#include "Game.h"
#include "LayeredFramebuffer.h"
#include "Texture3D.h"
#include "math/Frustum.h"
#include "rendering/FileTexture.h"
#include "rendering/Framebuffer.h"
#include "rendering/Shader.h"
#include "rendering/VertexBuffer.h"
#include "rendering/Window.h"
#include "utils/Array.h"
#include "utils/List.h"
#include "utils/Random.h"
#include "utils/Utils.h"
#include "wrapper/GL.h"

static constexpr float STEP = 1.0f / 31.5f;

static Window window;

static Shader cubeShader;
static Shader noiseShader;
static Shader particleShader;
static Shader backgroundShader;
static Shader blurShader;
static Framebuffer<1> shadowBuffer;
static Framebuffer<1> blurShadowBuffer;
static LayeredFramebuffer noiceBuffer;
static FileTexture bricks;
static FileTexture bricksBump;
static FileTexture bricksNormal;
static VertexBuffer rectangleBuffer;
static VertexBuffer emptyBuffer;
static Frustum frustum{60.0f, 0.1f, 1000.0f, window.getSize()};

static Matrix projection;
static Matrix view;
static Matrix shadowView;
static Matrix shadowProjectionView;
static Matrix model;

static Button up{GLFW_KEY_SPACE, "Up"};
static Button down{GLFW_KEY_LEFT_SHIFT, "Down"};
static Button left{GLFW_KEY_A, "left"};
static Button right{GLFW_KEY_D, "right"};
static Button front{GLFW_KEY_W, "front"};
static Button back{GLFW_KEY_S, "back"};
static Button toggle{GLFW_KEY_T, "toggle"};
static Button scaleUp{GLFW_KEY_G, "scale up"};
static Button scaleDown{GLFW_KEY_H, "scale down"};
static Button stepsUp{GLFW_KEY_Y, "steps up"};
static Button stepsDown{GLFW_KEY_U, "steps down"};
static Button fineStepsUp{GLFW_KEY_I, "fine steps up"};
static Button fineStepsDown{GLFW_KEY_O, "fine steps down"};
static Button modeToggle{GLFW_KEY_C, "mode toggle"};
static Button primaryMouse{GLFW_MOUSE_BUTTON_1, "primary click"};
static Button timeUp{GLFW_KEY_N, "time up"};
static Button timeDown{GLFW_KEY_M, "time down"};
static Button tesselationUp{GLFW_KEY_4, "time up"};
static Button tesselationDown{GLFW_KEY_5, "time down"};

static Vector3 oldPosition;
static Vector3 position{-32.0f, 0.0f, -120.0f};
static float oldHeight = 0.0f;
static float height = 0.0f;
static float heightScale = 0.01f;
static int steps = 1;
static int fineSteps = 1;
static bool mode = false;
static float timeTicks = 0.0f;
static int tesselation = 1;

static Vector3 emitterPos;
static float emitterAge = 999999.0f;
static float timeFactor = 1.0f;

static void tickTimeFactors() {
    if(timeUp.isDown()) {
        timeFactor *= 1.05f;
    }
    if(timeDown.isDown()) {
        timeFactor /= 1.05f;
    }
    timeTicks++;
}

static void tickMovement() {
    oldHeight = height;
    oldPosition = position;
    if(up.isDown()) {
        height += 1.0f;
    }
    if(down.isDown()) {
        height -= 1.0f;
    }
    constexpr float speed = 3.5f;
    if(left.isDown()) {
        position += Vector3(speed, 0.0f, 0.0f);
    }
    if(right.isDown()) {
        position -= Vector3(speed, 0.0f, 0.0f);
    }
    if(front.isDown()) {
        position += Vector3(0.0f, 0.0f, speed);
    }
    if(back.isDown()) {
        position -= Vector3(0.0f, 0.0f, speed);
    }
}

