package payment

import (
	"encoding/hex"
	"encoding/xml"
	"fmt"
	"net/http"
	"net/url"
	"strings"

	"gitea.futuresens.co.uk/futuresens/cmstypes"
	"gitea.futuresens.co.uk/futuresens/hardlink/types"
	_ "github.com/denisenkom/go-mssqldb"
	log "github.com/sirupsen/logrus"
)

// XML parsing structs
type (
	TransactionRec struct {
		XMLName          xml.Name `xml:"TransactionPayload"`
		AmountMinorUnits string   `xml:"amount"`
		TransactionType  string   `xml:"transactionType"`
	}

	TransactionResultXML struct {
		XMLName xml.Name   `xml:"TransactionResult"`
		Entries []EntryXML `xml:"Entry"`
	}

	EntryXML struct {
		Key   string `xml:"Key"`
		Value string `xml:"Value"`
	}

	TransactionConfirmation struct {
		XMLName               xml.Name `xml:"TransactionConfirmation"`
		Result                string   `xml:"Result"`
		Errors                string   `xml:"Errors"`
		ErrorDescription      string   `xml:"ErrorDescription"`
		ReceiptDataCardholder string   `xml:"ReceiptDataCardholder"`
	}

	PaymentResult struct {
		Fields            map[string]string
		CardholderReceipt string
		Status            cmstypes.StatusRec
	}

	TransactionInfo struct {
		transactionRes   string
		transactionState string
	}
)

// ParseTransactionResult parses the XML into entries.
func (tr *TransactionResultXML) ParseTransactionResult(data []byte) error {
	if err := xml.Unmarshal(data, &tr); err != nil {
		return fmt.Errorf("XML unmarshal: %w", err)
	}
	return nil
}

func (ti *TransactionInfo) FillFromTransactionResult(trResult TransactionResultXML) {
	for _, e := range trResult.Entries {
		switch e.Key {
		case types.TransactionResult:
			ti.transactionRes = e.Value
		case types.TransactionState:
			ti.transactionState = e.Value
		}
	}
}

func (r *PaymentResult) FillFromTransactionResult(trResult TransactionResultXML) {
	if r.Fields == nil {
		r.Fields = make(map[string]string)
	}

	for _, e := range trResult.Entries {
		switch e.Key {

		case types.ReceiptData, types.ReceiptDataMerchant:
			// intentionally ignored

		case types.ReceiptDataCardholder:
			r.CardholderReceipt = e.Value

		case types.TransactionResult:
			r.Status.Message = e.Value
			r.Status.Code = http.StatusOK
			r.Fields[e.Key] = e.Value

		default:
			r.Fields[e.Key] = e.Value
		}
	}
}

// BuildRedirectURL builds the redirect URL to send the guest to after payment.
func BuildPaymentRedirectURL(result map[string]string) string {
	res := result[types.TransactionResult]

	// Transaction approved?
	if strings.EqualFold(res, types.ResultApproved) {
		// Transaction confirmed?
		if strings.EqualFold(result[types.ConfirmResult], types.ResultApproved) {
			log.WithField(types.LogResult, result[types.ConfirmResult]).
				Info("Transaction approved and confirmed")

			return buildSuccessURL(result)
		}

		// Not confirmed
		log.WithFields(log.Fields{types.LogFieldError: result[types.ConfirmResult], types.LogFieldDescription: result[types.ConfirmErrors]}).
			Error("Transaction approved but not confirmed")

		return BuildFailureURL(result[types.ConfirmResult], result[types.ConfirmErrors])
	}

	// Not approved
	return BuildFailureURL(res, result[types.Errors])
}

func BuildPreauthRedirectURL(result map[string]string) (string, bool) {
	res := result[types.TransactionResult]
	tType := result[types.TransactionType]

	// Transaction approved?
	if strings.EqualFold(res, types.ResultApproved) {
		switch {
		// Transaction type AccountVerification?
		case strings.EqualFold(tType, types.AccountVerificationType):
			log.WithField(types.LogResult, result[types.TransactionResult]).
				Info("Account verification approved")

			return buildSuccessURL(result), false

		// Transaction type Sale?
		case strings.EqualFold(tType, types.SaleTransactionType):
			// Transaction confirmed?
			log.WithField(types.LogResult, result[types.ConfirmResult]).
				Info("Amount preauthorized successfully")

			return buildSuccessURL(result), true
		}
	}

	// Not approved
	return BuildFailureURL(res, result[types.Errors]), false
}

func buildSuccessURL(result map[string]string) string {
	q := url.Values{}
	q.Set("CardNumber", hex.EncodeToString([]byte(result[types.PAN_MASKED])))
	q.Set("ExpiryDate", hex.EncodeToString([]byte(result[types.EXPIRY_DATE])))
	q.Set("TxnReference", result[types.Reference])
	q.Set("CardHash", hex.EncodeToString([]byte(result[types.CardHash])))
	q.Set("CardReference", hex.EncodeToString([]byte(result[types.CardReference])))
	return (&url.URL{
		Path:     types.CheckinSuccessfulEndpoint,
		RawQuery: q.Encode(),
	}).String()
}

func BuildFailureURL(msgType, description string) string {
	q := url.Values{}
	if msgType != "" {
		description = fmt.Sprintf("Transaction %s", strings.ToLower(msgType))
	}
	if description != "" {
		msgType = types.ResultError
	}

	log.WithFields(log.Fields{types.LogFieldError: msgType, types.LogFieldDescription: description}).
		Error("Transaction failed")

	q.Set("MsgType", msgType)
	q.Set("Description", description)
	return (&url.URL{
		Path:     types.CheckinUnsuccessfulEndpoint,
		RawQuery: q.Encode(),
	}).String()
}