/*
    Copyright © 2019 by The qTox Project Contributors

    This file is part of qTox, a Qt-based graphical interface for Tox.

    qTox is libre 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.

    qTox 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 qTox.  If not, see <http://www.gnu.org/licenses/>.
*/

#ifndef ICHAT_LOG_H
#define ICHAT_LOG_H

#include "message.h"
#include "src/core/core.h"
#include "src/core/toxfile.h"
#include "src/core/toxpk.h"
#include "src/friendlist.h"
#include "src/grouplist.h"
#include "src/model/chatlogitem.h"
#include "src/model/friend.h"
#include "src/model/group.h"
#include "src/persistence/history.h"
#include "src/util/strongtype.h"
#include "src/widget/searchtypes.h"

#include <cassert>

using ChatLogIdx =
    NamedType<size_t, struct ChatLogIdxTag, Orderable, UnderlyingAddable, UnitlessDifferencable, Incrementable>;
Q_DECLARE_METATYPE(ChatLogIdx);

struct SearchPos
{
    // Index to the chat log item we want
    ChatLogIdx logIdx;
    // Number of matches we've had. This is always number of matches from the
    // start even if we're searching backwards.
    size_t numMatches;

    bool operator==(const SearchPos& other) const
    {
        return tie() == other.tie();
    }

    bool operator!=(const SearchPos& other) const
    {
        return tie() != other.tie();
    }

    bool operator<(const SearchPos& other) const
    {
        return tie() < other.tie();
    }

    std::tuple<ChatLogIdx, size_t> tie() const
    {
        return std::tie(logIdx, numMatches);
    }
};

struct SearchResult
{
    bool found;
    SearchPos pos;
    size_t start;
    size_t len;

    // This is unfortunately needed to shoehorn our API into the highlighting
    // API of above classes. They expect to re-search the same thing we did
    // for some reason
    QRegularExpression exp;
};

class IChatLog : public QObject
{
    Q_OBJECT
public:
    virtual ~IChatLog() = default;

    /**
     * @brief Returns reference to item at idx
     * @param[in] idx
     * @return Variant type referencing either a ToxFile or Message
     * @pre idx must be between currentFirstIdx() and currentLastIdx()
     */
    virtual const ChatLogItem& at(ChatLogIdx idx) const = 0;

    /**
     * @brief searches forwards through the chat log until phrase is found according to parameter
     * @param[in] startIdx inclusive start idx
     * @param[in] phrase phrase to find (may be modified by parameter)
     * @param[in] parameter search parameters
     */
    virtual SearchResult searchForward(SearchPos startIdx, const QString& phrase,
                                       const ParameterSearch& parameter) const = 0;

    /**
     * @brief searches backwards through the chat log until phrase is found according to parameter
     * @param[in] startIdx inclusive start idx
     * @param[in] phrase phrase to find (may be modified by parameter)
     * @param[in] parameter search parameters
     */
    virtual SearchResult searchBackward(SearchPos startIdx, const QString& phrase,
                                        const ParameterSearch& parameter) const = 0;

    /**
     * @brief The underlying chat log instance may not want to start at 0
     * @return Current first valid index to call at() with
     */
    virtual ChatLogIdx getFirstIdx() const = 0;

    /**
     * @return current last valid index to call at() with
     */
    virtual ChatLogIdx getNextIdx() const = 0;

    struct DateChatLogIdxPair
    {
        QDate date;
        ChatLogIdx idx;
    };

    /**
     * @brief Gets indexes for each new date starting at startDate
     * @param[in] startDate date to start searching from
     * @param[in] maxDates maximum number of dates to be returned
     */
    virtual std::vector<DateChatLogIdxPair> getDateIdxs(const QDate& startDate,
                                                        size_t maxDates) const = 0;

    virtual std::size_t size() const = 0;

signals:
    void itemUpdated(ChatLogIdx idx);
};

#endif /*ICHAT_LOG_H*/