#include "EditorHelpers.hpp"
#include <cmath>

#include <glm/gtc/matrix_inverse.hpp>
#include <vector>

namespace renderer {
namespace editor {
Mesh makeWireCube ( float size ) {
    float              h     = size * 0.5f;
    std::vector<float> verts = {
        -h, -h, -h, h, -h, -h, h, -h, -h, h, -h, h, h, -h, h, -h, -h, h, -h, -h, h, -h, -h, -h,

        -h, h, -h, h, h, -h, h, h, -h, h, h, h, h, h, h, -h, h, h, -h, h, h, -h, h, -h,

        -h, -h, -h, -h, h, -h, h, -h, -h, h, h, -h, h, -h, h, h, h, h, -h, -h, h, -h, h, h };

    Mesh m;
    m.createFromPositions( verts, true );
    return m;
}

Mesh makeCircleWire ( float radius, int segments ) {
    if( segments < 3 )
        segments = 3;

    std::vector<float> verts;
    verts.reserve( segments * 3 );

    const float twoPi = 6.28318530717958647692f;

    for( int i = 0; i < segments; ++i ) {
        int   ni   = ( i + 1 ) % segments;
        float ti   = (float)i / (float)segments;
        float angi = ti * twoPi;
        float xi   = cosf( angi ) * radius;
        float zi   = sinf( angi ) * radius;

        float tni   = (float)ni / (float)segments;
        float angni = tni * twoPi;
        float xni   = cosf( angni ) * radius;
        float zni   = sinf( angni ) * radius;

        verts.push_back( xi );
        verts.push_back( 0.0f );
        verts.push_back( zi );

        verts.push_back( xni );
        verts.push_back( 0.0f );
        verts.push_back( zni );
    }

    Mesh m;
    m.createFromPositions( verts, true );
    return m;
}

Mesh makeCircleFilled ( float radius, int segments ) {
    if( segments < 3 )
        segments = 3;

    std::vector<float> data;
    data.reserve( ( segments + 2 ) * 5 );

    const float twoPi = 6.28318530717958647692f;

    float cx = 0.0f, cz = 0.0f;
    float cu = 0.5f, cv = 0.5f;

    for( int i = 0; i < segments; ++i ) {
        int i1 = i;
        int i2 = ( i + 1 ) % segments;

        float t1   = (float)i1 / (float)segments;
        float ang1 = t1 * twoPi;
        float x1   = cosf( ang1 ) * radius;
        float z1   = sinf( ang1 ) * radius;
        float u1   = ( x1 / ( radius * 2.0f ) ) + 0.5f;
        float v1   = ( z1 / ( radius * 2.0f ) ) + 0.5f;

        float t2   = (float)i2 / (float)segments;
        float ang2 = t2 * twoPi;
        float x2   = cosf( ang2 ) * radius;
        float z2   = sinf( ang2 ) * radius;
        float u2   = ( x2 / ( radius * 2.0f ) ) + 0.5f;
        float v2   = ( z2 / ( radius * 2.0f ) ) + 0.5f;

        data.push_back( cx );
        data.push_back( 0.0f );
        data.push_back( cz );
        data.push_back( cu );
        data.push_back( cv );

        data.push_back( x1 );
        data.push_back( 0.0f );
        data.push_back( z1 );
        data.push_back( u1 );
        data.push_back( v1 );

        data.push_back( x2 );
        data.push_back( 0.0f );
        data.push_back( z2 );
        data.push_back( u2 );
        data.push_back( v2 );
    }

    Mesh m;
    m.createFromPosTex( data );
    return m;
}

bool makeRayFromMouse ( const glm::vec2& mousePx, int fbw, int fbh, const glm::mat4& view,
                        const glm::mat4& proj, const glm::vec3& camPos, glm::vec3& outOrigin,
                        glm::vec3& outDir ) {
    if( fbw <= 0 || fbh <= 0 )
        return false;

    float ndcX = ( mousePx.x / (float)fbw ) * 2.0f - 1.0f;
    float ndcY = 1.0f - ( mousePx.y / (float)fbh ) * 2.0f;

    glm::vec4 nearPointNDC( ndcX, ndcY, -1.0f, 1.0f );
    glm::vec4 farPointNDC( ndcX, ndcY, 1.0f, 1.0f );

    glm::mat4 invPV = glm::inverse( proj * view );

    glm::vec4 nearWorld = invPV * nearPointNDC;
    glm::vec4 farWorld  = invPV * farPointNDC;
    if( nearWorld.w == 0.0f || farWorld.w == 0.0f )
        return false;

    nearWorld /= nearWorld.w;
    farWorld /= farWorld.w;

    glm::vec3 nearPos = glm::vec3( nearWorld );
    glm::vec3 farPos  = glm::vec3( farWorld );

    outOrigin = nearPos;
    outDir    = glm::normalize( farPos - nearPos );

    if( !isfinite( outDir.x ) || !isfinite( outDir.y ) || !isfinite( outDir.z ) ) {
        outOrigin = camPos;
        outDir    = glm::normalize( glm::vec3( 0.0f, 0.0f, -1.0f ) );
    }

    return true;
}
}   // namespace editor
}   // namespace renderer