package arifpay

import (
	"bytes"
	"context"
	"encoding/json"
	"errors"
	"fmt"
	"io"
	"net/http"

	"github.com/SamuelTariku/FortuneBet-Backend/internal/config"
	"github.com/SamuelTariku/FortuneBet-Backend/internal/domain"
	"github.com/SamuelTariku/FortuneBet-Backend/internal/services/wallet"
	"github.com/google/uuid"
)

type ArifpayService struct {
	cfg           *config.Config
	transferStore wallet.TransferStore
	walletSvc     *wallet.Service
	httpClient    *http.Client
}

func NewArifpayService(cfg *config.Config, transferStore wallet.TransferStore, walletSvc *wallet.Service, httpClient *http.Client) *ArifpayService {
	return &ArifpayService{
		cfg:           cfg,
		transferStore: transferStore,
		walletSvc:     walletSvc,
		httpClient:    httpClient,
	}
}

func (s *ArifpayService) CreateCheckoutSession(req domain.CheckoutSessionClientRequest, isDeposit bool) (map[string]any, error) {
	// Generate unique nonce
	nonce := uuid.NewString()

	var NotifyURL string

	if isDeposit{
		NotifyURL = s.cfg.ARIFPAY.C2BNotifyUrl
	}else{
		NotifyURL = s.cfg.ARIFPAY.B2CNotifyUrl
	}

	// Construct full checkout request
	checkoutReq := domain.CheckoutSessionRequest{
		CancelURL:      s.cfg.ARIFPAY.CancelUrl,
		Phone:          req.CustomerPhone, // must be in format 2519...
		Email:          req.CustomerEmail,
		Nonce:          nonce,
		SuccessURL:     s.cfg.ARIFPAY.SuccessUrl,
		ErrorURL:       s.cfg.ARIFPAY.ErrorUrl,
		NotifyURL:      NotifyURL,
		PaymentMethods: s.cfg.ARIFPAY.PaymentMethods,
		ExpireDate:     s.cfg.ARIFPAY.ExpireDate,
		Items: []struct {
			Name        string  `json:"name"`
			Quantity    int     `json:"quantity"`
			Price       float64 `json:"price"`
			Description string  `json:"description"`
		}{
			{
				Name:        s.cfg.ARIFPAY.ItemName,
				Quantity:    s.cfg.ARIFPAY.Quantity,
				Price:       req.Amount,
				Description: s.cfg.ARIFPAY.Description,
			},
		},
		Beneficiaries: []struct {
			AccountNumber string  `json:"accountNumber"`
			Bank          string  `json:"bank"`
			Amount        float64 `json:"amount"`
		}{
			{
				AccountNumber: s.cfg.ARIFPAY.BeneficiaryAccountNumber,
				Bank:          s.cfg.ARIFPAY.Bank,
				Amount:        req.Amount,
			},
		},
		Lang: s.cfg.ARIFPAY.Lang,
	}

	// Marshal to JSON
	payload, err := json.Marshal(checkoutReq)
	if err != nil {
		return nil, fmt.Errorf("failed to marshal checkout request: %w", err)
	}

	// Send request to Arifpay API
	url := fmt.Sprintf("%s/api/checkout/session", s.cfg.ARIFPAY.BaseURL)
	httpReq, err := http.NewRequest("POST", url, bytes.NewBuffer(payload))
	if err != nil {
		return nil, err
	}
	httpReq.Header.Set("Content-Type", "application/json")
	httpReq.Header.Set("x-arifpay-key", s.cfg.ARIFPAY.APIKey)

	resp, err := s.httpClient.Do(httpReq)
	if err != nil {
		return nil, err
	}
	defer resp.Body.Close()

	// Read response
	body, err := io.ReadAll(resp.Body)
	if err != nil {
		return nil, err
	}

	if resp.StatusCode != http.StatusOK {
		return nil, fmt.Errorf("failed to create checkout session: %s", string(body))
	}

	// Optionally unmarshal response to struct
	var result map[string]interface{}
	if err := json.Unmarshal(body, &result); err != nil {
		return nil, fmt.Errorf("invalid response from Arifpay: %w", err)
	}

	data := result["data"].(map[string]interface{})
	// paymentURL := data["paymentUrl"].(string)

