/****************************************************************************
**
** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
** All rights reserved.
** Contact: Nokia Corporation (qt-info@nokia.com)
**
** This file is part of the qt3to4 porting application of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** No Commercial Usage
** This file contains pre-release code and may not be distributed.
** You may use this file in accordance with the terms and conditions
** contained in the Technology Preview License Agreement accompanying
** this package.
**
** GNU Lesser General Public License Usage
** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 2.1 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL included in the
** packaging of this file.  Please review the following information to
** ensure the GNU Lesser General Public License version 2.1 requirements
** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
**
** In addition, as a special exception, Nokia gives you certain additional
** rights.  These rights are described in the Nokia Qt LGPL Exception
** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
**
** If you have questions regarding the use of this file, please contact
** Nokia at qt-info@nokia.com.
**
**
**
**
**
**
**
**
** $QT_END_LICENSE$
**
****************************************************************************/

#include "preprocessorcontrol.h"
#include "fileporter.h"
#include "replacetoken.h"
#include "logger.h"
#include "tokenizer.h"
#include "filewriter.h"
#include <QFile>
#include <QDir>
#include <QFileInfo>
#include <QHash>
#include <QtDebug>

QT_BEGIN_NAMESPACE

using namespace TokenEngine;
using namespace Rpp;

FilePorter::FilePorter(PreprocessorCache &preprocessorCache)
:preprocessorCache(preprocessorCache)
,tokenReplacementRules(PortingRules::instance()->getTokenReplacementRules())
,headerReplacements(PortingRules::instance()->getHeaderReplacements())
,replaceToken(tokenReplacementRules)
{
    foreach (const QString &headerName, PortingRules::instance()->getHeaderList(PortingRules::Qt4)) {
        qt4HeaderNames.insert(headerName.toLatin1());
    }
}

/*
    Ports a file given by fileName, which should be an absolute file path.
*/
void FilePorter::port(QString fileName)
{
    // Get file tokens from cache.
    TokenContainer sourceTokens = preprocessorCache.sourceTokens(fileName);
    if(sourceTokens.count() == 0)
        return;

    Logger::instance()->beginSection();

    // Get include directive replacements.
    const Rpp::Source * source = preprocessorCache.sourceTree(fileName);
    PreprocessReplace preprocessReplace(source, PortingRules::instance()->getHeaderReplacements());
    TextReplacements sourceReplacements = preprocessReplace.getReplacements();

    // Get token replacements.
    sourceReplacements += replaceToken.getTokenTextReplacements(sourceTokens);

    // Apply the replacements to the source text.
    QByteArray portedContents = sourceReplacements.apply(sourceTokens.fullText());

    // Add include directives for classes that are no longer implicitly
    // included via other headers. This step needs to be done after the token
    // replacements, since we need to know which new class names that has been
    // inserted in the source.
    portedContents = includeAnalyse(portedContents);

    // Check if any changes has been made.
    if(portedContents == sourceTokens.fullText()) {
        Logger::instance()->addEntry(
            new PlainLogEntry(QLatin1String("Info"), QLatin1String("Porting"),  QLatin1String("No changes made to file ") + fileName));
        Logger::instance()->commitSection();
        return;
    }

    // Write file, commit log if write was successful.
    FileWriter::WriteResult result = FileWriter::instance()->writeFileVerbously(fileName, portedContents);
    Logger *logger = Logger::instance();
    if (result == FileWriter::WriteSucceeded) {
        logger->commitSection();
    } else if (result == FileWriter::WriteFailed) {
        logger->revertSection();
        logger->addEntry(
            new PlainLogEntry(QLatin1String("Error"), QLatin1String("Porting"),  QLatin1String("Error writing to file ") + fileName));
    } else if (result == FileWriter::WriteSkipped) {
        logger->revertSection();
        logger->addEntry(
            new PlainLogEntry(QLatin1String("Error"), QLatin1String("Porting"),  QLatin1String("User skipped file ") + fileName));
    } else {
        // Internal error.
        logger->revertSection();
        const QString errorString = QLatin1String("Internal error in qt3to4 - FileWriter returned invalid result code while writing to ") + fileName;
        logger->addEntry(new PlainLogEntry(QLatin1String("Error"), QLatin1String("Porting"), errorString));
    }
}

QSet<QByteArray> FilePorter::usedQtModules()
{
    return m_usedQtModules;
}

TextReplacements FilePorter::includeDirectiveReplacements()
{
    return TextReplacements();
}

