/**

 * Relational pipes

 * Copyright © 2019 František Kučera (Frantovo.cz, GlobalCode.info)

 *

 * 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, version 3 of the License.

 *

 * 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, see <http://www.gnu.org/licenses/>.

 */

#pragma once

#include <stdexcept>

#include <libxml++-2.6/libxml++/libxml++.h>

#include "lib/uri.h"

#include "lib/INIReader.h"

#include "lib/BasicUnescapingProcessor.h"

#include "lib/BackspaceUnescapingProcessor.h"

#include "lib/JavaPropertiesUnescapingProcessor.h"

#include "lib/JavaPropertiesDialect.h"

#include "lib/XMLNameCodec.h"

using namespace relpipe::in::ini::lib;

namespace relpipe {

namespace in {

namespace xmltable {

class HierarchicalINIContentHandler : public INIContentHandler {

private:

	xmlpp::DomParser* domParser;

	XMLNameCodec nameCodec;

	xmlpp::Element* currentSection = nullptr;

	enum class TreeStyle {

		Standard,

		Literal,

	};

	TreeStyle parseTreeStyle(const std::string& name) {

		if (name == "standard") return TreeStyle::Standard;

		else if (name == "literal") return TreeStyle::Literal;

		else throw std::invalid_argument(std::string("Unknown tree style: ") + name);

	}

	TreeStyle treeStyle = TreeStyle::Literal;

	/**

	 * TODO: use a common method

	 */

	bool parseBoolean(const std::string& value) {

		if (value == "true") return true;

		else if (value == "false") return false;

		else throw std::invalid_argument(std::string("Unable to parse boolean value: ") + value + " (expecting true or false)");

	}

	bool treeWithNamespaces = false;

public:

	HierarchicalINIContentHandler(xmlpp::DomParser* domParser) : domParser(domParser) {

	}

	virtual ~HierarchicalINIContentHandler() {

	}

	void startDocument() override {

		if (currentSection) throw std::out_of_range("Lunatic INI parser send us multiple documents.");

	};

	void endDocument() override {

	};

	void startSection(const SectionStartEvent& event) override {

		currentSection = currentSection->add_child(treeStyle == TreeStyle::Literal ? nameCodec.encode(event.name) : "section");

		if (treeStyle == TreeStyle::Literal) currentSection->set_attribute("type", "section");

		currentSection->set_attribute("name", event.name);

		if (event.comment.size()) currentSection->set_attribute("comment", event.comment);

	};

	void endSection() override {

		currentSection = currentSection->get_parent();

		if (currentSection == nullptr) throw std::out_of_range("Lunatic INI parser tried to end a section without starting it before.");

	};

	void entry(const EntryEvent& event) override {

		xmlpp::Element* entry = currentSection->add_child(treeStyle == TreeStyle::Literal ? nameCodec.encode(event.fullKey) : "entry");

		if (treeStyle == TreeStyle::Literal) entry->set_attribute("type", "entry");

		if (event.comment.size()) entry->set_attribute("comment", event.comment);

		entry->add_child_text(event.value);

	};

	void comment(const CommentEvent& event) override {

		xmlpp::Element* comment = currentSection->add_child("comment");

		if (treeStyle == TreeStyle::Literal) comment->set_attribute("type", "comment");

		comment->add_child_text(event.comment);

	}

	void whitespace(const WhitespaceEvent& event) override {

		xmlpp::Element* whitespace = currentSection->add_child("whitespace");

		if (treeStyle == TreeStyle::Literal) whitespace->set_attribute("type", "whitespace");

		whitespace->add_child_text(event.whitespace);

	}

	bool setOption(const std::string& uri, const std::string& value) {

		if (uri == xml::TreeWithNamespaces) treeWithNamespaces = parseBoolean(value);

		else if (uri == xml::TreeStyle) treeStyle = parseTreeStyle(value);

		else return false;

		return true;

	}

};

// TODO: support also other styles/mappings e.g. <section/> and <entry/> with INI names only in the XML attributes (and thus without @type="section|entry")

// or map INI comments and whitespace to native XML comments and text nodes (but there will be no metadata like line/event numbers)

// TODO: optional namespaces (xmlns)

class XMLDocumentConstructor {

private:

	std::istream* input = nullptr;

	xmlpp::DomParser* parser = nullptr;

	std::shared_ptr<INIReader> reader;

	std::shared_ptr<HierarchicalINIContentHandler> handler;

public:

	XMLDocumentConstructor(std::istream* input, xmlpp::DomParser* parser) : input(input), parser(parser) {

		reader.reset(INIReader::create(*input));

		reader->addUnescapingProcessor(std::make_shared<BasicUnescapingProcessor>(), unescaping::Basic, true);

		reader->addUnescapingProcessor(std::make_shared<JavaPropertiesUnescapingProcessor>(), unescaping::JavaProperties, false);

		reader->addUnescapingProcessor(std::make_shared<BackspaceUnescapingProcessor>(), unescaping::Backspace, true);

		reader->addDialect(std::make_shared<JavaPropertiesDialect>(), dialect::JavaProperties, false);

		handler = std::make_shared<HierarchicalINIContentHandler>(parser);

	}

	void setOption(const std::string& uri, const std::string& value) {

		if (handler->setOption(uri, value)) return;

		reader->setOption(uri, value);

	}

	void process() {

		reader->addHandler(handler.get());

		reader->process();

	}

};

}

}

}