Update transfer handlers to show and use card transformer that will use currency transformer as well if their field is not nil

db/transfer.go

@@ -14,6 +14,9 @@ type Transfer struct {
 	ToCardID                uint
 	ToCard                  *Card
 	Value                   uint64
+	HaveDifferentCurrencies bool
+	FromValue               uint64
+	ToValue                 uint64
 	Date                    time.Time
 	UserID                  uint
 	User                    *User
@@ -36,34 +39,65 @@ func (t *Transfer) SetUserID(id uint) {
 
 var (
 	ERROR_TRANSFER_FROMCARD_INVALID_USERID       = errors.New("Transfer's UserID and FromCard's UserID are not equal")
-	ERROR_TRANSFER_FROMCARD_INSUFFICIENT_BALANCE = errors.New("FromCard's Balance is lower than Transfer's Value")
+	ERROR_TRANSFER_FROMCARD_INSUFFICIENT_BALANCE = errors.New("FromCard's Balance is lower than Transfer's Value or FromValue")
 	ERROR_TRANSFER_TOCARD_INVALID_USERID         = errors.New("Transfer's UserID and ToCard's UserID are not equal")
+	ERROR_TRANSFER_CURRENCY_INCOSISTENCE         = errors.New("Transfer is using differenct currencies but FromValue or ToValue is not set approprietly")
 )
 
+func (t *Transfer) validateTransfer(fromCard, toCard *Card) error {
+	if fromCard.UserID != t.UserID {
+		return ERROR_TRANSFER_FROMCARD_INVALID_USERID
+	}
+	if toCard.UserID != t.UserID {
+		return ERROR_TRANSFER_TOCARD_INVALID_USERID
+	}
+	diffCurs := fromCard.CurrencyID != toCard.CurrencyID
+	if diffCurs && (t.FromValue == 0 || t.ToValue == 0) {
+		return ERROR_TRANSFER_CURRENCY_INCOSISTENCE
+	}
+	if !diffCurs && fromCard.Balance < t.Value {
+		return ERROR_TRANSFER_FROMCARD_INSUFFICIENT_BALANCE
+	}
+	if diffCurs && fromCard.Balance < t.FromValue {
+		return ERROR_TRANSFER_FROMCARD_INSUFFICIENT_BALANCE
+	}
+	return nil
+}
+
 func (t *Transfer) BeforeCreate(tx *gorm.DB) error {
 	fromCard := &Card{}
 	if err := tx.Find(fromCard, t.FromCardID).Error; err != nil {
 		return err
 	}
-	if fromCard.UserID != t.UserID {
+	toCard := &Card{}
-		return ERROR_TRANSFER_FROMCARD_INVALID_USERID
+	if err := tx.Find(toCard, t.ToCardID).Error; err != nil {
+		return err
 	}
-	if fromCard.Balance < t.Value {
+	if err := t.validateTransfer(fromCard, toCard); err != nil {
-		return ERROR_TRANSFER_FROMCARD_INSUFFICIENT_BALANCE
+		return err
 	}
+
+	t.HaveDifferentCurrencies = fromCard.CurrencyID != toCard.CurrencyID
+	// on same CurrencyID fromCard and toCard should use Value
+	if !t.HaveDifferentCurrencies {
 		fromCard.Balance -= t.Value
 		if err := tx.Save(fromCard).Error; err != nil {
 			return err
 		}
 		//
-	toCard := &Card{}
+		toCard.Balance += t.Value
-	if err := tx.Find(toCard, t.ToCardID).Error; err != nil {
+		if err := tx.Save(toCard).Error; err != nil {
 			return err
 		}
-	if toCard.UserID != t.UserID {
+		return nil
-		return ERROR_TRANSFER_TOCARD_INVALID_USERID
 	}
-	toCard.Balance += t.Value
+	// on DIFFERENT CurrencyID fromCard should use FromValue and toCard should use ToValue
+	fromCard.Balance -= t.FromValue
+	if err := tx.Save(fromCard).Error; err != nil {
+		return err
+	}
+	//
+	toCard.Balance += t.ToValue
 	if err := tx.Save(toCard).Error; err != nil {
 		return err
 	}
@@ -71,39 +105,43 @@ func (t *Transfer) BeforeCreate(tx *gorm.DB) error {
 }
 
