// Copyright (c) 2022 Dominic Masters
// 
// This software is released under the MIT License.
// https://opensource.org/licenses/MIT

#include "dawnopengl.hpp"
#include "game/DawnGame.hpp"
#include "display/RenderManager.hpp"

using namespace Dawn;

RenderManager::RenderManager() :
  IRenderManager(),
  renderPipeline(this)
{
  backBuffer = std::make_shared<BackBufferRenderTarget>(*this);
}

void RenderManager::init(std::weak_ptr<DawnGame> game) {
  this->game = game;
  
  // Lock the common shaders
  lockSimpleTextured = shaderManager.lockShader<SimpleTexturedShader>();
  simpleTexturedShader = shaderManager.getShader<SimpleTexturedShader>(
    lockSimpleTextured
  );
  
  lockUIShaderProgram = shaderManager.lockShader<UIShader>();
  uiShader = shaderManager.getShader<UIShader>(lockUIShaderProgram);

  lockFontShader = shaderManager.lockShader<FontShader>();
  fontShader = shaderManager.getShader<FontShader>(lockFontShader);
  renderPipeline.init();
  assertNoGLError();

  // Prepare the initial values
  glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
  assertNoGLError();
  glBlendFuncSeparate(
    GL_SRC_ALPHA,
    GL_ONE_MINUS_SRC_ALPHA,
    GL_ONE,
    GL_ONE_MINUS_SRC_ALPHA
  );
  assertNoGLError();
  glDepthMask(GL_TRUE);
  assertNoGLError();
  glDepthFunc(GL_LESS);
  assertNoGLError();
}

std::shared_ptr<RenderTarget> RenderManager::getBackBuffer() {
  return backBuffer;
}

RenderPipeline * RenderManager::getRenderPipeline() {
  return &renderPipeline;
}

ShaderManager * RenderManager::getShaderManager() {
  return &shaderManager;
}

void RenderManager::setRenderFlags(flag_t flags) {
  renderFlags = flags;
  
  if((flags & RENDER_MANAGER_RENDER_FLAG_DEPTH_TEST) == 0) {
    glDisable(GL_DEPTH_TEST);
  } else {
    glEnable(GL_DEPTH_TEST);
  }
  assertNoGLError();

  if((flags & RENDER_MANAGER_RENDER_FLAG_BLEND) == 0) {
    glDisable(GL_BLEND);
  } else {
    glEnable(GL_BLEND);
  }
  assertNoGLError();
}

void RenderManager::update() {
  this->getRenderPipeline()->render();
}

RenderManager::~RenderManager() {
  shaderManager.releaseShader<SimpleTexturedShader>(lockSimpleTextured);
  shaderManager.releaseShader<UIShader>(lockUIShaderProgram);
  shaderManager.releaseShader<FontShader>(lockFontShader);
}