/*****************************************************************************
 * This file is part of KDevelop
 * Copyright (c) 2011-2012 Sven Brauch <svenbrauch@googlemail.com>           *
 *                                                                           *
 * 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, see <http://www.gnu.org/licenses/>.     *
 *****************************************************************************
 */


#ifndef PYCOMPLETIONHELPERS_H
#define PYCOMPLETIONHELPERS_H

#include <language/duchain/declaration.h>

#include <QString>
#include <QList>
#include <QVariant>

#include "pythoncompletionexport.h"

using namespace KDevelop;

namespace Python {

void createArgumentList(Declaration* dec, QString& ret, QList<QVariant>* highlighting, int atArg = 0, bool includeTypes = true);

class TokenList;

class KDEVPYTHONCOMPLETION_EXPORT ExpressionParser {
public:
    ExpressionParser(QString code);
    
    enum Status {
        InvalidStatus,
        NothingFound,
        ExpressionFound,
        CommaFound,
        EventualCallFound,
        InitializerFound,
        FromFound,
        MemberAccessFound,
        ImportFound,
        GeneratorFound,
        RaiseFound,
        ForFound,
        ExceptFound,
        ColonFound,
        InFound,
        ClassFound,
        DefFound,
        EqualsFound,
        MeaninglessKeywordFound, // "and", "if", "return", ...
        NoCompletionKeywordFound // "for"
    };
    
    QString popExpression(Status* status);
    QString getRemainingCode();
    QString getScannedCode();
    QString skipUntilStatus(Status requestedStatus, bool* ok, int* expressionsSkipped = 0);
    TokenList popAll();
    void reset();
    int trailingWhitespace();
    
private:
    QString m_code;
    int m_cursorPositionInString;
};

struct TokenListEntry {
public:
    TokenListEntry(ExpressionParser::Status status_, QString expression_, int charOffset_)
    : status(status_)
    , expression(expression_)
    , charOffset(charOffset_) {};
    ExpressionParser::Status status;
    QString expression;
    int charOffset;
};

class TokenList : public QList<TokenListEntry> {
public:
    /**
     * @brief Reset the internal pointer to the last item, or offsetAtEnd items before
     **/
    void reset(int offsetAtEnd = 0) {
        m_internalPtr = length() - offsetAtEnd;
    };
    /**
     * @brief Set the internal pointer to "index".
     **/
    void seek(int index) {
        m_internalPtr = index;
    };
    /**
     * @brief Get the last item and advance the internal pointer.
     *
     * @return :TokenListEntry the item if the internal pointer is valid, an invalid item otherwise
     **/
    TokenListEntry weakPop() {
        m_internalPtr --;
        if ( m_internalPtr < 0 ) {
            return TokenListEntry(ExpressionParser::InvalidStatus, QString::null, -1);
        }
        return at(m_internalPtr);
    };
    // First returned value is the *expression count* index, the second one is the *character count*.
    // Oh yeah, the expressions count from the right, the characters count from the left. Convenient, huh?
    // (see PythonCodeCompletionContext::summonParentForEventualCall for an example why that makes sense)
    QPair<int, int> nextIndexOfStatus(ExpressionParser::Status status, int offsetFromEnd = 0) const {
        int currentIndex = length() - 1 - offsetFromEnd;
        while ( currentIndex >= 0 ) {
            if ( at(currentIndex).status == status ) {
                return QPair<int, int>(length() - currentIndex, at(currentIndex).charOffset);
            }
            currentIndex -= 1;
        }
        return QPair<int, int>(-1, -1);
    };
    
    QString toString() {
        QString ret;
        int pos = 0;
        foreach ( TokenListEntry item, *this ) {
            ret.append(
                "offset " + QString::number(item.charOffset) + 
                " position " + QString::number(pos) +
                ": status " + QString::number(item.status) +
                ", expression " + item.expression + "\n"
            );
            pos ++;
        }
        return ret;
    };
private:
    int m_internalPtr;
};

}

#endif