 var (
-	ERROR_TRANSFER_FROMCARD_IDZERO             = errors.New("Transfer's FromCardID is zero")
+	ERROR_TRANSFER_TOCARD_INSUFFICIENT_BALANCE = errors.New("Transfer's ToCard's Balance is lower than Value of ToValue of transfer")
-	ERROR_TRANSFER_TOCARD_IDZERO               = errors.New("Transfer's ToCardID is zero")
-	ERROR_TRANSFER_TOCARD_INSUFFICIENT_BALANCE = errors.New("Transfer's ToCard's Balance is lower than value of transfer")
 )
 
 func (t *Transfer) BeforeUpdate(tx *gorm.DB) error {
-	var original Transfer
+	var original *Transfer
-	if err := tx.Find(&original, t.ID).Error; err != nil {
+	if err := tx.Find(original, t.ID).Error; err != nil {
 		return err
 	}
-	if original.FromCardID == 0 {
+	var origFromCard *Card
-		return ERROR_TRANSFER_FROMCARD_IDZERO
+	if err := tx.Find(origFromCard, original.FromCardID).Error; err != nil {
-	}
-	var origFromCard Card
-	if err := tx.Find(&origFromCard, original.FromCardID).Error; err != nil {
 		return err
 	}
-	origFromCard.Balance += original.Value
+	var origToCard *Card
-	if err := tx.Save(origFromCard).Error; err != nil {
+	if err := tx.Find(origToCard, original.ToCardID).Error; err != nil {
 		return err
 	}
 
-	if original.ToCardID == 0 {
+	diffCurs := origFromCard.CurrencyID != origToCard.CurrencyID
-		return ERROR_TRANSFER_FROMCARD_IDZERO
+	if !diffCurs {
-	}
+		origFromCard.Balance += original.Value
-	var origToCard Card
-	if err := tx.Find(&origToCard, original.ToCardID).Error; err != nil {
-		return err
-	}
 		if origToCard.Balance < original.Value {
 			return ERROR_TRANSFER_TOCARD_INSUFFICIENT_BALANCE
 		}
 		origToCard.Balance -= original.Value
+	} else {
+		if original.FromValue == 0 || original.ToValue == 0 {
+			return ERROR_TRANSFER_CURRENCY_INCOSISTENCE
+		}
+		origFromCard.Balance += original.FromValue
+		if origToCard.Balance < original.ToValue {
+			return ERROR_TRANSFER_TOCARD_INSUFFICIENT_BALANCE
+		}
+		origToCard.Balance -= original.ToValue
+	}
+	if err := tx.Save(origFromCard).Error; err != nil {
+		return err
+	}
 	if err := tx.Save(origToCard).Error; err != nil {
 		return err
 	}
@@ -112,25 +150,35 @@ func (t *Transfer) BeforeUpdate(tx *gorm.DB) error {
 	if err := tx.Find(fromCard, t.FromCardID).Error; err != nil {
 		return err
 	}
-	if fromCard.UserID != t.UserID {
+	toCard := &Card{}
-		return ERROR_TRANSFER_FROMCARD_INVALID_USERID
+	if err := tx.Find(toCard, t.ToCardID).Error; err != nil {
+		return err
 	}
-	if fromCard.Balance < t.Value {
+	if err := t.validateTransfer(fromCard, toCard); err != nil {
-		return ERROR_TRANSFER_FROMCARD_INSUFFICIENT_BALANCE
+		return err
 	}
+
+	t.HaveDifferentCurrencies = fromCard.CurrencyID != toCard.CurrencyID
+	// on same CurrencyID fromCard and toCard should use Value
+	if !t.HaveDifferentCurrencies {
 		fromCard.Balance -= t.Value
 		if err := tx.Save(fromCard).Error; err != nil {
 			return err
 		}
 		//
-	toCard := &Card{}
+		toCard.Balance += t.Value
-	if err := tx.Find(toCard, t.ToCardID).Error; err != nil {
+		if err := tx.Save(toCard).Error; err != nil {
 			return err
 		}
-	if toCard.UserID != t.UserID {
+		return nil
-		return ERROR_TRANSFER_TOCARD_INVALID_USERID
 	}
-	toCard.Balance += t.Value
+	// on DIFFERENT CurrencyID fromCard should use FromValue and toCard should use ToValue
+	fromCard.Balance -= t.FromValue
+	if err := tx.Save(fromCard).Error; err != nil {
+		return err
+	}
+	//
+	toCard.Balance += t.ToValue
 	if err := tx.Save(toCard).Error; err != nil {
 		return err
 	}
@@ -142,18 +190,31 @@ func (t *Transfer) AfterDelete(tx *gorm.DB) error {
 	if err := tx.Find(fromCard, t.FromCardID).Error; err != nil {
 		return err
 	}
-	fromCard.Balance += t.Value
-	if err := tx.Save(fromCard).Error; err != nil {
-		return err
-	}
 	toCard := &Card{}
 	if err := tx.Find(toCard, t.ToCardID).Error; err != nil {
 		return err
 	}
+	diffCurs := fromCard.CurrencyID != toCard.CurrencyID
+	if !diffCurs {
+		fromCard.Balance += t.Value
 		if toCard.Balance < t.Value {
 			return ERROR_TRANSFER_TOCARD_INSUFFICIENT_BALANCE
 		}
 		toCard.Balance -= t.Value
+		return nil
+	} else {
+		if t.FromValue == 0 || t.ToValue == 0 {
+			return ERROR_TRANSFER_CURRENCY_INCOSISTENCE
+		}
+		fromCard.Balance += t.FromValue
+		if toCard.Balance < t.ToValue {
+			return ERROR_TRANSFER_TOCARD_INSUFFICIENT_BALANCE
+		}
+		toCard.Balance -= t.ToValue
+	}
+	if err := tx.Save(fromCard).Error; err != nil {
+		return err
+	}
 	if err := tx.Save(toCard).Error; err != nil {
 		return err
 	}

