SP mods

data/ui_scripts/mods/__init__.lua

@@ -0,0 +1,3 @@
+if (game:issingleplayer()) then
+    require("loading")
+end

data/ui_scripts/mods/loading.lua

@@ -0,0 +1,116 @@
+game:addlocalizedstring("MENU_MODS", "MODS")
+game:addlocalizedstring("MENU_MODS_DESC", "Load installed mods.")
+game:addlocalizedstring("LUA_MENU_MOD_DESC_DEFAULT", "Load &&1.")
+game:addlocalizedstring("LUA_MENU_MOD_DESC", "&&1\nAuthor: &&2\nVersion: &&3")
+game:addlocalizedstring("LUA_MENU_OPEN_STORE", "Open store")
+game:addlocalizedstring("LUA_MENU_OPEN_STORE_DESC", "Download and install mods.")
+game:addlocalizedstring("LUA_MENU_LOADED_MOD", "Loaded mod: ^2&&1")
+game:addlocalizedstring("LUA_MENU_AVAILABLE_MODS", "Available mods")
+game:addlocalizedstring("LUA_MENU_UNLOAD", "Unload")
+game:addlocalizedstring("LUA_MENU_UNLOAD_DESC", "Unload the currently loaded mod.")
+
+function createdivider(menu, text)
+	local element = LUI.UIElement.new( {
+		leftAnchor = true,
+		rightAnchor = true,
+		left = 0,
+		right = 0,
+		topAnchor = true,
+		bottomAnchor = false,
+		top = 0,
+		bottom = 33.33
+	})
+
+	element.scrollingToNext = true
+	element:addElement(LUI.MenuBuilder.BuildRegisteredType("h1_option_menu_titlebar", {
+		title_bar_text = Engine.ToUpperCase(text)
+	}))
+
+	menu.list:addElement(element)
+end
+
+function string:truncate(length)
+	if (#self <= length) then
+		return self
+	end
+
+	return self:sub(1, length - 3) .. "..."
+end
+
+LUI.addmenubutton("main_campaign", {
+	index = 6,
+	text = "@MENU_MODS",
+	description = Engine.Localize("@MENU_MODS_DESC"),
+	callback = function()
+		LUI.FlowManager.RequestAddMenu(nil, "mods_menu")
+	end
+})
+
+function getmodname(path)
+	local name = path
+	local desc = Engine.Localize("@LUA_MENU_MOD_DESC_DEFAULT", name)
+	local infofile = path .. "/info.json"
+
+	if (io.fileexists(infofile)) then
+		pcall(function()
+			local data = json.decode(io.readfile(infofile))
+			desc = Engine.Localize("@LUA_MENU_MOD_DESC", 
+				data.description, data.author, data.version)
+			name = data.name
+		end)
+	end
+
+	return name, desc
+end
+
+LUI.MenuBuilder.m_types_build["mods_menu"] = function(a1)
+	local menu = LUI.MenuTemplate.new(a1, {
+		menu_title = "@MENU_MODS",
+		exclusiveController = 0,
+		menu_width = 400,
+		menu_top_indent = LUI.MenuTemplate.spMenuOffset,
+		showTopRightSmallBar = true
+	})
+
+	local modfolder = game:getloadedmod()
+	if (modfolder ~= "") then
+		createdivider(menu, Engine.Localize("@LUA_MENU_LOADED_MOD", getmodname(modfolder):truncate(24)))
+
+		menu:AddButton("@LUA_MENU_UNLOAD", function()
+			Engine.Exec("unloadmod")
+		end, nil, true, nil, {
+			desc_text = Engine.Localize("@LUA_MENU_UNLOAD_DESC")
+		})
+	end
+
+	createdivider(menu, Engine.Localize("@LUA_MENU_AVAILABLE_MODS"))
+
+	if (io.directoryexists("mods")) then
+		local mods = io.listfiles("mods/")
+		for i = 1, #mods do
+			if (io.directoryexists(mods[i]) and not io.directoryisempty(mods[i])) then
+				local name, desc = getmodname(mods[i])
+
+				if (mods[i] ~= modfolder) then
+					game:addlocalizedstring(name, name)
+					menu:AddButton(name, function()
+						Engine.Exec("loadmod " .. mods[i])
+					end, nil, true, nil, {
+						desc_text = desc
+					})
+				end
+			end
+		end
+	end
+	
+	menu:AddBackButton(function(a1)
+		Engine.PlaySound(CoD.SFX.MenuBack)
+		LUI.FlowManager.RequestLeaveMenu(a1)
+	end)
+
+	LUI.Options.InitScrollingList(menu.list, nil)
+	menu:CreateBottomDivider()
+	menu.optionTextInfo = LUI.Options.AddOptionTextInfo(menu)
+
+	return menu
+end

src/client/component/filesystem.cpp

@@ -8,6 +8,7 @@
 
 #include <utils/hook.hpp>
 #include <utils/string.hpp>
+#include <utils/io.hpp>
 
 namespace filesystem
 {
@@ -70,6 +71,40 @@ namespace filesystem
 		return this->name_;
 	}
 