QByteArray FilePorter::includeAnalyse(QByteArray fileContents)
{
    // Tokenize file contents agein, since it has changed.
    QVector<TokenEngine::Token> tokens  = tokenizer.tokenize(fileContents);
    TokenEngine::TokenContainer tokenContainer(fileContents, tokens);
    IncludeDirectiveAnalyzer includeDirectiveAnalyzer(tokenContainer);

    // Get list of used classes.
    QSet<QByteArray> classes = includeDirectiveAnalyzer.usedClasses();

    // Iterate class list and find which modules are used. This info is used elswhere
    // by when porting the .pro file.
    const QHash<QByteArray, QByteArray> classLibraryList = PortingRules::instance()->getClassLibraryList();
    foreach (const QByteArray &className, classes) {
        m_usedQtModules.insert(classLibraryList.value(className));
    }

    // Get list of included headers.
    QSet<QByteArray> headers = includeDirectiveAnalyzer.includedHeaders();

    // Find classes that is missing an include directive and that has a needHeader rule.
    const QHash<QByteArray, QByteArray> neededHeaders = PortingRules::instance()->getNeededHeaders();
    QList<QByteArray> insertHeaders;
    foreach (const QByteArray &className, classes) {
        if (!headers.contains((className.toLower() + QByteArray(".h"))) &&
            !headers.contains(className)) {
            const QByteArray insertHeader = neededHeaders.value(className);
            if (insertHeader != QByteArray())
                insertHeaders.append((QByteArray("#include <") + insertHeader + QByteArray(">")));
        }
    }

    const QByteArray lineEnding = detectLineEndings(fileContents);
    
    // Insert include directives undeclared classes.
    int insertCount = insertHeaders.count();
    if (insertCount > 0) {
        QByteArray insertText;
        QByteArray logText;

        insertText += QByteArray("//Added by qt3to4:") + lineEnding;
        logText += QByteArray("In file ");
        logText += Logger::instance()->globalState.value(QLatin1String("currentFileName")).toLocal8Bit();
        logText += QByteArray(": Added the following include directives:\n");
        foreach (const QByteArray &headerName, insertHeaders) {
            insertText = insertText + headerName + lineEnding;
            logText += QByteArray("\t");
            logText += headerName + QByteArray(" ");
        }

        const int insertLine = 0;
        Logger::instance()->updateLineNumbers(insertLine, insertCount + 1);
        const int insertPos = includeDirectiveAnalyzer.insertPos();
        fileContents.insert(insertPos, insertText);
        Logger::instance()->addEntry(new PlainLogEntry(QLatin1String("Info"), QLatin1String("Porting"), QString::fromLatin1(logText.constData())));
    }

    return fileContents;
}

PreprocessReplace::PreprocessReplace(const Rpp::Source *source, const QHash<QByteArray, QByteArray> &headerReplacements)
:headerReplacements(headerReplacements)
{
    // Walk preprocessor tree.
    evaluateItem(source);
}

TextReplacements PreprocessReplace::getReplacements()
{
    return replacements;
}
/*
    Replaces headers no longer present with support headers.
*/
void PreprocessReplace::evaluateIncludeDirective(const Rpp::IncludeDirective *directive)
{
    const QByteArray headerPathName = directive->filename();
    const TokenEngine::TokenList headerPathTokens = directive->filenameTokens();

    // Get the file name part of the file path.
    const QByteArray headerFileName = QFileInfo(QString::fromLatin1(headerPathName.constData())).fileName().toUtf8();

    // Check if we should replace the filename.
    QByteArray replacement = headerReplacements.value(headerFileName);

    // Also check lower-case version to catch incorrectly capitalized file names on Windows.
    if (replacement.isEmpty())
        replacement = headerReplacements.value(headerFileName.toLower());

    const int numTokens = headerPathTokens.count();
    if (numTokens > 0 && !replacement.isEmpty()) {
        // Here we assume that the last token contains a part of the file name.
        const TokenEngine::Token lastToken = headerPathTokens.token(numTokens -1);
        int endPos = lastToken.start + lastToken.length;
        // If the file name is specified in quotes, then the quotes will be a part
        // of the token. Decrement endpos to leave out the ending quote when replacing.
        if (directive->includeType() == IncludeDirective::QuoteInclude)
            --endPos;
        const int length = headerFileName.count();
        const int startPos = endPos - length;
        replacements.insert(replacement, startPos, length);
        addLogSourceEntry(QString::fromLatin1((headerFileName + QByteArray(" -> ") + replacement).constData()),
                          headerPathTokens.tokenContainer(0), headerPathTokens.containerIndex(0));
    }
}

