/*
 * This file is part of OpenTTD.
 * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
 * OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
 */

/** @file script_info.cpp Implementation of ScriptInfo. */

#include "../stdafx.h"
#include "../settings_type.h"

#include "squirrel_helper.hpp"

#include "script_info.hpp"
#include "script_scanner.hpp"
#include "../3rdparty/fmt/format.h"

#include "../safeguards.h"

bool ScriptInfo::CheckMethod(const char *name) const
{
	if (!this->engine->MethodExists(this->SQ_instance, name)) {
		this->engine->ThrowError(fmt::format("your info.nut/library.nut doesn't have the method '{}'", name));
		return false;
	}
	return true;
}

/* static */ SQInteger ScriptInfo::Constructor(HSQUIRRELVM vm, ScriptInfo *info)
{
	/* Set some basic info from the parent */
	Squirrel::GetInstance(vm, &info->SQ_instance, 2);
	/* Make sure the instance stays alive over time */
	sq_addref(vm, &info->SQ_instance);

	info->scanner = (ScriptScanner *)Squirrel::GetGlobalPointer(vm);
	info->engine = info->scanner->GetEngine();

	/* Ensure the mandatory functions exist */
	static const char * const required_functions[] = {
		"GetAuthor",
		"GetName",
		"GetShortName",
		"GetDescription",
		"GetVersion",
		"GetDate",
		"CreateInstance",
	};
	for (size_t i = 0; i < lengthof(required_functions); i++) {
		if (!info->CheckMethod(required_functions[i])) return SQ_ERROR;
	}

	/* Get location information of the scanner */
	info->main_script = info->scanner->GetMainScript();
	info->tar_file = info->scanner->GetTarFile();

	/* Cache the data the info file gives us. */
	if (!info->engine->CallStringMethod(info->SQ_instance, "GetAuthor", &info->author, MAX_GET_OPS)) return SQ_ERROR;
	if (!info->engine->CallStringMethod(info->SQ_instance, "GetName", &info->name, MAX_GET_OPS)) return SQ_ERROR;
	if (!info->engine->CallStringMethod(info->SQ_instance, "GetShortName", &info->short_name, MAX_GET_OPS)) return SQ_ERROR;
	if (!info->engine->CallStringMethod(info->SQ_instance, "GetDescription", &info->description, MAX_GET_OPS)) return SQ_ERROR;
	if (!info->engine->CallStringMethod(info->SQ_instance, "GetDate", &info->date, MAX_GET_OPS)) return SQ_ERROR;
	if (!info->engine->CallIntegerMethod(info->SQ_instance, "GetVersion", &info->version, MAX_GET_OPS)) return SQ_ERROR;
	if (!info->engine->CallStringMethod(info->SQ_instance, "CreateInstance", &info->instance_name, MAX_CREATEINSTANCE_OPS)) return SQ_ERROR;

	/* The GetURL function is optional. */
	if (info->engine->MethodExists(info->SQ_instance, "GetURL")) {
		if (!info->engine->CallStringMethod(info->SQ_instance, "GetURL", &info->url, MAX_GET_OPS)) return SQ_ERROR;
	}

	/* Check if we have settings */
	if (info->engine->MethodExists(info->SQ_instance, "GetSettings")) {
		if (!info->GetSettings()) return SQ_ERROR;
	}

	return 0;
}

bool ScriptInfo::GetSettings()
{
	return this->engine->CallMethod(this->SQ_instance, "GetSettings", nullptr, MAX_GET_SETTING_OPS);
}

SQInteger ScriptInfo::AddSetting(HSQUIRRELVM vm)
{
	ScriptConfigItem config;
	uint items = 0;

	int easy_value = INT32_MIN;
	int medium_value = INT32_MIN;
	int hard_value = INT32_MIN;

	/* Read the table, and find all properties we care about */
	sq_pushnull(vm);
	while (SQ_SUCCEEDED(sq_next(vm, -2))) {
		const SQChar *key_string;
		if (SQ_FAILED(sq_getstring(vm, -2, &key_string))) return SQ_ERROR;
		std::string key = StrMakeValid(key_string);

		if (key == "name") {
			const SQChar *sqvalue;
			if (SQ_FAILED(sq_getstring(vm, -1, &sqvalue))) return SQ_ERROR;

