#include "GfxContext.h"

#include <GL/glew.h>

#include "Batch2D.h"
#include "Framebuffer.h"

GfxContext::GfxContext(
    const GfxContext* parent, 
    const Viewport& viewport, 
    Batch2D* g2d
) : parent(parent), 
    viewport(viewport), 
    g2d(g2d) 
{}

GfxContext::~GfxContext() {
    if (g2d) {
        g2d->flush();
    }

    while (scissorsCount--) {
        Window::popScissor();
    }

    if (parent == nullptr)
        return;

    if (fbo != parent->fbo) {
        if (fbo) {
            fbo->unbind();
        }
        if (parent->fbo) {
            parent->fbo->bind();
        }
    }

    Window::viewport(
        0, 0,
        parent->viewport.getWidth(), 
        parent->viewport.getHeight()
    );

    if (depthMask != parent->depthMask) {
        glDepthMask(parent->depthMask);
    }
    if (depthTest != parent->depthTest) {
        if (depthTest) glDisable(GL_DEPTH_TEST);
        else glEnable(GL_DEPTH_TEST);
    }
    if (cullFace != parent->cullFace) {
        if (cullFace) glDisable(GL_CULL_FACE);
        else glEnable(GL_CULL_FACE);
    }
    if (blendMode != parent->blendMode) {
        Window::setBlendMode(parent->blendMode);
    }
}

const Viewport& GfxContext::getViewport() const {
    return viewport;
}

Batch2D* GfxContext::getBatch2D() const {
    return g2d;
}

GfxContext GfxContext::sub() const {
    auto ctx = GfxContext(this, viewport, g2d);
    ctx.depthTest = depthTest;
    ctx.cullFace = cullFace;
    return ctx;
}

void GfxContext::setViewport(const Viewport& viewport) {
    this->viewport = viewport;
    Window::viewport(
        0, 0,
        viewport.getWidth(),
        viewport.getHeight()
    );
}

void GfxContext::setFramebuffer(Framebuffer* fbo) {
    if (this->fbo == fbo)
        return;
    this->fbo = fbo;
    if (fbo) {
        fbo->bind();
    }
}

void GfxContext::setDepthMask(bool flag) {
    if (depthMask == flag)
        return;
    depthMask = flag;
    glDepthMask(GL_FALSE + flag);
}

void GfxContext::setDepthTest(bool flag) {
    if (depthTest == flag)
        return;
    depthTest = flag;
    if (flag) {
        glEnable(GL_DEPTH_TEST);
    } else {
        glDisable(GL_DEPTH_TEST);
    }
}

void GfxContext::setCullFace(bool flag) {
    if (cullFace == flag)
        return;
    cullFace = flag;
    if (flag) {
        glEnable(GL_CULL_FACE);
    } else {
        glDisable(GL_CULL_FACE);
    }
}

void GfxContext::setBlendMode(blendmode mode) {
    if (blendMode == mode)
        return;
    blendMode = mode;
    Window::setBlendMode(mode);
}

void GfxContext::setScissors(glm::vec4 area) {
    Window::pushScissor(area);
    scissorsCount++;
}