fix(amm): apply slippage to exact-output input

apps/amm/qml/components/swap/SwapCard.qml

@@ -52,10 +52,16 @@ Rectangle {
 
     readonly property real feeAmount: swapState.feeAmount(parsedSellAmount)
     readonly property real minReceivedAmount: swapState.minReceived(parsedBuyAmount, slippageTolerancePercent)
+    readonly property real maxSentAmount: swapState.maxSent(parsedSellAmount, slippageTolerancePercent)
     readonly property real priceImpactPercent: swapState.priceImpactPercent(parsedSellAmount, parsedBuyAmount, sellReserve, buyReserve)
 
-    readonly property string swapMode: editingSide === "buy" ? "swap-exact-output" : "swap-exact-input"
-    readonly property string swapModeText: editingSide === "buy" ? qsTr("Exact output") : qsTr("Exact input")
+    readonly property bool exactOutput: editingSide === "buy"
+    readonly property string swapMode: exactOutput ? "swap-exact-output" : "swap-exact-input"
+    readonly property string swapModeText: exactOutput ? qsTr("Exact output") : qsTr("Exact input")
+    readonly property string limitLabel: exactOutput ? qsTr("Max sent") : qsTr("Min received")
+    readonly property string limitText: exactOutput
+        ? swapState.formatTokenAmount(maxSentAmount, sellToken ? sellToken.symbol : "")
+        : swapState.formatTokenAmount(minReceivedAmount, buyToken ? buyToken.symbol : "")
 
     readonly property bool hasAmount: editingSide === "sell" ? parsedSellInput > 0 : parsedBuyInput > 0
     readonly property bool tokensSelected: sellToken !== null && buyToken !== null
@@ -102,7 +108,8 @@ Rectangle {
             "buyToken": buyToken ? buyToken.symbol : "",
             "sellAmount": formatAmountValue(parsedSellAmount),
             "buyAmount": formatAmountValue(parsedBuyAmount),
-            "minReceived": formatAmountValue(minReceivedAmount),
+            "minReceived": exactOutput ? "" : formatAmountValue(minReceivedAmount),
+            "maxSent": exactOutput ? formatAmountValue(maxSentAmount) : "",
             "feeAmount": swapState.formatTokenAmount(feeAmount, sellToken ? sellToken.symbol : ""),
             "priceImpactPercent": swapState.formatPercent(priceImpactPercent),
             "priceImpactPercentValue": priceImpactPercent,
@@ -211,7 +218,8 @@ Rectangle {
             feeText: swapState.formatTokenAmount(root.feeAmount, root.sellToken ? root.sellToken.symbol : "")
             priceImpactText: swapState.formatPercent(root.priceImpactPercent)
             priceImpactPercent: root.priceImpactPercent
-            minReceivedText: swapState.formatTokenAmount(root.minReceivedAmount, root.buyToken ? root.buyToken.symbol : "")
+            limitLabel: root.limitLabel
+            limitText: root.limitText
         }
 
         SlippageToleranceControl {

apps/amm/qml/components/swap/SwapConfirmationSummary.qml

@@ -22,16 +22,22 @@ ColumnLayout {
             spacing: 4
 
             Text {
+                objectName: "swapPayLabel"
                 Layout.fillWidth: true
-                text: qsTr("You pay")
+                text: root.snapshot.swapMode === "swap-exact-output"
+                    ? qsTr("You pay at most")
+                    : qsTr("You pay")
                 color: root.theme.colors.textSecondary
                 font.pixelSize: 12
             }
 
             Text {
+                objectName: "swapPayAmount"
                 Layout.fillWidth: true
                 text: qsTr("%1 %2")
-                    .arg(root.snapshot.sellAmount || "")
+                    .arg(root.snapshot.swapMode === "swap-exact-output"
+                        ? root.snapshot.maxSent || ""
+                        : root.snapshot.sellAmount || "")
                     .arg(root.snapshot.sellToken || "")
                 color: root.theme.colors.textPrimary
                 font.bold: true
@@ -54,16 +60,22 @@ ColumnLayout {
             spacing: 4
 
             Text {
+                objectName: "swapReceiveLabel"
                 Layout.fillWidth: true
-                text: qsTr("You receive at least")
+                text: root.snapshot.swapMode === "swap-exact-output"
+                    ? qsTr("You receive")
+                    : qsTr("You receive at least")
                 color: root.theme.colors.textSecondary
                 font.pixelSize: 12
             }
 
