/* $Id$ */

/** @file ai_scanner.cpp allows scanning AI scripts */

#include "../stdafx.h"

#include "../debug.h"

#include "../openttd.h"

#include "../string_func.h"

#include "../fileio_func.h"

#include "../fios.h"

#include "../network/network.h"

#include "../core/random_func.hpp"

#include <sys/types.h>

#include <sys/stat.h>

#include <squirrel.h>

#include "../script/squirrel.hpp"

#include "../script/squirrel_helper.hpp"

#include "../script/squirrel_class.hpp"

#include "ai.hpp"

#include "ai_info.hpp"

#include "ai_scanner.hpp"

#include "api/ai_controller.hpp"

void AIScanner::ScanDir(const char *dirname, bool library_dir, char *library_depth)

{

	extern bool FiosIsValidFile(const char *path, const struct dirent *ent, struct stat *sb);

	extern bool FiosIsHiddenFile(const struct dirent *ent);

	struct stat sb;

	struct dirent *dirent;

	DIR *dir;

	char d_name[MAX_PATH];

	char script_name[MAX_PATH];

	dir = ttd_opendir(dirname);

	/* Dir not found, so do nothing */

	if (dir == NULL) return;

	/* Walk all dirs trying to find a dir in which 'main.nut' exists */

	while ((dirent = readdir(dir)) != NULL) {

		ttd_strlcpy(d_name, FS2OTTD(dirent->d_name), sizeof(d_name));

		/* Valid file, not '.' or '..', not hidden */

		if (!FiosIsValidFile(dirname, dirent, &sb)) continue;

		if (strcmp(d_name, ".") == 0 || strcmp(d_name, "..") == 0) continue;

		if (FiosIsHiddenFile(dirent) && strncasecmp(d_name, PERSONAL_DIR, strlen(d_name)) != 0) continue;

		if (S_ISDIR(sb.st_mode)) {

			/* Create the full-length script-name */

			ttd_strlcpy(script_name, dirname, sizeof(script_name));

			ttd_strlcat(script_name, d_name, sizeof(script_name));

			ttd_strlcat(script_name, PATHSEP, sizeof(script_name));

			if (library_dir && library_depth == NULL) {

				ScanDir(script_name, library_dir, d_name);

				continue;

			}

		}

		if (S_ISREG(sb.st_mode)) {

			if (library_dir) continue;

			char *ext = strrchr(d_name, '.');

			if (ext == NULL || strcasecmp(ext, ".tar") != 0) continue;

			/* Create the full path to the tarfile */

			char tarname[MAX_PATH];

			ttd_strlcpy(tarname, dirname, sizeof(tarname));

			ttd_strlcat(tarname, d_name, sizeof(tarname));

			/* Now the script-name starts with the first dir in the tar */

			if (FioTarFirstDir(tarname) == NULL) continue;

			ttd_strlcpy(script_name, "%aitar%", sizeof(tarname));

			ttd_strlcat(script_name, FioTarFirstDir(tarname), sizeof(script_name));

			FioTarAddLink(script_name, FioTarFirstDir(tarname));

			/* The name of the AI is the name of the tar minus the .tar */

			*ext = '\0';

		}

		if (!library_dir) {

			/* We look for the file 'info.nut' inside the AI dir.. if it doesn't exists, it isn't an AI */

			ttd_strlcat(script_name, "info.nut", sizeof(script_name));

			if (FioCheckFileExists(script_name, AI_DIR)) {

				char load_script[MAX_PATH];

				ttd_strlcpy(load_script, script_name, sizeof(load_script));

				/* Remove the 'info.nut' part and replace it with 'main.nut' */

				script_name[strlen(script_name) - 8] = '\0';

				ttd_strlcat(script_name, "main.nut", sizeof(script_name));

				DEBUG(ai, 6, "[script] Loading script '%s' for AI handling", load_script);

				this->current_script = script_name;

				this->current_dir = d_name;

				this->engine->LoadScript(load_script);