+	std::unordered_set<std::string>& get_search_paths()
+	{
+		static std::unordered_set<std::string> search_paths{};
+		return search_paths;
+	}
+
+	std::string read_file(const std::string& path)
+	{
+		for (const auto& search_path : get_search_paths())
+		{
+			const auto path_ = search_path + "/" + path;
+			if (utils::io::file_exists(path_))
+			{
+				return utils::io::read_file(path_);
+			}
+		}
+
+		return {};
+	}
+
+	bool read_file(const std::string& path, std::string* data)
+	{
+		for (const auto& search_path : get_search_paths())
+		{
+			const auto path_ = search_path + "/" + path;
+			if (utils::io::read_file(path_, data))
+			{
+				return true;
+			}
+		}
+
+		return false;
+	}
+
 	class component final : public component_interface
 	{
 	public:
@@ -87,6 +122,10 @@ namespace filesystem
 			utils::hook::call(SELECT_VALUE(0x1403B8D31, 0x1404EE3D0), register_custom_path_stub);
 			utils::hook::call(SELECT_VALUE(0x1403B8D51, 0x1404EE3F0), register_custom_path_stub);
 			utils::hook::call(SELECT_VALUE(0x1403B8D90, 0x1404EE42F), register_custom_path_stub);
+
+			get_search_paths().insert(".");
+			get_search_paths().insert("h1-mod");
+			get_search_paths().insert("data");
 		}
 	};
 }

src/client/component/filesystem.hpp

@@ -16,4 +16,8 @@ namespace filesystem
 		std::string name_;
 		std::string buffer_;
 	};
+
+	std::unordered_set<std::string>& get_search_paths();
+	std::string read_file(const std::string& path);
+	bool read_file(const std::string& path, std::string* data);
 }

src/client/component/fonts.cpp

@@ -3,6 +3,7 @@
 
 #include "fonts.hpp"
 #include "console.hpp"
+#include "filesystem.hpp"
 
 #include "game/game.hpp"
 #include "game/dvars.hpp"
@@ -36,6 +37,13 @@ namespace fonts
 			return font;
 		}
 
+		void free_font(game::TTF* font)
+		{
+			utils::memory::get_allocator()->free(font->buffer);
+			utils::memory::get_allocator()->free(font->name);
+			utils::memory::get_allocator()->free(font);
+		}
+
 		game::TTF* load_font(const std::string& name)
 		{
 			return font_data.access<game::TTF*>([&](font_data_t& data_) -> game::TTF*
@@ -51,9 +59,7 @@ namespace fonts
 					data = i->second;
 				}
 
-				if (data.empty()
-					&& !utils::io::read_file(utils::string::va("h1-mod/%s", name.data()), &data)
-					&& !utils::io::read_file(utils::string::va("data/%s", name.data()), &data))
+				if (data.empty() && !filesystem::read_file(name, &data))
 				{
 					return nullptr;
 				}
@@ -98,6 +104,20 @@ namespace fonts
 		});
 	}
 
+	void clear()
+	{
+		font_data.access([&](font_data_t& data_)
+		{
+			for (auto& font : data_.fonts)
+			{
+				free_font(font.second);
+			}
+
+			data_.fonts.clear();
+			utils::hook::set<int>(SELECT_VALUE(0x14F09DBB8, 0x14FD61EE8), 0); // reset registered font count
+		});
+	}
+
 	class component final : public component_interface
 	{
 	public:

src/client/component/fonts.hpp

@@ -3,4 +3,5 @@
 namespace fonts
 {
 	void add(const std::string& name, const std::string& data);
+	void clear();
 }

src/client/component/game_console.cpp

@@ -571,7 +571,7 @@ namespace game_console
 	{
 		if (key == game::keyNum_t::K_F10)
 		{
-			if (!game::Com_InFrontEnd())
+			if (!game::Com_InFrontend())
 			{
 				return false;
 			}

src/client/component/input.cpp

@@ -15,13 +15,21 @@ namespace input
 		utils::hook::detour cl_char_event_hook;
 		utils::hook::detour cl_key_event_hook;
 
