#include <chrono>                   // for operator""s, chrono_literals
#include <iostream>                 // for cout, ostream
#include <fstream>
#include <memory>                   // for allocator, shared_ptr
#include <string>                   // for string, operator<<
#include <thread>                   // for sleep_for
#include <array>

#include <ftxui/dom/elements.hpp>  // for hflow, paragraph, separator, hbox, vbox, filler, operator|, border, Element
#include <ftxui/dom/node.hpp>      // for Render
#include <ftxui/screen/box.hpp>    // for ftxui
#include <ftxui/component/loop.hpp>
#include <ftxui/screen/color.hpp>

#include <SFML/Window.hpp>
#include <SFML/System.hpp>
#include <SFML/Graphics.hpp>

#include <fmt/core.h>
#include "dbc.hpp"
#include "gui.hpp"
#include "rand.hpp"
#include "components.hpp"
#include "systems.hpp"
#include "collider.hpp"

using std::string;
using namespace fmt;
using namespace std::chrono_literals;
using namespace ftxui;
using namespace Components;

std::array<sf::Color, 10> VALUES{
  sf::Color{1, 4, 2},  // black
  sf::Color{9, 29, 16}, // dark dark
  sf::Color{14, 50, 26}, // dark mid
  sf::Color{0, 109, 44}, // dark light
  sf::Color{63, 171, 92}, // mid
  sf::Color{161, 217, 155}, // light dark
  sf::Color{199, 233, 192}, // light mid
  sf::Color{229, 245, 224}, // light light
  sf::Color{255, 255, 255}, // white
  sf::Color::Transparent, // white
};

sf::Color GUI::color(int val) {
  return VALUES[size_t(val)];
}

sf::Color GUI::color(Value val) {
  return VALUES[size_t(val)];
}

GUI::GUI() :
  $game_map(GAME_MAP_X, GAME_MAP_Y),
  $window(sf::VideoMode(VIDEO_X,VIDEO_Y), "Roguish"),
  $screen(SCREEN_X, SCREEN_Y),
  $map_screen(0,0),
  $view_port{0,0},
  $map_font_size(BASE_MAP_FONT_SIZE),
  $line_spacing(0)
{
  $font.loadFromFile("./assets/text.otf");
  resize_map(BASE_MAP_FONT_SIZE);
  int res = $hit_buf.loadFromFile("./assets/hit.wav");
  dbc::check(res, "failed to load hit.wav");
  $hit_sound.setBuffer($hit_buf);

  $ui_text.setFont($font);
  $ui_text.setPosition(0,0);
  $ui_text.setCharacterSize(UI_FONT_SIZE);
  $ui_text.setFillColor(color(Value::LIGHT_LIGHT));

  $game_map.generate();
}

void GUI::create_renderer() {
  auto player = $world.get<Player>();

  $map_view = Renderer([&] {
    System::draw_map($world, $game_map, $canvas, $view_port.x, $view_port.y);
    return canvas($canvas);
  });

  $document = Renderer([&, player]{
    const auto& player_combat = $world.component<Combat>(player.entity);
    const auto& log = $world.get<ActionLog>();

    $status_text = player_combat.hp > 0 ? "NOT DEAD" : "DEAD!!!!!!";

    std::vector<Element> log_list;
    for(auto msg : log.messages) {
      log_list.push_back(text(msg));
    }
    auto log_box = vbox(log_list) | yflex_grow | border;

    return hbox({
        hflow(
          vbox(
              text(format("HP: {: >3}", player_combat.hp)) | border,
              text($status_text) | border,
              separator(),
              log_box
              )  | flex_grow
        ),
        separator(),
        hbox(),
    });
  });
}

bool GUI::handle_events() {
  sf::Event event;
  bool event_happened = false;

  while($window.pollEvent(event)) {
    if(event.type == sf::Event::Closed) {
      $window.close();
    } else if(event.type ==  sf::Event::KeyPressed) {
      auto player = $world.get<Player>();
      auto& player_motion = $world.component<Motion>(player.entity);

      if(sf::Keyboard::isKeyPressed(sf::Keyboard::Left)) {
        player_motion.dx = -1;
        event_happened = true;
      } else if(sf::Keyboard::isKeyPressed(sf::Keyboard::Right)) {
        player_motion.dx = 1;
        event_happened = true;
      } else if(sf::Keyboard::isKeyPressed(sf::Keyboard::Up)) {
        player_motion.dy = -1;
        event_happened = true;
      } else if(sf::Keyboard::isKeyPressed(sf::Keyboard::Down)) {
        player_motion.dy = 1;
        event_happened = true;
      } else if(sf::Keyboard::isKeyPressed(sf::Keyboard::Equal)) {
        resize_map($map_font_size + 10);
      } else if(sf::Keyboard::isKeyPressed(sf::Keyboard::Hyphen)) {
        resize_map($map_font_size - 10);
      }
    }
  }

  return event_happened;
}


sf::Sprite &GUI::get_text_sprite(wchar_t tile) {
  if(!$sprites.contains(tile)) {
    sf::Glyph glyph = $font.getGlyph(tile, $map_font_size, false);
    // WARNING! we actually have to do this here because SFML caches
    // the glyphs on the font texture, so this gets loaded each time
    // we get a new glyph from the font.
    $font_texture = $font.getTexture($map_font_size);
    sf::Sprite sprite($font_texture);
    sprite.setTextureRect(glyph.textureRect);
    $sprites[tile] = sprite;
  }

  return $sprites[tile];
}

void GUI::run_systems() {
  auto player = $world.get<Player>();
  System::enemy_pathing($world, $game_map, player);
  System::motion($world, $game_map);
  System::combat($world, player);
}