static void tickParallaxSettings() {
    if(scaleUp.isDown()) {
        heightScale += 0.005f;
    }
    if(scaleDown.isDown()) {
        heightScale -= 0.005f;
        if(heightScale < 0.0f) {
            heightScale = 0.0f;
        }
    }

    if(stepsUp.wasReleased()) {
        steps++;
    }
    if(stepsDown.wasReleased() && steps > 1) {
        steps--;
    }
    if(fineStepsUp.wasReleased()) {
        fineSteps++;
    }
    if(fineStepsDown.wasReleased() && fineSteps > 1) {
        fineSteps--;
    }
    if(modeToggle.wasReleased()) {
        mode = !mode;
    }
}

static void tickTesselation() {
    if(tesselationUp.isDown()) {
        tesselation++;
    }
    if(tesselationDown.isDown() && tesselation > 1) {
        tesselation--;
    }
}

static void tickGame() {
    tickTimeFactors();
    tickMovement();
    tickParallaxSettings();
    tickTesselation();

    printf("\rFPS: %.2f", window.getFrameClock().getUpdatesPerSecond());
    fflush(stdout);
}

static void prepareMatrices(float lag) {
    projection = frustum.updateProjection();

    view.translateTo(Vector3(0.0f, 0.0f, 0.0f));
    view.translate(Utils::interpolate(oldPosition, position, lag));
    float h = -32.0f + (oldHeight - height) * lag;
    view.translateY(h);
    shadowView.translateTo(Vector3(-32.0f - 180.0f, h, -340.0f));

    shadowProjectionView.translateTo(Vector3(0.0f, 0.0f, 0.0f));
    shadowProjectionView.scale(0.5f);
    shadowProjectionView.translate(Vector3(0.5f, 0.5f, 0.5f));
    shadowProjectionView *= projection;
    shadowProjectionView *= shadowView;
}

static void renderNoise() {
    GL::setViewport(64, 64);
    noiseShader.use();
    noiceBuffer.bindAndClear();
    noiseShader.setFloat("height", oldHeight * STEP);
    for(int i = 0; i < 64; i++) {
        noiseShader.setFloat("layer", i * STEP - 1.0f);
        noiceBuffer.bindLayer(i);
        rectangleBuffer.draw(6);
    }
}

static void renderCubes(Matrix& view) {
    GL::setViewport(window.getSize().width, window.getSize().height);
    cubeShader.use();
    cubeShader.setMatrix("proj", projection.getValues());
    cubeShader.setMatrix("view", view.getValues());
    cubeShader.setMatrix("shadow", shadowProjectionView.getValues());
    cubeShader.setFloat("height", oldHeight * STEP * 0.5f);
    cubeShader.setVector("viewPos", -position + Vector3(0.0f, 32.0f, 0.0f));
    cubeShader.setVector("lightPos", Vector3());
    cubeShader.setFloat("heightScale", heightScale);
    cubeShader.setInt("steps", steps);
    cubeShader.setInt("fineSteps", fineSteps);
    cubeShader.setInt("kajetan", mode);

    noiceBuffer.bindTextureTo(0);
    bricks.bindTo(1);
    bricksBump.bindTo(2);
    bricksNormal.bindTo(3);
    blurShadowBuffer.bindTextureTo(0, 4);
    shadowBuffer.bindTextureTo(0, 5);

    for(int i = 0; i < 3; i++) {
        model.translateTo(Vector3(80.0f * i, 0.0f, 0.0f));
        cubeShader.setMatrix("model", model.getValues());
        emptyBuffer.drawPoints(64 * 64 * 64);
    }
}

static void pickParticleCenter() {
    if(!primaryMouse.wasReleased()) {
        return;
    }
    noiceBuffer.bindTextureTo(0);
    static float buffer[64][64][64];
    glGetTexImage(GL_TEXTURE_3D, 0, GL_RED, GL_FLOAT, buffer);

    float hWidth = window.getSize().width * 0.5f;
    float hHeight = window.getSize().height * 0.5f;

    float x = (window.buttons.getMouseX() - hWidth) / hWidth;
    float y = -(window.buttons.getMouseY() - hHeight) / hHeight;

    float aspect = hWidth / hHeight;
    float tan = tanf((0.5f * frustum.fieldOfView) * M_PI / 180.0f);
    float q = 1.0f / tan;

