/******************************************************************************
 * Icinga 2                                                                   *
 * Copyright (C) 2012-2015 Icinga Development Team (http://www.icinga.org)    *
 *                                                                            *
 * This program 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; either version 2             *
 * of the License, or (at your option) any later version.                     *
 *                                                                            *
 * This program 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 this program; if not, write to the Free Software Foundation     *
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA.             *
 ******************************************************************************/

#include "config/configtype.hpp"
#include "config/vmops.hpp"
#include "base/objectlock.hpp"
#include "base/convert.hpp"
#include "base/singleton.hpp"
#include "base/function.hpp"
#include <boost/foreach.hpp>

using namespace icinga;

ConfigType::ConfigType(const String& name, const DebugInfo& debuginfo)
	: m_Name(name), m_RuleList(new TypeRuleList()), m_DebugInfo(debuginfo)
{ }

String ConfigType::GetName(void) const
{
	return m_Name;
}

String ConfigType::GetParent(void) const
{
	return m_Parent;
}

void ConfigType::SetParent(const String& parent)
{
	m_Parent = parent;
}

TypeRuleList::Ptr ConfigType::GetRuleList(void) const
{
	return m_RuleList;
}

DebugInfo ConfigType::GetDebugInfo(void) const
{
	return m_DebugInfo;
}

void ConfigType::AddParentRules(std::vector<TypeRuleList::Ptr>& ruleLists, const ConfigType::Ptr& item)
{
	ConfigType::Ptr parent;
	if (item->m_Parent.IsEmpty()) {
		if (item->GetName() != "DynamicObject")
			parent = ConfigType::GetByName("DynamicObject");
	} else {
		parent = ConfigType::GetByName(item->m_Parent);
	}

	if (parent) {
		AddParentRules(ruleLists, parent);
		ruleLists.push_back(parent->m_RuleList);
	}
}

void ConfigType::ValidateItem(const String& name, const Object::Ptr& object, const DebugInfo& debugInfo, const TypeRuleUtilities *utils)
{
	String location = "Object '" + name + "' (Type: '" + GetName() + "')";

	if (!debugInfo.Path.IsEmpty())
		location += " at " + debugInfo.Path + ":" + Convert::ToString(debugInfo.FirstLine);
	
	std::vector<String> locations;
	locations.push_back(location);

	std::vector<TypeRuleList::Ptr> ruleLists;
	AddParentRules(ruleLists, this);
	ruleLists.push_back(m_RuleList);

	ValidateObject(object, ruleLists, locations, utils);
}

String ConfigType::LocationToString(const std::vector<String>& locations)
{
	bool first = true;
	String stack;
	BOOST_FOREACH(const String& location, locations) {
		if (!first)
			stack += " -> ";
		else
			first = false;

		stack += location;
	}

	return stack;
}

void ConfigType::ValidateAttribute(const String& key, const Value& value,
    const std::vector<TypeRuleList::Ptr>& ruleLists, std::vector<String>& locations,
    const TypeRuleUtilities *utils)
{
	TypeValidationResult overallResult = ValidationUnknownField;
	std::vector<TypeRuleList::Ptr> subRuleLists;
	String hint;

	locations.push_back("Key " + key);

	BOOST_FOREACH(const TypeRuleList::Ptr& ruleList, ruleLists) {
		TypeRuleList::Ptr subRuleList;
		TypeValidationResult result = ruleList->ValidateAttribute(key, value, &subRuleList, &hint, utils);

		if (subRuleList)
			subRuleLists.push_back(subRuleList);

		if (overallResult == ValidationOK)
			continue;

		if (result == ValidationOK) {
			overallResult = result;
			continue;
		}

		if (result == ValidationInvalidType)
			overallResult = result;
	}

	if (overallResult == ValidationUnknownField)
		BOOST_THROW_EXCEPTION(ScriptError("Unknown attribute: " + LocationToString(locations)));
	else if (overallResult == ValidationInvalidType) {
		String message = "Invalid value: " + LocationToString(locations);

		if (!hint.IsEmpty())
			message += ": " + hint;