			}

		} else {

			/* We look for the file 'library.nut' inside the library dir.. */

			ttd_strlcat(script_name, "library.nut", sizeof(script_name));

			if (FioCheckFileExists(script_name, AI_DIR)) {

				char load_script[MAX_PATH];

				char dir_name[MAX_PATH];

				char d_name_2[MAX_PATH];

				/* In case the directory has a dot in it, ignore it, as that is the

				 *  indicator for multiple versions of the same library */

				ttd_strlcpy(d_name_2, d_name, sizeof(d_name_2));

				char *e = strrchr(d_name_2, '.');

				if (e != NULL) *e = '\0';

				ttd_strlcpy(load_script, script_name, sizeof(load_script));

				ttd_strlcpy(dir_name, library_depth, sizeof(dir_name));

				ttd_strlcat(dir_name, ".", sizeof(dir_name));

				ttd_strlcat(dir_name, d_name_2, sizeof(dir_name));

				/* Remove the 'library.nut' part and replace it with 'main.nut' */

				script_name[strlen(script_name) - 11] = '\0';

				ttd_strlcat(script_name, "main.nut", sizeof(script_name));

				DEBUG(ai, 6, "[script] Loading script '%s' for Squirrel library", load_script);

				this->current_script = script_name;

				this->current_dir = dir_name;

				this->engine->LoadScript(load_script);

			}

		}

	}

	closedir(dir);

}

void AIScanner::ScanAIDir()

{

	char buf[MAX_PATH];

	Searchpath sp;

	FOR_ALL_SEARCHPATHS(sp) {

		FioAppendDirectory(buf, MAX_PATH, sp, AI_DIR);

		if (FileExists(buf)) this->ScanDir(buf, false);

		ttd_strlcat(buf, "library" PATHSEP, MAX_PATH);

		if (FileExists(buf)) this->ScanDir(buf, true);

	}

}

void AIScanner::RescanAIDir()

{

	extern void ScanForTarFiles();

	ScanForTarFiles();

	this->ScanAIDir();

}

AIScanner::AIScanner()

{

	this->engine = new Squirrel();

	/* Create the AIInfo class, and add the RegisterAI function */

	DefSQClass <AIInfo> SQAIInfo("AIInfo");

	SQAIInfo.PreRegister(engine);

	SQAIInfo.AddConstructor<void (AIInfo::*)(), 1>(engine, "x");

	SQAIInfo.DefSQAdvancedMethod(this->engine, &AIInfo::AddSetting, "AddSetting");

	SQAIInfo.PostRegister(engine);

	this->engine->AddMethod("RegisterAI", &AIInfo::Constructor, 2, "tx");

	/* Create the AILibrary class, and add the RegisterLibrary function */

	this->engine->AddClassBegin("AILibrary");

	this->engine->AddClassEnd();

	this->engine->AddMethod("RegisterLibrary", &AILibrary::Constructor, 2, "tx");

	/* Mark this class as global pointer */

	this->engine->SetGlobalPointer(this);

	/* Scan the AI dir for scripts */

	this->ScanAIDir();

	/* Create the dummy AI */

	this->engine->AddMethod("RegisterDummyAI", &AIInfo::DummyConstructor, 2, "tx");

	this->current_script = (char *)"%_dummy";

	this->current_dir = (char *)"%_dummy";

	extern void AI_CreateAIInfoDummy(HSQUIRRELVM vm);

	AI_CreateAIInfoDummy(this->engine->GetVM());

}

AIScanner::~AIScanner()

{

	AIInfoList::iterator it = this->info_list.begin();

	for (; it != this->info_list.end(); it++) {

		AIInfo *i = (*it).second;

		delete i;

	}

	delete this->engine;

}

bool AIScanner::ImportLibrary(const char *library, const char *class_name, int version, HSQUIRRELVM vm, AIController *controller)