+		bool lui_running()
+		{
+			return *game::hks::lua_state != nullptr;
+		}
+
 		void cl_char_event_stub(const int local_client_num, const int key)
 		{
-			ui_scripting::notify("keypress",
+			if (lui_running())
 			{
-				{"keynum", key},
-				{"key", game::Key_KeynumToString(key, 0, 1)},
-			});
+				ui_scripting::notify("keypress",
+				{
+					{"keynum", key},
+					{"key", game::Key_KeynumToString(key, 0, 1)},
+				});
+			}
 
 			if (!game_console::console_char_event(local_client_num, key))
 			{
@@ -33,11 +41,14 @@ namespace input
 
 		void cl_key_event_stub(const int local_client_num, const int key, const int down)
 		{
-			ui_scripting::notify(down ? "keydown" : "keyup", 
+			if (lui_running())
 			{
-				{"keynum", key},
-				{"key", game::Key_KeynumToString(key, 0, 1)},
-			});
+				ui_scripting::notify(down ? "keydown" : "keyup",
+				{
+					{"keynum", key},
+					{"key", game::Key_KeynumToString(key, 0, 1)},
+				});
+			}
 
 			if (!game_console::console_key_event(local_client_num, key, down))
 			{

src/client/component/materials.cpp

@@ -3,6 +3,7 @@
 
 #include "materials.hpp"
 #include "console.hpp"
+#include "filesystem.hpp"
 
 #include "game/game.hpp"
 #include "game/dvars.hpp"
@@ -20,6 +21,7 @@ namespace materials
 	{
 		utils::hook::detour db_material_streaming_fail_hook;
 		utils::hook::detour material_register_handle_hook;
+		utils::hook::detour db_get_material_index_hook;
 
 		struct material_data_t
 		{
@@ -68,6 +70,16 @@ namespace materials
 			return material;
 		}
 
+		void free_material(game::Material* material)
+		{
+			material->textureTable->u.image->textures.___u0.map->Release();
+			material->textureTable->u.image->textures.shaderView->Release();
+			utils::memory::get_allocator()->free(material->textureTable->u.image);
+			utils::memory::get_allocator()->free(material->textureTable);
+			utils::memory::get_allocator()->free(material->name);
+			utils::memory::get_allocator()->free(material);
+		}
+
 		game::Material* load_material(const std::string& name)
 		{
 			return material_data.access<game::Material*>([&](material_data_t& data_) -> game::Material*
@@ -83,9 +95,7 @@ namespace materials
 					data = i->second;
 				}
 
-				if (data.empty()
-					&& !utils::io::read_file(utils::string::va("h1-mod/materials/%s.png", name.data()), &data)
-					&& !utils::io::read_file(utils::string::va("data/materials/%s.png", name.data()), &data))
+				if (data.empty() && !filesystem::read_file(utils::string::va("materials/%s.png", name.data()), &data))
 				{
 					data_.materials[name] = nullptr;
 					return nullptr;
@@ -136,6 +146,16 @@ namespace materials
 
 			return db_material_streaming_fail_hook.invoke<int>(material);
 		}
+
+		unsigned int db_get_material_index_stub(game::Material* material)
+		{
+			if (material->constantTable == &constant_table)
+			{
+				return 0;
+			}
+
+			return db_get_material_index_hook.invoke<unsigned int>(material);
+		}
 	}
 
 	void add(const std::string& name, const std::string& data)
@@ -146,6 +166,24 @@ namespace materials
 		});
 	}
 
+	void clear()
+	{
+		material_data.access([&](material_data_t& data_)
+		{
+			for (auto& material : data_.materials)
+			{
+				if (material.second == nullptr)
+				{
+					continue;
+				}
+
+				free_material(material.second);
+			}
+
+			data_.materials.clear();
+		});
+	}
+
 	class component final : public component_interface
 	{
 	public:
@@ -158,6 +196,7 @@ namespace materials
 
 			material_register_handle_hook.create(game::Material_RegisterHandle, material_register_handle_stub);
 			db_material_streaming_fail_hook.create(SELECT_VALUE(0x1401D3180, 0x1402C6260), db_material_streaming_fail_stub);
+			db_get_material_index_hook.create(SELECT_VALUE(0x1401CAD00, 0x1402BBB20), db_get_material_index_stub);
 		}
 	};
 }

src/client/component/materials.hpp

@@ -3,4 +3,5 @@
 namespace materials
 {
 	void add(const std::string& name, const std::string& data);
+	void clear();
 }

