// SPDX-License-Identifier: MIT
#ifndef DBC_STATEMENT_HANDLER_H
#define DBC_STATEMENT_HANDLER_H

#include "dbc_database.h"
#include "typefactory.h"
#include <string>
#include <unordered_map>

/** Mutable state belonging to one file parse. Handlers do not retain it. */
struct DbcParseContext {
  DbcDatabase &database;
  FrameInfo *currentFrame = nullptr;
};

class DbcStatementHandler {
  public:
    virtual ~DbcStatementHandler() = default;
    virtual void Handle (const std::string &line, DbcParseContext &context) const = 0;
};

class DbcFrameHandler : public DbcStatementHandler {
  public:
    void Handle (const std::string &line, DbcParseContext &context) const override;
  private:
    static FrameInfo ParseFrameLine (const std::string &line);
};

class DbcSignalHandler : public DbcStatementHandler {
  public:
    void Handle (const std::string &line, DbcParseContext &context) const override;
  private:
    static SignalInfo ParseSignalLine (const std::string &line);
};

class DbcCommentHandler : public DbcStatementHandler {
  public:
    void Handle (const std::string &line, DbcParseContext &context) const override;
  private:
    static void ParseCommentLine (const std::string &line, DbcDatabase &database);
};

/** Exact-key dispatch to handlers created once per registration via TypeFactory. */
class DbcStatementDispatcher {
  public:
    DbcStatementDispatcher();

    template <class Handler>
    void RegisterType (const std::string &keyword) {
      m_factory.registerType<Handler> (keyword);
      m_handlers.insert_or_assign (keyword, m_factory.create (keyword));
    }

    /** Returns false for an unregistered keyword; input must be trimmed. */
    bool Dispatch (const std::string &line, DbcParseContext &context) const;

  private:
    TypeFactory<std::string, DbcStatementHandler> m_factory;
    std::unordered_map<std::string, std::shared_ptr<DbcStatementHandler> > m_handlers;
};

#endif /* DBC_STATEMENT_HANDLER_H */