#pragma once

#include <memory>
#include <QList>
#include <libtoken.h>
#include "libsyntax.h"

namespace ast_basic {
    // 抽象语法树 ================================================================================================
    /**
     * @brief 抽象语法树集合节点/表达式节点
     */
    class IExprInst {
    public:
        virtual ~IExprInst() = default;

        /**
         * @brief 获取表达式的解析规则
         * @return
         */
        virtual std::shared_ptr<const lib_syntax::ExprRule> definedRule() const = 0;
        //=====================================================
        /**
         * 获取语法节点的源码文件路径.
         * 
         * \return 文件路径
         */
        virtual QString filePath() const = 0;
        /**
         * 获取语法节点关联token序列.
         * 
         * \return token序列
         */
        virtual QList<std::shared_ptr<const lib_token::IToken>> tokens() const = 0;
        /**
         * 解析过程中，向表达式内部添加token实例.
         * 
         * \param token_inst 实例
         */
        virtual void addToken(std::shared_ptr<const lib_token::IToken> token_inst) = 0;
        //=====================================================
        /**
         * @brief 子表达式集合
         * @return
         */
        virtual QList<std::shared_ptr<const IExprInst>> children() const = 0;
        /**
         * @brief 添加子表达式.
         * 
         * \param inst 子表达式实例
         */
        virtual void addChild(std::shared_ptr<const IExprInst> inst) = 0;
    };


    // 基础语法树构成 ==========================================================================================
    /**
     * @brief 表达式节点
     */
    class LIBSYNTAX_EXPORT ExpressionElement : public ast_basic::IExprInst, public std::enable_shared_from_this<ExpressionElement> {
    private:
        std::shared_ptr<const lib_syntax::ExprRule> _expr_rule;
        QList<std::shared_ptr<const IExprInst>> children_store;
        QList<std::shared_ptr<const lib_token::IToken>> tokens_bind;

    public:
        ExpressionElement(std::shared_ptr<const lib_syntax::ExprRule> bind);

        // 通过 Expression 继承
        std::shared_ptr<const lib_syntax::ExprRule> definedRule() const override;
        QString filePath() const override;

        QList<std::shared_ptr<const lib_token::IToken>> tokens() const override;
        void addToken(std::shared_ptr<const lib_token::IToken> token_inst) override;

        QList<std::shared_ptr<const IExprInst>> children() const override;
        void addChild(std::shared_ptr<const IExprInst> inst) override;
    };

    class LIBSYNTAX_EXPORT ExpressionContext : public lib_syntax::IContext, public std::enable_shared_from_this<ExpressionContext> {
    private:
        QList<std::shared_ptr<const lib_syntax::IBasicRule>> rule_stack;
        QList<std::shared_ptr<IExprInst>> expression_stack;
        QList<std::shared_ptr<const ast_basic::IExprInst>> document_store;
        QString current_file_path;
        QList<std::tuple<QString, int, QString>> errors_storage;

    public:
        ExpressionContext();

        virtual void setCurrentFile(const QString& path);
        virtual QString currentFile() const;

        // 通过 IContext 继承
        std::shared_ptr<ast_basic::IExprInst> currentExprInst() const override;
        void pushExprInst(std::shared_ptr<ast_basic::IExprInst> current_inst) override;
        std::shared_ptr<ast_basic::IExprInst> popExprInst() override;

        std::shared_ptr<const lib_syntax::IBasicRule> currentExprRule() const override;
        void pushExprRule(std::shared_ptr<const lib_syntax::IBasicRule> inst) override;
        std::shared_ptr<const lib_syntax::IBasicRule> popExprRule() override;
        virtual QList<std::shared_ptr<const lib_syntax::IBasicRule>> currentExpressionRuleStack() const;

        virtual void appendDoc(std::shared_ptr<ast_basic::IExprInst> inst) override;
        virtual QList<std::shared_ptr<const ast_basic::IExprInst>> getDocs() const override;

        void appendParseErrors(const QString& file_path, int start, const QString& error_msg) override;
        QStringList errors() const override;
        void clearErrors(const QString& file_path, int start) override;
    };
}