	// Store transfer in DB
	transfer := domain.CreateTransfer{
		Amount:          domain.Currency(req.Amount),
		Verified:        false,
		Type:            domain.DEPOSIT,
		ReferenceNumber: nonce,
		SessionID:       fmt.Sprintf("%v", data["sessionId"]),
		Status:          string(domain.PaymentStatusPending),
	}

	if _, err := s.transferStore.CreateTransfer(context.Background(), transfer); err != nil {
		return nil, err
	}

	return data, nil
}

func (s *ArifpayService) CancelCheckoutSession(ctx context.Context, sessionID string) (*domain.CancelCheckoutSessionResponse, error) {
	// Build the cancel URL
	url := fmt.Sprintf("%s/api/sandbox/checkout/session/%s", s.cfg.ARIFPAY.BaseURL, sessionID)

	// Create the request
	req, err := http.NewRequestWithContext(ctx, http.MethodPost, url, nil)
	if err != nil {
		return nil, fmt.Errorf("failed to create request: %w", err)
	}

	// Add headers
	req.Header.Set("Content-Type", "application/json")
	req.Header.Set("x-arifpay-key", s.cfg.ARIFPAY.APIKey)

	// Execute request
	resp, err := s.httpClient.Do(req)
	if err != nil {
		return nil, fmt.Errorf("failed to execute cancel request: %w", err)
	}
	defer resp.Body.Close()

	// Read response body
	body, err := io.ReadAll(resp.Body)
	if err != nil {
		return nil, fmt.Errorf("failed to read cancel response: %w", err)
	}

	// Handle non-200 status codes
	if resp.StatusCode != http.StatusOK {
		return nil, fmt.Errorf("cancel request failed: status=%d, body=%s", resp.StatusCode, string(body))
	}

	// Decode into response struct
	var cancelResp domain.CancelCheckoutSessionResponse
	if err := json.Unmarshal(body, &cancelResp); err != nil {
		return nil, fmt.Errorf("failed to unmarshal cancel response: %w", err)
	}

	return &cancelResp, nil
}

func (s *ArifpayService) HandleWebhook(ctx context.Context, req domain.WebhookRequest, userId int64, isDepost bool) error {
	// 1. Get transfer by SessionID
	transfer, err := s.transferStore.GetTransferByReference(ctx, req.Transaction.TransactionID)
	if err != nil {
		return err
	}

	wallets, err := s.walletSvc.GetWalletsByUser(ctx, userId)
	if err != nil {
		return err
	}

	if transfer.Verified {
		return errors.New("transfer already verified")
	}

	// 2. Update transfer status
	newStatus := req.Transaction.TransactionStatus
	// if req.Transaction.TransactionStatus != "" {
	// 	newStatus = req.Transaction.TransactionStatus
	// }

	err = s.transferStore.UpdateTransferStatus(ctx, transfer.ID, newStatus)
	if err != nil {
		return err
	}

	err = s.transferStore.UpdateTransferVerification(ctx, transfer.ID, true)
	if err != nil {
		return err
	}

	// 3. If SUCCESS -> update customer wallet balance
	if (newStatus == "SUCCESS" && isDepost) || (newStatus == "FAILED" && !isDepost) {
		_, err = s.walletSvc.AddToWallet(ctx, wallets[0].ID, domain.Currency(req.TotalAmount), domain.ValidInt64{}, transfer.PaymentMethod, domain.PaymentDetails{
			ReferenceNumber: domain.ValidString{
				Value: req.Transaction.TransactionID,
				Valid: true,
			},
			BankNumber: domain.ValidString{
				Value: "",
				Valid: false,
			},
		}, "")
		if err != nil {
			return err
		}
	}

	return nil
}

func (s *ArifpayService) ExecuteTelebirrB2CTransfer(ctx context.Context, req domain.ArifpayB2CRequest, userId int64) error {
	// Step 1: Create Session
	referenceNum := uuid.NewString()

	sessionReq := domain.CheckoutSessionClientRequest{
		Amount:        req.Amount,
		CustomerEmail: req.CustomerEmail,
		CustomerPhone: req.CustomerPhone,
	}

	sessionResp, err := s.CreateCheckoutSession(sessionReq, false)
	if err != nil {
		return fmt.Errorf("failed to create session: %w", err)
	}

