Suggestions from last recipe

modfiles/backend/data/Factory.lua

@@ -10,6 +10,7 @@ local Product = require("backend.data.Product")
 ---@field archived boolean
 ---@field name string
 ---@field matrix_free_items FPItemPrototype[]?
+---@field last_recipe_items FPItemPrototype[]?
 ---@field blueprints string[]
 ---@field notes string
 ---@field productivity_boni { string: ModuleEffectValue }
@@ -32,6 +33,7 @@ local function init(name)
 
         name = name,
         matrix_free_items = nil,
+        last_recipe_items = nil,
         blueprints = {},
         notes = "",
         productivity_boni = {},
@@ -182,6 +184,7 @@ end
 ---@field class "Factory"
 ---@field name string
 ---@field matrix_free_items FPPackedPrototype[]?
+---@field last_recipe_items FPPackedPrototype[]?
 ---@field blueprints string[]
 ---@field notes string
 ---@field productivity_boni { string: ModuleEffectValue }
@@ -194,6 +197,7 @@ function Factory:pack()
         class = self.class,
         name = self.name,
         matrix_free_items = prototyper.util.simplify_prototypes(self.matrix_free_items, "type"),
+        last_recipe_items = prototyper.util.simplify_prototypes(self.last_recipe_items, "type"),
         blueprints = self.blueprints,
         notes = self.notes,
         productivity_boni = self.productivity_boni,
@@ -209,6 +213,7 @@ local function unpack(packed_self)
 
     -- Product prototypes will be automatically unpacked by the validation process
     unpacked_self.matrix_free_items = packed_self.matrix_free_items
+    unpacked_self.last_recipe_items = packed_self.last_recipe_items
     unpacked_self.blueprints = packed_self.blueprints
     unpacked_self.notes = packed_self.notes
     unpacked_self.productivity_boni = packed_self.productivity_boni

modfiles/locale/en/config.cfg

@@ -331,6 +331,8 @@ choose_unrestricted_items=Choose unrestricted items
 choose_unrestricted_items_tt=Choose [font=default-bold]__1__[/font] unrestricted __2__ in total, so the matrix solver can determine a unique solution.\n\nThe left side lists the constrained items, while the right side contains the unrestricted ones. Click on any item to move it to the other side.\n\nUnrestricted items may become byproducts or ingredients, depending on the solver’s solution.
 unrestricted_items_balanced=Unrestricted items balanced
 unrestricted_items_balanced_tt=The current selection of unrestricted items is balanced.\n\nTo choose different unrestricted items, constrain one of the current ones first.
+last_recipe_items=From last recipe
+other_items=Other Items
 turn_unrestricted=Switch [font=default-bold]__1__[/font] to be constrained
 turn_constrained=Switch [font=default-bold]__1__[/font] to be unrestricted
 solver_choice=Solver

modfiles/ui/dialogs/recipe_dialog.lua

@@ -90,9 +90,31 @@ local function attempt_adding_line(player, recipe_id, modal_data)
         util.messages.raise(player, "error", {"fp.error_no_compatible_machine"}, 1)
     else
         local floor = util.context.get(player, "Floor")  --[[@as Floor]]
+        local factory = util.context.get(player, "Factory")  --[[@as Factory]]
         local relative_object = OBJECT_INDEX[modal_data.add_after_line_id]  --[[@as LineObject]]
         floor:insert(line, relative_object, "next")  -- if not relative, insert uses last line
 