{

	/* Internally we store libraries as 'library.version' */

	char library_name[1024];

	snprintf(library_name, sizeof(library_name), "%s.%d", library, version);

	/* Check if the library + version exists */

	AILibraryList::iterator iter = this->library_list.find(library_name);

	if (iter == this->library_list.end()) {

		char error[1024];

		/* Now see if the version doesn't exist, or the library */

		iter = this->library_list.find(library);

		if (iter == this->library_list.end()) {

			snprintf(error, sizeof(error), "couldn't find library '%s'", library);

		} else {

			snprintf(error, sizeof(error), "this AI is expecting library '%s' to be version %d, but the latest available is version %d", library, version, (*iter).second->GetVersion());

		}

		sq_throwerror(vm, OTTD2FS(error));

		return false;

	}

	/* Get the current table/class we belong to */

	HSQOBJECT parent;

	sq_getstackobj(vm, 1, &parent);

	char fake_class[1024];

	int next_number;

	/* Check if we already have this library loaded.. if so, fill fake_class

	 *  with the class-name it is nested in */

	if (!controller->LoadedLibrary(library_name, &next_number, &fake_class[0], sizeof(fake_class))) {

		/* Create a new fake internal name */

		snprintf(fake_class, sizeof(fake_class), "_internalNA%d", next_number);

		/* Load the library in a 'fake' namespace, so we can link it to the name the user requested */

		sq_pushroottable(vm);

		sq_pushstring(vm, OTTD2FS(fake_class), -1);

		sq_newclass(vm, SQFalse);

		/* Load the library */

		if (!Squirrel::LoadScript(vm, (*iter).second->GetScriptName(), false)) {

			char error[1024];

			snprintf(error, sizeof(error), "there was a compile error when importing '%s' version %d", library, version);

			sq_throwerror(vm, OTTD2FS(error));

			return false;

		}

		/* Create the fake class */

		sq_newslot(vm, -3, SQFalse);

		sq_pop(vm, 1);

		controller->AddLoadedLibrary(library_name, fake_class);

	}

	/* Find the real class inside the fake class (like 'sets.Vector') */

	sq_pushroottable(vm);

	sq_pushstring(vm, OTTD2FS(fake_class), -1);

	if (SQ_FAILED(sq_get(vm, -2))) {

		sq_throwerror(vm, _SC("internal error assigning library class"));

		return false;

	}

	sq_pushstring(vm, OTTD2FS((*iter).second->GetInstanceName()), -1);

	if (SQ_FAILED(sq_get(vm, -2))) {

		char error[1024];

		snprintf(error, sizeof(error), "unable to find class '%s' in the library '%s' version %d", (*iter).second->GetInstanceName(), library, version);

		sq_throwerror(vm, OTTD2FS(error));

		return false;

	}

	HSQOBJECT obj;

	sq_getstackobj(vm, -1, &obj);

	sq_pop(vm, 3);

	if (StrEmpty(class_name)) {

		sq_pushobject(vm, obj);

		return true;

	}

	/* Now link the name the user wanted to our 'fake' class */

	sq_pushobject(vm, parent);

	sq_pushstring(vm, OTTD2FS(class_name), -1);

	sq_pushobject(vm, obj);

	sq_newclass(vm, SQTrue);

	sq_newslot(vm, -3, SQFalse);

	sq_pop(vm, 1);

	sq_pushobject(vm, obj);

	return true;

}

void AIScanner::RegisterLibrary(AILibrary *library)

{

	const char *ai_name_without_version = library->GetDirName();

	char ai_name[1024];

	snprintf(ai_name, sizeof(ai_name), "%s.%d", library->GetDirName(), library->GetVersion());

	/* Check if we register twice; than the first always wins */

	if (this->library_list.find(ai_name) != this->library_list.end()) {

		/* In case they are not the same dir, give a warning */

		if (strcasecmp(library->GetScriptName(), this->library_list[ai_name]->GetScriptName()) != 0) {