    Vector3 direction(x / (q / aspect), y / q, 1.0f);
    direction[2] = -direction[2];
    direction.normalize();

    Vector3 pos = -position;
    pos[1] = 32.0f;
    pos[1] = 32.0f;
    for(int i = 0; i < 150; i++) {
        int x = pos[0] + 0.5f;
        int y = pos[1] + 0.5f;
        int z = pos[2] + 0.5f;
        if(x >= 0 && x < 64 && y >= 0 && y < 64 && z >= 0 && z < 64 &&
           buffer[x][y][z] > 0.5f) {
            emitterPos = pos + Vector3(0.0f, height, 0.0f);
            emitterAge = timeTicks;
            break;
        }
        pos += direction;
    }
}

static void renderParticles(float lag) {
    glPointSize(5.0f);
    particleShader.use();
    particleShader.setMatrix("proj", projection.getValues());
    Matrix m;
    m.translateTo(Utils::interpolate(oldPosition, position, lag));
    m.translateY(-32.0f - (oldHeight + (height - oldHeight) * lag));
    particleShader.setMatrix("view", m.getValues());
    particleShader.setFloat("time", timeTicks + lag);

    GL::enableBlending();
    glDepthMask(false);

    pickParticleCenter();
    particleShader.setFloat("timeFactor", timeFactor);

    particleShader.setVector("position", emitterPos);
    particleShader.setFloat("age", emitterAge);
    particleShader.setVector("color", Vector4(1.0f, 0.0f, 0.0f, 1.0f));
    particleShader.setInt("seedBase", 0);
    emptyBuffer.drawPoints(200000);

    particleShader.setVector("position", emitterPos);
    particleShader.setFloat("age", emitterAge + 5);
    particleShader.setVector("color", Vector4(0.0f, 1.0f, 0.0f, 1.0f));
    particleShader.setInt("seedBase", 1);
    emptyBuffer.drawPoints(10000);

    particleShader.setVector("position", emitterPos);
    particleShader.setFloat("age", emitterAge + 10);
    particleShader.setVector("color", Vector4(0.0f, 0.0f, 1.0f, 1.0f));
    particleShader.setInt("seedBase", 2);
    emptyBuffer.drawPoints(5000);

    particleShader.setVector("position", emitterPos);
    particleShader.setFloat("age", emitterAge + 20);
    particleShader.setVector("color", Vector4(0.0f, 1.0f, 1.0f, 1.0f));
    particleShader.setInt("seedBase", 2);
    emptyBuffer.drawPoints(5000);

    glDepthMask(true);
    GL::disableBlending();
}

static void renderBackground(Matrix& view) {
    backgroundShader.use();
    blurShadowBuffer.bindTextureTo(0, 0);
    backgroundShader.setMatrix("proj", frustum.updateProjection().getValues());
    backgroundShader.setMatrix("view", view.getValues());
    model.translateTo(Vector3(0.0f, 0.0f, 0.0f));
    model.scale(Vector3(520.0f, 180.0f, 1.0f));
    model.translate(Vector3(-260.0f, -40.0f, -200.0f));
    model.rotateX(-5.0f);
    backgroundShader.setMatrix("model", model.getValues());
    backgroundShader.setMatrix("shadow", shadowProjectionView.getValues());
    backgroundShader.setInt("splits", tesselation);

    glPatchParameteri(GL_PATCH_VERTICES, 1);
    glDrawArrays(GL_PATCHES, 0, 1);
}

static void renderGame(float lag) {
    if(toggle.isDown()) {
        glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
    } else {
        glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
    }

