#include <chrono>                   // for operator""s, chrono_literals
#include <thread>                   // for sleep_for
#include "dinkyecs.hpp"
#include "events.hpp"
#include "dbc.hpp"
#include "render.hpp"
#include "lights.hpp"
#include <filesystem>
#include <fcntl.h>
#include "constants.hpp"
#include "point.hpp"
#include <fmt/core.h>
#include <locale>
#include <codecvt>
#include <vector>
#include <ft2build.h>
#include FT_FREETYPE_H

using namespace fmt;
using namespace ftxui;
using namespace std::chrono_literals;
using lighting::LightSource, lighting::LightRender;
namespace fs = std::filesystem;
using std::string, std::wstring, std::vector;

const Point GRID_SIZE={15,8};
const int DEFAULT_FONT_SIZE=200;

struct FontGrid {
  size_t width;
  size_t height;
  vector<vector<string>> $chars;
  std::wstring_convert<std::codecvt_utf8_utf16<wchar_t>> $converter;

  FontGrid(size_t width, size_t height) :
    width(width), height(height),
    $chars(height, vector<string>(width, ""))
  {
  }

  void render(wchar_t start_char, bool fill) {
    wchar_t cur_char = start_char;

    for(size_t y = 0; y < height; ++y) {
      for(size_t x = 0; x < width; ++x) {
        if(!fill) {
          cur_char += (x+1) * (y+1);
        }

        wstring out_w{cur_char};
        $chars[y][x] = from_unicode(out_w);
      }
    }
  }

  string from_unicode(wstring input) {
    try {
      return $converter.to_bytes(input);
    } catch(...) {
      return $converter.to_bytes(L"?");
    }
  }

  wchar_t to_unicode_char(size_t x, size_t y) {
    try {
      string input = $chars[y][x]; // BUG: bounds check this instead
      return $converter.from_bytes(input)[0];
    } catch(...) {
      return L'?';
    }
  }

  string at(size_t x, size_t y) {
    return $chars[y][x];
  }

  unsigned int page_size() {
    return width * height;
  }

};

struct WhatTheColor {
  int h;
  int s;
  int v;
  Component h_slider;
  Component s_slider;
  Component v_slider;
};

class GUI {
  public:
  DinkyECS::World& $world;
  Panel $font_view;
  Panel $status_ui;
  Canvas $canvas;
  SFMLRender $renderer;
  FontGrid $font_grid;
  wchar_t $start_char = L'\u28cc';
  wchar_t $fill_char = WCHAR_MIN;
  WhatTheColor $fg_color;
  WhatTheColor $bg_color;
  Component $fg_settings;
  Component $bg_settings;

  GUI(DinkyECS::World &world) :
    $world(world),
    $font_view(GAME_MAP_POS, 0, GRID_SIZE.x, GRID_SIZE.y, true),
    $status_ui(0, 0, SCREEN_WIDTH, SCREEN_HEIGHT),
    $font_grid(GRID_SIZE.x, GRID_SIZE.y),
    $fg_color{.h=20, .s=50, .v=20},
    $bg_color{.h=100, .s=100, .v=100}
  {
    resize_fonts(DEFAULT_FONT_SIZE);
    $font_grid.render($start_char, false);
  }

  void resize_fonts(int new_size) {
    println("RESIZE MAP TO {}", new_size);
    $renderer.resize_grid(new_size, $font_view);
    // set canvas to best size
    $canvas = Canvas($font_view.width * 2, $font_view.height * 4);
  }

  void draw_font_grid() {
    for(size_t y = 0; y < $font_grid.height; y++) {
      for(size_t x = 0; x < $font_grid.width; x++) {
        $canvas.DrawText(x * 2, y * 4, $font_grid.at(x, y), [&](auto &pixel) {
          pixel.foreground_color = Color::HSV($fg_color.h, $fg_color.s, $fg_color.v);
          pixel.background_color = Color::HSV($bg_color.h, $bg_color.s, $bg_color.v);
        });
      }
    }
  }

  void create_renderer() {
    $renderer.init_terminal();

    $font_view.set_renderer(Renderer([&]{
        draw_font_grid();
        return canvas($canvas);
    }));