		BOOST_THROW_EXCEPTION(ScriptError(message));
	}

	if (!subRuleLists.empty() && value.IsObject() && !value.IsObjectType<Array>())
		ValidateObject(value, subRuleLists, locations, utils);
	else if (!subRuleLists.empty() && value.IsObjectType<Array>())
		ValidateArray(value, subRuleLists, locations, utils);

	locations.pop_back();
}

void ConfigType::ValidateObject(const Object::Ptr& object,
    const std::vector<TypeRuleList::Ptr>& ruleLists, std::vector<String>& locations,
    const TypeRuleUtilities *utils)
{
	BOOST_FOREACH(const TypeRuleList::Ptr& ruleList, ruleLists) {
		BOOST_FOREACH(const String& require, ruleList->GetRequires()) {
			locations.push_back("Attribute '" + require + "'");

			Value value = VMOps::GetField(object, require);

			if (value.IsEmpty())
				BOOST_THROW_EXCEPTION(ScriptError("Required attribute is missing: " + LocationToString(locations)));

			locations.pop_back();
		}

		String validator = ruleList->GetValidator();

		if (!validator.IsEmpty()) {
			Function::Ptr func = ScriptGlobal::Get(validator, &Empty);

			if (!func)
				BOOST_THROW_EXCEPTION(std::invalid_argument("Validator function '" + validator + "' does not exist."));

			std::vector<Value> arguments;
			arguments.push_back(LocationToString(locations));
			arguments.push_back(object);

			func->Invoke(arguments);
		}
	}

	Dictionary::Ptr dictionary = dynamic_pointer_cast<Dictionary>(object);

	if (dictionary) {
		ObjectLock olock(dictionary);

		BOOST_FOREACH(const Dictionary::Pair& kv, dictionary) {
			ValidateAttribute(kv.first, kv.second, ruleLists, locations, utils);
		}
	} else {
		Type::Ptr type = object->GetReflectionType();

		if (!type)
			return;

		for (int i = 0; i < type->GetFieldCount(); i++) {
			Field field = type->GetFieldInfo(i);

			if (!(field.Attributes & FAConfig))
				continue;

			ValidateAttribute(field.Name, object->GetField(i), ruleLists, locations, utils);
		}
	}
}

void ConfigType::ValidateArray(const Array::Ptr& array,
    const std::vector<TypeRuleList::Ptr>& ruleLists, std::vector<String>& locations,
    const TypeRuleUtilities *utils)
{
	BOOST_FOREACH(const TypeRuleList::Ptr& ruleList, ruleLists) {
		BOOST_FOREACH(const String& require, ruleList->GetRequires()) {
			size_t index = Convert::ToLong(require);

			locations.push_back("Attribute '" + require + "'");

			if (array->GetLength() < index)
				BOOST_THROW_EXCEPTION(ScriptError("Required array index is missing: " + LocationToString(locations)));

			locations.pop_back();
		}

		String validator = ruleList->GetValidator();

		if (!validator.IsEmpty()) {
			Function::Ptr func = ScriptGlobal::Get(validator, &Empty);

			if (!func)
				BOOST_THROW_EXCEPTION(std::invalid_argument("Validator function '" + validator + "' does not exist."));

			std::vector<Value> arguments;
			arguments.push_back(LocationToString(locations));
			arguments.push_back(array);

			func->Invoke(arguments);
		}
	}

	ObjectLock olock(array);

	int index = 0;
	String key;
	BOOST_FOREACH(const Value& value, array) {
		key = Convert::ToString(index);
		index++;

		ValidateAttribute(key, value, ruleLists, locations, utils);
	}
}

void ConfigType::Register(void)
{
	ConfigTypeRegistry::GetInstance()->Register(GetName(), this);
}

ConfigType::Ptr ConfigType::GetByName(const String& name)
{
	return ConfigTypeRegistry::GetInstance()->GetItem(name);
}

ConfigTypeRegistry::ItemMap ConfigType::GetTypes(void)
{
	return ConfigTypeRegistry::GetInstance()->GetItems();
}

void ConfigType::DiscardTypes(void)
{
	ConfigTypeRegistry::GetInstance()->Clear();
}

ConfigTypeRegistry *ConfigTypeRegistry::GetInstance(void)
{
	return Singleton<ConfigTypeRegistry>::GetInstance();
}