/* $Id$ */

/** @file ai_controller.hpp The controller of the AI. */

#ifndef AI_CONTROLLER_HPP
#define AI_CONTROLLER_HPP

#include <map>
#ifndef AI_SQUIRREL_HPP
struct ltstr { bool operator()(const char *s1, const char *s2) const { return strcmp(s1, s2) < 0; } };
#endif /* AI_SQUIRREL_HPP */

/**
 * The Controller, the class each AI should extend. It creates the AI, makes
 *  sure the logic kicks in correctly, and that GetTick() has a valid value.
 */
class AIController {
	friend class AISquirrel;

public:
	static const char *GetClassName() { return "AIController"; }

	/**
	 * Initializer of the AIController.
	 */
	AIController(const char *script, const char *class_name);

	/**
	 * Destructor of the AIController.
	 */
	~AIController();

	/**
	 * This function is called to start your AI. Your AI starts here. If you
	 *   return from this function, your AI dies, so make sure that doesn't
	 *   happen. It is okay to use while() {} loops, as long as you put a
	 *   Sleep() in it to give the rest of the game time to do things. Also
	 *   don't keep the system busy for too long, as people will consider
	 *   that annoying.
	 * @note Cannot be called from within your AI.
	 */
	void Start();

	/**
	 * Increase the internal ticker. You should never call this yourself,
	 *   as it is called by the OpenTTD system itself.
	 * @note Cannot be called from within your AI.
	 */
	void IncreaseTick();

	/**
	 * Find at which tick your AI currently is.
	 * @return returns the current tick.
	 */
	uint GetTick();

	/**
	 * Sleep for X ticks. The code continues after this line when the X AI ticks
	 *   are passed. Mind that an AI tick is different from in-game ticks and
	 *   differ per AI speed.
	 * @param ticks the ticks to wait
	 * @post the value of GetTick() will be changed exactly 'ticks' in value after
	 *   calling this.
	 */
	static void Sleep(uint ticks);

	/**
	 * When Squirrel triggers a print, this function is called.
	 *  Squirrel calls this when 'print' is used, or when the script made an error.
	 * @param error_msg If true, it is a Squirrel error message.
	 * @param message The message Squirrel logged.
	 * @note Use AILog.Info/Warning/Error instead of 'print'.
	 */
	static void Print(bool error_msg, const char *message);

private:
	typedef std::map<const char *, const char *, ltstr> LoadedLibraryList;

	uint tick;
	class Squirrel *engine;
	HSQOBJECT *SQ_instance;
	LoadedLibraryList loaded_library;
	int loaded_library_count;
	const char *script;
	const char *class_name;

	/**
	 * Register all classes that are known inside the NoAI API.
	 */
	void RegisterClasses();

	/**
	 * Check if a library is already loaded. If found, fake_class_name is filled
	 *  with the fake class name as given via AddLoadedLibrary. If not found,
	 *  next_number is set to the next number available for the fake namespace.
	 * @param library_name The library to check if already loaded.
	 * @param next_number The next available number for a library if not already loaded.
	 * @param fake_class_name The name the library has if already loaded.
	 * @param fake_class_name_len The maximum length of fake_class_name.
	 * @return True if the library is already loaded.
	 */
	bool LoadedLibrary(const char *library_name, int *next_number, char *fake_class_name, int fake_class_name_len);

	/**
	 * Add a library as loaded.
	 */
	void AddLoadedLibrary(const char *library_name, const char *fake_class_name);
};

#endif /* AI_CONTROLLER_HPP */