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** This file is part of the Qt Build Suite.
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** 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
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#include "itemreader.h"
#include "asttools.h"
#include "itemreaderastvisitor.h"
#include <logging/translator.h>
#include <parser/qmljsengine_p.h>
#include <parser/qmljslexer_p.h>
#include <parser/qmljsparser_p.h>
#include <tools/error.h>
#include <QExplicitlySharedDataPointer>
#include <QFile>
#include <QFileInfo>
#include <QSharedData>
#include <QTextStream>

namespace qbs {
namespace Internal {

class ASTCacheValueData : public QSharedData
{
    Q_DISABLE_COPY(ASTCacheValueData)
public:
    ASTCacheValueData()
        : ast(0)
        , processing(false)
    {
    }

    QString code;
    QbsQmlJS::Engine engine;
    QbsQmlJS::AST::UiProgram *ast;
    bool processing;
};

class ASTCacheValue
{
public:
    ASTCacheValue()
        : d(new ASTCacheValueData)
    {
    }

    ASTCacheValue(const ASTCacheValue &other)
        : d(other.d)
    {
    }

    void setProcessingFlag(bool b) { d->processing = b; }
    bool isProcessing() const { return d->processing; }

    void setCode(const QString &code) { d->code = code; }
    QString code() const { return d->code; }

    QbsQmlJS::Engine *engine() const { return &d->engine; }

    void setAst(QbsQmlJS::AST::UiProgram *ast) { d->ast = ast; }
    QbsQmlJS::AST::UiProgram *ast() const { return d->ast; }
    bool isValid() const { return d->ast; }

private:
    QExplicitlySharedDataPointer<ASTCacheValueData> d;
};

class ItemReader::ASTCache : public QHash<QString, ASTCacheValue> {};


ItemReader::ItemReader(BuiltinDeclarations *builtins, const Logger &logger)
    : m_pool(0)
    , m_builtins(builtins)
    , m_logger(logger)
    , m_astCache(new ASTCache)
{
}

ItemReader::~ItemReader()
{
    delete m_astCache;
}

void ItemReader::setSearchPaths(const QStringList &searchPaths)
{
    m_searchPaths = searchPaths;
}

void ItemReader::pushExtraSearchPaths(const QStringList &extraSearchPaths)
{
    m_extraSearchPaths.push(extraSearchPaths);
}

void ItemReader::popExtraSearchPaths()
{
    m_extraSearchPaths.pop();
}

QStringList ItemReader::searchPaths() const
{
    QStringList paths = m_searchPaths;
    if (!m_extraSearchPaths.isEmpty())
        paths += m_extraSearchPaths.top();
    return paths;
}

void ItemReader::clearItemCache()
{
    m_itemCache.clear();
}

void ItemReader::cacheDirectoryEntries(const QString &dirPath, const QStringList &entries)
{
    m_directoryEntries.insert(dirPath, entries);
}

bool ItemReader::findDirectoryEntries(const QString &dirPath, QStringList *entries) const
{
    const QHash<QString, QStringList>::ConstIterator it = m_directoryEntries.constFind(dirPath);
    if (it == m_directoryEntries.constEnd())
        return false;
    *entries = it.value();
    return true;
}

Item *ItemReader::readFile(const QString &filePath, bool enableItemCache)
{
    Item * const item = internalReadFile(filePath, enableItemCache).rootItem;
    return item;
}

QSet<QString> ItemReader::filesRead() const
{
    return m_filesRead;
}

ItemReaderResult ItemReader::internalReadFile(const QString &filePath, bool enableItemCache)
{
    ItemReaderResult result;
    if (enableItemCache) {
        result = m_itemCache.value(filePath);
        if (result.rootItem)
            return result;
    }

    ASTCacheValue &cacheValue = (*m_astCache)[filePath];
    if (cacheValue.isValid()) {
        if (Q_UNLIKELY(cacheValue.isProcessing()))
            throw ErrorInfo(Tr::tr("Loop detected when importing '%1'.").arg(filePath));
    } else {
        QFile file(filePath);
        if (Q_UNLIKELY(!file.open(QFile::ReadOnly)))
            throw ErrorInfo(Tr::tr("Couldn't open '%1'.").arg(filePath));

        m_filesRead.insert(filePath);
        const QString code = QTextStream(&file).readAll();
        QbsQmlJS::Lexer lexer(cacheValue.engine());
        lexer.setCode(code, 1);
        QbsQmlJS::Parser parser(cacheValue.engine());

        file.close();
        if (!parser.parse()) {
            QList<QbsQmlJS::DiagnosticMessage> parserMessages = parser.diagnosticMessages();
            if (Q_UNLIKELY(!parserMessages.isEmpty())) {
                ErrorInfo err;
                foreach (const QbsQmlJS::DiagnosticMessage &msg, parserMessages)
                    err.append(msg.message, toCodeLocation(filePath, msg.loc));
                throw err;
            }
        }

        cacheValue.setCode(code);
        cacheValue.setAst(parser.ast());
    }

    ItemReaderASTVisitor itemReader(this, &result);
    itemReader.setFilePath(QFileInfo(filePath).absoluteFilePath());
    itemReader.setSourceCode(cacheValue.code());
    cacheValue.setProcessingFlag(true);
    cacheValue.ast()->accept(&itemReader);
    cacheValue.setProcessingFlag(false);

    if (enableItemCache)
        m_itemCache.insert(filePath, result);

    return result;
}

} // namespace Internal
} // namespace qbs