+        log("[FP] RecipeDialog: Creating suggestions for recipe: " .. recipe_proto.name)
+        local last_recipe_items = {}
+        for _, p in ipairs(recipe_proto.products) do
+            local item_proto = prototyper.util.find("items", p.name, p.type)
+            if item_proto then
+                table.insert(last_recipe_items, item_proto)
+            end
+        end
+        for _, i in ipairs(recipe_proto.ingredients) do
+            local item_proto = prototyper.util.find("items", i.name, i.type)
+            if item_proto then
+                table.insert(last_recipe_items, item_proto)
+            end
+        end
+        factory.last_recipe_items = last_recipe_items
+
+        log("[FP] RecipeDialog: Set " .. #last_recipe_items .. " items from last recipe for factory '" .. factory.name .. "'.")
+        local item_names = ""
+        for _, item in ipairs(last_recipe_items) do item_names = item_names .. item.name .. ", " end
+        log("[FP] RecipeDialog: Items are: " .. item_names)
+
         local recipe_name = recipe_proto.localised_name
         if not (recipe_proto.custom or player.force.recipes[recipe_proto.name].enabled) then
             util.messages.raise(player, "warning", {"fp.warning_recipe_disabled", recipe_name}, 2)

modfiles/ui/main/production_box.lua

@@ -18,6 +18,7 @@ local function refresh_solver_frame(player)
     solver_flow.clear()
 
     local factory_data = solver.generate_factory_data(player, factory)
+
     local matrix_metadata = matrix_engine.get_matrix_solver_metadata(factory_data)
     if matrix_metadata.num_rows == 0 then return end  -- skip if there are no active lines
     local linear_dependence_data = matrix_engine.get_linear_dependence_data(factory_data, matrix_metadata)
@@ -68,16 +69,55 @@ local function refresh_solver_frame(player)
         item_count = item_count + #matrix_metadata.free_items
 
         if needs_choice then
-            local flow_constrained = solver_flow.add{type="flow", direction="horizontal"}
-            build_item_flow(flow_constrained, "constrained", linear_dependence_data.allowed_free_items)
-            item_count = item_count + #linear_dependence_data.allowed_free_items
+            log("[FP] SolverUI: Needs choice. Processing items.")
+            local last_recipe_items_to_display = {}
+            local other_items = {}
+            local allowed_free_items = linear_dependence_data.allowed_free_items
+
+            local function base_name(item)
+                if (item.base_name ~= nil) then return item.base_name
+                else return item.name
+                end
+            end
+
+            local last_recipe_map = {}
+            for _, item in ipairs(factory.last_recipe_items or {}) do
+                last_recipe_map[base_name(item)] = true
+            end
+
+            for _, item in ipairs(allowed_free_items) do
+                if last_recipe_map[base_name(item)] then
+                    table.insert(last_recipe_items_to_display, item)
+                else
+                    table.insert(other_items, item)
+                end
+            end
+            log("[FP] SolverUI: Separated into " .. #last_recipe_items_to_display .. " from last recipe and " .. #other_items .. " other items.")
+
+            if #last_recipe_items_to_display > 0 then
+                solver_flow.add{type="label", caption={"fp.last_recipe_items"}, style="bold_label"}
+                local flow_priority = solver_flow.add{type="flow", direction="horizontal"}
+                build_item_flow(flow_priority, "constrained", last_recipe_items_to_display)
+                item_count = item_count + #last_recipe_items_to_display
+            end
+
+            if #other_items > 0 then
+                if #last_recipe_items_to_display > 0 then
+                    solver_flow.add{type="label", caption={"fp.other_items"}, style="bold_label"}
+                end
+                local flow_constrained = solver_flow.add{type="flow", direction="horizontal"}
+                build_item_flow(flow_constrained, "constrained", other_items)
+                item_count = item_count + #other_items
+            end
         end
 
         -- This is some total bullshit because extra_bottom_padding_when_activated doesn't work
         local total_width = 180 + (4 * 12) + (item_count * 40)
         local interface_width = util.globals.ui_state(player).main_dialog_dimensions.width
         local box_width = interface_width - MAGIC_NUMBERS.list_width
         solver_flow.style.bottom_padding = (total_width > box_width) and 16 or 4
+    else
+        log("[FP] SolverUI: Solver is balanced.")
     end
 end