/*

 * This file is part of the API Extractor project.

 *

 * Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).

 *

 * Contact: PySide team <contact@pyside.org>

 *

 * This program is free software; you can redistribute it and/or

 * modify it under the terms of the GNU General Public License

 * version 2 as published by the Free Software Foundation.

 *

 * 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, write to the Free Software

 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA

 * 02110-1301 USA

 *

 */

#include "fileout.h"

#include "reporthandler.h"

#include <QtCore/QTextCodec>

#include <QtCore/QFileInfo>

#include <QtCore/QDir>

#include <cstdio>

bool FileOut::dummy = false;

bool FileOut::diff = false;

#ifdef Q_OS_LINUX

const char* colorDelete = "\033[31m";

const char* colorAdd = "\033[32m";

const char* colorInfo = "\033[36m";

const char* colorReset = "\033[0m";

#else

const char* colorDelete = "";

const char* colorAdd = "";

const char* colorInfo = "";

const char* colorReset = "";

#endif

FileOut::FileOut(QString n):

        name(n),

        stream(&tmp),

        isDone(false)

{}

static int* lcsLength(QList<QByteArray> a, QList<QByteArray> b)

{

    const int height = a.size() + 1;

    const int width = b.size() + 1;

    int *res = new int[width * height];

    for (int row = 0; row < height; row++)

        res[width * row] = 0;

    for (int col = 0; col < width; col++)

        res[col] = 0;

    for (int row = 1; row < height; row++) {

        for (int col = 1; col < width; col++) {

            if (a[row-1] == b[col-1])

                res[width * row + col] = res[width * (row-1) + col-1] + 1;

            else

                res[width * row + col] = qMax(res[width * row     + col-1],

                                              res[width * (row-1) + col]);

        }

    }

    return res;

}

enum Type {

    Add,

    Delete,

    Unchanged

};

struct Unit

{

    Unit(Type type, int pos) :

            type(type),

            start(pos),

            end(pos) {}

    Type type;

    int start;

    int end;

    void print(QList<QByteArray> a, QList<QByteArray> b)

    {

            if (type == Unchanged) {

                if ((end - start) > 9) {

                    for (int i = start; i <= start + 2; i++)

                        std::printf("  %s\n", a[i].data());

                    std::printf("%s=\n= %d more lines\n=%s\n", colorInfo, end - start - 6, colorReset);

                    for (int i = end - 2; i <= end; i++)

                        std::printf("  %s\n", a[i].data());

                } else {

                    for (int i = start; i <= end; i++)

                        std::printf("  %s\n", a[i].data());

                }

            } else if (type == Add) {

                std::printf("%s", colorAdd);

                for (int i = start; i <= end; i++)

                    std::printf("+ %s\n", b[i].data());

                std::printf("%s", colorReset);

            } else if (type == Delete) {

                std::printf("%s", colorDelete);

                for (int i = start; i <= end; i++)

                    std::printf("- %s\n", a[i].data());

                std::printf("%s", colorReset);

            }

    }

};

static QList<Unit*> *unitAppend(QList<Unit*> *res, Type type, int pos)

{

    if (!res) {

        res = new QList<Unit*>;

        res->append(new Unit(type, pos));

        return res;

    }

    Unit *last = res->last();

    if (last->type == type)

        last->end = pos;

    else

        res->append(new Unit(type, pos));

    return res;

}

static QList<Unit*> *diffHelper(int *lcs, QList<QByteArray> a, QList<QByteArray> b, int row, int col)

{

    if (row > 0 && col > 0 && (a[row-1] == b[col-1])) {

        return unitAppend(diffHelper(lcs, a, b, row - 1, col - 1), Unchanged, row - 1);

    } else {

        int width = b.size() + 1;

        if ((col > 0)

            && (row == 0 || lcs[width * row + col-1] >= lcs[width *(row-1) + col])) {

            return unitAppend(diffHelper(lcs, a, b, row, col - 1), Add, col - 1);

        } else if ((row > 0)

            && (col == 0 || lcs[width * row + col-1] < lcs[width *(row-1) + col])) {

            return unitAppend(diffHelper(lcs, a, b, row - 1, col), Delete, row - 1);

        }

    }

    delete lcs;

    return 0;

}

static void diff(QList<QByteArray> a, QList<QByteArray> b)

{

    QList<Unit*> *res = diffHelper(lcsLength(a, b), a, b, a.size(), b.size());

    for (int i = 0; i < res->size(); i++) {

        Unit *unit = res->at(i);

        unit->print(a, b);

        delete(unit);

    }

    delete(res);

}

bool FileOut::done()

{

    Q_ASSERT(!isDone);

    if (name.isEmpty())

        return false;

    isDone = true;

    bool fileEqual = false;

    QFile fileRead(name);

    QFileInfo info(fileRead);

    stream.flush();

    QByteArray original;

    if (info.exists() && (diff || (info.size() == tmp.size()))) {

        if (!fileRead.open(QIODevice::ReadOnly)) {

            ReportHandler::warning(QString("failed to open file '%1' for reading")

                                   .arg(fileRead.fileName()));

            return false;

        }

        original = fileRead.readAll();

        fileRead.close();

        fileEqual = (original == tmp);

    }

    if (!fileEqual) {

        if (!FileOut::dummy) {

            QDir dir(info.absolutePath());

            if (!dir.mkpath(dir.absolutePath())) {

                ReportHandler::warning(QString("unable to create directory '%1'")

                                       .arg(dir.absolutePath()));

                return false;

            }

            QFile fileWrite(name);

            if (!fileWrite.open(QIODevice::WriteOnly)) {

                ReportHandler::warning(QString("failed to open file '%1' for writing")

                                       .arg(fileWrite.fileName()));

                return false;

            }

            QTextCodec::setCodecForCStrings(QTextCodec::codecForName("UTF-8"));

            stream.setDevice(&fileWrite);

            stream << tmp;

        }

        if (diff) {

            std::printf("%sFile: %s%s\n", colorInfo, qPrintable(name), colorReset);

            ::diff(original.split('\n'), tmp.split('\n'));

            std::printf("\n");

        }

        return true;

    }

    return false;

}