take cmdline arg for lua scripts to execute at application start

If a lua script is passed as an argument to wesnoth, wesnoth will
actually instantiate the application_lua_kernel defined in the
previous commits, initialize it, and run the script in that
environment.

src/commandline_options.cpp

@@ -185,6 +185,7 @@ commandline_options::commandline_options (const std::vector<std::string>& args)
 		("render-image", po::value<two_strings>()->multitoken(), "takes two arguments: <image> <output>. Like screenshot, but instead of a map, takes a valid wesnoth 'image path string' with image path functions, and outputs to a windows .bmp file")
 		("rng-seed", po::value<unsigned int>(), "seeds the random number generator with number <arg>. Example: --rng-seed 0")
 		("screenshot", po::value<two_strings>()->multitoken(), "takes two arguments: <map> <output>. Saves a screenshot of <map> to <output> without initializing a screen. Editor must be compiled in for this to work.")
+		("script", po::value<std::string>(), "file containing a lua script to control the client")
 		("server,s", po::value<std::string>()->implicit_value(std::string()), "connects to the host <arg> if specified or to the first host in your preferences.")
 		("username", po::value<std::string>(), "uses <username> when connecting to a server, ignoring other preferences.")
 		("password", po::value<std::string>(), "uses <password> when connecting to a server, ignoring other preferences.")
@@ -430,6 +431,8 @@ commandline_options::commandline_options (const std::vector<std::string>& args)
 		screenshot_map_file = vm["screenshot"].as<two_strings>().get<0>();
 		screenshot_output_file = vm["screenshot"].as<two_strings>().get<1>();
 	}
+	if (vm.count("script"))
+		script_file = vm["script"].as<std::string>();
 	if (vm.count("server"))
 		server = vm["server"].as<std::string>();
 	if (vm.count("username"))

src/commandline_options.hpp

@@ -188,6 +188,8 @@ friend std::ostream& operator<<(std::ostream &os, const commandline_options& cmd
 	boost::optional<std::string> screenshot_map_file;
 	/// Output file to put screenshot in. Second parameter given after --screenshot.
 	boost::optional<std::string> screenshot_output_file;
+	/// File to load lua script (mp-bot) from.
+	boost::optional<std::string> script_file;
 	/// True if --strict-validation was given on the command line. Makes Wesnoth trust validation errors as fatal WML errors and create WML exception, if so.
 	bool strict_validation;
 	/// Non-empty if --test was given on the command line. Goes directly into test mode, into a scenario, if specified.

src/game_launcher.cpp

@@ -50,6 +50,7 @@
 #include "preferences_display.hpp"      // for detect_video_settings, etc
 #include "resources.hpp"                // for config_manager
 #include "savegame.hpp"                 // for clean_saves, etc
+#include "scripting/application_lua_kernel.hpp"
 #include "sdl/utils.hpp"                // for surface
 #include "serialization/compression.hpp"  // for format::NONE
 #include "serialization/string_utils.hpp"  // for split
@@ -443,6 +444,36 @@ bool game_launcher::init_video()
 	return true;
 }
 
+bool game_launcher::init_lua_script()
+{
+	// start the application lua kernel, register it in resources, and load script file, if script file is present
+	if (cmdline_opts_.script_file)
+	{
+		filesystem::scoped_istream sf = filesystem::istream_file(*cmdline_opts_.script_file);
+
+		if (!sf->fail()) {
+			/* Cancel all "jumps" to editor / campaign / multiplayer */
+			jump_to_multiplayer_ = false;
+			jump_to_editor_ = false;
+			jump_to_campaign_.jump_ = false;
+
+			std::string full_script((std::istreambuf_iterator<char>(*sf)), std::istreambuf_iterator<char>());
+
+			std::cerr << "\nRunning lua script: " << *cmdline_opts_.script_file << std::endl;
+
+			resources::app_lua_kernel = new application_lua_kernel();
+			resources::app_lua_kernel->initialize(this);
+
+			resources::app_lua_kernel->run(full_script.c_str());
+
+			return true;
+		} else {
+			std::cerr << "Scripting disabled, encountered failure when opening " << *cmdline_opts_.script_file << std::endl;
+		}
+	}
+	return false;
+}
+
 bool game_launcher::play_test()
 {
 	static bool first_time = true;

src/game_launcher.hpp

@@ -62,6 +62,7 @@ class game_launcher
 	bool init_video();
 	bool init_language();
 	bool init_joystick();
+	bool init_lua_script();
 
 	bool play_test();
 	bool play_screenshot_mode();

src/resources.cpp

@@ -23,6 +23,7 @@ namespace resources
 	game_data            *gamedata = NULL;
 	filter_context	     *filter_con = NULL;
 	LuaKernel            *lua_kernel = NULL;
+	application_lua_kernel *app_lua_kernel = NULL;
 	persist_manager      *persist = NULL;
 	game_display         *screen = NULL;
 	soundsource::manager *soundsources = NULL;

src/resources.hpp

@@ -25,6 +25,7 @@ class gamemap;
 class game_data;
 class filter_context;
 class LuaKernel;
+class application_lua_kernel;
 class play_controller;
 class team;
 class fake_unit_manager;
@@ -50,6 +51,7 @@ namespace resources
 	extern game_board             *gameboard;
 	extern game_data              *gamedata;
 	extern LuaKernel              *lua_kernel;     // Set by game_events::manager.
+	extern application_lua_kernel *app_lua_kernel;
 	extern persist_manager        *persist;
 	extern game_classification    *classification;
 	extern game_display           *screen;

src/wesnoth.cpp

@@ -508,6 +508,23 @@ static void warn_early_init_failure()
 			  << "in the command line with the --data-dir switch or as the only argument.\n";
 }
 
+/**
+ * Handles the lua script command line arguments if present.
+ * This function will only run once.
+ */
+static void handle_lua_script_args(game_launcher * game, commandline_options & cmdline_opts)
+{
+	static bool first_time = true;
+
+	if (!first_time) return;
+
+	first_time = false;
+
+	if (cmdline_opts.script_file && !game->init_lua_script()) {
+		std::cerr << "could not load lua script: " << *cmdline_opts.script_file << std::endl;
+	}
+}
+
 /**
  * Setups the game environment and enters
  * the titlescreen or game loops.
@@ -625,6 +642,8 @@ static int do_gameloop(const std::vector<std::string>& args)
 
 		loadscreen_manager.reset();
 
+		handle_lua_script_args(&*game,cmdline_opts);
+
 		if(cmdline_opts.unit_test) {
 			if(cmdline_opts.timeout) {
 				std::cerr << "The wesnoth built-in timeout feature has been removed.\n" << std::endl;