/**
 * paradiso - Paradigmen der Softwareentwicklung
 *
 * (c) Copyright 2023-2025 Hartmut Seichter and Contributors
 *
 */

#include <paradiso/bitmap.hpp>
#include <paradiso/bitmap_io.hpp>
#include <paradiso/context.hpp>
#include <paradiso/geometry.hpp>
#include <paradiso/renderer.hpp>
#include <paradiso/shader.hpp>
#include <paradiso/sprite.hpp>
#include <paradiso/utils.hpp>
#include <paradiso/vector.hpp>
#include <paradiso/window.hpp>

#include <chrono>
#include <thread>

#include <iostream>

static const unsigned int FRAME_RATE = 60;

static const unsigned int WINDOW_WIDTH = 800;
static const unsigned int WINDOW_HEIGHT = 480;
static const unsigned int WINDOW_SCALE = 2;

static const char ACTION_KEY = ' ';

static constexpr float SCROLLING_SPEED_INC_FACTOR = 1.0002f;

// x,y+h --- x+w,y+h
//   |          |
//   |          |
//   |          |
//  x,y ----- x+w,y
struct AABB {
    paradiso::Vector2<float> position{};
    paradiso::Vector2<float> size{};

    bool is_colliding_with(const AABB& other) {
        return position.x() < other.position.x() + other.size.x() &&
               position.x() + size.x() > other.position.x() &&
               position.y() < other.position.y() + other.size.y() &&
               position.y() + size.y() > other.position.y();
    }
};

struct Background {
    static constexpr float INIT_SCROLLING_SPEED = 0.003f;

    float scrolling_speed = INIT_SCROLLING_SPEED;

    std::array<paradiso::Sprite, 2> sprites;
    paradiso::Renderer renderer{};

    paradiso::Bitmap image =
        paradiso::BitmapIO::get().load("PNG/background.png");

    void init() {
        // For resetting.
        scrolling_speed = INIT_SCROLLING_SPEED;

        sprites = {paradiso::Sprite{
                       .bitmap = image,
                       .pivot = {paradiso::Vector2<float>::make(0.0f, 0.0f)},
                       .scale = {paradiso::Vector2<float>::make(1.0f, 1.0f)}},
                   paradiso::Sprite{
                       .bitmap = image,
                       .pivot = {paradiso::Vector2<float>::make(2.0f, 0.0f)},
                       .scale = {paradiso::Vector2<float>::make(1.0f, 1.0f)}}};
    }

    void update() {
        for (auto& sprite : sprites) {
            sprite.pivot.x() -= scrolling_speed;
            if (sprite.pivot.x() <= -2.0f) {
                sprite.pivot.x() += 4.0f;
            }
        }
    }

    void draw(const paradiso::Shader& shader) {
        for (const auto& sprite : sprites) {
            shader.set_uniform("pivot", sprite.pivot);
            shader.set_uniform("scale", sprite.scale);
            shader.set_uniform("rotation", sprite.rotation);
            renderer.draw(sprite, shader);
        }
    }
};

struct Ground {
    static constexpr float INIT_SCROLLING_SPEED = 0.009f;

    float scrolling_speed = INIT_SCROLLING_SPEED;

    std::array<paradiso::Sprite, 2> sprites;
    paradiso::Renderer renderer{};

    // Maybe put this into 'init()' because we might use the other textures
    // like snow, ice, ... and then we can parameterize this.
    paradiso::Bitmap image =
        paradiso::BitmapIO::get().load("PNG/groundGrass.png");

    AABB aabb{};

    void init() {
        // For resetting.
        scrolling_speed = INIT_SCROLLING_SPEED;

