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#ifndef DIRGUARD_H
#define DIRGUARD_H

#include <dirent.h>
#include <string>
#include <Noncopyable.h>

/**
 * Used to manage opening/closing a directory via opendir()/closedir(), so
 * we can write exception-safe code.
 */
class DirGuard : private Noncopyable {
public:

	/**
	 * Initializes the guard by attempting to open the given directory.  If
	 * throwOnFailure==true and the open fails, IOException is thrown.  If
	 * throwOnFailure==false and the open fails, the directory is simply marked
	 * as closed and no exception is thrown.  Callers can call isClosed()
	 * immediately after creating the object to determine whether the open
	 * succeeded.
	 */
	explicit DirGuard(const std::string &dirName, bool throwOnFailure = true);
	~DirGuard();

	/**
	 * Returns a pointer to the encapsulated DIR structure.  If the directory
	 * has been closed, this returns NULL.
	 */
	operator DIR*();

	/**
	 * Closes the directory, if not already closed.  After this, the directory
	 * is flagged as closed and will not be closed again (either by the
	 * destructor or this method).  Manual close capability is provided for
	 * compatibility with code that wants to close the directory itself, and
	 * throw an exception if closure failed.
	 *
	 * \return if the directory is not closed, returns the return value of
	 * closedir().  If the directory was already closed, returns 0.  errno can
	 * be queried to determine reasons for failure.
	 */
	int close();

	bool isClosed() const {
		return closed;
	}

private:
	DIR *d;
	bool closed;
};

#endif
