Adding minetest.clear_craft

Modifications by est31: grammar fixes in doc + error messages and
a little style fix, no functional change.

5 files changed, 178 insertions, 1 deletions

diff --git a/doc/lua_api.txt b/doc/lua_api.txt
index 297566068..a59a9c0f2 100644
--- a/doc/lua_api.txt
+++ b/doc/lua_api.txt
@@ -1847,6 +1847,14 @@ Call these functions only at load time!
 * `minetest.register_craftitem(name, item definition)`
 * `minetest.register_alias(name, convert_to)`
 * `minetest.register_craft(recipe)`
+    * Check recipe table syntax for different types below.
+* `minetest.clear_craft(recipe)`
+    * Will erase existing craft based either on output item or on input recipe.
+    * Specify either output or input only. If you specify both, input will be ignored. For input use the same recipe table
+      syntax as for `minetest.register_craft(recipe)`. For output specify only the item, without a quantity.
+    * If no erase candidate could be found, Lua exception will be thrown.
+    * Warning! The type field ("shaped","cooking" or any other) will be ignored if the recipe
+      contains output. Erasing is then done independently from the crafting method.
 * `minetest.register_ore(ore definition)`
 * `minetest.register_decoration(decoration definition)`
 * `minetest.override_item(name, redefinition)`
diff --git a/src/craftdef.cpp b/src/craftdef.cpp
index d3f1edaf9..45d3018a7 100644
--- a/src/craftdef.cpp
+++ b/src/craftdef.cpp
@@ -960,6 +960,96 @@ public:
 
 		return recipes;
 	}
+
+	virtual bool clearCraftRecipesByOutput(const CraftOutput &output, IGameDef *gamedef)
+	{
+		std::map<std::string, std::vector<CraftDefinition*> >::iterator vec_iter =
+			m_output_craft_definitions.find(output.item);
+
+		if (vec_iter == m_output_craft_definitions.end())
+			return false;
+
+		std::vector<CraftDefinition*> &vec = vec_iter->second;
+		for (std::vector<CraftDefinition*>::iterator i = vec.begin();
+				i != vec.end(); ++i) {
+			CraftDefinition *def = *i;
+			// Recipes are not yet hashed at this point
+			std::vector<CraftDefinition*> &unhashed_inputs_vec = m_craft_defs[(int) CRAFT_HASH_TYPE_UNHASHED][0];
+			std::vector<CraftDefinition*> new_vec_by_input;
+			/* We will preallocate necessary memory addresses, so we don't need to reallocate them later.
+				This would save us some performance. */
+			new_vec_by_input.reserve(unhashed_inputs_vec.size());
+			for (std::vector<CraftDefinition*>::iterator i2 = unhashed_inputs_vec.begin();
+					i2 != unhashed_inputs_vec.end(); ++i2) {
+				if (def != *i2) {
+					new_vec_by_input.push_back(*i2);
+				}
+			}
+			m_craft_defs[(int) CRAFT_HASH_TYPE_UNHASHED][0].swap(new_vec_by_input);
+		}
+		m_output_craft_definitions.erase(output.item);
+		return true;
+	}
+
+	virtual bool clearCraftRecipesByInput(CraftMethod craft_method, unsigned int craft_grid_width,
+		const std::vector<std::string> &recipe, IGameDef *gamedef)
+	{
+		bool all_empty = true;
+		for (std::vector<std::string>::size_type i = 0;
+				i < recipe.size(); i++) {
+			if (!recipe[i].empty()) {
+				all_empty = false;
+				break;
+			}
+		}
+		if (all_empty)
+			return false;
+
+		CraftInput input(craft_method, craft_grid_width, craftGetItems(recipe, gamedef));
+		// Recipes are not yet hashed at this point
+		std::vector<CraftDefinition*> &unhashed_inputs_vec = m_craft_defs[(int) CRAFT_HASH_TYPE_UNHASHED][0];
+		std::vector<CraftDefinition*> new_vec_by_input;
+		bool got_hit = false;
+		for (std::vector<CraftDefinition*>::size_type
+				i = unhashed_inputs_vec.size(); i > 0; i--) {
+			CraftDefinition *def = unhashed_inputs_vec[i - 1];
+			/* If the input doesn't match the recipe definition, this recipe definition later
+				will be added back in source map. */
+			if (!def->check(input, gamedef)) {
+				new_vec_by_input.push_back(def);
+				continue;
+			}
+			CraftOutput output = def->getOutput(input, gamedef);
+			got_hit = true;
+			std::map<std::string, std::vector<CraftDefinition*> >::iterator
+				vec_iter = m_output_craft_definitions.find(output.item);
+			if (vec_iter == m_output_craft_definitions.end())
+				continue;
+			std::vector<CraftDefinition*> &vec = vec_iter->second;
+			std::vector<CraftDefinition*> new_vec_by_output;
+			/* We will preallocate necessary memory addresses, so we don't need
+				to reallocate them later. This would save us some performance. */
+			new_vec_by_output.reserve(vec.size());
+			for (std::vector<CraftDefinition*>::iterator i = vec.begin();
+					i != vec.end(); ++i) {
+				/* If pointers from map by input and output are not same,
+					we will add 'CraftDefinition*' to a new vector. */
+				if (def != *i) {
+					/* Adding dereferenced iterator value (which are
+						'CraftDefinition' reference) to a new vector. */
+					new_vec_by_output.push_back(*i);
+				}
+			}
+			// Swaps assigned to current key value with new vector for output map.
+			m_output_craft_definitions[output.item].swap(new_vec_by_output);
+		}
+		if (got_hit)
+			// Swaps value with new vector for input map.
+			m_craft_defs[(int) CRAFT_HASH_TYPE_UNHASHED][0].swap(new_vec_by_input);
+
+		return got_hit;
+	}
+
 	virtual std::string dump() const
 	{
 		std::ostringstream os(std::ios::binary);
diff --git a/src/craftdef.h b/src/craftdef.h
index cebb2d7ae..695ee0c2c 100644
--- a/src/craftdef.h
+++ b/src/craftdef.h
@@ -426,6 +426,10 @@ public:
 	virtual std::vector<CraftDefinition*> getCraftRecipes(CraftOutput &output,
 			IGameDef *gamedef, unsigned limit=0) const=0;
 