src/client/component/mods.cpp

@@ -0,0 +1,119 @@
+#include <std_include.hpp>
+#include "loader/component_loader.hpp"
+
+#include "game/game.hpp"
+#include "game/dvars.hpp"
+
+#include "command.hpp"
+#include "console.hpp"
+#include "scheduler.hpp"
+#include "filesystem.hpp"
+#include "materials.hpp"
+#include "fonts.hpp"
+#include "mods.hpp"
+
+#include <utils/hook.hpp>
+#include <utils/io.hpp>
+
+namespace mods
+{
+	std::string mod_path{};
+
+	namespace
+	{
+		utils::hook::detour db_release_xassets_hook;
+		bool release_assets = false;
+
+		void db_release_xassets_stub()
+		{
+			if (release_assets)
+			{
+				materials::clear();
+				fonts::clear();
+			}
+
+			db_release_xassets_hook.invoke<void>();
+		}
+
+		void restart()
+		{
+			scheduler::once([]()
+			{
+				release_assets = true;
+				game::Com_Shutdown("");
+				release_assets = false;
+			}, scheduler::pipeline::main);
+		}
+	}
+
+	class component final : public component_interface
+	{
+	public:
+		void post_unpack() override
+		{
+			if (!game::environment::is_sp())
+			{
+				return;
+			}
+
+			if (!utils::io::directory_exists("mods"))
+			{
+				utils::io::create_directory("mods");
+			}
+
+			db_release_xassets_hook.create(SELECT_VALUE(0x1401CD560, 0x1402BF160), db_release_xassets_stub);
+
+			command::add("loadmod", [](const command::params& params)
+			{
+				if (params.size() < 2)
+				{
+					console::info("Usage: loadmod mods/<modname>");
+					return;
+				}
+
+				if (!game::Com_InFrontend())
+				{
+					console::info("Cannot load mod while in-game!\n");
+					game::CG_GameMessage(0, "^1Cannot unload mod while in-game!");
+					return;
+				}
+
+				const auto path = params.get(1);
+				if (!utils::io::directory_exists(path))
+				{
+					console::info("Mod %s not found!\n", path);
+					return;
+				}
+
+				console::info("Loading mod %s\n", path);
+				filesystem::get_search_paths().erase(mod_path);
+				filesystem::get_search_paths().insert(path);
+				mod_path = path;
+				restart();
+			});
+
+			command::add("unloadmod", [](const command::params& params)
+			{
+				if (mod_path.empty())
+				{
+					console::info("No mod loaded\n");
+					return;
+				}
+
+				if (!game::Com_InFrontend())
+				{
+					console::info("Cannot unload mod while in-game!\n");
+					game::CG_GameMessage(0, "^1Cannot unload mod while in-game!");
+					return;
+				}
+
+				console::info("Unloading mod %s\n", mod_path.data());
+				filesystem::get_search_paths().erase(mod_path);
+				mod_path.clear();
+				restart();
+			});
+		}
+	};
+}
+
+REGISTER_COMPONENT(mods::component)

src/client/component/mods.hpp

@@ -0,0 +1,6 @@
+#pragma once
+
+namespace mods
+{
+	extern std::string mod_path;
+}

src/client/game/scripting/lua/engine.cpp

@@ -4,6 +4,7 @@
 
 #include "../execution.hpp"
 #include "../../../component/logfile.hpp"
+#include "../../../component/filesystem.hpp"
 
 #include <utils/io.hpp>
 
@@ -49,18 +50,17 @@ namespace scripting::lua::engine
 	{
 		stop();
 
-		load_scripts("h1-mod/scripts/");
-		load_scripts("data/scripts/");
-
-		if (game::environment::is_sp())
+		for (const auto& path : filesystem::get_search_paths())
 		{
-			load_scripts("h1-mod/scripts/sp/");
-			load_scripts("data/scripts/sp/");
-		}
-		else
-		{
-			load_scripts("h1-mod/scripts/mp/");
-			load_scripts("data/scripts/mp/");
+			load_scripts(path + "/scripts/");
+			if (game::environment::is_sp())
+			{
+				load_scripts(path + "/scripts/sp/");
+			}
+			else
+			{
+				load_scripts(path + "/scripts/mp/");
+			}
 		}
 
 		running = true;