	// Step 2: Execute Transfer
	transferURL := fmt.Sprintf("%s/api/Telebirr/b2c/transfer", s.cfg.ARIFPAY.BaseURL)
	reqBody := map[string]any{
		"Sessionid":   sessionResp["sessionId"],
		"Phonenumber": req.PhoneNumber,
	}

	payload, err := json.Marshal(reqBody)
	if err != nil {
		return fmt.Errorf("failed to marshal transfer request: %w", err)
	}

	transferReq, err := http.NewRequestWithContext(ctx, http.MethodPost, transferURL, bytes.NewBuffer(payload))
	if err != nil {
		return fmt.Errorf("failed to build transfer request: %w", err)
	}
	transferReq.Header.Set("Content-Type", "application/json")
	transferReq.Header.Set("x-arifpay-key", s.cfg.ARIFPAY.APIKey)

	transferResp, err := s.httpClient.Do(transferReq)
	if err != nil {
		return fmt.Errorf("failed to execute transfer request: %w", err)
	}
	defer transferResp.Body.Close()

	if transferResp.StatusCode >= 300 {
		body, _ := io.ReadAll(transferResp.Body)
		return fmt.Errorf("transfer failed with status %d: %s", transferResp.StatusCode, string(body))
	}

	// Step 3: Store transfer in DB
	transfer := domain.CreateTransfer{
		Amount:          domain.Currency(req.Amount),
		Verified:        false,
		Type:            domain.WITHDRAW, // B2C = payout
		ReferenceNumber: referenceNum,
		SessionID:       fmt.Sprintf("%v", sessionResp["sessionId"]),
		Status:          string(domain.PaymentStatusPending),
		PaymentMethod:   domain.TRANSFER_ARIFPAY,
	}
	if _, err := s.transferStore.CreateTransfer(ctx, transfer); err != nil {
		return fmt.Errorf("failed to store transfer: %w", err)
	}

	// Step 4: Deduct from wallet
	userWallets, err := s.walletSvc.GetWalletsByUser(ctx, userId)
	if err != nil {
		return fmt.Errorf("failed to get user wallets: %w", err)
	}
	if len(userWallets) == 0 {
		return fmt.Errorf("no wallet found for user %d", userId)
	}

	_, err = s.walletSvc.DeductFromWallet(
		ctx,
		userWallets[0].ID,
		domain.Currency(req.Amount),
		domain.ValidInt64{},
		domain.TRANSFER_ARIFPAY,
		"",
	)
	if err != nil {
		return fmt.Errorf("failed to deduct from wallet: %w", err)
	}

	return nil
}

func (s *ArifpayService) ExecuteCBEB2CTransfer(ctx context.Context, req domain.ArifpayB2CRequest, userId int64) error {
	// Step 1: Create Session
	referenceNum := uuid.NewString()

	sessionReq := domain.CheckoutSessionClientRequest{
		Amount:        req.Amount,
		CustomerEmail: req.CustomerEmail,
		CustomerPhone: req.CustomerPhone,
	}

	sessionResp, err := s.CreateCheckoutSession(sessionReq, false)
	if err != nil {
		return fmt.Errorf("cbebirr: failed to create session: %w", err)
	}

	// Step 2: Execute Transfer
	transferURL := fmt.Sprintf("%s/api/Cbebirr/b2c/transfer", s.cfg.ARIFPAY.BaseURL)
	reqBody := map[string]any{
		"Sessionid":   sessionResp["sessionId"],
		"Phonenumber": req.PhoneNumber,
	}

	payload, err := json.Marshal(reqBody)
	if err != nil {
		return fmt.Errorf("cbebirr: failed to marshal transfer request: %w", err)
	}

	transferReq, err := http.NewRequestWithContext(ctx, http.MethodPost, transferURL, bytes.NewBuffer(payload))
	if err != nil {
		return fmt.Errorf("cbebirr: failed to build transfer request: %w", err)
	}
	transferReq.Header.Set("Content-Type", "application/json")
	transferReq.Header.Set("x-arifpay-key", s.cfg.ARIFPAY.APIKey)

	transferResp, err := s.httpClient.Do(transferReq)
	if err != nil {
		return fmt.Errorf("cbebirr: failed to execute transfer request: %w", err)
	}
	defer transferResp.Body.Close()

	if transferResp.StatusCode >= 300 {
		body, _ := io.ReadAll(transferResp.Body)
		return fmt.Errorf("cbebirr: transfer failed with status %d: %s", transferResp.StatusCode, string(body))
	}

