/**
 * Relational pipes
 * Copyright © 2020 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 <string>
#include <sstream>

#include <relpipe/common/type/typedefs.h>
#include <relpipe/reader/RelpipeReaderException.h>

#include "uri.h"
#include "Dialect.h"
#include "EscapingProcessor.h"

namespace relpipe {
namespace out {
namespace ini {

class INIWriter {
private:
	std::ostream& output;
	std::wstring_convert<std::codecvt_utf8<wchar_t>> convertor; // TODO: local system encoding or generate INI always in UTF-8 like XML?

	std::string keyValueSeparator = " = ";
	std::string commentSeparatorForSections = " ; ";
	std::string commentSeparatorForEntries = " ; ";
	std::string commentSeparatorStandalone = "; ";

	bool hasContent = false;

	/**
	 * TODO: use a common method
	 */
	bool parseBoolean(const relpipe::common::type::StringX& value) {
		if (value == L"true") return true;
		else if (value == L"false") return false;
		else throw relpipe::reader::RelpipeReaderException(L"Unable to parse boolean value: " + value + L" (expecting true or false)");
	}

	std::string escape(const relpipe::common::type::StringX& value, EscapingProcessor::TextType type) {
		relpipe::common::type::StringX result = value;
		EscapingProcessor::QuotingType quotingType = EscapingProcessor::QuotingType::None;
		for (ConfiguredEscapingProcessor p : escapingProcessors) if (p.enbaled) result = p.processor->escape(result, type, quotingType);
		return convertor.to_bytes(result);
	}

	class ConfiguredEscapingProcessor {
	public:
		std::shared_ptr<EscapingProcessor> processor;
		const relpipe::common::type::StringX uri;
		bool enbaled;

		ConfiguredEscapingProcessor(std::shared_ptr<EscapingProcessor> processor, const relpipe::common::type::StringX uri, bool enbaled) : processor(processor), uri(uri), enbaled(enbaled) {
		}

	};

	std::vector<ConfiguredEscapingProcessor> escapingProcessors;

	bool setEscaping(const relpipe::common::type::StringX& uri, const relpipe::common::type::StringX& value) {
		for (ConfiguredEscapingProcessor& p : escapingProcessors) {
			if (p.uri == uri) {
				p.enbaled = parseBoolean(value);
				return true;
			}
		}
		return false;
	}

	class ConfiguredDialect {
	public:
		std::shared_ptr<Dialect> dialect;
		const relpipe::common::type::StringX uri;

		ConfiguredDialect(std::shared_ptr<Dialect> dialect, const relpipe::common::type::StringX uri) : dialect(dialect), uri(uri) {
		}

	};

	std::vector<ConfiguredDialect> dialects;

	void setDialect(const relpipe::common::type::StringX& uri) {
		for (ConfiguredDialect& d : dialects) {
			if (d.uri == uri) {
				d.dialect->apply(*this);
				return;
			}
		}
		throw relpipe::reader::RelpipeReaderException(L"Unsupported INI dialect: " + uri);
	}

public:

	class SectionStartEvent {
	public:
		relpipe::common::type::StringX comment;
		relpipe::common::type::StringX name;
		relpipe::common::type::StringX tag;
	};

	class EntryEvent {
	public:
		relpipe::common::type::StringX comment;
		relpipe::common::type::StringX key;
		relpipe::common::type::StringX subKey;
		relpipe::common::type::StringX value;
	};

	class CommentEvent {
	public:
		relpipe::common::type::StringX comment;
	};

	class WhitespaceEvent {
	public:
		relpipe::common::type::StringX whitespace;
	};

	INIWriter(std::ostream& output) : output(output) {
	}

	virtual ~INIWriter() {
	};

	void setOption(relpipe::common::type::StringX uri, relpipe::common::type::StringX value) {
		// TODO: setOption(): escaping, quotes, allow-sections
		if (uri == option::Dialect) setDialect(value);
		else if (uri == option::CommentSeparatorForSections) commentSeparatorForSections = convertor.to_bytes(value);
		else if (uri == option::CommentSeparatorForEntries) commentSeparatorForEntries = convertor.to_bytes(value);
		else if (uri == option::CommentSeparatorStandalone) commentSeparatorStandalone = convertor.to_bytes(value);
		else if (uri == option::KeyValueSeparator) keyValueSeparator = convertor.to_bytes(value);
		else if (uri == option::AllowSections);
		else if (uri == option::Quotes);
		else if (setEscaping(uri, value));
		else throw relpipe::reader::RelpipeReaderException(L"Unsupported writer option: " + uri);
	}

	void addDialect(std::shared_ptr<Dialect> dialect, const relpipe::common::type::StringX uri, bool enabledByDefault) {
		dialects.push_back({dialect, uri});
		if (enabledByDefault) dialect->apply(*this);
	}

	void addEscapingProcessor(std::shared_ptr<EscapingProcessor> processor, const relpipe::common::type::StringX uri, bool enabledByDefault) {
		escapingProcessors.push_back({processor, uri, enabledByDefault});
	}

	void startDocument() {
	}

	void endDocument() {
		output.flush();
	}

	void startSection(const SectionStartEvent& event) {
		if (hasContent) output << std::endl;
		output << "[" << escape(event.name, EscapingProcessor::TextType::SectionName) << "]";
		if (event.tag.size()) output << "[" << escape(event.tag, EscapingProcessor::TextType::SectionTag) << "]";
		if (event.comment.size()) output << commentSeparatorForSections << escape(event.comment, EscapingProcessor::TextType::SectionComment);
		output << std::endl;
		hasContent = true;
	}

	void endSection() {
		output.flush();
	}

	void entry(const EntryEvent& event) {
		output << escape(event.key, EscapingProcessor::TextType::EntryKey);
		if (event.subKey.size()) output << "[" << escape(event.subKey, EscapingProcessor::TextType::EntrySubKey) << "]";
		output << keyValueSeparator << escape(event.value, EscapingProcessor::TextType::EntryValue);
		if (event.comment.size()) output << commentSeparatorForEntries << escape(event.comment, EscapingProcessor::TextType::EntryComment);
		output << std::endl;
		hasContent = true;
	}

	void comment(const CommentEvent& event) {
		output << commentSeparatorStandalone << escape(event.comment, EscapingProcessor::TextType::StandaloneComment);
		output << std::endl;
		hasContent = true;
	}

	void whitespace(const WhitespaceEvent& event) {
		for (wchar_t ch : event.whitespace) {
			if (ch == L' ') output << " ";
			else if (ch == L'\t') output << "\t";
			else if (ch == L'\n') output << "\n";
			else if (ch == L'\r'); // TODO: keep CR?
			else; // TODO: throw exception if whitespace contains unexpected data? (should not happen)
		}
		hasContent = true;
	}



};

}
}
}