add explanation about auto signature generation, fix loan ui bug

loan UI now colors rows correctly and data is being displayed on change

src/ui/loans.py

@@ -73,13 +73,45 @@ class LoanWindow(QtWidgets.QMainWindow, Ui_MainWindow):
             ),
         )
         self.loanTable.setItem(0, 6, QtWidgets.QTableWidgetItem(retdate))
+        book = data.book
+        book.loan_to = data.return_date
+        book.load_from = data.loan_date
+        book.returned = data.returned
+        match self.check_book(book):
+            case "overdue":
+                for i in range(7):
+                    self.loanTable.item(0, i).setBackground(
+                        QtGui.QColor(255, 0, 0, 100)
+                    )
+            case "ok":
+                for i in range(7):
+                    self.loanTable.item(0, i).setBackground(
+                        QtGui.QColor(105, 255, 51, 100)
+                    )
+            case "returned":
+                for i in range(7):
+                    self.loanTable.item(0, i).setBackground(
+                        QtGui.QColor(102, 153, 153, 100)
+                    )
+
+    def check_book(self, book):
+        today = QtCore.QDate.currentDate().toString("yyyy-MM-dd")
+        returnDate = stringToDate(book.loan_to).toString("yyyy-MM-dd")
+        returned = book.returned
+        if returned == 1:
+            return "returned"
+        else:
+            if returnDate < today:
+                return "overdue"
+            else:
+                return "ok"
 
     def loadLoans(self):
         loans = self.db.getAllLoans()
-        loanlist = []
         for loan in loans:
             self.insertRow(loan)
-        return loanlist
+
+        return loans
 
     def filterResults(self):
         mode = (
@@ -89,6 +121,7 @@ class LoanWindow(QtWidgets.QMainWindow, Ui_MainWindow):
             if self.radio_current.isChecked()
             else "overdue"
         )
+        log.debug("Switching mode to {}", mode)
         self.loanTable.setRowCount(0)
         today = QtCore.QDate.currentDate()
         for loan in self.loans: