#include "framebuffer.h"
#include "texture.h"

#include <iostream>

const FrameBuffer* FrameBuffer::screen = new FrameBuffer(0);

FrameBuffer::FrameBuffer() :
    allocated(true),
    m_target(GL_FRAMEBUFFER)
{
    glGenFramebuffers(1, &m_frameBufferId);
}

FrameBuffer::~FrameBuffer()
{
    if(allocated)
        glDeleteFramebuffers(1, &m_frameBufferId);
    for(Texture* t : m_textures)
    {
        t->unbind();
        delete(t);
    }
}

void FrameBuffer::addTexture(Texture* tex, GLenum attachment)
{
    if(m_frameBufferId != 0)
    {
        m_textures.push_back(tex);
        bindFBO();
        if(tex->isCubeMap())
            glFramebufferTexture(m_target, attachment, tex->getId(), 0);
        else
            glFramebufferTexture2D(GL_FRAMEBUFFER, attachment, tex->getTarget(), tex->getId(), 0);
        if((attachment != GL_DEPTH_ATTACHMENT && attachment != GL_STENCIL_ATTACHMENT) && attachment != GL_DEPTH_STENCIL_ATTACHMENT)
            m_attachments.push_back(attachment);
    }
}

void FrameBuffer::initColorAttachments()
{
    if(m_frameBufferId != 0 && m_attachments.size() != 0)
    {
        bindFBO();
        glDrawBuffers(m_attachments.size(), m_attachments.data());
    }
    else
    {
        glDrawBuffer(GL_NONE);
        glReadBuffer(GL_NONE);
    }
    check();
}

void FrameBuffer::deleteTextures()
{
    for(Texture* t : m_textures)
        delete(t);
    m_textures.clear();
    glDrawBuffer(GL_NONE);
}

void FrameBuffer::bindFBO() const
{
    glBindFramebuffer(m_target, m_frameBufferId);
}

bool FrameBuffer::check()
{
    GLenum err;
    err = glCheckFramebufferStatus(GL_FRAMEBUFFER);
    if (err != GL_FRAMEBUFFER_COMPLETE) {
        std::cerr << "FBO not complete (error = " << err << ") : ";
        switch (err) {
        case GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT:
            std::cerr << "GL_FRAMEBUFFER_INCOMPLETE_ATTACHMENT";
            break;
        case GL_FRAMEBUFFER_INCOMPLETE_MISSING_ATTACHMENT:
            std::cerr << "GL_FRAMEBUFFER_INCOMPLETE_MISSING_ATTACHMENT";
            break;
        case GL_FRAMEBUFFER_INCOMPLETE_DRAW_BUFFER:
            std::cerr << "GL_FRAMEBUFFER_INCOMPLETE_DRAW_BUFFER";
            break;
        case GL_FRAMEBUFFER_INCOMPLETE_READ_BUFFER:
            std::cerr << "GL_FRAMEBUFFER_INCOMPLETE_READ_BUFFER";
            break;
        case GL_FRAMEBUFFER_UNSUPPORTED:
            std::cerr << "GL_FRAMEBUFFER_UNSUPPORTED";
            break;
        default:
            std::cerr << "Unknown ERROR";
        }
        std::cerr << std::endl;
    }
    return err == GL_FRAMEBUFFER_COMPLETE;
}

Texture* FrameBuffer::getTexture(int texId)
{
    if(m_frameBufferId != 0)
        return m_textures[texId];
    else
        return NULL;
}