src/client/game/symbols.hpp

@@ -33,10 +33,12 @@ namespace game
 
 	WEAK symbol<void()> Com_Frame_Try_Block_Function{0x1401CE8D0, 0x1400D8310};
 	WEAK symbol<CodPlayMode()> Com_GetCurrentCoDPlayMode{0, 0x1405039A0};
-	WEAK symbol<bool()> Com_InFrontEnd{0x1400E4B30, 0x140176A30};
+	WEAK symbol<bool()> Com_InFrontend{0x1400E4B30, 0x140176A30};
 	WEAK symbol<void(float, float, int)> Com_SetSlowMotion{0, 0x1400DB790};
 	WEAK symbol<void(errorParm code, const char* message, ...)> Com_Error{0x1403509C0, 0x1400D78A0};
 	WEAK symbol<void()> Com_Quit_f{0x140352BE0, 0x1400DA830};
+	WEAK symbol<void(char const* finalMessage)> Com_Shutdown{0x140353B70, 0x1400DB8A0};
+
 	WEAK symbol<void()> Quit{0x140352D90, 0x1400DA830};
 
 	WEAK symbol<void(int localClientNum, const char* message)> CG_GameMessage{0x1401389A0, 0x140220CC0};
@@ -47,6 +49,7 @@ namespace game
 		bool isAlternate, char* outputBuffer, int bufferLen)> CG_GetWeaponDisplayName{0x14016EC30, 0x1400B5840};
 
 	WEAK symbol<bool()> CL_IsCgameInitialized{0x14017EE30, 0x140245650};
+	WEAK symbol<void(int a1)> CL_VirtualLobbyShutdown{0, 0x140256D40};
 
 	WEAK symbol<void(int hash, const char* name, const char* buffer)> Dvar_SetCommand{0x1403C72B0, 0x1404FD0A0};
 	WEAK symbol<dvar_t*(const char* name)> Dvar_FindVar{0x1403C5D50, 0x1404FBB00};

src/client/game/ui_scripting/lua/context.cpp

@@ -13,6 +13,7 @@
 #include "../../../component/localized_strings.hpp"
 #include "../../../component/fastfiles.hpp"
 #include "../../../component/scripting.hpp"
+#include "../../../component/mods.hpp"
 
 #include "component/game_console.hpp"
 #include "component/scheduler.hpp"
@@ -25,6 +26,31 @@ namespace ui_scripting::lua
 {
 	namespace
 	{
+		const auto json_script = utils::nt::load_resource(LUA_JSON);
+
+		void setup_json(sol::state& state)
+		{
+			const auto json = state.safe_script(json_script, &sol::script_pass_on_error);
+			handle_error(json);
+			state["json"] = json;
+		}
+
+		void setup_io(sol::state& state)
+		{
+			state["io"]["fileexists"] = utils::io::file_exists;
+			state["io"]["writefile"] = utils::io::write_file;
+			state["io"]["movefile"] = utils::io::move_file;
+			state["io"]["filesize"] = utils::io::file_size;
+			state["io"]["createdirectory"] = utils::io::create_directory;
+			state["io"]["directoryexists"] = utils::io::directory_exists;
+			state["io"]["directoryisempty"] = utils::io::directory_is_empty;
+			state["io"]["listfiles"] = utils::io::list_files;
+			state["io"]["copyfolder"] = utils::io::copy_folder;
+			state["io"]["removefile"] = utils::io::remove_file;
+			state["io"]["removedirectory"] = utils::io::remove_directory;
+			state["io"]["readfile"] = static_cast<std::string(*)(const std::string&)>(utils::io::read_file);
+		}
+
 		void setup_types(sol::state& state, scheduler& scheduler)
 		{
 			struct game
@@ -138,6 +164,11 @@ namespace ui_scripting::lua
 				return std::string(buffer);
 			};
 
+			game_type["getloadedmod"] = [](const game&)
+			{
+				return mods::mod_path;
+			};
+
 			auto userdata_type = state.new_usertype<userdata>("userdata_");
 
 			userdata_type["new"] = sol::property(
@@ -322,6 +353,8 @@ namespace ui_scripting::lua
 		                            sol::lib::math,
 		                            sol::lib::table);
 
+		setup_json(this->state_);
+		setup_io(this->state_);
 		setup_types(this->state_, this->scheduler_);
 
 		if (type == script_type::file)

src/client/game/ui_scripting/lua/engine.cpp

@@ -3,6 +3,7 @@
 #include "context.hpp"
 
 #include "../../../component/ui_scripting.hpp"
+#include "../../../component/filesystem.hpp"
 
 #include <utils/io.hpp>
 #include <utils/nt.hpp>
@@ -52,18 +53,17 @@ namespace ui_scripting::lua::engine
 		load_code(lui_common);
 		load_code(lui_updater);
 