        // The image's height is 71 px.
        float scale_y = 71.0f / WINDOW_HEIGHT;

        float pivot_y = -1.0f + scale_y;

        sprites = {
            paradiso::Sprite{
                .bitmap = image,
                .pivot = {paradiso::Vector2<float>::make(0.0f, pivot_y)},
                .scale = {paradiso::Vector2<float>::make(1.0f, scale_y)}},
            paradiso::Sprite{
                .bitmap = image,
                .pivot = {paradiso::Vector2<float>::make(2.0f, pivot_y)},
                .scale = {paradiso::Vector2<float>::make(1.0f, scale_y)}}};

        // We'll make the height half the height of the texture.
        // (If you want 1:1 size, you need to double the scale of the sprite.)
        aabb = AABB{.position = {paradiso::Vector2<float>::make(-1.0f, -1.0f)},
                    .size = {paradiso::Vector2<float>::make(2.0f, scale_y)}};
    }

    void update() {
        for (auto& sprite : sprites) {
            sprite.pivot.x() -= scrolling_speed;
            if (sprite.pivot.x() <= -2.0f) {
                sprite.pivot.x() += 4.0f;
            }
        }
    }

    void draw(const paradiso::Shader& shader) {
        for (const auto& sprite : sprites) {
            shader.set_uniform("pivot", sprite.pivot);
            shader.set_uniform("scale", sprite.scale);
            shader.set_uniform("rotation", sprite.rotation);
            renderer.draw(sprite, shader);
        }
    }
};

struct Rocks {
    static constexpr float INIT_SCROLLING_SPEED = 0.006f;
    static constexpr float GAP_SIZE = 1.6f;

    float scrolling_speed = INIT_SCROLLING_SPEED;

    paradiso::Sprite top_sprite;
    paradiso::Sprite bottom_sprite;

    paradiso::Renderer top_renderer{};
    paradiso::Renderer bottom_renderer{};

    // Maybe put this into 'init()' because we might use the other textures
    // like snow, ice, ... and then we can parameterize this.
    paradiso::Bitmap top_image =
        paradiso::BitmapIO::get().load("PNG/rockGrassDown.png");
    paradiso::Bitmap bottom_image =
        paradiso::BitmapIO::get().load("PNG/rockGrass.png");

    AABB top_aabb;
    AABB bottom_aabb;

    void init(float x, bool reset_scrolling_speed = false) {
        if (reset_scrolling_speed) {
            scrolling_speed = INIT_SCROLLING_SPEED;
        }

        // The image's size is 108x239 px.
        float scale_x = 108.0f / WINDOW_WIDTH;
        float scale_y = 239.0f / WINDOW_HEIGHT;
        auto scale = paradiso::Vector2<float>{
            paradiso::Vector2<float>::make(scale_x, scale_y)};

        float top_position_y =
            1.0f - scale_y + (std::rand() % 60) / 100.0f + 0.04f;
        float bottom_position_y = top_position_y - GAP_SIZE;

        top_sprite = paradiso::Sprite{
            .bitmap = top_image,
            .pivot = {paradiso::Vector2<float>::make(x, top_position_y)},
            .scale = scale};

        bottom_sprite = paradiso::Sprite{
            .bitmap = bottom_image,
            .pivot = {paradiso::Vector2<float>::make(x, bottom_position_y)},
            .scale = scale};

        // We'll make the width a quarter the width of the texture.
        // (If you want 1:1 size, you need to double the scale of the sprite.)
        auto size = paradiso::Vector2<float>{
            paradiso::Vector2<float>::make(scale_x / 2, scale_y * 2)};

        auto top_position =
            paradiso::Vector2<float>{paradiso::Vector2<float>::make(
                top_sprite.pivot.x() - size.x() / 2,
                top_sprite.pivot.y() - size.y() / 2)};

        auto bottom_position =
            paradiso::Vector2<float>{paradiso::Vector2<float>::make(
                bottom_sprite.pivot.x() - size.x() / 2,
                bottom_sprite.pivot.y() - size.y() / 2)};

        top_aabb = AABB{top_position, size};
        bottom_aabb = AABB{bottom_position, size};
    }

    void update() {
        top_sprite.pivot.x() -= scrolling_speed;
        bottom_sprite.pivot.x() -= scrolling_speed;

        // +----------+
        // |          |
        // |          |
        // |  #  #-------- the x it is.
        // |   \      |
        // |    \     |
        // +-----\----+
        //        \
        //         *------ the x we need.