handlers/card.go

@@ -1,12 +1,22 @@
 package handlers
 
 import (
+	"fmt"
+	"strconv"
+
 	"git.qowevisa.me/Qowevisa/fin-check-api/db"
 	"git.qowevisa.me/Qowevisa/fin-check-api/types"
 	"github.com/gin-gonic/gin"
+	"gorm.io/gorm"
 )
 
 var cardTransform func(inp *db.Card) types.DbCard = func(inp *db.Card) types.DbCard {
+	var curr types.DbCurrency
+	if inp.Currency != nil {
+		curr = currencyTransform(inp.Currency)
+	} else {
+		curr = types.DbCurrency{}
+	}
 	return types.DbCard{
 		ID:             inp.ID,
 		Name:           inp.Name,
@@ -15,6 +25,8 @@ var cardTransform func(inp *db.Card) types.DbCard = func(inp *db.Card) types.DbC
 		CreditLine:     inp.CreditLine,
 		LastDigits:     inp.LastDigits,
 		CurrencyID:     inp.CurrencyID,
+		Currency:       curr,
+		DisplayName:    fmt.Sprintf("%s •%s", inp.Name, inp.LastDigits),
 	}
 }
 
@@ -51,9 +63,20 @@ func CardGetAll(c *gin.Context) {
 		c.JSON(500, types.ErrorResponse{Message: err.Error()})
 		return
 	}
+	preloadCurrencies := c.DefaultQuery("preload_currencies", "false")
+	shouldPreloadCurrencies := false
+	if val, err := strconv.ParseBool(preloadCurrencies); err == nil {
+		shouldPreloadCurrencies = val
+	}
 	dbc := db.Connect()
 	var entities []*db.Card
-	if err := dbc.Find(&entities, db.Card{UserID: userID}).Error; err != nil {
+	var tx *gorm.DB
+	if shouldPreloadCurrencies {
+		tx = dbc.Preload("Currency")
+	} else {
+		tx = dbc
+	}
+	if err := tx.Find(&entities, db.Card{UserID: userID}).Error; err != nil {
 		c.JSON(500, types.ErrorResponse{Message: err.Error()})
 		return
 	}

handlers/transfer.go

@@ -1,18 +1,52 @@
 package handlers
 
 import (
+	"fmt"
+
 	"git.qowevisa.me/Qowevisa/fin-check-api/db"
 	"git.qowevisa.me/Qowevisa/fin-check-api/types"
 	"github.com/gin-gonic/gin"
 )
 
