#include "AudioDevice.hpp"
#include "Color.hpp"
#include "Keyboard.hpp"
#include "Matrix.hpp"
#include "Mesh.hpp"
#include "Model.hpp"
#include "RadiansDegrees.hpp"
#include "raylib.h"
#include <concepts>
#include <functional>
#include <memory>
#include <optional>
#include <raylib-cpp.hpp>
#include <cmath>
#include <algorithm>
#include <iostream>
#include <vector>

#define SKYBOX_IMPLEMENTATION
#include "skybox.hpp"

void DrawBoundedModel(raylib::Model &model, auto transformer) {
    // store the original transform to apply a different transform to the
    // model without affecting the next time we draw
    raylib::Matrix oldTransform = model.GetTransform();

    // apply the transform that we get from whatever the transformer callback
    // gives us
    raylib::Matrix transform = transformer(model.GetTransform());

    // apply the transform that we got from the transformer to the model
    model.SetTransform(transform);

    // draw the model, passing the origin and default scale as arguments since
    // the transform is already applied to the model
    model.Draw({ 0, 0, 0 }, 1.0f, raylib::Color::White());

    // get the bounding box of the model after applying the transform
    auto box = model.GetTransformedBoundingBox();

    // draw the bounding box of the model using raylib's built in function
    DrawBoundingBox(box, raylib::Color::White());

    // restore the model's transform to its original state so that the next time we
    // draw the model, it doesn't have the previous transform applied to it
    model.SetTransform(oldTransform);
}

class Component {
public:
    struct Entity *e;
    virtual void Setup() = 0;
    virtual void Update(float dt) = 0;
    virtual void Cleanup() = 0;
};

struct Entity {
    std::vector<std::shared_ptr<Component>> components;

    template<std::derived_from<Component> T>
    T &AddComponent() {
        auto out = components.emplace_back(std::make_shared<T>());
        out->e = this;
        return out;
    }

    template<std::derived_from<Component> T>
    std::optional<std::reference_wrapper<T>> GetComponent() {
        for (auto &c : components) {
            T *cast = dynamic_cast<T *>(c.get());
            if (cast) {
                return *cast;
            }
        }

        return { };
    }
};

struct TransformComponent : public Component {
    raylib::Transform t;

    void Setup() override { }

    void Update(float dt) override { }

    void Cleanup() override { }
};

struct DrawModelComponent : public Component {
    raylib::Model *model;

    void Setup() override { }

    void Update(float dt) override {
        //DrawBoundedModel(model, []());
    }

    void Cleanup() override { }
};

raylib::Degree angle_normalize(raylib::Degree angle) {
    float decimal = float(angle) - int(angle);
    int normalized = (int(angle) % 360 + 360) % 360;
    return raylib::Degree(normalized + decimal);
}

int main() {
    raylib::Window window(800, 600, "CS381 - Assignment 3");
    window.SetState(FLAG_WINDOW_RESIZABLE);
    raylib::AudioDevice audio;

    raylib::Model penguin("models/penguin.glb");

    // behind and above the penguin (in penguin-local space)
    const float CAM_DIST = 512.0f;
    const float CAM_HEIGHT = 256.0f;
    const float CAM_ANGULAR_VELOCITY = 2.0f;
    const float CAM_PITCH_MIN = -0.5f;
    const float CAM_PITCH_MAX = 1.5f;

    float camYaw = 3.14f; // offset by 90 deg so it faces in the proper direction
    float camPitch = 0;

    raylib::Camera3D camera(
        { 0, CAM_DIST * std::sin(camPitch), CAM_DIST * std::cos(camPitch) },
        { 0, 0, 0 },
        { 0, 1, 0 },
        45.0f);

    raylib::Model ground = raylib::Mesh::Plane(10000, 10000, 50, 50, 25);

    raylib::Texture snowTexture("textures/snow.jpg");
    ground.GetMaterials()[0].maps[MATERIAL_MAP_DIFFUSE].texture = snowTexture;

    cs381::SkyBox skybox("textures/skybox.png");

    std::vector<Entity> entities;

    Entity &e = entities.emplace_back();
    e.AddComponent<TransformComponent>();
    e.AddComponent<DrawModelComponent>();

    // penguin physics
    raylib::Vector3 position = { 0, 0, 0 };
    raylib::Vector3 velocity = { 0, 0, 0 };
    float heading = 0.0f;
    float speed = 0.0f;

    // units/s
    const float ACCELERATION = 100.0f;

    // in radians
    const float ANGULAR_VELOCITY = 3.14f;

    window.SetTargetFPS(60); // save cpu cycles

    while (!window.ShouldClose()) {
        window.BeginDrawing();
        window.ClearBackground(raylib::Color::Gray());

        float dt = window.GetFrameTime();

        position += velocity * dt * 0.5f;

        // movement for penguin
        if (IsKeyDown(KEY_W)) {
            speed += ACCELERATION * dt;
        }

        if (IsKeyDown(KEY_S)) {
            speed -= ACCELERATION * dt;
        }

        if (IsKeyDown(KEY_A)) {
            heading += ANGULAR_VELOCITY * dt;
        }

        if (IsKeyDown(KEY_D)) {
            heading -= ANGULAR_VELOCITY * dt;
        }

        if (IsKeyDown(KEY_SPACE)) {
            speed = 0.0f;
        }

        velocity = raylib::Vector3 {
            std::sin(heading) * speed,
            0.0f,
            std::cos(heading) * speed
        };

        // ds = 1/2 * (v0 + v1) * dt
        position += velocity * dt * 0.5f;

        // movement for camera
        if (IsKeyDown(KEY_LEFT)) {
            camYaw += CAM_ANGULAR_VELOCITY * dt;
        }
        if (IsKeyDown(KEY_RIGHT)) {
            camYaw -= CAM_ANGULAR_VELOCITY * dt;
        }
        if (IsKeyDown(KEY_UP)) {
            camPitch += CAM_ANGULAR_VELOCITY * dt;
        }
        if (IsKeyDown(KEY_DOWN)) {
            camPitch -= CAM_ANGULAR_VELOCITY * dt;
        }

        // clamp the angle between
        camPitch = std::clamp(camPitch, CAM_PITCH_MIN, CAM_PITCH_MAX);

        // x = cos(pitch) * sin(yaw)
        // y = sin(pitch)
        // z = cos(pitch) * cos(yaw)
        float yaw = camYaw + heading; // follow penguin
        raylib::Vector3 camOffset = {
            CAM_DIST * std::cos(camPitch) * std::sin(yaw),
            CAM_DIST * std::sin(camPitch) + CAM_HEIGHT,
            CAM_DIST * std::cos(camPitch) * std::cos(yaw)
        };
        camera.SetPosition(position + camOffset);
        camera.SetTarget(position);

        camera.BeginMode();
        skybox.Draw();

        ground.Draw({ 0, 0, 0 }, 1.0f, raylib::Color::White());

        DrawBoundedModel(penguin, [&position, &heading](raylib::Matrix transform) {
            return transform
                .RotateY(heading)
                .Scale(40, 40, 40)
                .Translate(position);
        });

        camera.EndMode();
        window.EndDrawing();
    }

    return 0;
}