//
// This file is part of Kepka,
// an unofficial desktop version of Telegram messaging app,
// see https://github.com/procxx/kepka
//
// Kepka 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 3 of the License, or
// (at your option) any later version.
//
// It 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.
//
// In addition, as a special exception, the copyright holders give permission
// to link the code of portions of this program with the OpenSSL library.
//
// Full license: https://github.com/procxx/kepka/blob/master/LICENSE
// Copyright (c) 2014-2017 John Preston, https://desktop.telegram.org
// Copyright (c) 2017- Kepka Contributors, https://github.com/procxx
//
#pragma once

#include "dialogs/dialogs_common.h"
#include "dialogs/dialogs_row.h"
#include "structs.h"

class PeerData;
namespace Dialogs {

class List {
public:
	List(SortMode sortMode);
	List(const List &other) = delete;
	List &operator=(const List &other) = delete;

	int size() const {
		return _count;
	}
	bool isEmpty() const {
		return size() == 0;
	}
	bool contains(PeerId peerId) const {
		return _rowByPeer.contains(peerId);
	}
	Row *getRow(PeerId peerId) const {
		return _rowByPeer.value(peerId);
	}
	Row *rowAtY(qint32 y, qint32 h) const {
		auto i = cfind(y, h);
		if (i == cend() || (*i)->pos() != ((y > 0) ? (y / h) : 0)) {
			return nullptr;
		}
		return *i;
	}

	Row *addToEnd(History *history);
	Row *adjustByName(const PeerData *peer);
	Row *addByName(History *history);
	bool moveToTop(PeerId peerId);
	void adjustByPos(Row *row);
	bool del(PeerId peerId, Row *replacedBy = nullptr);
	void remove(Row *row);
	void clear();

	class const_iterator {
	public:
		using value_type = Row *;
		using pointer = Row **;
		using reference = Row *&;

		explicit const_iterator(Row *p)
		    : _p(p) {}
		inline Row *operator*() const {
			return _p;
		}
		inline Row *const *operator->() const {
			return &_p;
		}
		inline bool operator==(const const_iterator &other) const {
			return _p == other._p;
		}
		inline bool operator!=(const const_iterator &other) const {
			return !(*this == other);
		}
		inline const_iterator &operator++() {
			_p = next(_p);
			return *this;
		}
		inline const_iterator operator++(int) {
			const_iterator result(*this);
			++(*this);
			return result;
		}
		inline const_iterator &operator--() {
			_p = prev(_p);
			return *this;
		}
		inline const_iterator operator--(int) {
			const_iterator result(*this);
			--(*this);
			return result;
		}
		inline const_iterator operator+(int j) const {
			const_iterator result = *this;
			return result += j;
		}
		inline const_iterator operator-(int j) const {
			const_iterator result = *this;
			return result -= j;
		}
		inline const_iterator &operator+=(int j) {
			if (j < 0) return (*this -= (-j));
			while (j--) ++*this;
			return *this;
		}
		inline const_iterator &operator-=(int j) {
			if (j < 0) return (*this += (-j));
			while (j--) --*this;
			return *this;
		}

	private:
		Row *_p;
		friend class List;
	};
	friend class const_iterator;
	using iterator = const_iterator;

	const_iterator cbegin() const {
		return const_iterator(_begin);
	}
	const_iterator cend() const {
		return const_iterator(_end);
	}
	const_iterator begin() const {
		return cbegin();
	}
	const_iterator end() const {
		return cend();
	}
	iterator begin() {
		return iterator(_begin);
	}
	iterator end() {
		return iterator(_end);
	}
	const_iterator cfind(Row *value) const {
		return value ? const_iterator(value) : cend();
	}
	const_iterator find(Row *value) const {
		return cfind(value);
	}
	iterator find(Row *value) {
		return value ? iterator(value) : end();
	}
	const_iterator cfind(int y, int h) const {
		adjustCurrent(y, h);
		return iterator(_current);
	}
	const_iterator find(int y, int h) const {
		return cfind(y, h);
	}
	iterator find(int y, int h) {
		adjustCurrent(y, h);
		return iterator(_current);
	}

	~List();

private:
	void adjustCurrent(int y, int h) const;
	bool insertBefore(Row *row, Row *before);
	bool insertAfter(Row *row, Row *after);
	static Row *next(Row *row) {
		return row->_next;
	}
	static Row *prev(Row *row) {
		return row->_prev;
	}

	std::unique_ptr<Row> _last;
	Row *_begin;
	Row *_end;
	SortMode _sortMode;
	int _count = 0;

	typedef QHash<PeerId, Row *> RowByPeer;
	RowByPeer _rowByPeer;

	mutable Row *_current; // cache
};

} // namespace Dialogs