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// G4VNavigation
//
// Class description:
//
// Navigation interface common between all navigator types.

// Author: Guilherme Amadio (CERN), March 2022
// --------------------------------------------------------------------
#ifndef G4VNAVIGATION_HH
#define G4VNAVIGATION_HH 1

#include "G4ThreeVector.hh"

class G4LogicalVolume;
class G4VPhysicalVolume;
class G4NavigationHistory;

/**
 * @brief G4VNavigation class holds the common navigation interface
 * for all geometry navigator types.
 */

class G4VNavigation
{
  public:

    /**
     * Virtual Destructor.
     */
    virtual ~G4VNavigation() = default;

    /**
     * Searches positioned volumes in mother at current top level of @p history
     * for volume containing @p globalPoint. Do not test against @p blockedVol.
     * If a containing volume is found, push it onto navigation history state.
     *  @param[in,out] history Navigation history.
     *  @param[in,out] blockedVol Blocked volume to be ignored in queries.
     *  @param[in,out] blockedNum Copy number for blocked replica volumes.
     *  @param[in,out] globalPoint Point in global coordinates system.
     *  @param[in,out] globalDirection Pointer to global direction or null.
     *  @param[in,out] localPoint Point in local coordinates system.
     *  @returns Whether a containing volume has been found.
     */
    virtual G4bool LevelLocate(G4NavigationHistory& history,
                         const G4VPhysicalVolume* blockedVol,
                         const G4int blockedNum,
                         const G4ThreeVector& globalPoint,
                         const G4ThreeVector* globalDirection,
                         const G4bool pLocatedOnEdge,
                               G4ThreeVector& localPoint) = 0;

    /**
     * Computes the length of a step to the next boundary.
     * Do not test against @p pBlockedPhysical. Identify the next candidate
     * volume (if a daughter of current volume), and return it in:
     * pBlockedPhysical, blockedReplicaNo.
     *  @param[in] localPoint Local point.
     *  @param[in] localDirection Local vector direction.
     *  @param[in] currentProposedStepLength Current proposed step length.
     *  @param[in,out] newSafety New safety.
     *  @param[in,out] history Navigation history.
     *  @param[in,out] validExitNormal Flag to indicate whether exit normal is
     *                 valid or not.
     *  @param[in,out] exitNormal Exit normal.
     *  @param[in,out] entering Flag to indicate whether entering a volume.
     *  @param[in,out] exiting Flag to indicate whether exiting a volume.
     *  @param[in,out] pBlockedPhysical Blocked physical volume that should be
     *                 ignored in queries.
     *  @param[in,out] blockedReplicaNo Copy number for blocked replica volumes.
     *  @returns Length from current point to next boundary surface along
     *           @p localDirection.
     */
    virtual G4double ComputeStep(const G4ThreeVector& localPoint,
                                 const G4ThreeVector& localDirection,
                                 const G4double currentProposedStepLength,
                                       G4double& newSafety,
                                       G4NavigationHistory& history,
                                       G4bool& validExitNormal,
                                       G4ThreeVector& exitNormal,
                                       G4bool& exiting,
                                       G4bool& entering,
                                       G4VPhysicalVolume*(*pBlockedPhysical),
                                       G4int& blockedReplicaNo) = 0;

    /**
     * Computes the distance to the closest surface.
     *  @param[in] localPoint Local point.
     *  @param[in] history Navigation history.
     *  @param[in] pMaxLength Maximum step length beyond which volumes
     *             need not be checked.
     *  @returns Length from current point to closest surface.
     */
    virtual G4double ComputeSafety(const G4ThreeVector& localpoint,
                                   const G4NavigationHistory& history,
                                   const G4double pMaxLength = DBL_MAX) = 0;

    /**
     * Updates internal navigation state to take into account that location
     * has been moved, but remains within the @p motherPhysical volume.
     *  @param[in] motherPhysical Current physical volume.
     *  @param[in] localPoint Local point.
     */
    virtual void RelocateWithinVolume(G4VPhysicalVolume* /* motherPhysical */,
                                      const G4ThreeVector& /* localPoint */)
    {
      /* do nothing by default */
    }

    /**
     * Gets current verbosity level.
     */
    virtual G4int GetVerboseLevel() const { return fVerbose; }

    /**
     * Sets current verbosity level.
     */
    virtual void SetVerboseLevel(G4int level) { fVerbose = level; }

    /**
     * Sets check mode.
     * When enabled, forces navigator to run in "check mode", hence using
     * additional verifications and stricter condictions for ensuring
     * correctness. Effective only when G4VERBOSE is enabled.
     */
    void CheckMode(G4bool mode) { fCheck = mode; }

  protected:

    G4int fVerbose = 0;
    G4bool fCheck = false;
};

#endif