			DEBUG(ai, 0, "Registering two libraries with the same name");

			DEBUG(ai, 0, "  1: %s", this->library_list[ai_name]->GetScriptName());

			DEBUG(ai, 0, "  2: %s", library->GetScriptName());

			DEBUG(ai, 0, "The first is taking precedence");

		}

		/* Delete the new AILibrary, as we will be using the old one */

		delete library;

		return;

	}

	this->library_list[strdup(ai_name)] = library;

	/* Insert the global name too, so we if the library is known at all */

	if (this->library_list.find(ai_name_without_version) == this->library_list.end()) {

		this->library_list[strdup(ai_name_without_version)] = library;

	} else if (this->library_list[ai_name_without_version]->GetVersion() < library->GetVersion()) {

		this->library_list[ai_name_without_version] = library;

	}

}

void AIScanner::RegisterAI(AIInfo *info)

{

	const char *ai_name = info->GetDirName();

	/* Check if we register twice; than the first always wins */

	if (this->info_list.find(ai_name) != this->info_list.end()) {

		/* In case they are not the same dir, give a warning */

		if (strcasecmp(info->GetScriptName(), this->info_list[ai_name]->GetScriptName()) != 0) {

			DEBUG(ai, 0, "Registering two AIs with the same name");

			DEBUG(ai, 0, "  1: %s", this->info_list[ai_name]->GetScriptName());

			DEBUG(ai, 0, "  2: %s", info->GetScriptName());

			DEBUG(ai, 0, "The first is taking precedence");

		}

		/* Delete the new AIInfo, as we will be using the old one */

		delete info;

		return;

	}

	this->info_list[strdup(ai_name)] = info;

}

void AIScanner::UnregisterAI(AIInfo *info)

{

	this->info_list.erase(info->GetDirName());

}

AIInfo *AIScanner::SelectRandomAI()

{

	if (this->info_list.size() == 0) {

		DEBUG(ai, 0, "No suitable AI found, loading 'dummy' AI.");

		return this->info_dummy;

	}

	/* Find a random AI */

	uint pos;

	if (_networking) pos = InteractiveRandomRange((uint16)this->info_list.size());

	else             pos =            RandomRange((uint16)this->info_list.size());

	/* Find the Nth item from the array */

	AIInfoList::iterator it = this->info_list.begin();

	for (; pos > 0; pos--) it++;

	AIInfoList::iterator first_it = it;

	AIInfo *i = (*it).second;

	if (!i->AllowStartup()) {

		/* We can't start this AI, try to find the next best */

		do {

			it++;

			if (it == this->info_list.end()) it = this->info_list.begin();

			/* Back at the beginning? We can't start an AI. */

			if (first_it == it) {

				DEBUG(ai, 0, "No suitable AI found, loading 'dummy' AI.");

				return this->info_dummy;

			}

			i = (*it).second;

		} while (!i->AllowStartup());

	}

	return i;

}

AIInfo *AIScanner::FindAI(const char *name)

{

	if (this->info_list.size() == 0) return NULL;

	if (name == NULL) return NULL;

	AIInfoList::iterator it = this->info_list.begin();

	for (; it != this->info_list.end(); it++) {

		AIInfo *i = (*it).second;

		if (strcasecmp(name, (*it).first) == 0 && i->AllowStartup()) {

			return i;

		}

	}

	return NULL;

}

char *AIScanner::GetAIConsoleList(char *p, const char *last)

{

	p += seprintf(p, last, "List of AIs:\n");

	AIInfoList::iterator it = this->info_list.begin();

	for (; it != this->info_list.end(); it++) {

		AIInfo *i = (*it).second;

		if (!i->AllowStartup()) continue;

		p += seprintf(p, last, "%10s: %s\n", (*it).first, i->GetDescription());

	}

	p += seprintf(p, last, "\n");

	return p;

}