-		load_scripts("h1-mod/ui_scripts/");
-		load_scripts("data/ui_scripts/");
-
-		if (game::environment::is_sp())
+		for (const auto& path : filesystem::get_search_paths())
 		{
-			load_scripts("h1-mod/ui_scripts/sp/");
-			load_scripts("data/ui_scripts/sp/");
-		}
-		else
-		{
-			load_scripts("h1-mod/ui_scripts/mp/");
-			load_scripts("data/ui_scripts/mp/");
+			load_scripts(path + "/ui_scripts/");
+			if (game::environment::is_sp())
+			{
+				load_scripts(path + "/ui_scripts/sp/");
+			}
+			else
+			{
+				load_scripts(path + "/ui_scripts/mp/");
+			}
 		}
 	}
 

src/client/resource.hpp

@@ -18,3 +18,5 @@
 
 #define LUI_COMMON            309
 #define LUI_UPDATER           310
+
+#define LUA_JSON              311

src/client/resource.rc

@@ -121,6 +121,8 @@ ICON_IMAGE            RCDATA "resources/icon.png"
 LUI_COMMON            RCDATA "resources/ui_scripts/common.lua"
 LUI_UPDATER           RCDATA "resources/ui_scripts/updater.lua"
 
+LUA_JSON              RCDATA "resources/json.lua"
+
 #endif    // English (United States) resources
 /////////////////////////////////////////////////////////////////////////////
 