        // @Efficiency: We could just scroll it with the sprite.
        top_aabb.position.x() = top_sprite.pivot.x() - top_aabb.size.x() / 2;
        bottom_aabb.position.x() =
            bottom_sprite.pivot.x() - bottom_aabb.size.x() / 2;

        if (top_sprite.pivot.x() <= -1.2f) {
            // Reset.
            init(1.2f);
            return;
        }
    }

    void draw(const paradiso::Shader& shader) {
        shader.set_uniform("pivot", top_sprite.pivot);
        shader.set_uniform("scale", top_sprite.scale);
        shader.set_uniform("rotation", top_sprite.rotation);
        top_renderer.draw(top_sprite, shader);

        shader.set_uniform("pivot", bottom_sprite.pivot);
        shader.set_uniform("scale", bottom_sprite.scale);
        shader.set_uniform("rotation", bottom_sprite.rotation);
        bottom_renderer.draw(bottom_sprite, shader);
    }
};

struct Plane {
    static constexpr float GRAVITY = -0.001f;
    static constexpr float JUMP_VELOCITY = 0.03f;
    static constexpr float MAX_VELOCITY = 0.03f;

    static constexpr float INIT_POSITION_Y = 0.0f;
    static constexpr float INIT_VELOCITY_Y = 0.0f;
    static constexpr float INIT_ROTATION = 0.0f;

    static const unsigned int ANIM_INTERVAL = 10;

    // Animation sprites
    std::array<paradiso::Sprite, 3> sprites;
    std::array<paradiso::Renderer, 3> renderers;

    unsigned int anim_counter = 0;

    // The direction where 'current_sprite' should go because the animation
    // shouldn't loop.
    int anim_direction = 1;

    unsigned int current_sprite = 0;

    float position_y = INIT_POSITION_Y;
    float velocity_y = INIT_VELOCITY_Y;
    float rotation = INIT_ROTATION;

    AABB aabb;

    void init() {
        // The image's size is 88x73 px.
        float scale_x = 88.0f / WINDOW_WIDTH;
        float scale_y = 73.0f / WINDOW_HEIGHT;

        auto pivot = paradiso::Vector2<float>{
            paradiso::Vector2<float>::make(0.0f, position_y)};
        auto scale = paradiso::Vector2<float>{
            paradiso::Vector2<float>::make(scale_x, scale_y)};

        sprites = {
            paradiso::Sprite{.bitmap = paradiso::BitmapIO::get().load(
                                 "PNG/Planes/planeRed1.png"),
                             .pivot = pivot,
                             .scale = scale},
            paradiso::Sprite{.bitmap = paradiso::BitmapIO::get().load(
                                 "PNG/Planes/planeRed2.png"),
                             .pivot = pivot,
                             .scale = scale},
            paradiso::Sprite{.bitmap = paradiso::BitmapIO::get().load(
                                 "PNG/Planes/planeRed3.png"),
                             .pivot = pivot,
                             .scale = scale},
        };

        // For resetting.
        position_y = INIT_POSITION_Y;
        velocity_y = INIT_VELOCITY_Y;
        rotation = INIT_ROTATION;

        // We'll make the size half the size of the texture.
        // (If you want 1:1 size, you need to double the scale of the sprite.)
        auto size = paradiso::Vector2<float>{
            paradiso::Vector2<float>::make(scale_x, scale_y)};

