/*
 * This file is part of the AzerothCore Project. See AUTHORS file for Copyright information
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program. If not, see <http://www.gnu.org/licenses/>.
 */

#ifndef _MMAP_TERRAIN_BUILDER_H
#define _MMAP_TERRAIN_BUILDER_H

#include "WorldModel.h"

#include "G3D/Array.h"
#include "G3D/Vector3.h"
#include "G3D/Matrix3.h"

namespace MMAP
{
    enum Spot
    {
        TOP     = 1,
        RIGHT   = 2,
        LEFT    = 3,
        BOTTOM  = 4,
        ENTIRE  = 5
    };

    enum Grid
    {
        GRID_V8,
        GRID_V9
    };

    static const int V9_SIZE = 129;
    static const int V9_SIZE_SQ = V9_SIZE * V9_SIZE;
    static const int V8_SIZE = 128;
    static const int V8_SIZE_SQ = V8_SIZE * V8_SIZE;
    static const float GRID_SIZE = 533.3333f;
    static const float GRID_PART_SIZE = GRID_SIZE / V8_SIZE;

    // see contrib/extractor/system.cpp, CONF_use_minHeight
    static const float INVALID_MAP_LIQ_HEIGHT = -500.f;
    static const float INVALID_MAP_LIQ_HEIGHT_MAX = 5000.0f;

    // see following files:
    // contrib/extractor/system.cpp
    // src/server/game/Map.cpp

    struct MeshData
    {
        G3D::Array<float> solidVerts;
        G3D::Array<int> solidTris;

        G3D::Array<float> liquidVerts;
        G3D::Array<int> liquidTris;
        G3D::Array<uint8> liquidType;

        // offmesh connection data
        G3D::Array<float> offMeshConnections;   // [p0y,p0z,p0x,p1y,p1z,p1x] - per connection
        G3D::Array<float> offMeshConnectionRads;
        G3D::Array<unsigned char> offMeshConnectionDirs;
        G3D::Array<unsigned char> offMeshConnectionsAreas;
        G3D::Array<unsigned short> offMeshConnectionsFlags;
    };

    class TerrainBuilder
    {
    public:
        TerrainBuilder(const std::string &mapsPath, bool skipLiquid);
        ~TerrainBuilder();

        TerrainBuilder(const TerrainBuilder& tb) = delete;

        void loadMap(uint32 mapID, uint32 tileX, uint32 tileY, MeshData& meshData);
        bool loadVMap(uint32 mapID, uint32 tileX, uint32 tileY, MeshData& meshData);
        void loadOffMeshConnections(uint32 mapID, uint32 tileX, uint32 tileY, MeshData& meshData, const char* offMeshFilePath);

        [[nodiscard]] bool usesLiquids() const { return !m_skipLiquid; }

        // vert and triangle methods
        static void transform(std::vector<G3D::Vector3>& original, std::vector<G3D::Vector3>& transformed,
                              float scale, G3D::Matrix3& rotation, G3D::Vector3& position);
        static void copyVertices(std::vector<G3D::Vector3>& source, G3D::Array<float>& dest);
        static void copyIndices(std::vector<VMAP::MeshTriangle>& source, G3D::Array<int>& dest, int offest, bool flip);
        static void copyIndices(G3D::Array<int>& src, G3D::Array<int>& dest, int offset);
        static void cleanVertices(G3D::Array<float>& verts, G3D::Array<int>& tris);
    private:
        /// Loads a portion of a map's terrain
        bool loadMap(uint32 mapID, uint32 tileX, uint32 tileY, MeshData& meshData, Spot portion);

        /// Sets loop variables for selecting only certain parts of a map's terrain
        void getLoopVars(Spot portion, int& loopStart, int& loopEnd, int& loopInc);

        /// Controls whether liquids are loaded
        bool m_skipLiquid;

        /// Load the map terrain from file
        bool loadHeightMap(uint32 mapID, uint32 tileX, uint32 tileY, G3D::Array<float>& vertices, G3D::Array<int>& triangles, Spot portion);

        /// Get the vector coordinate for a specific position
        void getHeightCoord(int index, Grid grid, float xOffset, float yOffset, float* coord, float* v);

        /// Get the triangle's vector indices for a specific position
        void getHeightTriangle(int square, Spot triangle, int* indices, bool liquid = false);

        /// Determines if the specific position's triangles should be rendered
        bool isHole(int square, const uint16 holes[16][16]);

        /// Get the liquid vector coordinate for a specific position
        void getLiquidCoord(int index, int index2, float xOffset, float yOffset, float* coord, float* v);

        /// Get the liquid type for a specific position
        uint8 getLiquidType(int square, const uint8 liquid_type[16][16]);

        std::string m_mapsPath;
        std::string m_vmapsPath;
    };
}

#endif