	// Step 3: Store transfer in DB
	transfer := domain.CreateTransfer{
		Amount:          domain.Currency(req.Amount),
		Verified:        false,
		Type:            domain.WITHDRAW, // B2C = payout
		ReferenceNumber: referenceNum,
		SessionID:       fmt.Sprintf("%v", sessionResp["sessionId"]),
		Status:          string(domain.PaymentStatusPending),
		PaymentMethod:   domain.TRANSFER_ARIFPAY,
	}
	if _, err := s.transferStore.CreateTransfer(ctx, transfer); err != nil {
		return fmt.Errorf("cbebirr: failed to store transfer: %w", err)
	}

	// Step 4: Deduct from user wallet
	userWallets, err := s.walletSvc.GetWalletsByUser(ctx, userId)
	if err != nil {
		return fmt.Errorf("cbebirr: failed to get user wallets: %w", err)
	}
	if len(userWallets) == 0 {
		return fmt.Errorf("cbebirr: no wallet found for user %d", userId)
	}

	_, err = s.walletSvc.DeductFromWallet(
		ctx,
		userWallets[0].ID,
		domain.Currency(req.Amount),
		domain.ValidInt64{},
		domain.TRANSFER_ARIFPAY,
		"",
	)
	if err != nil {
		return fmt.Errorf("cbebirr: failed to deduct from wallet: %w", err)
	}

	return nil
}

func (s *ArifpayService) ExecuteMPesaB2CTransfer(ctx context.Context, req domain.ArifpayB2CRequest, userId int64) error {
	// Step 1: Create Session
	referenceNum := uuid.NewString()

	sessionReq := domain.CheckoutSessionClientRequest{
		Amount:        req.Amount,
		CustomerEmail: req.CustomerEmail,
		CustomerPhone: req.CustomerPhone,
	}

	sessionResp, err := s.CreateCheckoutSession(sessionReq, false)
	if err != nil {
		return fmt.Errorf("Mpesa: failed to create session: %w", err)
	}

	// Step 2: Execute Transfer
	transferURL := fmt.Sprintf("%s/api/Mpesa/b2c/transfer", s.cfg.ARIFPAY.BaseURL)
	reqBody := map[string]any{
		"Sessionid":   sessionResp["sessionId"],
		"Phonenumber": req.PhoneNumber,
	}

	payload, err := json.Marshal(reqBody)
	if err != nil {
		return fmt.Errorf("Mpesa: failed to marshal transfer request: %w", err)
	}

	transferReq, err := http.NewRequestWithContext(ctx, http.MethodPost, transferURL, bytes.NewBuffer(payload))
	if err != nil {
		return fmt.Errorf("Mpesa: failed to build transfer request: %w", err)
	}
	transferReq.Header.Set("Content-Type", "application/json")
	transferReq.Header.Set("x-arifpay-key", s.cfg.ARIFPAY.APIKey)

	transferResp, err := s.httpClient.Do(transferReq)
	if err != nil {
		return fmt.Errorf("Mpesa: failed to execute transfer request: %w", err)
	}
	defer transferResp.Body.Close()

	if transferResp.StatusCode >= 300 {
		body, _ := io.ReadAll(transferResp.Body)
		return fmt.Errorf("Mpesa: transfer failed with status %d: %s", transferResp.StatusCode, string(body))
	}

	// Step 3: Store transfer in DB
	transfer := domain.CreateTransfer{
		Amount:          domain.Currency(req.Amount),
		Verified:        false,
		Type:            domain.WITHDRAW, // B2C = payout
		ReferenceNumber: referenceNum,
		SessionID:       fmt.Sprintf("%v", sessionResp["sessionId"]),
		Status:          string(domain.PaymentStatusPending),
		PaymentMethod:   domain.TRANSFER_ARIFPAY,
	}
	if _, err := s.transferStore.CreateTransfer(ctx, transfer); err != nil {
		return fmt.Errorf("Mpesa: failed to store transfer: %w", err)
	}

	// Step 4: Deduct from user wallet
	userWallets, err := s.walletSvc.GetWalletsByUser(ctx, userId)
	if err != nil {
		return fmt.Errorf("Mpesa: failed to get user wallets: %w", err)
	}
	if len(userWallets) == 0 {
		return fmt.Errorf("Mpesa: no wallet found for user %d", userId)
	}