        // Center it.
        auto position = paradiso::Vector2<float>{paradiso::Vector2<float>::make(
            pivot.x() - size.x() / 2, pivot.y() - size.y() / 2)};

        aabb = AABB{position, size};
    }

    void update(const paradiso::Window::KeyboardInputStack& input) {
        if (anim_counter < ANIM_INTERVAL) {
            anim_counter++;
        } else {
            anim_counter = 0;

            current_sprite += anim_direction;
            if (current_sprite >= sprites.size() - 1) {
                anim_direction = -1;
            } else if (current_sprite == 0) {
                anim_direction = 1;
            }
        }

        if (input.size() && input.top().key == ACTION_KEY &&
            input.top().action == 1) {
            velocity_y += JUMP_VELOCITY;
        } else {
            velocity_y += GRAVITY;
        }

        velocity_y = std::clamp(velocity_y, -MAX_VELOCITY, MAX_VELOCITY);
        position_y += velocity_y;

        // +-------------+
        // |             |
        // |             |
        // |             |
        // |      #--------- the y it is.
        // |             |
        // |      #      |
        // |       \     |
        // +--------\----+
        //           \   
        //            *--- the y we need.

        // @Efficiency: We could just add the velocity.
        aabb.position.y() = position_y - aabb.size.y() / 2;

        rotation = velocity_y * 500.0f;
    }

    void draw(const paradiso::Shader& shader) {
        auto sprite = sprites[current_sprite];
        sprite.rotation = rotation * (std::numbers::pi / 180.0f);
        sprite.pivot.y() = position_y;

        shader.set_uniform("pivot", sprite.pivot);
        shader.set_uniform("scale", sprite.scale);
        shader.set_uniform("rotation", sprite.rotation);
        renderers[current_sprite].draw(sprite, shader);
    }
};

struct StartText {
    static const unsigned int TAP_ANIM_INTERVAL = 40;

    // textGetReady.png, tapLeft.png, tapRight.png
    std::array<paradiso::Sprite, 3> base_sprites;
    std::array<paradiso::Renderer, 3> base_renderers;

    // tap.png, tapTick.png
    std::array<paradiso::Sprite, 2> tap_sprites;
    std::array<paradiso::Renderer, 2> tap_renderers;

    unsigned int tap_anim_counter = 0;
    unsigned int current_tap_sprite = 0;

    void init() {
        base_sprites = {
            // textGetReady.png
            paradiso::Sprite{
                .bitmap =
                    paradiso::BitmapIO::get().load("PNG/UI/textGetReady.png"),
                .pivot = {paradiso::Vector2<float>::make(0.0f, 0.5f)},
                // The image's size is 400x73 px.
                .scale = {paradiso::Vector2<float>::make(
                    400.0f / WINDOW_WIDTH, 73.0f / WINDOW_HEIGHT)}},
            // tapLeft.png
            paradiso::Sprite{
                .bitmap = paradiso::BitmapIO::get().load("PNG/UI/tapLeft.png"),
                .pivot = {paradiso::Vector2<float>::make(0.5f, 0.0f)},
                // The image's size is 85x42 px.
                .scale = {paradiso::Vector2<float>::make(
                    85.0f / WINDOW_WIDTH, 42.0f / WINDOW_HEIGHT)}},
            // tapRight.png
            paradiso::Sprite{
                .bitmap = paradiso::BitmapIO::get().load("PNG/UI/tapRight.png"),
                .pivot = {paradiso::Vector2<float>::make(-0.5f, 0.0f)},
                // The image's size is 85x42 px.
                .scale = {paradiso::Vector2<float>::make(
                    85.0f / WINDOW_WIDTH, 42.0f / WINDOW_HEIGHT)}},
        };

        tap_sprites = {
            // tap.png
            paradiso::Sprite{
                .bitmap = paradiso::BitmapIO::get().load("PNG/UI/tap.png"),
                .pivot = {paradiso::Vector2<float>::make(0.0f, -0.5f)},
                // The image's size is 59x59 px.
                .scale = {paradiso::Vector2<float>::make(
                    59.0f / WINDOW_WIDTH, 59.0f / WINDOW_HEIGHT)}},
            // tapTick.png
            paradiso::Sprite{
                .bitmap = paradiso::BitmapIO::get().load("PNG/UI/tapTick.png"),
                .pivot = {paradiso::Vector2<float>::make(0.0f, -0.5f)},
                // The image's size is 59x59 px.
                .scale = {paradiso::Vector2<float>::make(
                    59.0f / WINDOW_WIDTH, 59.0f / WINDOW_HEIGHT)}},
        };
    }

