Create sell orders

db/init.sql

@@ -47,7 +47,7 @@ CREATE TABLE orders(
     side ORDER_SIDE NOT NULL,
     quantity BIGINT NOT NULL,
     price BIGINT NOT NULL,
-    invoice_id UUID NOT NULL REFERENCES invoices(id),
+    invoice_id UUID REFERENCES invoices(id),
     order_id UUID REFERENCES orders(id)
 );
 ALTER TABLE orders ADD CONSTRAINT order_price CHECK(price > 0 AND price < 100);

db/market.go

@@ -107,7 +107,7 @@ func (db *DB) FetchOrders(where *FetchOrdersWhere, orders *[]Order) error {
 func (db *DB) CreateOrder(tx *sql.Tx, ctx context.Context, order *Order) error {
 	if _, err := tx.ExecContext(ctx, ""+
 		"INSERT INTO orders(share_id, pubkey, side, quantity, price, invoice_id) "+
-		"VALUES ($1, $2, $3, $4, $5, $6)",
+		"VALUES ($1, $2, $3, $4, $5, CASE WHEN $6 = '' THEN NULL ELSE $6::UUID END)",
 		order.ShareId, order.Pubkey, order.Side, order.Quantity, order.Price, order.InvoiceId); err != nil {
 		return err
 	}
@@ -131,7 +131,7 @@ func (db *DB) FetchUserOrders(pubkey string, orders *[]Order) error {
 		"FROM orders o " +
 		"JOIN invoices i ON o.invoice_id = i.id " +
 		"JOIN shares s ON o.share_id = s.id " +
-		"WHERE o.pubkey = $1 AND i.confirmed_at IS NOT NULL " +
+		"WHERE o.pubkey = $1 AND ( (o.side = 'BUY' AND i.confirmed_at IS NOT NULL) OR o.side = 'SELL' ) " +
 		"ORDER BY o.created_at DESC"
 	rows, err := db.Query(query, pubkey)
 	if err != nil {
@@ -153,7 +153,7 @@ func (db *DB) FetchMarketOrders(marketId int64, orders *[]Order) error {
 		"FROM orders o " +
 		"JOIN shares s ON o.share_id = s.id " +
 		"JOIN invoices i ON i.id = o.invoice_id " +
-		"WHERE s.market_id = $1 AND i.confirmed_at IS NOT NULL " +
+		"WHERE s.market_id = $1 AND ( (o.side = 'BUY' AND i.confirmed_at IS NOT NULL) OR o.side = 'SELL' ) " +
 		"ORDER BY o.created_at DESC"
 	rows, err := db.Query(query, marketId)
 	if err != nil {
@@ -266,16 +266,16 @@ func (db *DB) FetchMarketStats(marketId int64, stats *MarketStats) error {
 	return nil
 }
 
-func (db *DB) FetchUserBalance(marketId int64, pubkey string, balance *map[string]any) error {
+func (db *DB) FetchUserBalance(tx *sql.Tx, ctx context.Context, marketId int, pubkey string, balance *map[string]any) error {
 	query := "" +
 		"SELECT s.description, " +
 		"SUM(CASE WHEN o.side = 'BUY' THEN o.quantity ELSE -o.quantity END) " +
 		"FROM orders o " +
 		"JOIN invoices i ON i.id = o.invoice_id " +
 		"JOIN shares s ON s.id = o.share_id " +
-		"WHERE o.pubkey = $1 AND s.market_id = $2 AND i.confirmed_at IS NOT NULL AND o.order_id IS NOT NULL " +
+		"WHERE o.pubkey = $1 AND s.market_id = $2 AND ( (o.side = 'BUY' AND i.confirmed_at IS NOT NULL AND o.order_id IS NOT NULL) OR o.side = 'SELL' ) " +
 		"GROUP BY o.pubkey, s.description"
-	rows, err := db.Query(query, pubkey, marketId)
+	rows, err := tx.QueryContext(ctx, query, pubkey, marketId)
 	if err != nil {
 		return err
 	}

