Implement safe item transactions

itemcontroller.lua

@@ -70,7 +70,7 @@ local function loadState(fname, node)
   return controller
 end
 
-local function itemList(groups, wBudget, hBudget, savedState, onClick, setPage)
+local function itemList(groups, wBudget, hBudget, savedState, onClick, setPage, runImport)
   local state = savedState or {}
   state.tab = state.tab or 1
 
@@ -86,10 +86,21 @@ local function itemList(groups, wBudget, hBudget, savedState, onClick, setPage)
         state.tab = state.tab - 1
         setPage(nil)
       end
+      return true
     end
   }
 
-  local _btnNext = Text:new{
+  local btnImport = Text:new{
+    text = "IMPORT",
+    bgColor = colors.gray,
+    fgColor = colors.white,
+    onClick = function(e, x, y, s)
+      runImport()
+      return true
+    end
+  }
+
+  local btnNext = Text:new{
     text = " > ",
     bgColor = state.tab == pages and colors.black or colors.gray,
     fgColor = state.tab == pages and colors.red or colors.white,
@@ -98,17 +109,21 @@ local function itemList(groups, wBudget, hBudget, savedState, onClick, setPage)
         state.tab = state.tab + 1
         setPage(nil)
       end
+      return true
     end
   }
-  local btnNext = Padding:new{
-    left = wBudget - _btnNext:getWidth() - btnPrev:getWidth(),
-    element = _btnNext
-  }
 
   local tabLine = List:new{
     children = {
       btnPrev,
-      btnNext
+      Padding:new{
+        left = math.floor((wBudget - btnPrev:getWidth() - btnNext:getWidth() - btnImport:getWidth())/2),
+        element = btnImport
+      },
+      Padding:new{
+        left = wBudget - btnPrev:getWidth() - btnImport:getWidth() - btnNext:getWidth(),
+        element = btnNext
+      }
     },
     vertical = false
   }
@@ -182,11 +197,8 @@ local function updatePageRender(state, pages)
     state.currentPage = state.nextPage
     state.nextPage = nil
 
-    if changingPage then
-      state.pageState = nil
-    end
     state.monitor.clear()
-    state._pageRender = pages[state.currentPage](state)
+    state._pageRender = pages[state.currentPage](state, changingPage)
   end
 end
 
@@ -212,7 +224,7 @@ local function renderDefault(state, rootElement)
 end
 
 local PAGES = {
-  MAIN = function(state)
+  MAIN = function(state, newPage)
     local found = ItemGroup.collectStacks(state.controller:find(function(stack)
       return not stack:isEmpty()
     end))
@@ -223,16 +235,27 @@ local PAGES = {
       found,
       state.width,
       state.height,
-      state.pageState,
+      state.pageState[state.currentPage],
       function(element, x, y, source, group)
         print("Clicked: "..group:getDisplayName())
         return true
       end,
       function(page)
         state.nextPage = page or state.currentPage
+      end,
+      function()
+        print("Importing...")
+        -- Safely handle transfers, priming computer for a full reset/rescan in case server stops mid-transaction
+        state:itemTransaction(function()
+          for _,nodeStack in state.node:find(function(s) return not s:isEmpty() end) do
+            if not state.controller:insertStack(nodeStack) then
+              print("Couldn't find a free slot for: "..(nodeStack:getDisplayName() or nodeStack:getName() or "[EMPTY]"))
+            end
+          end
+        end)
       end
     )
-    state.pageState = pageState
+    state.pageState[state.currentPage] = pageState
     listResult:setParent(state.monitor)
 
     return function()
@@ -240,11 +263,11 @@ local PAGES = {
     end
   end,
 
-  GROUP_DETAIL = function(state)
+  GROUP_DETAIL = function(state, newPage)
 
   end,
 
-  REQUEST = function(state)
+  REQUEST = function(state, newPage)
 
   end
 }
@@ -258,14 +281,24 @@ local width, height = monitor.getSize()
 
 local CONTROLLER_STATE = {
   controller = controller,
+  node = accessNode,
   width = width,
   height = height,
   monitor = monitor,
   nextPage = "MAIN",
   exit = false,
-  pageState = {}
+  pageState = {},
+  lock = lock,
+  unlock = unlock,
+  isLocked = isLocked
 }
 
+function CONTROLLER_STATE:itemTransaction(transact)
+  self.lock()
+  transact()
+  self.unlock()
+end
+
 os.queueEvent("dummy_event")
 while not CONTROLLER_STATE.exit do
   updatePageRender(CONTROLLER_STATE, PAGES)

storage/init.lua

@@ -88,8 +88,8 @@ function Storage:find(query)
 end
 
 -- Find all stacks eligible to accept the given query
-function Storage:findInsertTargets(query)
-  local result = self:find(function(stack) return stack:isEmpty() or stack:matches(query) end)
+function Storage:findInsertTargets(sourceStack)
+  local result = self:find(function(stack) return sourceStack:canTransfer(stack) end)
 
   -- Insertion should prioritize filling populated stacks
   table.sort(result, function(a, b) return a:getcount() > b:getCount() end)
@@ -97,13 +97,27 @@ function Storage:findInsertTargets(query)
   return result
 end
 
-function Storage:findExtractTargets(query)
-    local result = self:find(query)
+function Storage:findExtractTargets(targetStack)
+  -- Only transfer non-empty stacks
+  local result = self:find(function(stack) return (not stack:isEmpty()) and stack:canTransfer(targetStack) end)
 
-    -- Extraction should prioritize emptying populated stacks
-    table.sort(result, function(a, b) return a:getcount() < b:getCount() end)
+  -- Extraction should prioritize emptying populated stacks
+  table.sort(result, function(a, b) return a:getcount() < b:getCount() end)
 
-    return result
+  return result
+end
+
+function Storage:insertStack(stack)
+  local targets = self:findInsertTargets(stack)
+
+  for _,target in ipairs(targets) do
+    if stack:isEmpty() then
+      return true
+    end
+    stack:transferTo(target)
+  end
+
+  return false
 end
 
 return Storage

storage/itemstack.lua

@@ -211,12 +211,13 @@ end
 
 
 -- Determines if two stacks can be transferred to eachother
+-- Empty stacks are always valid transfer nodes
 function ItemStack:canTransfer(stack)
-  return self.name == stack.name and
+  return self:isEmpty() or stack:isEmpty() or (self.name == stack.name and
           self.damage == stack.damage and
           self.maxDamage == stack.maxDamage and
           self.displayName == stack.displayName and
-          objEquals(self.enchantments, stack.enchantments)
+          objEquals(self.enchantments, stack.enchantments))
 end
 
 local function queryField(query, field)