             Text {
+                objectName: "swapReceiveAmount"
                 Layout.fillWidth: true
                 text: qsTr("%1 %2")
-                    .arg(root.snapshot.minReceived || "")
+                    .arg(root.snapshot.swapMode === "swap-exact-output"
+                        ? root.snapshot.buyAmount || ""
+                        : root.snapshot.minReceived || "")
                     .arg(root.snapshot.buyToken || "")
                 color: root.theme.colors.textPrimary
                 font.bold: true
@@ -81,8 +93,11 @@ ColumnLayout {
         priceImpactText: root.snapshot.priceImpactPercent || ""
         priceImpactPercent: Number(root.snapshot.priceImpactPercentValue) || 0
         slippageText: root.snapshot.slippageTolerance || ""
-        minReceivedText: qsTr("%1 %2")
-            .arg(root.snapshot.minReceived || "")
-            .arg(root.snapshot.buyToken || "")
+        limitLabel: root.snapshot.swapMode === "swap-exact-output"
+            ? qsTr("Max sent")
+            : qsTr("Min received")
+        limitText: root.snapshot.swapMode === "swap-exact-output"
+            ? qsTr("%1 %2").arg(root.snapshot.maxSent || "").arg(root.snapshot.sellToken || "")
+            : qsTr("%1 %2").arg(root.snapshot.minReceived || "").arg(root.snapshot.buyToken || "")
     }
 }

apps/amm/qml/components/swap/SwapSummary.qml

@@ -10,7 +10,8 @@ Item {
     property string priceImpactText: ""
     property real priceImpactPercent: 0
     property string slippageText: ""
-    property string minReceivedText: ""
+    property string limitLabel: qsTr("Min received")
+    property string limitText: ""
 
     readonly property color priceImpactColor: {
         if (root.priceImpactPercent > 5) return "#F08A76";
@@ -126,20 +127,22 @@ Item {
             Layout.fillWidth: true
 
             Text {
+                objectName: "swapLimitLabel"
                 anchors.left: parent.left
                 anchors.verticalCenter: parent.verticalCenter
                 color: root.theme.colors.textSecondary
                 font.pixelSize: 12
-                text: qsTr("Min received")
+                text: root.limitLabel
             }
 
             Text {
+                objectName: "swapLimitValue"
                 anchors.right: parent.right
                 anchors.verticalCenter: parent.verticalCenter
                 color: root.theme.colors.textPrimary
                 font.bold: true
                 font.pixelSize: 12
-                text: root.minReceivedText
+                text: root.limitText
             }
         }
     }

apps/amm/tests/qml/tst_SwapPage.qml

@@ -53,5 +53,59 @@ Item {
             tryCompare(dialog, "opened", false)
             compare(card.sellInput, "1")
         }
+
+        function test_exactOutputUsesMaximumInputLimit() {
+            const page = createTemporaryObject(pageComponent, root)
+            verify(page)
+
+            const card = findChild(page, "swapCard")
+            const dialog = findChild(page, "swapPreviewDialog")
+            verify(card)
+            verify(dialog)
+
+            card.setToken("sell", page.tokens[0])
+            card.setToken("buy", page.tokens[1])
+            card.slippageTolerancePercent = 10
+            card.buyInput = "1000"
+            card.editingSide = "buy"
+            tryCompare(card, "canSubmit", true)
+
+            const snapshot = card.buildSnapshot()
+            compare(snapshot.swapMode, "swap-exact-output")
+            compare(snapshot.buyAmount, "1000.00")
+            compare(snapshot.minReceived, "")
+            verify(snapshot.maxSent.length > 0)
+            verify(Number(snapshot.maxSent) > Number(snapshot.sellAmount))
+
+            dialog.openWithSnapshot(snapshot)
+            tryCompare(dialog, "opened", true)
+            tryCompare(findChild(dialog, "swapPayLabel"), "text", "You pay at most")
+            compare(findChild(dialog, "swapPayAmount").text, snapshot.maxSent + " " + snapshot.sellToken)
+            compare(findChild(dialog, "swapReceiveLabel").text, "You receive")
+            compare(findChild(dialog, "swapReceiveAmount").text, snapshot.buyAmount + " " + snapshot.buyToken)
+            compare(findChild(dialog, "swapLimitLabel").text, "Max sent")
+            compare(findChild(dialog, "swapLimitValue").text, snapshot.maxSent + " " + snapshot.sellToken)
+        }
+
+        function test_exactInputUsesMinimumOutputLimit() {
+            const page = createTemporaryObject(pageComponent, root)
+            verify(page)
+
+            const card = findChild(page, "swapCard")
+            verify(card)
+            card.setToken("sell", page.tokens[0])
+            card.setToken("buy", page.tokens[1])
+            card.slippageTolerancePercent = 10
+            card.sellInput = "1"
+            card.editingSide = "sell"
+            tryCompare(card, "canSubmit", true)
+
+            const snapshot = card.buildSnapshot()
+            compare(snapshot.swapMode, "swap-exact-input")
+            compare(snapshot.sellAmount, "1.00")
+            compare(snapshot.maxSent, "")
+            verify(snapshot.minReceived.length > 0)
+            verify(Number(snapshot.minReceived) < Number(snapshot.buyAmount))
+        }
     }
 }