Support multiple transaction parts in the row interpreter.

Moves category determination, amount and memo to all take parameters. Then implement getTransactionParts which grabs transaction information from the details field, falling back to the envelope and amount if none is provided.
This way, the row interpreter consistently breaks up transactions into parts. The DataTransformer remains in charge of turning transaction parts into full transactions. This includes taking the part of a transaction into account when calculating the import ID.

lib/data_transformer.js

@@ -15,22 +15,27 @@ class DataTransformer {
     async transformRow(row) {
         let rowInterpreter = new RowInterpreter(row, await this.ynabCategoryIds());
 
-        return [{
+        let baseTransaction = {
             account_id: this.ynabAccountId,
-            category_id: rowInterpreter.categoryId(),
             date: rowInterpreter.date(this.dateFormat),
-            amount: rowInterpreter.amount(),
             payee_name: rowInterpreter.payeeName(),
-            memo: rowInterpreter.memo(),
-            cleared: 'cleared',
-            import_id: this.calculateImportIdForRow(row)
-        }];
+            cleared: 'cleared'
+        };
+
+        return rowInterpreter.getTransactionParts().map((transactionPart, partIndex) => {            
+            return Object.assign({
+                category_id: transactionPart.categoryId,
+                amount: transactionPart.amount,
+                memo: transactionPart.memo,
+                import_id: this.calculateImportIdForTransaction(row, partIndex)
+            }, baseTransaction);
+        });
     }
 
-    calculateImportIdForRow(row) {
+    calculateImportIdForTransaction(row, part) {
         let transactionHash = hash.MD5(row);
         let occurenceIndex = this.transactionHashes[transactionHash] = (this.transactionHashes[transactionHash] || 0) + 1
-        let importId = "GBI:" + hash.MD5(Object.assign({ occurence: occurenceIndex, rerun: this.rerunIndex }, row));
+        let importId = "GBI:" + hash.MD5(Object.assign({ part: part, occurence: occurenceIndex, rerun: this.rerunIndex }, row));
 
         return importId;
     }

lib/row_interpreter.js

@@ -6,37 +6,61 @@ class RowInterpreter {
         this.ynabCategoryIds = ynabCategoryIds;
     }
 
-    categoryId() {
-        let envelopeName = this.row.Envelope.split(': ').pop();
+    getTransactionParts() {
+        let parts = this.row.Details.split('||').reduce((parts, transactionPart) => {
+            let envelopeAndAmount = transactionPart.split('|');
+            if (envelopeAndAmount[0] !== '' && envelopeAndAmount.length === 2) parts.push(envelopeAndAmount);
 
-        return this.ynabCategoryIds[envelopeName];
-    }
+            return parts;
+        }, []);
 
-    date(dateFormat) {
-        return moment(this.row.Date, dateFormat).format('YYYY-MM-DD');
-    }
+        if (parts.length === 0) parts.push([this.row.Envelope, this.row.Amount]);
 
-    amount() {
-        let amount = parseFloat(this.row.Amount.replace(',', ''));
+        return parts.map((part) => {
+            let categoryId = this.categoryForEnvelope(part[0]);
 
-        return Math.round(amount * 1000);
+            return {
+                categoryId: categoryId,
+                amount: this.amountAsMilliunits(part[1]),
+                memo: this.memoForCategory(categoryId)
+            };
+        });
     }
-
+
+    date(dateFormat) {
+        return moment(this.row.Date, dateFormat).format('YYYY-MM-DD');
+    }
+
     payeeName() {
         return this.row.Name.length == 0 ? null : this.row.Name.substring(0, 50);
     }
+
+    memoForCategory(category) {
+        let memo = this.row.Notes;
 
-    memo() {
-        let memo = this.row.Notes + this.row.Details;
-
-        if (!this.categoryId() && this.row.Envelope.length > 0) {
+        if (!category && this.row.Envelope.length > 0) {
             if (memo.length > 0) memo += " ";
             memo += "Original envelope: " + this.row.Envelope;
         }
         let truncatedMemo = memo.substring(0, 100);
-
+        
         return truncatedMemo;
     }
+
+    categoryForEnvelope(envelope) {
+        let envelopeName = envelope.split(': ').pop();
+
+        // Handle income by converting unallocated parts to money to be budgeted.
+        if (envelopeName === '[Unallocated]') envelopeName = 'To be Budgeted';
+
+        return this.ynabCategoryIds[envelopeName];
+    }
+
+    amountAsMilliunits(rawAmount) {
+        let amount = parseFloat(rawAmount.replace(',', ''));
+
+        return Math.round(amount * 1000);
+    }
 }
 
 module.exports = RowInterpreter;