enables buying of goods and reducing the wealth of the actor who bought the good and proclaiming it loudly in chat.

src/module/documents/character.mjs

@@ -310,8 +310,133 @@ export class Character extends Actor {
         return updateObject;
     }
 
-    reduceWealth(by) {
-        console.log('Reichtum reduziert um ', by)
+    /**
+     * reduce the wealth owned by this character by the given amount in Silver
+     * @param by amount of Silver to reduce the wealth by the character
+     * @returns {boolean}
+     */
+
+    async reduceWealth(by) {
+
+        const ducats = this.itemTypes["Equipment"].filter(p => p.name === "Dukate")
+        const silver = this.itemTypes["Equipment"].filter(p => p.name === "Silbertaler")
+        const kreutzer = this.itemTypes["Equipment"].filter(p => p.name === "Kreuzer")
+        const heller = this.itemTypes["Equipment"].filter(p => p.name === "Heller")
+
+        let ducatsAmount = 0
+        let silverAmount = 0
+        let kreutzerAmount = 0
+        let hellerAmount = 0
+
+        ducats.forEach(d => {
+            ducatsAmount += d.system.quantity ?? 1
+        })
+
+        silver.forEach(s => {
+            silverAmount += s.system.quantity ?? 1
+        })
+
+        kreutzer.forEach(k => {
+            kreutzerAmount += k.system.quantity ?? 1
+        })
+
+        heller.forEach(h => {
+            hellerAmount += h.system.quantity ?? 1
+        })
+
+        // Convert total wealth to silver
+        let totalSilver = ducatsAmount * 10 + silverAmount + kreutzerAmount * 0.1 + hellerAmount * 0.01;
+
+        if (totalSilver < by) {
+            return false; // Indicate that the reduction can't be performed
+        }
+
+        // Subtract the given sum from total silver
+        totalSilver -= by;
+
+        // Handle if the total goes below zero
+        if (totalSilver < 0) totalSilver = 0;
+
+        // Convert back to coinages
+        let newDucats = Math.floor(totalSilver / 10);
+        totalSilver %= 10;
+
+        let newSilver = Math.floor(totalSilver);
+        totalSilver %= 1;
+
+        let newKreutzer = Math.floor(totalSilver / 0.1);
+        totalSilver %= 0.1;
+
+        let newHeller = Math.round(totalSilver / 0.01);
+
+        // remove all coinage items
+
+        let deleteDocuments = []
+        ducats.forEach(d => deleteDocuments.push(d._id))
+        silver.forEach(s => deleteDocuments.push(s._id))
+        kreutzer.forEach(k => deleteDocuments.push(k._id))
+        heller.forEach(h => deleteDocuments.push(h._id))
+
+        await this.deleteEmbeddedDocuments('Item', deleteDocuments)
+
+        // rebuild coinage documents
+        const compendiumOfCoins = game.packs.get('DSA_4-1.Currency');
+
+        if (newDucats > 0) {
+            let coin = compendiumOfCoins.index.find(coin => coin.name === "Dukate")
+            const ducatDocument = await compendiumOfCoins.getDocument(coin._id);
+            try {
+                this.createEmbeddedDocuments('Item', [ducatDocument]).then(
+                    embeddedDocuments => {
+                        embeddedDocuments[0].update({"system.quantity": newDucats}).then(_ => {
+                            console.log("created new Ducats with qty of", newDucats)
+                        })
+                    })
+            } catch (err) {
+            }
+        }
+        if (newSilver > 0) {
+            let coin = compendiumOfCoins.index.find(coin => coin.name === "Silbertaler")
+            const silverDocument = await compendiumOfCoins.getDocument(coin._id);
+            try {
+                this.createEmbeddedDocuments('Item', [silverDocument]).then(
+                    embeddedDocuments => {
+                        embeddedDocuments[0].update({"system.quantity": newSilver}).then(_ => {
+                            console.log("created new Silver with qty of", newSilver)
+                        })
+                    })
+            } catch (err) {
+            }
+        }
+
+        if (newKreutzer > 0) {
+            let coin = compendiumOfCoins.index.find(coin => coin.name === "Kreuzer")
+            const kreutzerDocument = await compendiumOfCoins.getDocument(coin._id);
+            try {
+                this.createEmbeddedDocuments('Item', [kreutzerDocument]).then(
+                    embeddedDocuments => {
+                        embeddedDocuments[0].update({"system.quantity": newKreutzer}).then(_ => {
+                            console.log("created new Kreutzer with qty of", newKreutzer)
+                        })
+                    })
+            } catch (err) {
+            }
+        }
+
+        if (newHeller > 0) {
+            let coin = compendiumOfCoins.index.find(coin => coin.name === "Heller")
+            const hellerDocument = await compendiumOfCoins.getDocument(coin._id);
+            try {
+                this.createEmbeddedDocuments('Item', [hellerDocument]).then(
+                    embeddedDocuments => {
+                        embeddedDocuments[0].update({"system.quantity": newHeller}).then(_ => {
+                            console.log("created new Heller with qty of", newHeller)
+                        })
+                    })
+            } catch (err) {
+            }
+        }
+
         return true
     }
 

src/module/sheets/merchantSheet.mjs

@@ -102,22 +102,24 @@ export class MerchantSheet extends HandlebarsApplicationMixin(ActorSheetV2) {
         });
 
         const actor = game.actors.get(actorId)
-
-
-        let wealth = 0
-
-        actor.itemTypes["Equipment"].forEach(coin => {
-            if (coin.system.category.indexOf("Währung") !== -1) {
-                wealth += (coin.system.quantity * coin.system.currencyDenominator)
+        const canBuy = await actor.reduceWealth(item.system.price)
+        if (canBuy) { // returns false when the wealth cant be reduced sufficiently
+            actor.createEmbeddedDocuments('Item', [item]).then(documents => {
+                documents[0].update({'system.quantity': 1})
+            })
+            if (item.system.quantity != -1) { // -1 means infinite
+                if (item.system.quantity > 1) {
+                    item.update({'system.quantity': item.system.quantity - 1})
+                } else {
+                    this.document.deleteEmbeddedDocuments('Item', [item._id]) // delete when the quantity is equal to 0
+                }
             }
-        })
-
-        if (wealth >= item.system.price) {
-
-            actor.reduceWealth(item.system.price)
-            actor.createEmbeddedDocuments('Item', [item])
-            this.document.deleteEmbeddedDocuments('Item', [item._id])
-
+            ChatMessage.create({
+                user: game.user._id,
+                speaker: {actor},
+                content: `hat ${item.name} für ${game.DSA41.displayCurrency(item.system.price)} gekauft`,
+                type: CONST.CHAT_MESSAGE_TYPES.IC
+            })
         } else {
             ui.notifications.error(item.name + " ist zu teuer für " + actor.name)
         }