#ifndef __SITECING_COMPONENT_SO_H
#define __SITECING_COMPONENT_SO_H

#include <sys/types.h>
#include <sys/stat.h>
#include <string>
#include <map>
#include <list>
#include "sitecing/acomponent.h"

/**
 * @file
 * @brief Classes related to the .so components handling.
 */

namespace sitecing {
    using namespace std;

    /**
     * The 'class' component object.
     */
    class component_so {
	public:
	    /**
	     * The type of the component instantiating function.
	     */
	    typedef acomponent *(*egg_t)();
	    /**
	     * Type for storing the list of instances and the reference counts.
	     */
	    typedef map<acomponent*,int> used_chickens_t;
	    /**
	     * The type for storing the list of unused instances.
	     */
	    typedef list<acomponent*> free_chickens_t;

	    /**
	     * The .so file name.
	     */
	    string sofile;
	    /**
	     * The stat structure for the .so loaded.
	     */
	    struct stat stso;
	    /**
	     * The dloaded .so handle.
	     */
	    void *dl;
	    /**
	     * Pointer to the instatiator function.
	     */
	    egg_t egg;
	    /**
	     * The list of instances in use.
	     */
	    used_chickens_t chickens_used;
	    /**
	     * The list of unused instances.
	     */
	    free_chickens_t chickens_free;

	    /**
	     * @param soname the .so file name
	     */
	    component_so(const string& soname);
	    ~component_so();
	    /**
	     * Check whether the loaded .so is in sync with the disk file.
	     */
	    bool is_uptodate() const;

	    /**
	     * @todo TODO: wish I could remember -- document me.
	     */
	    acomponent* allocate_chicken();
	    /**
	     * @todo TODO: wish I could remember -- document me.
	     */
	    void allocate_chicken(acomponent *ac);
	    /**
	     * @todo TODO: wish I could remember -- document me.
	     */
	    void deallocate_chicken(acomponent *ac);
    };

    /**
     * The component instance container.
     */
    class so_component {
	public:
	    /**
	     * Pointer to the component 'class'.
	     */
	    component_so *hen;
	    /**
	     * The instance in question.
	     */
	    acomponent* ac;

	    so_component()
		: hen(0), ac(0) { }
	    /**
	     * @param h the 'class' object.
	     * @param scif pointer to the interface to the site-C-ing core.
	     */
	    so_component(component_so *h,sitecing_interface *scif);
	    /**
	     * Copy constructor
	     * @param s source instance.
	     */
	    so_component(const so_component& s)
		: hen(0), ac(0) { attach(s); }
	    ~so_component() { detach(); }

	    /**
	     * Assignment operator.
	     * @param s source instance.
	     */
	    so_component& operator=(const so_component& s) {
		attach(s); return *this;
	    }

	    /**
	     * @todo TODO: wish I could remember the details -- document me.
	     * @param h the 'class' object.
	     * @param a the instance to be attached.
	     */
	    void attach(component_so *h,acomponent *a);
	    /**
	     * @todo TODO: wish I could remember the details -- document me.
	     * @param s the source instance.
	     */
	    void attach(const so_component& s) { attach(s.hen,s.ac); }
	    /**
	     * @todo TODO: wish I could remember the details -- document me.
	     */
	    void detach();
    };

    /**
     * The typed component instance container template.
     * @param CT the component class.
     */
    template<typename CT>
	class so_component_t : public sitecing::so_component {
	    public:
		/**
		 * @param s The untyped instance container.
		 */
		so_component_t(const so_component& s)
		    : so_component(s) { }

		/**
		 * typed dereference operator
		 * @return the pointer to the most derived component instance
		 * @see acomponent::__the_most_derived_this()
		 */
		CT* operator->() {
		    return static_cast<CT*>(ac->__the_most_derived_this());
		}
	};
    
}

#endif /* __SITECING_COMPONENT_SO_H */