src/client/resources/json.lua

@@ -0,0 +1,388 @@
+--
+-- json.lua
+--
+-- Copyright (c) 2020 rxi
+--
+-- Permission is hereby granted, free of charge, to any person obtaining a copy of
+-- this software and associated documentation files (the "Software"), to deal in
+-- the Software without restriction, including without limitation the rights to
+-- use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
+-- of the Software, and to permit persons to whom the Software is furnished to do
+-- so, subject to the following conditions:
+--
+-- The above copyright notice and this permission notice shall be included in all
+-- copies or substantial portions of the Software.
+--
+-- THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+-- IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+-- FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+-- AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+-- LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+-- OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+-- SOFTWARE.
+--
+
+local json = { _version = "0.1.2" }
+
+-------------------------------------------------------------------------------
+-- Encode
+-------------------------------------------------------------------------------
+
+local encode
+
+local escape_char_map = {
+  [ "\\" ] = "\\",
+  [ "\"" ] = "\"",
+  [ "\b" ] = "b",
+  [ "\f" ] = "f",
+  [ "\n" ] = "n",
+  [ "\r" ] = "r",
+  [ "\t" ] = "t",
+}
+
+local escape_char_map_inv = { [ "/" ] = "/" }
+for k, v in pairs(escape_char_map) do
+  escape_char_map_inv[v] = k
+end
+
+
+local function escape_char(c)
+  return "\\" .. (escape_char_map[c] or string.format("u%04x", c:byte()))
+end
+
+
+local function encode_nil(val)
+  return "null"
+end
+
+
+local function encode_table(val, stack)
+  local res = {}
+  stack = stack or {}
+
+  -- Circular reference?
+  if stack[val] then error("circular reference") end
+
+  stack[val] = true
+
+  if rawget(val, 1) ~= nil or next(val) == nil then
+    -- Treat as array -- check keys are valid and it is not sparse
+    local n = 0
+    for k in pairs(val) do
+      if type(k) ~= "number" then
+        error("invalid table: mixed or invalid key types")
+      end
+      n = n + 1
+    end
+    if n ~= #val then
+      error("invalid table: sparse array")
+    end
+    -- Encode
+    for i, v in ipairs(val) do
+      table.insert(res, encode(v, stack))
+    end
+    stack[val] = nil
+    return "[" .. table.concat(res, ",") .. "]"
+
+  else
+    -- Treat as an object
+    for k, v in pairs(val) do
+      if type(k) ~= "string" then
+        error("invalid table: mixed or invalid key types")
+      end
+      table.insert(res, encode(k, stack) .. ":" .. encode(v, stack))
+    end
+    stack[val] = nil
+    return "{" .. table.concat(res, ",") .. "}"
+  end
+end
+
+
+local function encode_string(val)
+  return '"' .. val:gsub('[%z\1-\31\\"]', escape_char) .. '"'
+end
+
+
+local function encode_number(val)
+  -- Check for NaN, -inf and inf
+  if val ~= val or val <= -math.huge or val >= math.huge then
+    error("unexpected number value '" .. tostring(val) .. "'")
+  end
+  return string.format("%.14g", val)
+end
+
+
+local type_func_map = {
+  [ "nil"     ] = encode_nil,
+  [ "table"   ] = encode_table,
+  [ "string"  ] = encode_string,
+  [ "number"  ] = encode_number,
+  [ "boolean" ] = tostring,
+}
+
+
+encode = function(val, stack)
+  local t = type(val)
+  local f = type_func_map[t]
+  if f then
+    return f(val, stack)
+  end
+  error("unexpected type '" .. t .. "'")
+end
+
+
+function json.encode(val)
+  return ( encode(val) )
+end
+
+
+-------------------------------------------------------------------------------
+-- Decode
+-------------------------------------------------------------------------------
+
+local parse
+
+local function create_set(...)
+  local res = {}
+  for i = 1, select("#", ...) do
+    res[ select(i, ...) ] = true
+  end
+  return res
+end
+
+local space_chars   = create_set(" ", "\t", "\r", "\n")
+local delim_chars   = create_set(" ", "\t", "\r", "\n", "]", "}", ",")
+local escape_chars  = create_set("\\", "/", '"', "b", "f", "n", "r", "t", "u")
+local literals      = create_set("true", "false", "null")
+
+local literal_map = {
+  [ "true"  ] = true,
+  [ "false" ] = false,
+  [ "null"  ] = nil,
+}
+
+
+local function next_char(str, idx, set, negate)
+  for i = idx, #str do
+    if set[str:sub(i, i)] ~= negate then
+      return i
+    end
+  end
+  return #str + 1
+end
+
+
+local function decode_error(str, idx, msg)
+  local line_count = 1
+  local col_count = 1
+  for i = 1, idx - 1 do
+    col_count = col_count + 1
+    if str:sub(i, i) == "\n" then
+      line_count = line_count + 1
+      col_count = 1
+    end
+  end
+  error( string.format("%s at line %d col %d", msg, line_count, col_count) )
+end
+
+
+local function codepoint_to_utf8(n)
+  -- http://scripts.sil.org/cms/scripts/page.php?site_id=nrsi&id=iws-appendixa
+  local f = math.floor
+  if n <= 0x7f then
+    return string.char(n)
+  elseif n <= 0x7ff then
+    return string.char(f(n / 64) + 192, n % 64 + 128)
+  elseif n <= 0xffff then
+    return string.char(f(n / 4096) + 224, f(n % 4096 / 64) + 128, n % 64 + 128)
+  elseif n <= 0x10ffff then
+    return string.char(f(n / 262144) + 240, f(n % 262144 / 4096) + 128,
+                       f(n % 4096 / 64) + 128, n % 64 + 128)