 var transferTransform func(inp *db.Transfer) types.DbTransfer = func(inp *db.Transfer) types.DbTransfer {
+	var fromCard types.DbCard
+	var toCard types.DbCard
+	if inp.FromCard != nil {
+		fromCard = cardTransform(inp.FromCard)
+	}
+	if inp.ToCard != nil {
+		toCard = cardTransform(inp.ToCard)
+	}
+	haveDiffCurrs := false
+	if inp.FromCard != nil && inp.FromCard.Currency != nil && inp.ToCard != nil && inp.ToCard.Currency != nil {
+		haveDiffCurrs = inp.FromCard.CurrencyID != inp.ToCard.CurrencyID
+	}
+	var showValue string
+	if haveDiffCurrs {
+		showValue = fmt.Sprintf("%d.%02d%s -> %d.%02d%s",
+			inp.FromValue/100,
+			inp.FromValue%100,
+			inp.FromCard.Currency.Symbol,
+			inp.ToValue/100,
+			inp.ToValue%100,
+			inp.ToCard.Currency.Symbol,
+		)
+	} else {
+		showValue = fmt.Sprintf("%d.%02d", inp.Value/100, inp.Value%100)
+	}
 	return types.DbTransfer{
 		ID:         inp.ID,
 		FromCardID: inp.FromCardID,
 		ToCardID:   inp.ToCardID,
 		Value:      inp.Value,
+		FromValue:  inp.FromValue,
+		ToValue:    inp.ToValue,
 		Date:       inp.Date,
+		//
+		ShowValue:               showValue,
+		HaveDifferentCurrencies: haveDiffCurrs,
+		FromCard:                fromCard,
+		ToCard:                  toCard,
 	}
 }
 
@@ -52,7 +86,7 @@ func TransferGetAll(c *gin.Context) {
 	}
 	dbc := db.Connect()
 	var entities []*db.Transfer
-	if err := dbc.Find(&entities, db.Transfer{UserID: userID}).Error; err != nil {
+	if err := dbc.Preload("FromCard.Currency").Preload("ToCard.Currency").Find(&entities, db.Transfer{UserID: userID}).Error; err != nil {
 		c.JSON(500, types.ErrorResponse{Message: err.Error()})
 		return
 	}
@@ -82,6 +116,8 @@ func TransferAdd(c *gin.Context) {
 		dst.ToCardID = src.ToCardID
 		dst.Value = src.Value
 		dst.Date = src.Date
+		dst.FromValue = src.FromValue
+		dst.ToValue = src.ToValue
 	})(c)
 }
 
@@ -107,6 +143,8 @@ func TransferPutId(c *gin.Context) {
 			dst.ToCardID = src.ToCardID
 			dst.Value = src.Value
 			dst.Date = src.Date
+			dst.FromValue = src.FromValue
+			dst.ToValue = src.ToValue
 		},
 		transferTransform,
 	)(c)

types/types.go

@@ -31,6 +31,9 @@ type DbCard struct {
 	CreditLine     uint64     `json:"credit_line" example:"500000"`
 	LastDigits     string     `json:"last_digits" example:"1111"`
 	CurrencyID     uint       `json:"currency_id" example:"1"`
+	Currency       DbCurrency `json:"currency"`
+	// Purely UI things
+	DisplayName string `json:"display_name" example:"CreditCard •4444"`
 }
 
 type DbCategory struct {
@@ -86,7 +89,14 @@ type DbTransfer struct {
 	FromCardID uint      `json:"from_card_id" example:"1"`
 	ToCardID   uint      `json:"to_card_id" example:"1"`
 	Value      uint64    `json:"value" example:"20000"`
+	FromValue  uint64    `json:"from_value" example:"20000"`
+	ToValue    uint64    `json:"to_value" example:"20000"`
 	Date       time.Time `json:"date" example:"29/11/2001 12:00"`
+	// Purely UI things
+	ShowValue               string `json:"show_value" example:"10.35$"`
+	HaveDifferentCurrencies bool   `json:"have_diff_currs" example:"false"`
+	FromCard                DbCard `json:"from_card"`
+	ToCard                  DbCard `json:"to_card"`
 }
 
 type DbItem struct {