	_, err = s.walletSvc.DeductFromWallet(
		ctx,
		userWallets[0].ID,
		domain.Currency(req.Amount),
		domain.ValidInt64{},
		domain.TRANSFER_ARIFPAY,
		"",
	)
	if err != nil {
		return fmt.Errorf("Mpesa: failed to deduct from wallet: %w", err)
	}

	return nil
}

func (s *ArifpayService) VerifyTransactionByTransactionID(ctx context.Context, req domain.ArifpayVerifyByTransactionIDRequest) (*domain.WebhookRequest, error) {
	endpoint := fmt.Sprintf("%s/api/checkout/getSessionByTransactionId", s.cfg.ARIFPAY.BaseURL)

	// Marshal request payload
	bodyBytes, err := json.Marshal(req)
	if err != nil {
		return nil, fmt.Errorf("failed to marshal request: %w", err)
	}

	// Build HTTP request
	httpReq, err := http.NewRequestWithContext(ctx, http.MethodPost, endpoint, bytes.NewBuffer(bodyBytes))
	if err != nil {
		return nil, fmt.Errorf("failed to create request: %w", err)
	}

	httpReq.Header.Set("x-arifpay-key", s.cfg.ARIFPAY.APIKey)

	// Execute request
	resp, err := s.httpClient.Do(httpReq)
	if err != nil {
		return nil, fmt.Errorf("failed to call verify transaction API: %w", err)
	}
	defer resp.Body.Close()

	// Read response body
	respBytes, err := io.ReadAll(resp.Body)
	if err != nil {
		return nil, fmt.Errorf("failed to read response: %w", err)
	}

	// Handle non-200 responses
	if resp.StatusCode != http.StatusOK {
		return nil, fmt.Errorf("API returned status %d: %s", resp.StatusCode, string(respBytes))
	}

	// Decode into domain response
	var result domain.WebhookRequest
	if err := json.Unmarshal(respBytes, &result); err != nil {
		return nil, fmt.Errorf("failed to unmarshal response: %w", err)
	}

	return &result, nil
}

func (s *ArifpayService) VerifyTransactionBySessionID(ctx context.Context, sessionID string) (*domain.WebhookRequest, error) {
	endpoint := fmt.Sprintf("%s/api/ms/transaction/status/%s", s.cfg.ARIFPAY.BaseURL, sessionID)

	// Create HTTP GET request
	httpReq, err := http.NewRequestWithContext(ctx, http.MethodGet, endpoint, nil)
	if err != nil {
		return nil, fmt.Errorf("failed to create request: %w", err)
	}

	// Set required headers
	httpReq.Header.Set("x-arifpay-key", s.cfg.ARIFPAY.APIKey)

	// Execute request
	resp, err := s.httpClient.Do(httpReq)
	if err != nil {
		return nil, fmt.Errorf("failed to call verify transaction API: %w", err)
	}
	defer resp.Body.Close()

	// Read response body
	respBytes, err := io.ReadAll(resp.Body)
	if err != nil {
		return nil, fmt.Errorf("failed to read response: %w", err)
	}

	// Handle non-200 responses
	if resp.StatusCode != http.StatusOK {
		return nil, fmt.Errorf("API returned status %d: %s", resp.StatusCode, string(respBytes))
	}

	// Decode into domain response
	var result domain.WebhookRequest
	if err := json.Unmarshal(respBytes, &result); err != nil {
		return nil, fmt.Errorf("failed to unmarshal response: %w", err)
	}

	return &result, nil
}

func (s *ArifpayService) GetPaymentMethodsMapping() []domain.ARIFPAYPaymentMethod {
	return []domain.ARIFPAYPaymentMethod{
		{ID: 1, Name: "ACCOUNT"},
		{ID: 2, Name: "NONYMOUS_ACCOUNT"},
		{ID: 3, Name: "ANONYMOUS_CARD"},
		{ID: 4, Name: "TELEBIRR"},
		{ID: 5, Name: "AWASH"},
		{ID: 6, Name: "AWASH_WALLET"},
		{ID: 7, Name: "PSS"},
		{ID: 8, Name: "CBE"},
		{ID: 9, Name: "AMOLE"},
		{ID: 10, Name: "BOA"},
		{ID: 11, Name: "KACHA"},
		{ID: 12, Name: "ETHSWITCH"},
		{ID: 13, Name: "TELEBIRR_USSD"},
		{ID: 14, Name: "HELLOCASH"},
		{ID: 15, Name: "MPESSA"},
	}
}