+	virtual bool clearCraftRecipesByOutput(const CraftOutput &output, IGameDef *gamedef) = 0;
+	virtual bool clearCraftRecipesByInput(CraftMethod craft_method,
+			unsigned int craft_grid_width, const std::vector<std::string> &recipe, IGameDef *gamedef) = 0;
+
 	// Print crafting recipes for debugging
 	virtual std::string dump() const=0;
 
diff --git a/src/script/lua_api/l_craft.cpp b/src/script/lua_api/l_craft.cpp
index 391a0133d..d135c689f 100644
--- a/src/script/lua_api/l_craft.cpp
+++ b/src/script/lua_api/l_craft.cpp
@@ -34,7 +34,6 @@ struct EnumString ModApiCraft::es_CraftMethod[] =
 	{0, NULL},
 };
 
-
 // helper for register_craft
 bool ModApiCraft::readCraftRecipeShaped(lua_State *L, int index,
 		int &width, std::vector<std::string> &recipe)
@@ -281,6 +280,80 @@ int ModApiCraft::l_register_craft(lua_State *L)
 	return 0; /* number of results */
 }
 
+// clear_craft({[output=item], [recipe={{item00,item10},{item01,item11}}])
+int ModApiCraft::l_clear_craft(lua_State *L)
+{
+	NO_MAP_LOCK_REQUIRED;
+	luaL_checktype(L, 1, LUA_TTABLE);
+	int table = 1;
+
+	// Get the writable craft definition manager from the server
+	IWritableCraftDefManager *craftdef =
+			getServer(L)->getWritableCraftDefManager();
+
+	std::string output = getstringfield_default(L, table, "output", "");
+	std::string type = getstringfield_default(L, table, "type", "shaped");
+	CraftOutput c_output(output, 0);
+	if (output != "") {
+		if (craftdef->clearCraftRecipesByOutput(c_output, getServer(L)))
+			return 0;
+		else
+			throw LuaError("No craft recipe known for output"
+					" (output=\"" + output + "\")");
+	}
+	std::vector<std::string> recipe;
+	int width = 0;
+	CraftMethod method = CRAFT_METHOD_NORMAL;
+	/*
+		CraftDefinitionShaped
+	*/
+	if (type == "shaped") {
+		lua_getfield(L, table, "recipe");
+		if (lua_isnil(L, -1))
+			throw LuaError("Either output or recipe has to be defined");
+		if (!readCraftRecipeShaped(L, -1, width, recipe))
+			throw LuaError("Invalid crafting recipe");
+	}
+	/*
+		CraftDefinitionShapeless
+	*/
+	else if (type == "shapeless") {
+		lua_getfield(L, table, "recipe");
+		if (lua_isnil(L, -1))
+			throw LuaError("Either output or recipe has to be defined");
+		if (!readCraftRecipeShapeless(L, -1, recipe))
+			throw LuaError("Invalid crafting recipe");
+	}
+	/*
+		CraftDefinitionCooking
+	*/
+	else if (type == "cooking") {
+		method = CRAFT_METHOD_COOKING;
+		std::string rec = getstringfield_default(L, table, "recipe", "");
+		if (rec == "")
+			throw LuaError("Crafting definition (cooking)"
+					" is missing a recipe");
+		recipe.push_back(rec);
+	}
+	/*
+		CraftDefinitionFuel
+	*/
+	else if (type == "fuel") {
+		method = CRAFT_METHOD_FUEL;
+		std::string rec = getstringfield_default(L, table, "recipe", "");
+		if (rec == "")
+			throw LuaError("Crafting definition (fuel)"
+					" is missing a recipe");
+		recipe.push_back(rec);
+	} else {
+		throw LuaError("Unknown crafting definition type: \"" + type + "\"");
+	}
+	if (!craftdef->clearCraftRecipesByInput(method, width, recipe, getServer(L)))
+		throw LuaError("No crafting specified for input");
+	lua_pop(L, 1);
+	return 0;
+}
+
 // get_craft_result(input)
 int ModApiCraft::l_get_craft_result(lua_State *L)
 {
@@ -431,4 +504,5 @@ void ModApiCraft::Initialize(lua_State *L, int top)
 	API_FCT(get_craft_recipe);
 	API_FCT(get_craft_result);
 	API_FCT(register_craft);
+	API_FCT(clear_craft);
 }
diff --git a/src/script/lua_api/l_craft.h b/src/script/lua_api/l_craft.h
index 548608776..eb2bce706 100644
--- a/src/script/lua_api/l_craft.h
+++ b/src/script/lua_api/l_craft.h
@@ -33,6 +33,7 @@ private:
 	static int l_get_craft_recipe(lua_State *L);
 	static int l_get_all_craft_recipes(lua_State *L);
 	static int l_get_craft_result(lua_State *L);
+	static int l_clear_craft(lua_State *L);
 
 	static bool readCraftReplacements(lua_State *L, int index,
 			CraftReplacements &replacements);