+  end
+  error( string.format("invalid unicode codepoint '%x'", n) )
+end
+
+
+local function parse_unicode_escape(s)
+  local n1 = tonumber( s:sub(1, 4),  16 )
+  local n2 = tonumber( s:sub(7, 10), 16 )
+   -- Surrogate pair?
+  if n2 then
+    return codepoint_to_utf8((n1 - 0xd800) * 0x400 + (n2 - 0xdc00) + 0x10000)
+  else
+    return codepoint_to_utf8(n1)
+  end
+end
+
+
+local function parse_string(str, i)
+  local res = ""
+  local j = i + 1
+  local k = j
+
+  while j <= #str do
+    local x = str:byte(j)
+
+    if x < 32 then
+      decode_error(str, j, "control character in string")
+
+    elseif x == 92 then -- `\`: Escape
+      res = res .. str:sub(k, j - 1)
+      j = j + 1
+      local c = str:sub(j, j)
+      if c == "u" then
+        local hex = str:match("^[dD][89aAbB]%x%x\\u%x%x%x%x", j + 1)
+                 or str:match("^%x%x%x%x", j + 1)
+                 or decode_error(str, j - 1, "invalid unicode escape in string")
+        res = res .. parse_unicode_escape(hex)
+        j = j + #hex
+      else
+        if not escape_chars[c] then
+          decode_error(str, j - 1, "invalid escape char '" .. c .. "' in string")
+        end
+        res = res .. escape_char_map_inv[c]
+      end
+      k = j + 1
+
+    elseif x == 34 then -- `"`: End of string
+      res = res .. str:sub(k, j - 1)
+      return res, j + 1
+    end
+
+    j = j + 1
+  end
+
+  decode_error(str, i, "expected closing quote for string")
+end
+
+
+local function parse_number(str, i)
+  local x = next_char(str, i, delim_chars)
+  local s = str:sub(i, x - 1)
+  local n = tonumber(s)
+  if not n then
+    decode_error(str, i, "invalid number '" .. s .. "'")
+  end
+  return n, x
+end
+
+
+local function parse_literal(str, i)
+  local x = next_char(str, i, delim_chars)
+  local word = str:sub(i, x - 1)
+  if not literals[word] then
+    decode_error(str, i, "invalid literal '" .. word .. "'")
+  end
+  return literal_map[word], x
+end
+
+
+local function parse_array(str, i)
+  local res = {}
+  local n = 1
+  i = i + 1
+  while 1 do
+    local x
+    i = next_char(str, i, space_chars, true)
+    -- Empty / end of array?
+    if str:sub(i, i) == "]" then
+      i = i + 1
+      break
+    end
+    -- Read token
+    x, i = parse(str, i)
+    res[n] = x
+    n = n + 1
+    -- Next token
+    i = next_char(str, i, space_chars, true)
+    local chr = str:sub(i, i)
+    i = i + 1
+    if chr == "]" then break end
+    if chr ~= "," then decode_error(str, i, "expected ']' or ','") end
+  end
+  return res, i
+end
+
+
+local function parse_object(str, i)
+  local res = {}
+  i = i + 1
+  while 1 do
+    local key, val
+    i = next_char(str, i, space_chars, true)
+    -- Empty / end of object?
+    if str:sub(i, i) == "}" then
+      i = i + 1
+      break
+    end
+    -- Read key
+    if str:sub(i, i) ~= '"' then
+      decode_error(str, i, "expected string for key")
+    end
+    key, i = parse(str, i)
+    -- Read ':' delimiter
+    i = next_char(str, i, space_chars, true)
+    if str:sub(i, i) ~= ":" then
+      decode_error(str, i, "expected ':' after key")
+    end
+    i = next_char(str, i + 1, space_chars, true)
+    -- Read value
+    val, i = parse(str, i)
+    -- Set
+    res[key] = val
+    -- Next token
+    i = next_char(str, i, space_chars, true)
+    local chr = str:sub(i, i)
+    i = i + 1
+    if chr == "}" then break end
+    if chr ~= "," then decode_error(str, i, "expected '}' or ','") end
+  end
+  return res, i
+end
+
+
+local char_func_map = {
+  [ '"' ] = parse_string,
+  [ "0" ] = parse_number,
+  [ "1" ] = parse_number,
+  [ "2" ] = parse_number,
+  [ "3" ] = parse_number,
+  [ "4" ] = parse_number,
+  [ "5" ] = parse_number,
+  [ "6" ] = parse_number,
+  [ "7" ] = parse_number,
+  [ "8" ] = parse_number,
+  [ "9" ] = parse_number,
+  [ "-" ] = parse_number,
+  [ "t" ] = parse_literal,
+  [ "f" ] = parse_literal,
+  [ "n" ] = parse_literal,
+  [ "[" ] = parse_array,
+  [ "{" ] = parse_object,
+}
+
+
+parse = function(str, idx)
+  local chr = str:sub(idx, idx)
+  local f = char_func_map[chr]
+  if f then
+    return f(str, idx)
+  end
+  decode_error(str, idx, "unexpected character '" .. chr .. "'")
+end
+
+
+function json.decode(str)
+  if type(str) ~= "string" then
+    error("expected argument of type string, got " .. type(str))
+  end
+  local res, idx = parse(str, next_char(str, 1, space_chars, true))
+  idx = next_char(str, idx, space_chars, true)
+  if idx <= #str then
+    decode_error(str, idx, "trailing garbage")
+  end
+  return res
+end
+
+
+return json

src/common/utils/io.cpp

@@ -104,6 +104,11 @@ namespace utils::io
 		return std::filesystem::is_empty(directory);
 	}
 
+	bool remove_directory(const std::string& directory)
+	{
+		return std::filesystem::remove_all(directory);
+	}
+
 	std::vector<std::string> list_files(const std::string& directory)
 	{
 		std::vector<std::string> files;

src/common/utils/io.hpp

@@ -16,6 +16,7 @@ namespace utils::io
 	bool create_directory(const std::string& directory);
 	bool directory_exists(const std::string& directory);
 	bool directory_is_empty(const std::string& directory);
+	bool remove_directory(const std::string& directory);
 	std::vector<std::string> list_files(const std::string& directory);
 	void copy_folder(const std::filesystem::path& src, const std::filesystem::path& target);
 }