Start refactoring the refactor that was started with command pattern refactoring.

Instead of attempting to keep all the Fit service functionality, move these into specific "Fitting Commands" that are designed to define a unit of work and it's undo. Then, we will have "GUI Commands" which are defined as actions taken by the user themselves - these will usually use one or more "Fitting Commands".

gui/fitCommands/fitAddModule.py

@@ -0,0 +1,70 @@
+import wx
+from service.fit import Fit
+
+import gui.mainFrame
+from gui import globalEvents as GE
+#from .helpers import ModuleInfoCache
+from eos.saveddata.module import Module, State
+import eos.db
+from logbook import Logger
+pyfalog = Logger(__name__)
+
+
+class FitAddModuleCommand(wx.Command):
+    """"
+    Fitting command that appends a module to a fit using the first available slot.
+
+    from sFit.appendModule
+    """
+    def __init__(self, fitID, itemID):
+        wx.Command.__init__(self, True, "Module Add")
+        self.fitID = fitID
+        self.itemID = itemID
+        self.new_position = None
+        self.change = None
+
+    def Do(self):
+        fitID = self.fitID
+        itemID = self.itemID
+        pyfalog.debug("Appending module for fit ({0}) using item: {1}", fitID, itemID)
+        fit = eos.db.getFit(fitID)
+        item = eos.db.getItem(itemID, eager=("attributes", "group.category"))
+
+        try:
+            self.module = Module(item)
+        except ValueError:
+            pyfalog.warning("Invalid item: {0}", itemID)
+            return False
+
+        if self.module.item.category.name == "Subsystem":
+            fit.modules.freeSlot(self.module.getModifiedItemAttr("subSystemSlot"))
+
+        if self.module.fits(fit):
+            self.module.owner = fit
+            numSlots = len(fit.modules)
+            fit.modules.append(self.module)
+            if self.module.isValidState(State.ACTIVE):
+                self.module.state = State.ACTIVE
+
+            # todo: fix these
+            # As some items may affect state-limiting attributes of the ship, calculate new attributes first
+            # self.recalc(fit)
+            # Then, check states of all modules and change where needed. This will recalc if needed
+            # self.checkStates(fit, m)
+
+            fit.fill()
+            eos.db.commit()
+
+            self.change = numSlots != len(fit.modules)
+            self.new_position = self.module.modPosition
+        else:
+            return False
+
+        return True
+
+    def Undo(self):
+        from .fitRemoveModule import FitRemoveModuleCommand  # Avoid circular import
+        if self.new_position:
+            cmd = FitRemoveModuleCommand(self.fitID, [self.new_position])
+            cmd.Do()
+        return True