server/router/handler/market.go

@@ -26,6 +26,7 @@ func HandleMarket(sc context.ServerContext) echo.HandlerFunc {
 			err      error
 			data     map[string]any
 			u        db.User
+			tx       *sql.Tx
 		)
 		if marketId, err = strconv.ParseInt(c.Param("id"), 10, 64); err != nil {
 			return echo.NewHTTPError(http.StatusBadRequest, "Bad Request")
@@ -48,8 +49,15 @@ func HandleMarket(sc context.ServerContext) echo.HandlerFunc {
 		}
 		if session := c.Get("session"); session != nil {
 			u = session.(db.User)
+			ctx, cancel := context_.WithTimeout(context_.TODO(), 10*time.Second)
+			defer cancel()
+			if tx, err = sc.Db.BeginTx(ctx, nil); err != nil {
+				return err
+			}
+			defer tx.Commit()
 			uBalance := make(map[string]any)
-			if err = sc.Db.FetchUserBalance(marketId, u.Pubkey, &uBalance); err != nil {
+			if err = sc.Db.FetchUserBalance(tx, ctx, int(marketId), u.Pubkey, &uBalance); err != nil {
+				tx.Rollback()
 				return err
 			}
 			lib.Merge(&data, &map[string]any{"user": uBalance})
@@ -181,43 +189,61 @@ func HandleOrder(sc context.ServerContext) echo.HandlerFunc {
 		}
 		description = fmt.Sprintf("%s %d %s shares @ %d sats [market:%d]", strings.ToUpper(o.Side), o.Quantity, s.Description, o.Price, s.MarketId)
 
-		// TODO: if SELL order, check share balance of user
+		if o.Side == "BUY" {
+			// === Create invoice ===
+			// We do this for BUY and SELL orders such that we can continue to use `invoice.confirmed_at IS NOT NULL`
+			// to check for confirmed orders
+			if invoice, err = sc.Lnd.CreateInvoice(tx, ctx, sc.Db, o.Pubkey, msats, description); err != nil {
+				tx.Rollback()
+				return err
+			}
+			// Create QR code to pay HODL invoice
+			if qr, err = lib.ToQR(invoice.PaymentRequest); err != nil {
+				tx.Rollback()
+				return err
+			}
+			if hash, err = lntypes.MakeHashFromStr(invoice.Hash); err != nil {
+				tx.Rollback()
+				return err
+			}
 
-		// Create HODL invoice
+			// Create (unconfirmed) order
-		if invoice, err = sc.Lnd.CreateInvoice(tx, ctx, sc.Db, o.Pubkey, msats, description); err != nil {
+			o.InvoiceId = invoice.Id
-			tx.Rollback()
+			if err := sc.Db.CreateOrder(tx, ctx, &o); err != nil {
-			return err
+				tx.Rollback()
-		}
+				return err
-		// Create QR code to pay HODL invoice
+			}
-		if qr, err = lib.ToQR(invoice.PaymentRequest); err != nil {
+			// need to commit before starting to poll invoice status
-			tx.Rollback()
+			tx.Commit()
-			return err
+			go sc.Lnd.CheckInvoice(sc.Db, hash)
-		}
+
-		if hash, err = lntypes.MakeHashFromStr(invoice.Hash); err != nil {
+			// TODO: find matching orders
-			tx.Rollback()
+
-			return err
+			data = map[string]any{
+				"id":     invoice.Id,
+				"bolt11": invoice.PaymentRequest,
+				"amount": msats,
+				"qr":     qr,
+			}
+			return c.JSON(http.StatusPaymentRequired, data)
 		}
 
-		// Create (unconfirmed) order
+		// sell order: check user balance
-		o.InvoiceId = invoice.Id
+		balance := make(map[string]any)
+		if err = sc.Db.FetchUserBalance(tx, ctx, s.MarketId, o.Pubkey, &balance); err != nil {
+			return err
+		}
+		if balance[s.Description].(int) < int(o.Quantity) {
+			tx.Rollback()
+			return c.JSON(http.StatusBadRequest, nil)
+		}
+		// SELL orders don't require payment by user
 		if err := sc.Db.CreateOrder(tx, ctx, &o); err != nil {
 			tx.Rollback()
 			return err
 		}
-
-		// need to commit before starting to poll invoice status
 		tx.Commit()
-		go sc.Lnd.CheckInvoice(sc.Db, hash)
+		return c.JSON(http.StatusCreated, nil)
-
-		// TODO: find matching orders
-
-		data = map[string]any{
-			"id":     invoice.Id,
-			"bolt11": invoice.PaymentRequest,
-			"amount": msats,
-			"qr":     qr,
-		}
-		return c.JSON(http.StatusPaymentRequired, data)
 	}
 }
 

vue/src/components/MarketOrders.vue

@@ -38,11 +38,20 @@ function mouseover (oid) {
 
 const click = (order) => {
   // redirect to form with prefilled inputs to match order
-  const stake = order.quantity * (100 - order.price)
+  if (order.side === 'BUY') {
-  const certainty = (100 - order.price) / 100
+    // match BUY YES with BUY NO and vice versa
-  const share = order.ShareDescription === 'YES' ? 'NO' : 'YES'
+    const stake = order.quantity * (100 - order.price)
-  const side = 'BUY'
+    const certainty = (100 - order.price) / 100
-  router.push(`/market/${marketId}/form?stake=${stake}&certainty=${certainty}&side=${side}&share=${share}`)
+    const share = order.ShareDescription === 'YES' ? 'NO' : 'YES'
+    router.push(`/market/${marketId}/form/buy?stake=${stake}&certainty=${certainty}&share=${share}`)
+  }
+  if (order.side === 'SELL') {
+    // match SELL YES with BUY YES and vice versa
+    const stake = order.quantity * order.price
+    const certainty = order.price / 100
+    const share = order.ShareDescription === 'YES' ? 'YES' : 'NO'
+    router.push(`/market/${marketId}/form/buy?stake=${stake}&certainty=${certainty}&share=${share}`)
+  }
 }
 
 const orders = ref([])

vue/src/components/SellOrderForm.vue

@@ -13,8 +13,8 @@
       <label>you sell:</label>
       <label>{{ shares }} {{ selected }} shares @ {{ price }} sats</label>
       <label>you make:</label>
-      <label>+{{ format(profit) }} sats</label>
+      <label>{{ format(profit) }} sats</label>
-      <button class="col-span-2" type="submit">submit sell order</button>
+      <button class="col-span-2" type="submit" :disabled="disabled">submit sell order</button>
     </form>
     <div v-if="err" class="red text-center">{{ err }}</div>
   </div>
@@ -34,7 +34,7 @@ const showForm = computed(() => selected.value !== null)
 const err = ref(null)
 
 // how many shares wants the user sell?
-const shares = ref(route.query.shares || 1)
+const shares = ref(route.query.shares || 0)
 // at which price?
 const price = ref(route.query.price || 50)
 // how high is the potential reward?
@@ -56,18 +56,12 @@ await fetch(url)
   .catch(console.error)
 // Currently, we only support binary markets.
 // (only events which can be answered with YES and NO)
-const yesShareId = computed(() => {
+const yesShareId = computed(() => market?.value.Shares.find(s => s.Description === 'YES').Id)
-  return market?.value.Shares.find(s => s.Description === 'YES').Id
+const noShareId = computed(() => market?.value.Shares.find(s => s.Description === 'NO').Id)
-})
+const shareId = computed(() => selected.value === 'YES' ? yesShareId.value : noShareId.value)
-const noShareId = computed(() => {
+const userShares = computed(() => (selected.value === 'YES' ? market.value.user?.YES : market.value.user?.NO) || 0)
-  return market?.value.Shares.find(s => s.Description === 'NO').Id
+
-})
+const disabled = computed(() => userShares.value === 0)
-const shareId = computed(() => {
-  return selected.value === 'YES' ? yesShareId.value : noShareId.value
-})
-const userShares = computed(() => {
-  return selected.value === 'YES' ? market.value.user.YES : market.value.user.NO
-})
 
 const submitForm = async () => {
   if (!session.isAuthenticated) return router.push('/login')