//========= Copyright Valve Corporation, All rights reserved. ============//
//
// Purpose:
//
// $NoKeywords: $
//=============================================================================//

#ifndef AI_WAYPOINT_H
#define AI_WAYPOINT_H

#if defined(_WIN32)
#pragma once
#endif

#include <mempool.h>

// ----------------------------------------------------------------------------
// Forward declarations
// ----------------------------------------------------------------------------

// ----------------------------------------------------------------------------
// Flags used in the flags field in AI_Waypoint_T
// ----------------------------------------------------------------------------
enum WaypointFlags_t {
    // The type of waypoint
    bits_WP_TO_DETOUR = 0x01,      // move to detour point.
    bits_WP_TO_PATHCORNER = 0x02,  // move to a path corner
    bits_WP_TO_NODE = 0x04,        // move to a node
    bits_WP_TO_GOAL = 0x08,        // move to an arbitrary point
    bits_WP_TO_DOOR = 0x10,        // move to position to open a door

    // Other flags for waypoint
    bits_WP_DONT_SIMPLIFY =
        0x20,  // Don't let the route code simplify this waypoint
};

// ----------------------------------------------------------------------------
// Purpose: Waypoints that make up an NPC's route.
// ----------------------------------------------------------------------------
struct AI_Waypoint_t {
   public:
    AI_Waypoint_t();
    AI_Waypoint_t(const Vector &vecPosition, float flYaw, Navigation_t navType,
                  int fWaypointFlags, int nNodeID);
    AI_Waypoint_t(const AI_Waypoint_t &from) {
        memcpy(this, &from, sizeof(*this));
        flPathDistGoal = -1;
        pNext = pPrev = NULL;
    }

    AI_Waypoint_t &operator=(const AI_Waypoint_t &from) {
        memcpy(this, &from, sizeof(*this));
        flPathDistGoal = -1;
        pNext = pPrev = NULL;
        return *this;
    }

    ~AI_Waypoint_t() {
        AssertValid();
        if (pNext) {
            pNext->AssertValid();
            pNext->pPrev = pPrev;
        }
        if (pPrev) {
            pPrev->AssertValid();
            pPrev->pNext = pNext;
        }
    }

    //---------------------------------

    void AssertValid() const {
#ifdef DEBUG
        Assert(!pNext || pNext->pPrev == this);
        Assert(!pPrev || pPrev->pNext == this);
#endif
    }

    //---------------------------------

    int Flags() const;
    Navigation_t NavType() const;

    // Flag modification method
    void ModifyFlags(int fFlags, bool bEnable);

    bool IsReducible() {
        return (pNext && m_iWPType == pNext->m_iWPType &&
                !(m_fWaypointFlags & (bits_WP_TO_GOAL | bits_WP_TO_PATHCORNER |
                                      bits_WP_DONT_SIMPLIFY)));
    }

    //---------------------------------

    void SetNext(AI_Waypoint_t *p);
    AI_Waypoint_t *GetNext() { return pNext; }
    const AI_Waypoint_t *GetNext() const { return pNext; }

    AI_Waypoint_t *GetPrev() { return pPrev; }
    const AI_Waypoint_t *GetPrev() const { return pPrev; }

    AI_Waypoint_t *GetLast();

    //---------------------------------

    const Vector &GetPos() const { return vecLocation; }
    void SetPos(const Vector &newPos) { vecLocation = newPos; }

    EHANDLE GetEHandleData() { return m_hData; }

    //---------------------------------
    //
    // Basic info
    //
    Vector vecLocation;
    float flYaw;  // Waypoint facing dir
    int iNodeID;  // If waypoint is a node, which one

    //---------------------------------
    //
    // Precalculated distances
    //
    float flPathDistGoal;

    //---------------------------------
    //
    // If following a designer laid path, the path-corner entity (if any)
    //
    EHANDLE hPathCorner;

    // Data specific to the waypoint type:
    //
    // PATHCORNER:	The path corner entity.
    // DOOR:		If moving to position to open a door, the handle of the door to
    // open.
    EHANDLE m_hData;

   private:
    int m_fWaypointFlags;    // See WaypointFlags_t
    Navigation_t m_iWPType;  // The type of waypoint

    AI_Waypoint_t *pNext;
    AI_Waypoint_t *pPrev;

    DECLARE_FIXEDSIZE_ALLOCATOR(AI_Waypoint_t);

   public:
    DECLARE_SIMPLE_DATADESC();
};

// ----------------------------------------------------------------------------
// Inline methods associated with AI_Waypoint_t
// ----------------------------------------------------------------------------
inline int AI_Waypoint_t::Flags() const { return m_fWaypointFlags; }

inline Navigation_t AI_Waypoint_t::NavType() const { return m_iWPType; }

inline void AI_Waypoint_t::ModifyFlags(int fFlags, bool bEnable) {
    if (bEnable)
        m_fWaypointFlags |= fFlags;
    else
        m_fWaypointFlags &= ~fFlags;
}

inline void AI_Waypoint_t::SetNext(AI_Waypoint_t *p) {
    if (pNext) {
        pNext->pPrev = NULL;
    }

    pNext = p;

    if (pNext) {
        if (pNext->pPrev) pNext->pPrev->pNext = NULL;

        pNext->pPrev = this;
    }
}

// ----------------------------------------------------------------------------
// Purpose: Holds an maintains a chain of waypoints

class CAI_WaypointList {
   public:
    CAI_WaypointList() : m_pFirstWaypoint(NULL) {}

    CAI_WaypointList(AI_Waypoint_t *pFirstWaypoint)
        : m_pFirstWaypoint(pFirstWaypoint) {}

    void Set(AI_Waypoint_t *route);

    void PrependWaypoints(AI_Waypoint_t *pWaypoints);
    void PrependWaypoint(const Vector &newPoint, Navigation_t navType,
                         unsigned waypointFlags, float flYaw = 0);

    bool IsEmpty() const { return (m_pFirstWaypoint == NULL); }

    AI_Waypoint_t *GetFirst() { return m_pFirstWaypoint; }
    const AI_Waypoint_t *GetFirst() const { return m_pFirstWaypoint; }

    AI_Waypoint_t *GetLast();
    const AI_Waypoint_t *GetLast() const;

    void RemoveAll();

   private:
    AI_Waypoint_t *m_pFirstWaypoint;  // Linked list of waypoints
};

// ----------------------------------------------------------------------------
#ifdef DEBUG
void AssertRouteValid(AI_Waypoint_t *route);
#else
#define AssertRouteValid(route) ((void)0)
#endif

// ----------------------------------------------------------------------------
// Utilities

void DeleteAll(AI_Waypoint_t *pWaypointList);

// ------------------------------------

inline void DeleteAll(AI_Waypoint_t **ppWaypointList) {
    DeleteAll(*ppWaypointList);
    *ppWaypointList = NULL;
}

// ------------------------------------

void AddWaypointLists(AI_Waypoint_t *pLeft, AI_Waypoint_t *pRight);

// ----------------------------------------------------------------------------

#endif  // AI_WAYPOINT_H