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** ensure the GNU Lesser General Public License version 3 requirements
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** Alternatively, this file may be used under the terms of the GNU
** General Public License version 2.0 or (at your option) the GNU General
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****************************************************************************/

#ifndef QBS_VALUE_H
#define QBS_VALUE_H

#include "forward_decls.h"
#include <tools/codelocation.h>
#include <QtCore/qvariant.h>

#include <vector>

namespace qbs {
namespace Internal {
class Item;
class ValueHandler;

class Value
{
public:
    enum Type
    {
        JSSourceValueType,
        ItemValueType,
        VariantValueType
    };

    Value(Type t, bool createdByPropertiesBlock);
    Value(const Value &other);
    virtual ~Value();

    Type type() const { return m_type; }
    virtual void apply(ValueHandler *) = 0;
    virtual ValuePtr clone() const = 0;
    virtual CodeLocation location() const { return {}; }

    Item *definingItem() const;
    virtual void setDefiningItem(Item *item);

    ValuePtr next() const;
    void setNext(const ValuePtr &next);

    bool createdByPropertiesBlock() const { return m_createdByPropertiesBlock; }
    void setCreatedByPropertiesBlock(bool b) { m_createdByPropertiesBlock = b; }
    void clearCreatedByPropertiesBlock() { m_createdByPropertiesBlock = false; }

private:
    Type m_type;
    Item *m_definingItem;
    ValuePtr m_next;
    bool m_createdByPropertiesBlock;
};

class ValueHandler
{
public:
    virtual void handle(JSSourceValue *value) = 0;
    virtual void handle(ItemValue *value) = 0;
    virtual void handle(VariantValue *value) = 0;
};

class JSSourceValue : public Value
{
    friend class ItemReaderASTVisitor;

    enum Flag
    {
        NoFlags = 0x00,
        SourceUsesBase = 0x01,
        SourceUsesOuter = 0x02,
        SourceUsesOriginal = 0x04,
        HasFunctionForm = 0x08,
        ExclusiveListValue = 0x10,
        BuiltinDefaultValue = 0x20,
    };
    Q_DECLARE_FLAGS(Flags, Flag)

public:
    explicit JSSourceValue(bool createdByPropertiesBlock);
    JSSourceValue(const JSSourceValue &other);

    static JSSourceValuePtr QBS_AUTOTEST_EXPORT create(bool createdByPropertiesBlock = false);
    ~JSSourceValue() override;

    void apply(ValueHandler *handler) override { handler->handle(this); }
    ValuePtr clone() const override;

    void setSourceCode(QStringView sourceCode) { m_sourceCode = sourceCode; }
    QStringView sourceCode() const { return m_sourceCode; }
    QString sourceCodeForEvaluation() const;

    void setLocation(int line, int column);
    int line() const { return m_line; }
    int column() const { return m_column; }
    CodeLocation location() const override;

    void setFile(const FileContextPtr &file) { m_file = file; }
    const FileContextPtr &file() const { return m_file; }

    void setSourceUsesBaseFlag() { m_flags |= SourceUsesBase; }
    bool sourceUsesBase() const { return m_flags.testFlag(SourceUsesBase); }
    bool sourceUsesOuter() const { return m_flags.testFlag(SourceUsesOuter); }
    bool sourceUsesOriginal() const { return m_flags.testFlag(SourceUsesOriginal); }
    bool hasFunctionForm() const { return m_flags.testFlag(HasFunctionForm); }
    void setHasFunctionForm(bool b);
    void setIsExclusiveListValue() { m_flags |= ExclusiveListValue; }
    bool isExclusiveListValue() { return m_flags.testFlag(ExclusiveListValue); }
    void setIsBuiltinDefaultValue() { m_flags |= BuiltinDefaultValue; }
    bool isBuiltinDefaultValue() const { return m_flags.testFlag(BuiltinDefaultValue); }

    const JSSourceValuePtr &baseValue() const { return m_baseValue; }
    void setBaseValue(const JSSourceValuePtr &v) { m_baseValue = v; }

    struct Alternative
    {
        struct PropertyData
        {
            PropertyData() = default;
            PropertyData(QString v, const CodeLocation &l) : value(std::move(v)), location(l) {}
            QString value;
            CodeLocation location;
        };

        Alternative() = default;
        Alternative(PropertyData c, PropertyData o, JSSourceValuePtr v)
            : condition(std::move(c)), overrideListProperties(std::move(o)), value(std::move(v)) {}
        Alternative clone() const
        {
            return Alternative(condition, overrideListProperties,
                               std::static_pointer_cast<JSSourceValue>(value->clone()));
        }

        PropertyData condition;
        PropertyData overrideListProperties;
        JSSourceValuePtr value;
    };
    using AltProperty = Alternative::PropertyData;

    const std::vector<Alternative> &alternatives() const { return m_alternatives; }
    void addAlternative(const Alternative &alternative) { m_alternatives.push_back(alternative); }
    void clearAlternatives();

    void setDefiningItem(Item *item) override;

private:
    QStringView m_sourceCode;
    int m_line;
    int m_column;
    FileContextPtr m_file;
    Flags m_flags;
    JSSourceValuePtr m_baseValue;
    std::vector<Alternative> m_alternatives;
};


class ItemValue : public Value
{
public:
    ItemValue(Item *item, bool createdByPropertiesBlock);
    static ItemValuePtr create(Item *item, bool createdByPropertiesBlock = false);

    Item *item() const { return m_item; }
    void setItem(Item *item) { m_item = item; }

private:
    void apply(ValueHandler *handler) override { handler->handle(this); }
    ValuePtr clone() const override;

    Item *m_item;
};


class VariantValue : public Value
{
public:
    explicit VariantValue(QVariant v);
    static VariantValuePtr create(const QVariant &v = QVariant());

    void apply(ValueHandler *handler) override { handler->handle(this); }
    ValuePtr clone() const override;

    const QVariant &value() const { return m_value; }

    static const VariantValuePtr &falseValue();
    static const VariantValuePtr &trueValue();
    static const VariantValuePtr &invalidValue();

private:
    QVariant m_value;
};

} // namespace Internal
} // namespace qbs

#endif // QBS_VALUE_H