//  mcthing.h
//
//  Base class for all entities in
//  This class is pure virtual to ensure that type is defined.

#ifndef _MCTHING_H_
#define _MCTHING_H_

#include "idman.h"

class mcContext;  // Forward declaration to avoid circular dependency

class mcThing
{
    static IDManager idman;
    int id;
protected:
    mcContext *mgr;

public:
    mcThing(mcContext *a_mgr)
        : mgr(a_mgr), id(idman.getNextID())
    { }
    virtual ~mcThing() { }

    // Type information
    enum type
    {
        LINE,
        STATION,
        STATION_NODE,
        LINE_SEGMENT,

        TYPE_COUNT  // back marker
    };
    virtual type getType() = 0;

    int getId() { return id; }
    virtual CString getName() = 0;

    // Function to determine whether the element can be deleted safely.
    // Basically, if any other elements depend on this one, then it can't
    // be deleted.
    virtual BOOL deletable()
    { return TRUE; }

    // Function to return a list of all the elements that *directly* depend
    // on this one. Direct dependence requires that the dependent element
    // includes a reference to this object (in DB parlance, contains a FK
    // reference).
    // Returns null if no dependents found.
    virtual CObList *getDependents()
    { return 0; }


    // SQL members

    // Name of the table into which elements of a particular type are to be
    // written
    virtual CString getSqlTable() = 0;

    // The content of the VALUES clause in the SQL INSERT statement.
    // Note: brackets are placed around this text, but commas and literals
    // must be supplied.
    virtual CString getSqlInsertData() = 0;

protected:
    // Utility function for putting literals around strings
    // Note: the intention is to substitute '' for ' where appropriate
    CString literal(const CString &string)
    {
        CString result("'");
        CString data(string);
        for (int litIdx = data.Find("'"); litIdx != -1;
                 litIdx = data.Find("'"))
        {
            result += data.Left(litIdx) + "''";
            data = data.Mid(litIdx + 1);
        }
        result += data + "'";
        return result;
    }
};

#endif  // _MCTHING_H_