			/* Don't allow '=' and ',' in configure setting names, as we need those
			 *  2 chars to nicely store the settings as a string. */
			auto replace_with_underscore = [](auto c) { return c == '=' || c == ','; };
			config.name = StrMakeValid(sqvalue);
			std::replace_if(config.name.begin(), config.name.end(), replace_with_underscore, '_');
			items |= 0x001;
		} else if (key == "description") {
			const SQChar *sqdescription;
			if (SQ_FAILED(sq_getstring(vm, -1, &sqdescription))) return SQ_ERROR;
			config.description = StrMakeValid(sqdescription);
			items |= 0x002;
		} else if (key == "min_value") {
			SQInteger res;
			if (SQ_FAILED(sq_getinteger(vm, -1, &res))) return SQ_ERROR;
			config.min_value = ClampTo<int32_t>(res);
			items |= 0x004;
		} else if (key == "max_value") {
			SQInteger res;
			if (SQ_FAILED(sq_getinteger(vm, -1, &res))) return SQ_ERROR;
			config.max_value = ClampTo<int32_t>(res);
			items |= 0x008;
		} else if (key == "easy_value") {
			SQInteger res;
			if (SQ_FAILED(sq_getinteger(vm, -1, &res))) return SQ_ERROR;
			easy_value = ClampTo<int32_t>(res);
			items |= 0x010;
		} else if (key == "medium_value") {
			SQInteger res;
			if (SQ_FAILED(sq_getinteger(vm, -1, &res))) return SQ_ERROR;
			medium_value = ClampTo<int32_t>(res);
			items |= 0x020;
		} else if (key == "hard_value") {
			SQInteger res;
			if (SQ_FAILED(sq_getinteger(vm, -1, &res))) return SQ_ERROR;
			hard_value = ClampTo<int32_t>(res);
			items |= 0x040;
		} else if (key == "custom_value") {
			// No longer parsed.
		} else if (key == "default_value") {
			SQInteger res;
			if (SQ_FAILED(sq_getinteger(vm, -1, &res))) return SQ_ERROR;
			config.default_value = ClampTo<int32_t>(res);
			items |= 0x080;
		} else if (key == "random_deviation") {
			SQInteger res;
			if (SQ_FAILED(sq_getinteger(vm, -1, &res))) return SQ_ERROR;
			config.random_deviation = ClampTo<int32_t>(abs(res));
			items |= 0x200;
		} else if (key == "step_size") {
			SQInteger res;
			if (SQ_FAILED(sq_getinteger(vm, -1, &res))) return SQ_ERROR;
			config.step_size = ClampTo<int32_t>(res);
		} else if (key == "flags") {
			SQInteger res;
			if (SQ_FAILED(sq_getinteger(vm, -1, &res))) return SQ_ERROR;
			config.flags = (ScriptConfigFlags)res;
			items |= 0x100;
		} else {
			this->engine->ThrowError(fmt::format("unknown setting property '{}'", key));
			return SQ_ERROR;
		}

		sq_pop(vm, 2);
	}
	sq_pop(vm, 1);

	/* Check if default_value is set. Although required, this was changed with
	 * 14.0, and as such, older AIs don't use it yet. So we convert the older
	 * values into a default_value. */
	if ((items & 0x080) == 0) {
		/* Easy/medium/hard should all three be defined. */
		if ((items & 0x010) == 0 || (items & 0x020) == 0 || (items & 0x040) == 0) {
			this->engine->ThrowError("please define all properties of a setting (min/max not allowed for booleans)");
			return SQ_ERROR;
		}

		config.default_value = medium_value;
		/* If not boolean and no random deviation set, calculate it based on easy/hard difference. */
		if ((config.flags & SCRIPTCONFIG_BOOLEAN) == 0 && (items & 0x200) == 0) {
			config.random_deviation = abs(hard_value - easy_value) / 2;
			items |= 0x200;
		}
		items |= 0x080;
	} else {
		/* For compatibility, also act like the default sets the easy/medium/hard. */
		items |= 0x010 | 0x020 | 0x040;
	}

	/* Don't allow both random_deviation and SCRIPTCONFIG_BOOLEAN to
	 * be set for the same config item. */
	if ((items & 0x200) != 0 && (config.flags & SCRIPTCONFIG_BOOLEAN) != 0) {
		this->engine->ThrowError("setting both random_deviation and CONFIG_BOOLEAN is not allowed");
		return SQ_ERROR;
	}

	/* Reset the bit for random_deviation as it's optional. */
	items &= ~0x200;

	/* Make sure all properties are defined */
	uint mask = (config.flags & SCRIPTCONFIG_BOOLEAN) ? 0x1F3 : 0x1FF;
	if (items != mask) {
		this->engine->ThrowError("please define all properties of a setting (min/max not allowed for booleans)");
		return SQ_ERROR;
	}

	this->config_list.emplace_back(config);
	return 0;
}

SQInteger ScriptInfo::AddLabels(HSQUIRRELVM vm)
{
	const SQChar *setting_name_str;
	if (SQ_FAILED(sq_getstring(vm, -2, &setting_name_str))) return SQ_ERROR;
	std::string setting_name = StrMakeValid(setting_name_str);

	ScriptConfigItem *config = nullptr;
	for (auto &item : this->config_list) {
		if (item.name == setting_name) config = &item;
	}

	if (config == nullptr) {
		this->engine->ThrowError(fmt::format("Trying to add labels for non-defined setting '{}'", setting_name));
		return SQ_ERROR;
	}
	if (!config->labels.empty()) return SQ_ERROR;

	/* Read the table and find all labels */
	sq_pushnull(vm);
	while (SQ_SUCCEEDED(sq_next(vm, -2))) {
		const SQChar *key_string;
		const SQChar *label;
		if (SQ_FAILED(sq_getstring(vm, -2, &key_string))) return SQ_ERROR;
		if (SQ_FAILED(sq_getstring(vm, -1, &label))) return SQ_ERROR;
		/* Because squirrel doesn't support identifiers starting with a digit,
		 * we skip the first character. */
		key_string++;
		int sign = 1;
		if (*key_string == '_') {
			/* When the second character is '_', it indicates the value is negative. */
			sign = -1;
			key_string++;
		}
		int key = atoi(key_string) * sign;
		config->labels[key] = StrMakeValid(label);

		sq_pop(vm, 2);
	}
	sq_pop(vm, 1);

	/* Check labels for completeness */
	config->complete_labels = true;
	for (int value = config->min_value; value <= config->max_value; value++) {
		if (config->labels.find(value) == config->labels.end()) {
			config->complete_labels = false;
			break;
		}
	}

	return 0;
}

const ScriptConfigItemList *ScriptInfo::GetConfigList() const
{
	return &this->config_list;
}

const ScriptConfigItem *ScriptInfo::GetConfigItem(const std::string_view name) const
{
	for (const auto &item : this->config_list) {
		if (item.name == name) return &item;
	}
	return nullptr;
}

int ScriptInfo::GetSettingDefaultValue(const std::string &name) const
{
	for (const auto &item : this->config_list) {
		if (item.name != name) continue;
		return item.default_value;
	}

	/* There is no such setting */
	return -1;
}