/*
    Replace line comments containing MOC_SKIP_BEGIN with #ifdef Q_MOC_RUN and MOC_SKIP_END with #endif
*/
void PreprocessReplace::evaluateText(const Rpp::Text *textLine)
{
    if (textLine->count() < 1)
        return;
 
    const TokenEngine::TokenContainer container = textLine->text().tokenContainer(0);
    foreach (Rpp::Token *token, textLine->tokenList()) {
        if (token->toLineComment()) {
            const int tokenIndex = token->index();
            const QByteArray text = container.text(tokenIndex);
            const TokenEngine::Token containerToken = container.token(tokenIndex);
           
            if (text.contains(QByteArray("MOC_SKIP_BEGIN"))) {
                replacements.insert(QByteArray("#ifndef Q_MOC_RUN"), containerToken.start, containerToken.length);
                addLogSourceEntry(QLatin1String("MOC_SKIP_BEGIN -> #ifndef Q_MOC_RUN"), container, tokenIndex);
            }        
            if (text.contains(QByteArray("MOC_SKIP_END"))) {
                replacements.insert(QByteArray("#endif"), containerToken.start, containerToken.length);
                addLogSourceEntry(QLatin1String("MOC_SKIP_END -> #endif"), container, tokenIndex);
            }
        }
    }
}

IncludeDirectiveAnalyzer::IncludeDirectiveAnalyzer(const TokenEngine::TokenContainer &fileContents)
:fileContents(fileContents)
{
    const QVector<Type> lexical = RppLexer().lex(fileContents);
    source = Preprocessor().parse(fileContents, lexical, &mempool);
    foundInsertPos = false;
    foundQtHeader = false;
    ifSectionCount = 0;
    insertTokenIndex = 0;

    evaluateItem(source);
}

/*
    Returns a position indicating where new include directives should be inserted.
*/
int IncludeDirectiveAnalyzer::insertPos()
{
    const TokenEngine::Token insertToken = fileContents.token(insertTokenIndex);
    return insertToken.start;
}

/*
    Returns a set of all headers included from this file.
*/
QSet<QByteArray> IncludeDirectiveAnalyzer::includedHeaders()
{
    return m_includedHeaders;
}

/*
    Returns a list of used Qt classes.
*/
QSet<QByteArray> IncludeDirectiveAnalyzer::usedClasses()
{
    return m_usedClasses;
}

/*
    Set insetionTokenindex to a token near other #include directives, preferably
    just after a block of include directives that includes other Qt headers.
*/
void IncludeDirectiveAnalyzer::evaluateIncludeDirective(const IncludeDirective *directive)
{
    const QByteArray filename = directive->filename();
    if (filename.isEmpty())
        return;

    m_includedHeaders.insert(filename);

    if (foundInsertPos || ifSectionCount > 1)
        return;

    const bool isQtHeader = (filename.at(0) == 'q' || filename.at(0) == 'Q');
    if (!isQtHeader && foundQtHeader) {
        foundInsertPos = true;
        return;
    }

    if (isQtHeader)
        foundQtHeader = true;

    // Get the last token for this directive.
    TokenEngine::TokenSection tokenSection = directive->text();
    const int newLineToken = 1;
    insertTokenIndex = tokenSection.containerIndex(tokenSection.count() - 1) + newLineToken;
}

/*
    Avoid inserting inside IfSections, except in the first one
    we see, which probably is the header multiple inclusion guard.
*/
void IncludeDirectiveAnalyzer::evaluateIfSection(const IfSection *ifSection)
{
    ++ifSectionCount;
    RppTreeWalker::evaluateIfSection(ifSection);
    --ifSectionCount;
}

/*
    Read all IdTokens and look for Qt class names.  Also, on
    the first IdToken set foundInsertPos to true

*/
void IncludeDirectiveAnalyzer::evaluateText(const Text *textLine)
{
    const int numTokens = textLine->count();
    for (int t = 0; t < numTokens; ++t) {
        Rpp::Token *token = textLine->token(t);
        if (token->toIdToken()) {
            foundInsertPos = true;
            const int containerIndex = token->index();
            const QByteArray tokenText = fileContents.text(containerIndex);
            m_usedClasses.insert(tokenText);
        }
    }
}

QT_END_NAMESPACE