#include "client/rendering/Engine.h"
#include "client/rendering/ShaderMatrix.h"
#include "gaming-core/wrapper/GL.h"

Engine::Engine(Shaders& shaders, Framebuffers& fb, const Size& size,
               RenderSettings& renderSettings)
    : shaders(shaders), framebuffers(fb), size(size),
      renderSettings(renderSettings), frustum(60.0f, 0.1f, 1000.0f, size) {
    TypedBuffer<Triangle> buffer(2);
    buffer.add(
        Triangle(Vertex(Vector3(-1.0f, -1.0f, 0.0f), Vector2(0, 0.0f)),
                 Vertex(Vector3(1.0f, 1.0f, 0.0f), Vector2(1.0f, 1.0f)),
                 Vertex(Vector3(-1.0f, 1.0f, 0.0f), Vector2(0.0f, 1.0f))));
    buffer.add(
        Triangle(Vertex(Vector3(-1.0f, -1.0f, 0.0f), Vector2(0, 0.0f)),
                 Vertex(Vector3(1.0f, -1.0f, 0.0f), Vector2(1.0f, 0.0f)),
                 Vertex(Vector3(1.0f, 1.0f, 0.0f), Vector2(1.0f, 1.0f))));
    rectangle.build(buffer);
}

void Engine::renderTick(float lag, Game& game) {
    updateWorldProjection();
    updateWorldView();

    if(renderSettings.shadows) {
        renderShadow(lag, game);
    }
    renderWorld(lag, game);
    if(renderSettings.ssao) {
        renderSSAO();
    }
    renderPostWorld();
    renderOverlay(lag, game);
}

void Engine::renderShadow(float lag, Game& game) {
    framebuffers.shadow.bindAndClear();
    GL::enableDepthTesting();
    shaders.shadow.use();
    worldShadowProjView = worldShadowProj;
    worldShadowProjView *= worldShadowView;
    shaders.shadow.setMatrix("projView", worldShadowProjView.getValues());
    model.clear();
    shaders.shadow.setMatrix("model", model.peek().getValues());
    ShaderMatrix sm(shaders.shadow, model, worldView);
    game.renderWorld(lag, sm);
}

void Engine::renderWorld(float lag, Game& game) {
    framebuffers.world.bindAndClear();
    GL::enableDepthTesting();
    shaders.world.use();

    Matrix rWorldShadowProjView;
    rWorldShadowProjView.scale(0.5f).translate(Vector3(0.5f, 0.5f, 0.5f));
    rWorldShadowProjView *= worldShadowProjView;

    shaders.world.setMatrix("projViewShadow", rWorldShadowProjView.getValues());
    shaders.world.setMatrix("proj", worldProj.getValues());
    worldView = Matrix();
    shaders.world.setMatrix("view", worldView.getValues());
    model.clear();
    shaders.world.setMatrix("model", model.peek().getValues());
    framebuffers.shadow.bindTextureTo(0, 1);
    shaders.world.setInt("shadows", renderSettings.shadows);
    shaders.world.setFloat("radius", renderSettings.testRadius);
    shaders.world.setFloat("zbias", renderSettings.testBias);
    ShaderMatrix sm(shaders.world, model, worldView);
    game.renderWorld(lag, sm);
}

void Engine::renderSSAO() {
    shaders.ssao.use();

    Matrix rProj;
    rProj.scale(0.5f).translate(Vector3(0.5f, 0.5f, 0.5f));
    rProj *= worldProj;

    shaders.ssao.setMatrix("proj", rProj.getValues());
    shaders.ssao.setInt("width", size.width);
    shaders.ssao.setInt("height", size.height);
    framebuffers.world.bindTextureTo(0, 0);
    framebuffers.world.bindTextureTo(4, 1);
    ssaoNoise.bindTo(2);
    framebuffers.ssao.bindAndClear();
    rectangle.draw();

    shaders.ssaoBlur.use();
    framebuffers.ssao.bindTextureTo(0, 0);
    framebuffers.ssaoBlur.bindAndClear();
    rectangle.draw();
}

void Engine::renderPostWorld() {
    GL::bindMainFramebuffer();
    GL::clear();
    shaders.postWorld.use();
    framebuffers.world.bindTextureTo(2, 0);
    framebuffers.ssaoBlur.bindTextureTo(0, 1);
    framebuffers.world.bindTextureTo(3, 2);
    framebuffers.world.bindTextureTo(1, 3);
    shaders.postWorld.setInt("ssao", renderSettings.ssao);
    shaders.postWorld.setInt("shadows", renderSettings.shadows);
    rectangle.draw();
}

void Engine::renderOverlay(float lag, Game& game) {
    GL::disableDepthTesting();
    shaders.overlay.use();

    Matrix m;
    m.scale(Vector3(2.0f / size.width, -2.0f / size.height, 1.0f))
        .translate(Vector3(-1.0f, 1.0f, 0.0f));
    shaders.overlay.setMatrix("view", m.getValues());
    model.clear();
    shaders.overlay.setMatrix("model", model.peek().getValues());

    GL::enableBlending();
    ShaderMatrix sm(shaders.overlay, model, m);
    game.renderOverlay(lag, sm, renderer);
    GL::disableBlending();
}

void Engine::updateWorldProjection() {
    worldProj = frustum.updateProjection();

    if(!renderSettings.shadows) {
        return;
    }

    worldShadowProj.set(0, Vector4(2.0f / 40.0f, 0.0f, 0.0f, 0.0f));
    worldShadowProj.set(1, Vector4(0.0f, 2.0f / 30.0f, 0.0f, 0.0f));
    worldShadowProj.set(2, Vector4(0.0f, 0.0f, -2.0f / (1000.0f - 0.1f), 0.0f));
    worldShadowProj.set(3, Vector4(0.0f, 0.0f, 0.0f, 1.0f));
}

void Engine::updateWorldView() {
    if(!renderSettings.shadows) {
        return;
    }

    Vector3 right(0.939693f, 0.0f, -0.34202f);
    Vector3 back(0.280166f, 0.573576f, 0.769751f);
    Vector3 up(-0.196175f, 0.819152f, -0.538986f);
    Vector3 center(16.0f, 24.0f, 24.0f);

    worldShadowView.set(
        0, Vector4(right[0], right[1], right[2], right.dot(-center)));
    worldShadowView.set(1, Vector4(up[0], up[1], up[2], up.dot(-center)));
    worldShadowView.set(2,
                        Vector4(back[0], back[1], back[2], back.dot(-center)));
    worldShadowView.set(3, Vector4(0.0f, 0.0f, 0.0f, 1.0f));
}