//
//  RenderableTextEntityItem.cpp
//  interface/src
//
//  Created by Brad Hefta-Gaub on 8/6/14.
//  Copyright 2014 High Fidelity, Inc.
//
//  Distributed under the Apache License, Version 2.0.
//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
//

#include <glm/gtx/quaternion.hpp>

#include <GeometryCache.h>
#include <PerfStat.h>
#include <Transform.h>

#include "RenderableTextEntityItem.h"
#include "GLMHelpers.h"

EntityItemPointer RenderableTextEntityItem::factory(const EntityItemID& entityID, const EntityItemProperties& properties) {
    EntityItemPointer entity{ new RenderableTextEntityItem(entityID) };
    entity->setProperties(properties);
    return entity;
}

RenderableTextEntityItem::~RenderableTextEntityItem() { 
    auto geometryCache = DependencyManager::get<GeometryCache>();
    if (_geometryID && geometryCache) {
        geometryCache->releaseID(_geometryID);
    }
    delete _textRenderer;
}

void RenderableTextEntityItem::render(RenderArgs* args) {
    PerformanceTimer perfTimer("RenderableTextEntityItem::render");
    Q_ASSERT(getType() == EntityTypes::Text);
    checkFading();
    
    static const float SLIGHTLY_BEHIND = -0.005f;
    float fadeRatio = _isFading ? Interpolate::calculateFadeRatio(_fadeStartTime) : 1.0f;
    bool transparent = fadeRatio < 1.0f;
    glm::vec4 textColor = glm::vec4(toGlm(getTextColorX()), fadeRatio);
    glm::vec4 backgroundColor = glm::vec4(toGlm(getBackgroundColorX()), fadeRatio);
    glm::vec3 dimensions = getDimensions();
    
    // Render background
    glm::vec3 minCorner = glm::vec3(0.0f, -dimensions.y, SLIGHTLY_BEHIND);
    glm::vec3 maxCorner = glm::vec3(dimensions.x, 0.0f, SLIGHTLY_BEHIND);
    
    
    // Batch render calls
    Q_ASSERT(args->_batch);
    gpu::Batch& batch = *args->_batch;

    bool success;
    Transform transformToTopLeft = getTransformToCenter(success);
    if (!success) {
        return;
    }
    if (getFaceCamera()) {
        //rotate about vertical to face the camera
        glm::vec3 dPosition = args->getViewFrustum().getPosition() - getPosition();
        // If x and z are 0, atan(x, z) is undefined, so default to 0 degrees
        float yawRotation = dPosition.x == 0.0f && dPosition.z == 0.0f ? 0.0f : glm::atan(dPosition.x, dPosition.z);
        glm::quat orientation = glm::quat(glm::vec3(0.0f, yawRotation, 0.0f));
        transformToTopLeft.setRotation(orientation);
    }
    transformToTopLeft.postTranslate(glm::vec3(-0.5f, 0.5f, 0.0f)); // Go to the top left
    transformToTopLeft.setScale(1.0f); // Use a scale of one so that the text is not deformed
    
    batch.setModelTransform(transformToTopLeft);
    auto geometryCache = DependencyManager::get<GeometryCache>();
    if (!_geometryID) {
        _geometryID = geometryCache->allocateID();
    }
    geometryCache->bindSimpleProgram(batch, false, transparent, false, false, true);
    geometryCache->renderQuad(batch, minCorner, maxCorner, backgroundColor, _geometryID);
    
    float scale = _lineHeight / _textRenderer->getFontSize();
    transformToTopLeft.setScale(scale); // Scale to have the correct line height
    batch.setModelTransform(transformToTopLeft);
    
    float leftMargin = 0.1f * _lineHeight, topMargin = 0.1f * _lineHeight;
    glm::vec2 bounds = glm::vec2(dimensions.x - 2.0f * leftMargin,
                                 dimensions.y - 2.0f * topMargin);
    _textRenderer->draw(batch, leftMargin / scale, -topMargin / scale, _text, textColor, bounds / scale);
    
}