    void update() {
        if (tap_anim_counter < TAP_ANIM_INTERVAL) {
            tap_anim_counter++;
        } else {
            tap_anim_counter = 0;
            current_tap_sprite = (current_tap_sprite + 1) % tap_sprites.size();
        }
    }

    void draw(const paradiso::Shader& shader) {
        for (unsigned int i = 0; i < base_sprites.size(); i++) {
            auto sprite = base_sprites[i];
            auto& renderer = base_renderers[i];

            shader.set_uniform("pivot", sprite.pivot);
            shader.set_uniform("scale", sprite.scale);
            shader.set_uniform("rotation", sprite.rotation);
            renderer.draw(sprite, shader);
        }

        auto tap_sprite = tap_sprites[current_tap_sprite];
        auto& tap_renderer = tap_renderers[current_tap_sprite];

        shader.set_uniform("pivot", tap_sprite.pivot);
        shader.set_uniform("scale", tap_sprite.scale);
        shader.set_uniform("rotation", tap_sprite.rotation);
        tap_renderer.draw(tap_sprite, shader);
    }
};

struct GameOverText {
    paradiso::Sprite sprite;
    paradiso::Renderer renderer{};

    paradiso::Bitmap image =
        paradiso::BitmapIO::get().load("PNG/UI/textGameOver.png");

    void init() {
        // The image's size is 412x78 px.
        float scale_x = 412.0f / WINDOW_WIDTH;
        float scale_y = 78.0f / WINDOW_HEIGHT;

        sprite = {.bitmap = image,
                  .pivot = {paradiso::Vector2<float>::make(0.0f, 0.0f)},
                  .scale = {paradiso::Vector2<float>::make(scale_x, scale_y)}};
    }

    void update() {
        // @ToDo: Make the sprite slide down.
    }

    void draw(const paradiso::Shader& shader) {
        shader.set_uniform("pivot", sprite.pivot);
        shader.set_uniform("scale", sprite.scale);
        shader.set_uniform("rotation", sprite.rotation);
        renderer.draw(sprite, shader);
    }
};

enum class GameState { Start, Playing, GameOver };

auto main() -> int {
    std::srand(std::time(nullptr));

    auto canvas_size = paradiso::Size{.width = WINDOW_WIDTH * WINDOW_SCALE,
                                      .height = WINDOW_HEIGHT * WINDOW_SCALE};

    // Unser Fenster, auf das wir rendern.
    auto window = paradiso::Window();
    window
        .set_size(canvas_size)                             // ... Größe
        .set_position(paradiso::Point{.x = 200, .y = 200}) // ... Position
        .set_title("ParadiSO.TappyPlane")                  // ... Titel
        .set_visible(true); // ... und jetzt anzeigen!

    // Der Fenster Context.
    auto context = paradiso::Context{};

    // Ein Shader (Schattierungsprogramm).
    auto shader = paradiso::Shader{};

    // Wir nutzen einen vorgefertigten Shader, der speziell für Sprites ist.
    shader.load_preset(paradiso::Shader::Preset::Sprite);

    // Ein Viewport stellt die Sicht der Kamera dar, d.h. bei quadratischen
    // Pixeln sollte hier auch eine dementsprechende Größe eingestellt
    // werden.
    context.set_viewport(paradiso::Rectangle{
        .position = paradiso::Point{.x = 0, .y = 0}, .size = canvas_size});

    // Conflower blue
    context.set_clearcolor(paradiso::RGBA::from_rgb(0x64, 0x95, 0xED));

