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#ifndef QBS_EVALUATOR_H
#define QBS_EVALUATOR_H

#include "forward_decls.h"
#include "itemobserver.h"
#include "qualifiedid.h"

#include <quickjs.h>

#include <QtCore/qhash.h>

#include <deque>
#include <functional>
#include <mutex>
#include <optional>
#include <stack>
#include <tuple>

namespace qbs {
namespace Internal {
class EvaluationData;
class FileTags;
class Logger;
class PropertyDeclaration;
class ScriptEngine;

class QBS_AUTOTEST_EXPORT Evaluator : private ItemObserver
{
    friend class SVConverter;

public:
    Evaluator(ScriptEngine *scriptEngine);
    ~Evaluator() override;

    ScriptEngine *engine() const { return m_scriptEngine; }
    JSClassID classId() const { return m_scriptClass; }
    JSValue property(const Item *item, const QString &name);

    JSValue value(const Item *item, const QString &name, bool *propertySet = nullptr);
    bool boolValue(const Item *item, const QString &name, bool *propertyWasSet = nullptr);
    int intValue(const Item *item, const QString &name, int defaultValue = 0,
                 bool *propertyWasSet = nullptr);
    FileTags fileTagsValue(const Item *item, const QString &name, bool *propertySet = nullptr);
    QString stringValue(const Item *item, const QString &name,
                        const QString &defaultValue = QString(), bool *propertyWasSet = nullptr);
    QStringList stringListValue(const Item *item, const QString &name,
                                bool *propertyWasSet = nullptr);
    std::optional<QStringList> optionalStringListValue(const Item *item, const QString &name,
                                bool *propertyWasSet = nullptr);

    QVariant variantValue(const Item *item, const QString &name, bool *propertySet = nullptr);

    void convertToPropertyType(const PropertyDeclaration& decl, const CodeLocation &loc,
                               JSValue &v);

    JSValue scriptValue(const Item *item);

    struct FileContextScopes
    {
        JSValue fileScope = JS_UNDEFINED;
        JSValue importScope = JS_UNDEFINED;
    };

    FileContextScopes fileContextScopes(const FileContextConstPtr &file);

    void setCachingEnabled(bool enabled) { m_valueCacheEnabled = enabled; }
    bool cachingEnabled() const { return m_valueCacheEnabled; }
    void clearCache(const Item *item);
    void invalidateCache(const Item *item);
    void clearCacheIfInvalidated(EvaluationData &edata);

    PropertyDependencies &propertyDependencies() { return m_propertyDependencies; }
    void clearPropertyDependencies() { m_propertyDependencies.clear(); }

    std::stack<QualifiedId> &requestedProperties() { return m_requestedProperties; }

    using EvalStack = std::deque<std::tuple<QString, const Item *, const Value *>>;
    EvalStack &evalStack() { return m_evalStack; }

    void handleEvaluationError(const Item *item, const QString &name);

    QString pathPropertiesBaseDir() const { return m_pathPropertiesBaseDir; }
    void setPathPropertiesBaseDir(const QString &dirPath) { m_pathPropertiesBaseDir = dirPath; }
    void clearPathPropertiesBaseDir() { m_pathPropertiesBaseDir.clear(); }

    bool isNonDefaultValue(const Item *item, const QString &name) const;
private:
    void onItemPropertyChanged(Item *item) override { invalidateCache(item); }
    JSValue evaluateProperty(const Item *item, const QString &name, bool *propertyWasSet);
    void clearCache(EvaluationData &edata);

    ScriptEngine * const m_scriptEngine;
    const JSClassID m_scriptClass;
    mutable QHash<const Item *, JSValue> m_scriptValueMap;
    mutable QHash<FileContextConstPtr, FileContextScopes> m_fileContextScopesMap;
    QString m_pathPropertiesBaseDir;
    PropertyDependencies m_propertyDependencies;
    std::stack<QualifiedId> m_requestedProperties;
    EvalStack m_evalStack;
    std::mutex m_cacheInvalidationMutex;
    Set<const Item *> m_invalidatedCaches;
    bool m_valueCacheEnabled = false;
};

void throwOnEvaluationError(ScriptEngine *engine,
                            const std::function<CodeLocation()> &provideFallbackCodeLocation);

class EvalCacheEnabler
{
public:
    EvalCacheEnabler(Evaluator *evaluator, const QString &baseDir) : m_evaluator(evaluator)
    {
        m_evaluator->setCachingEnabled(true);
        m_evaluator->setPathPropertiesBaseDir(baseDir);
    }

    ~EvalCacheEnabler() { reset(); }

    void reset()
    {
        m_evaluator->setCachingEnabled(false);
        m_evaluator->clearPathPropertiesBaseDir();
    }

private:
    Evaluator * const m_evaluator;
};

} // namespace Internal
} // namespace qbs

#endif // QBS_EVALUATOR_H