    GL::enableDepthTesting();
    prepareMatrices(lag);
    renderNoise();

    shadowBuffer.bindAndClear();
    renderCubes(shadowView);
    renderBackground(shadowView);

    blurShader.use();
    shadowBuffer.bindTextureTo(0, 0);
    blurShadowBuffer.bindAndClear();
    rectangleBuffer.draw(6);

    GL::bindMainFramebuffer();
    GL::clear();

    renderCubes(view);
    renderBackground(view);
    renderParticles(lag);
}

void Game::init() {
    WindowOptions options(4, 0, {1024, 620}, false, "test");
    Error error = window.open(options);
    if(error.has()) {
        error.message.printLine();
        return;
    }
    error = cubeShader.compile("resources/cubes.vs", "resources/cubes.gs",
                               "resources/cubes.fs");
    if(error.has()) {
        error.message.printLine();
        return;
    }
    error = noiseShader.compile("resources/noise.vs", "resources/noise.fs");
    if(error.has()) {
        error.message.printLine();
        return;
    }
    error = particleShader.compile("resources/particles.vs",
                                   "resources/particles.gs",
                                   "resources/particles.fs");
    if(error.has()) {
        error.message.printLine();
        return;
    }
    error = backgroundShader.compile(
        "resources/background.vs", "resources/background.fs",
        "resources/background.tcs", "resources/background.tes");
    if(error.has()) {
        error.message.printLine();
        return;
    }
    error = blurShader.compile("resources/blur.vs", "resources/blur.fs");
    if(error.has()) {
        error.message.printLine();
        return;
    }
    error = shadowBuffer.init(window.getSize(), TextureFormat::depth32(true));
    if(error.has()) {
        error.message.printLine();
        return;
    }
    error = blurShadowBuffer.init(window.getSize(),
                                  TextureFormat::float32(2, true));
    if(error.has()) {
        error.message.printLine();
        return;
    }
    error = bricks.load("resources/bricks.png", 0);
    if(error.has()) {
        error.message.printLine();
        return;
    }
    error = bricksBump.load("resources/bricks_bump.png", 0);
    if(error.has()) {
        error.message.printLine();
        return;
    }
    error = bricksNormal.load("resources/bricks_normal.png", 0);
    if(error.has()) {
        error.message.printLine();
        return;
    }
    noiceBuffer.init(64, 64, 64);
    window.buttons.add(up);
    window.buttons.add(down);
    window.buttons.add(left);
    window.buttons.add(right);
    window.buttons.add(front);
    window.buttons.add(back);
    window.buttons.add(toggle);
    window.buttons.add(scaleUp);
    window.buttons.add(scaleDown);
    window.buttons.add(stepsUp);
    window.buttons.add(stepsDown);
    window.buttons.add(fineStepsUp);
    window.buttons.add(fineStepsDown);
    window.buttons.add(modeToggle);
    window.buttons.add(timeUp);
    window.buttons.add(timeDown);
    window.buttons.add(tesselationUp);
    window.buttons.add(tesselationDown);
    window.buttons.addMouse(primaryMouse);

    bricks.setLinearFilter();
    bricksBump.setLinearFilter();
    bricksNormal.setLinearFilter();

    rectangleBuffer.init(Attributes().addFloat(2));
    float recData[6][2] = {{-1.0f, -1.0f}, {-1.0, 1.0}, {1.0, -1.0},
                           {1.0f, 1.0f},   {-1.0, 1.0}, {1.0, -1.0}};
    rectangleBuffer.setStaticData(sizeof(recData), recData);

    emptyBuffer.init(Attributes());

    struct Intern {
        void tick() {
            tickGame();
        }

        void render(float lag) {
            renderGame(lag);
        }

        bool isRunning() const {
            return true;
        }
    };
    Intern intern;
    window.run(intern, 50'000'000);
}