#ifndef AST_FOUNDATION_H
#define AST_FOUNDATION_H

#include "lex_foundation.h"
#include <QList>

namespace Ast {

    class ASTTree {
    public:
        virtual ~ASTTree() = default;

        virtual const ASTTree *parent() const = 0;
        virtual uint depth() const = 0;

        virtual QList<ASTTree *> children() const = 0;

        virtual uint count() const = 0;
        virtual ASTTree *child(uint index) const = 0;

        virtual QString toString() const = 0;
    };

    class ASTLeaf : public ASTTree {
    public:
        explicit ASTLeaf(ASTTree *parent, Lex::Token *inst);
        virtual ~ASTLeaf();

        virtual const ASTTree *parent() const override;
        virtual uint depth() const override;

        virtual QList<ASTTree *> children() const final;
        virtual uint count() const final;
        virtual ASTTree *child(uint) const final;

        virtual QString toString() const override;

    protected:
        Lex::Token *tokenIns() const;

    private:
        Lex::Token *const _store;
        ASTTree *const parent_ins;
    };

    class ASTList : public ASTTree {
    public:
        explicit ASTList(ASTTree *parent);
        virtual ~ASTList();

        virtual void resetChildren(const QList<ASTTree *> &tokens);

        // ASTTree interface
    public:
        virtual const ASTTree *parent() const override;
        virtual uint depth() const override;

        virtual QList<ASTTree *> children() const override final;
        virtual uint count() const override final;
        virtual ASTTree *child(uint index) const override final;

        /**
         * @brief 插入子节点
         * @param child
         */
        virtual void insert(uint idx, ASTTree *child);

        virtual QString toString() const override;

    private:
        QList<ASTTree *> _store;
        ASTTree *const parent_ins;
    };

} // namespace Ast

#endif // AST_FOUNDATION_H