#include "GridSystem.hpp"

#include <cmath>

namespace scene {
GridSystem::GridSystem ()
    : mCellSize( 1.0f ), mFloorY( 0.0f ), mGridWidth( 1000 ), mGridDepth( 1000 ), mWallHeight( 4 ) {
}

float GridSystem::getCellSize () const {
    return mCellSize;
}

float GridSystem::getFloorY () const {
    return mFloorY;
}

int GridSystem::getGridWidth () const {
    return mGridWidth;
}

int GridSystem::getGridDepth () const {
    return mGridDepth;
}

int GridSystem::getWallHeight () const {
    return mWallHeight;
}

glm::vec3 GridSystem::gridToWorld ( int gridX, int gridZ, float y ) const {
    float halfW = mGridWidth * 0.5f;
    float halfD = mGridDepth * 0.5f;

    float worldX = ( gridX - halfW ) * mCellSize + mCellSize * 0.5f;
    float worldZ = ( gridZ - halfD ) * mCellSize + mCellSize * 0.5f;

    return glm::vec3( worldX, y, worldZ );
}

glm::vec3 GridSystem::gridToWorldFloor ( int gridX, int gridZ ) const {
    return gridToWorld( gridX, gridZ, mFloorY );
}

bool GridSystem::worldToGrid ( const glm::vec3& worldPos, int& outGridX, int& outGridZ ) const {
    float halfW = mGridWidth * 0.5f;
    float halfD = mGridDepth * 0.5f;

    float localX = worldPos.x / mCellSize + halfW - 0.5f;
    float localZ = worldPos.z / mCellSize + halfD - 0.5f;

    outGridX = static_cast<int>( std::floor( localX ) );
    outGridZ = static_cast<int>( std::floor( localZ ) );

    return ( outGridX >= 0 && outGridX < mGridWidth && outGridZ >= 0 && outGridZ < mGridDepth );
}

glm::vec3 GridSystem::getCellCenter ( int gridX, int gridZ, int cellY ) const {
    float y = mFloorY + cellY * mCellSize + mCellSize * 0.5f;
    return gridToWorld( gridX, gridZ, y );
}

float GridSystem::getMinWorldX () const {
    float halfW = mGridWidth * 0.5f;
    return ( 0 - halfW ) * mCellSize;
}

float GridSystem::getMaxWorldX () const {
    float halfW = mGridWidth * 0.5f;
    return ( mGridWidth - 1 - halfW ) * mCellSize + mCellSize;
}

float GridSystem::getMinWorldZ () const {
    float halfD = mGridDepth * 0.5f;
    return ( 0 - halfD ) * mCellSize;
}

float GridSystem::getMaxWorldZ () const {
    float halfD = mGridDepth * 0.5f;
    return ( mGridDepth - 1 - halfD ) * mCellSize + mCellSize;
}

float GridSystem::getHalfWidth () const {
    return mGridWidth * 0.5f;
}

float GridSystem::getHalfDepth () const {
    return mGridDepth * 0.5f;
}

float GridSystem::getFrontWallZ () const {
    float halfD = mGridDepth * 0.5f;
    return ( 0 - halfD ) * mCellSize + mCellSize * 0.5f;
}

float GridSystem::getBackWallZ () const {
    float halfD = mGridDepth * 0.5f;
    return ( mGridDepth - 1 - halfD ) * mCellSize + mCellSize * 0.5f;
}

float GridSystem::getLeftWallX () const {
    float halfW = mGridWidth * 0.5f;
    return ( 0 - halfW ) * mCellSize + mCellSize * 0.5f;
}

float GridSystem::getRightWallX () const {
    float halfW = mGridWidth * 0.5f;
    return ( mGridWidth - 1 - halfW ) * mCellSize + mCellSize * 0.5f;
}

float GridSystem::getWallMinY () const {
    return mFloorY;
}

float GridSystem::getWallMaxY () const {
    return mFloorY + mWallHeight * mCellSize;
}

float GridSystem::getWallBaseY () const {
    return mFloorY + mCellSize;
}
}   // namespace scene