    $fg_color.h_slider = Slider("FG H:", &$fg_color.h, 0, 255, 1);
    $fg_color.s_slider = Slider("FG S:", &$fg_color.s, 0, 255, 1);
    $fg_color.v_slider = Slider("FG V:", &$fg_color.v, 0, 255, 1);
    $bg_color.h_slider = Slider("BG H:", &$bg_color.h, 0, 255, 1);
    $bg_color.s_slider = Slider("BG S:", &$bg_color.s, 0, 255, 1);
    $bg_color.v_slider = Slider("BG V:", &$bg_color.v, 0, 255, 1);

    $status_ui.set_renderer(Renderer([&]{
        return hbox({
          hflow(
              vbox(
                text(format("\\u{:x} {} MIN: {}, MAX: {}", int($fill_char), int($fill_char), WCHAR_MIN, WCHAR_MAX)) | border,
                separator(),
                text(format("FG H: {}, S: {}, V: {}",
                    $fg_color.h, $fg_color.s, $fg_color.v)) | border,
                $fg_color.h_slider->Render(),
                separator(),
                $fg_color.s_slider->Render(),
                separator(),
                $fg_color.v_slider->Render(),
                separator(),
                text(format("BG H: {}, S: {}, V: {}",
                    $bg_color.h, $bg_color.s, $bg_color.v)) | border,
                $bg_color.h_slider->Render(),
                separator(),
                $bg_color.s_slider->Render(),
                separator(),
                $bg_color.v_slider->Render()
              ) | flex_grow
          ),
          separator(),
          hbox(),
      });
    }));

    $status_ui.add($fg_color.h_slider);
    $status_ui.add($fg_color.s_slider);
    $status_ui.add($fg_color.v_slider);
    $status_ui.add($bg_color.h_slider);
    $status_ui.add($bg_color.s_slider);
    $status_ui.add($bg_color.v_slider);
  }

  void shutdown() {
    $renderer.close();
  }

  void select_cell(Point pos) {
    $fill_char = $font_grid.to_unicode_char(pos.x, pos.y);
    $font_grid.render($fill_char, true);
  }

  void deselect_cell() {
    $font_grid.render($start_char, false);
  }

  bool handle_ui_events() {
    bool event_happened;
    using KB = sf::Keyboard;
    sf::Event event;
    int font_size = $renderer.font_size();

    while($renderer.poll_event(event)) {
      if(event.type == sf::Event::Closed) {
        shutdown();
        return true;
      } else if(event.type ==  sf::Event::KeyPressed) {
        if(KB::isKeyPressed(KB::Up)) {
          $start_char = std::max(WCHAR_MIN+1, $start_char - $font_grid.page_size());
          $font_grid.render($start_char, false);
          event_happened = true;
          $renderer.clear_cache();
        } else if(KB::isKeyPressed(KB::Down)) {
          $start_char = std::min(WCHAR_MAX, $start_char + $font_grid.page_size());
          $font_grid.render($start_char, false);
          $renderer.clear_cache();
        } else if(KB::isKeyPressed(KB::Equal)) {
          resize_fonts(font_size + 10);
        } else if(KB::isKeyPressed(KB::Hyphen)) {
          resize_fonts(font_size - 10);
          event_happened = true;
        }
      } else if(sf::Mouse::isButtonPressed(sf::Mouse::Left)) {
        Point pos;
        if($renderer.mouse_position($font_view, pos)) {
          select_cell(pos);
          event_happened = true;
        } else if($renderer.mouse_position($status_ui, pos)) {
          $status_ui.mouse_click(Mouse::Button::Left, pos);
        }
      } else if(sf::Mouse::isButtonPressed(sf::Mouse::Right)) {
        deselect_cell();
      }
    }

    return event_happened;
  }

  void render_scene() {
    $renderer.clear();

    $status_ui.render();
    $renderer.draw($status_ui);

    $font_view.render();
    $renderer.draw($font_view);

    $renderer.display();
  }
};

int main(int argc, char *argv[]) {
  DinkyECS::World world;

  GUI gui(world);

  gui.create_renderer();

  do {
    gui.render_scene();

    if(gui.handle_ui_events()) {
      println("THERE WERE EVENTS");
    }

    std::this_thread::sleep_for(10ms);
  } while(gui.$renderer.is_open());

  return 0;
}