    // Der Asset Loader bekommt den Pfad.
    paradiso::BitmapIO::get().set_path("assets");

    // Wir initialisieren unsere Sachen.
    auto game_state = GameState::Start;

    auto background = Background{};
    auto ground = Ground{};
    auto rocks1 = Rocks{};
    auto rocks2 = Rocks{};
    auto plane = Plane{};
    auto start_text = StartText{};
    auto game_over_text = GameOverText{};

    background.init();
    ground.init();
    rocks1.init(1.2f, true); // We don't need to set this to true,
    rocks2.init(2.4f, true); // but why not?
    plane.init();
    start_text.init();
    game_over_text.init();

    auto top_aabb =
        AABB{.position = {paradiso::Vector2<float>::make(-1.0f, 1.0f)},
             .size = {paradiso::Vector2<float>::make(2.0f, 0.5f)}};

    while (window.update([&](paradiso::Window& window) -> bool {
        auto t1 = std::chrono::high_resolution_clock::now();

        if (window.keyboard_input().size() &&
            window.keyboard_input().top().key == 'Q') {
            // Update-Loop beenden.
            return false;
        }

        if (game_state == GameState::Start) {
            if (window.keyboard_input().size() &&
                window.keyboard_input().top().key == ACTION_KEY &&
                window.keyboard_input().top().action == 1) {
                game_state = GameState::Playing;

                // Make the plane jump for the first time.
                // @ToDo: The plane jumps too high because there was no gravity
                // before.
                plane.update(window.keyboard_input());
            }

            background.update();
            ground.update();
            start_text.update();
        } else if (game_state == GameState::Playing) {
            background.update();
            ground.update();

            rocks1.update();
            rocks2.update();

            plane.update(window.keyboard_input());

            background.scrolling_speed *= SCROLLING_SPEED_INC_FACTOR;
            ground.scrolling_speed *= SCROLLING_SPEED_INC_FACTOR;
            rocks1.scrolling_speed *= SCROLLING_SPEED_INC_FACTOR;
            rocks2.scrolling_speed *= SCROLLING_SPEED_INC_FACTOR;

            if (plane.aabb.is_colliding_with(rocks1.top_aabb) ||
                plane.aabb.is_colliding_with(rocks1.bottom_aabb) ||
                plane.aabb.is_colliding_with(rocks2.top_aabb) ||
                plane.aabb.is_colliding_with(rocks2.bottom_aabb) ||
                plane.aabb.is_colliding_with(top_aabb) ||
                plane.aabb.is_colliding_with(ground.aabb)) {
                game_state = GameState::GameOver;
            }
        } else if (game_state == GameState::GameOver) {
            if (window.keyboard_input().size() &&
                window.keyboard_input().top().key == ACTION_KEY) {

                // Reset everything.
                background.init();
                ground.init();
                rocks1.init(1.2f, true);
                rocks2.init(2.4f, true);
                plane.init();
                game_state = GameState::Start;
            }
        }

        context.set_viewport(paradiso::Rectangle{
            .position = paradiso::Point{.x = 0, .y = 0}, .size = canvas_size});
        context.clear();

        background.draw(shader);

        plane.draw(shader);

        rocks1.draw(shader);
        rocks2.draw(shader);

        ground.draw(shader);

        // Kinda dumb that we check the game state here the second time but I
        // like to seperate 'update' from 'draw'.
        if (game_state == GameState::Start) {
            start_text.draw(shader);
        } else if (game_state == GameState::GameOver) {
            game_over_text.draw(shader);
        }

        // Einen kurzen Moment warten, um auf 60 FPS zu kommen.
        auto t2 = std::chrono::high_resolution_clock::now();
        auto duration =
            std::chrono::duration_cast<std::chrono::microseconds>(t2 - t1);
        auto wait = std::chrono::microseconds(1000000 / FRAME_RATE) - duration;
        std::this_thread::sleep_for(wait);

        return true;
    })) {
    };

    return 0;
}