/****************************************************************************
**
** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
** Contact: http://www.qt-project.org/legal
**
** This file is part of the Qt Build Suite.
**
** Commercial License Usage
** Licensees holding valid commercial Qt licenses may use this file in
** accordance with the commercial license agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and Digia.  For licensing terms and
** conditions see http://qt.digia.com/licensing.  For further information
** use the contact form at http://qt.digia.com/contact-us.
**
** 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, Digia gives you certain additional
** rights.  These rights are described in the Digia Qt LGPL Exception
** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
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****************************************************************************/

#ifndef QBS_BUILDGRAPHEXECUTOR_H
#define QBS_BUILDGRAPHEXECUTOR_H

#include "forward_decls.h"
#include <buildgraph/artifact.h>
#include <buildgraph/scanresultcache.h>
#include <language/forward_decls.h>

#include <logging/logger.h>
#include <tools/buildoptions.h>
#include <tools/error.h>

#include <QObject>
#include <queue>

namespace qbs {
class ProcessResult;

namespace Internal {
class AutoMoc;
class ExecutorJob;
class FileTime;
class InputArtifactScannerContext;
class ProgressObserver;

class Executor : public QObject
{
    Q_OBJECT

public slots:
    void build();

public:
    Executor(const Logger &logger, QObject *parent = 0);
    ~Executor();

    void setProject(const TopLevelProjectPtr &project);
    void setProducts(const QList<ResolvedProductPtr> &productsToBuild);
    void setBuildOptions(const BuildOptions &buildOptions);
    void setProgressObserver(ProgressObserver *observer) { m_progressObserver = observer; }

    ErrorInfo error() const { return m_error; }

signals:
    void reportCommandDescription(const QString &highlight, const QString &message);
    void reportProcessResult(const qbs::ProcessResult &result);

    void finished();

private slots:
    void onProcessError(const qbs::ErrorInfo &err);
    void onProcessSuccess();
    void finish();

private:
    enum ExecutorState { ExecutorIdle, ExecutorRunning, ExecutorCanceling };

    struct ComparePriority
    {
        bool operator() (const Artifact *x, const Artifact *y) const;
    };

    typedef std::priority_queue<Artifact *, std::vector<Artifact *>, ComparePriority> Leaves;

    void doBuild();
    void prepareAllArtifacts(bool *sourceFilesChanged);
    void prepareReachableArtifacts(const Artifact::BuildState buildState);
    void prepareReachableArtifacts_impl(Artifact *artifact, const Artifact::BuildState buildState);
    void updateBuildGraph(Artifact::BuildState buildState);
    void updateBuildGraph_impl(Artifact *artifact, Artifact::BuildState buildState, QSet<Artifact *> &seenArtifacts);
    void initLeaves(const QList<Artifact *> &changedArtifacts);
    void initLeavesTopDown(Artifact *artifact, QSet<Artifact *> &seenArtifacts);
    bool scheduleJobs();
    void buildArtifact(Artifact *artifact);
    void finishJob(ExecutorJob *job, bool success);
    void finishArtifact(Artifact *artifact);
    void setState(ExecutorState);
    void addExecutorJobs(int jobNumber);
    void runAutoMoc();
    void insertLeavesAfterAddingDependencies(QVector<Artifact *> dependencies);
    void cancelJobs();
    void setupProgressObserver(bool mocWillRun);
    void doSanityChecks();
    void handleError(const ErrorInfo &error);

    bool mustExecuteTransformer(const TransformerPtr &transformer) const;
    bool isUpToDate(Artifact *artifact) const;
    void retrieveSourceFileTimestamp(Artifact *artifact) const;
    FileTime recursiveFileTime(const QString &filePath) const;
    void insertLeavesAfterAddingDependencies_recurse(Artifact *const artifact,
            QSet<Artifact *> *seenArtifacts, Leaves *leaves) const;
    QString configString() const;

    RulesEvaluationContextPtr m_evalContext;
    BuildOptions m_buildOptions;
    Logger m_logger;
    ProgressObserver *m_progressObserver;
    QList<ExecutorJob*> m_availableJobs;
    QHash<ExecutorJob*, Artifact *> m_processingJobs;
    ExecutorState m_state;
    TopLevelProjectPtr m_project;
    QList<ResolvedProductPtr> m_productsToBuild;
    QList<Artifact *> m_roots;
    Leaves m_leaves;
    ScanResultCache m_scanResultCache;
    InputArtifactScannerContext *m_inputArtifactScanContext;
    AutoMoc *m_autoMoc;
    int m_mocEffort;
    ErrorInfo m_error;
    bool m_explicitlyCanceled;
    FileTags m_activeFileTags;
    const bool m_doTrace;
    const bool m_doDebug;
};

} // namespace Internal
} // namespace qbs

#endif // QBS_BUILDGRAPHEXECUTOR_H