{}
		for _, h := range history {
			if h.GameID != nil {
				gameScores[*h.GameID]++
			}
		}

		// Sort by score descending
		sort.SliceStable(games, func(i, j int) bool {
			return gameScores[int64(games[i].ID)] > gameScores[int64(games[j].ID)]
		})

		// Pick top 3
		for _, g := range games[:min(3, len(games))] {
			recommendations = append(recommendations, domain.GameRecommendation{
				GameID:    g.ID,
				GameName:  g.GameName,
				Thumbnail: g.Thumbnail,
				Bets:      g.Bets,
				Reason:    "Based on your activity",
			})
		}
	} else {
		// Pick 3 random games for new users
		rand.Shuffle(len(games), func(i, j int) {
			games[i], games[j] = games[j], games[i]
		})

		for _, g := range games[:min(3, len(games))] {
			recommendations = append(recommendations, domain.GameRecommendation{
				GameID:    g.ID,
				GameName:  g.GameName,
				Thumbnail: g.Thumbnail,
				Bets:      g.Bets,
				Reason:    "Random pick",
			})
		}
	}

	return recommendations, nil
}

func toInt64Ptr(s string) *int64 {
	id, err := strconv.ParseInt(s, 10, 64)
	if err != nil {
		return nil
	}
	return &id
}

func (s *service) AddFavoriteGame(ctx context.Context, userID, gameID int64) error {
	return s.repo.AddFavoriteGame(ctx, userID, gameID)
}

func (s *service) RemoveFavoriteGame(ctx context.Context, userID, gameID int64) error {
	return s.repo.RemoveFavoriteGame(ctx, userID, gameID)
}

func (s *service) ListFavoriteGames(ctx context.Context, userID int64) ([]domain.GameRecommendation, error) {
	gameIDs, err := s.repo.ListFavoriteGames(ctx, userID)
	if err != nil {
		s.logger.Error("Failed to list favorite games", "userID", userID, "error", err)
		return nil, err
	}

	if len(gameIDs) == 0 {
		return []domain.GameRecommendation{}, nil
	}

	allGames, err := s.ListGames(ctx, "ETB") // You can use dynamic currency if needed
	if err != nil {
		return nil, err
	}

	var favorites []domain.GameRecommendation
	idMap := make(map[int64]bool)
	for _, id := range gameIDs {
		idMap[id] = true
	}

	for _, g := range allGames {
		if idMap[int64(g.ID)] {
			favorites = append(favorites, domain.GameRecommendation{
				GameID:    g.ID,
				GameName:  g.GameName,
				Thumbnail: g.Thumbnail,
				Bets:      g.Bets,
				Reason:    "Marked as favorite",
			})
		}
	}

	return favorites, nil
}