void GUI::resize_map(int new_size) {
  if(MIN_FONT_SIZE < new_size && new_size < MAX_FONT_SIZE) {
    $sprites.clear(); // need to reset the sprites for the new size
    $map_font_size = new_size;
    $base_glyph = $font.getGlyph(L'█', $map_font_size, false);
    auto bounds = $base_glyph.bounds;
    $line_spacing = $font.getLineSpacing($map_font_size);
    $view_port = {
      size_t(std::ceil((VIDEO_X - GAME_MAP_POS) / bounds.width)),
      size_t(std::ceil(VIDEO_Y / bounds.height))
    };
    // set canvas to best size
    $canvas = Canvas($view_port.x * 2, $view_port.y * 4);
    $map_screen = Screen($view_port.x, $view_port.y);
  }
}

void GUI::draw_screen(bool clear, float map_off_x, float map_off_y) {
  if(clear) $window.clear();
  std::string screenout = $screen.ToString();
  std::wstring main_screen_utf8 = $converter.from_bytes(screenout);
  $ui_text.setString(main_screen_utf8);
  $window.draw($ui_text);

  std::string map_screenout = $map_screen.ToString();
  std::wstring map_screen_utf8 = $converter.from_bytes(map_screenout);

  float y = 0.0f;
  float x = GAME_MAP_POS;
  // make a copy so we don't modify the cached one
  auto bg_sprite = get_text_sprite(L'█');
  auto bg_bounds = bg_sprite.getLocalBounds();
  bg_sprite.setColor(sf::Color(20,20,20));
  auto add_sprite = get_text_sprite(L'!');
  bool has_add = false;

  for(size_t i = 0; i < map_screen_utf8.size(); i++) {
    wchar_t tile = map_screen_utf8[i];

    if(tile == L'\n') {
      // don't bother processing newlines, just skip
      y += $line_spacing;
      x = GAME_MAP_POS;
    } else if(tile == L'\r') {
        continue; // skip these, just windows junk
    } else {
      // it's a visual cell
      bg_sprite.setPosition({x, y});
      sf::Sprite &sprite = get_text_sprite(tile);

      // should look into caching all this instead of calcing it each time
      auto sp_bounds = sprite.getLocalBounds();

      // calculate where to center the sprite, but only if it's smaller
      auto width_delta = bg_bounds.width > sp_bounds.width ? (bg_bounds.width - sp_bounds.width) / 2 : 0;
      auto height_delta = bg_bounds.height > sp_bounds.width ? (bg_bounds.height - sp_bounds.height) / 2 : 0;

      // TODO: need to center it inside the bg_sprite
      sprite.setPosition({x+width_delta, y+height_delta});

      if(tile == L'█') {
        sprite.setColor(sf::Color(80,80,80));
      } else if(tile == L'☺') {
        sprite.setColor(sf::Color::Blue);
      } else if(tile == L'Ω') {
        sprite.setColor(sf::Color::Red);
        // HACK: just playing with adding multiple characters for drawing
        add_sprite.setColor(sf::Color::Red);
        add_sprite.setPosition({x-3,y-3});
        has_add = true;
      } else if(tile == L'#') {
        sprite.setColor(sf::Color(5,5,5));
      } else {
        sprite.setColor(color(Value::MID));
      }

      // now draw the background sprite and sprite
      // TODO: this can become a standard sprite description
      $window.draw(bg_sprite);
      $window.draw(sprite);
      if(has_add) {
        $window.draw(add_sprite);
        has_add = false;
      }
      // next cell
      x += $base_glyph.advance;
    }
  }

  $window.display();
}

void GUI::shake() {
  $hit_sound.play();
  for(int i = 0; i < 10; ++i) {
    int x = Random::uniform<int>(-10,10);
    int y = Random::uniform<int>(-10,10);
    // add x/y back to draw screen
    draw_screen(true, x, y);
    std::this_thread::sleep_for(1ms);
  }
}

void GUI::configure_world() {
  dbc::check($game_map.room_count() > 1, "not enough rooms in map.");
  // configure a player as a fact of the world
  Player player{$world.entity()};
  $world.set<Player>(player);

  ActionLog log{{"Welcome to the game!"}};
  $world.set<ActionLog>(log);

  spatial_map collider;
  $world.set<spatial_map>(collider);

  $world.assign<Position>(player.entity, {$game_map.place_entity(0)});
  $world.assign<Motion>(player.entity, {0, 0});
  $world.assign<Combat>(player.entity, {100, 10});
  $world.assign<Tile>(player.entity, {PLAYER_TILE});

  auto enemy = $world.entity();
  $world.assign<Position>(enemy, {$game_map.place_entity(1)});
  $world.assign<Motion>(enemy, {0,0});
  $world.assign<Combat>(enemy, {20, 10});
  $world.assign<Tile>(enemy, {ENEMY_TILE});

  auto enemy2 = $world.entity();
  $world.assign<Position>(enemy2, {$game_map.place_entity(2)});
  $world.assign<Motion>(enemy2, {0,0});
  $world.assign<Combat>(enemy2, {20, 10});
  $world.assign<Tile>(enemy2, {"*"});

  auto gold = $world.entity();
  $world.assign<Position>(gold, {$game_map.place_entity($game_map.room_count() - 1)});
  $world.assign<Treasure>(gold, {100});
  $world.assign<Tile>(gold, {"$"});

  System::init_positions($world);
}

void GUI::render_scene() {
  $screen.Clear();
  $map_screen.Clear();
  Render($map_screen, $map_view->Render());
  Render($screen, $document->Render());

  draw_screen();
}

int GUI::main() {
  configure_world();
  create_renderer();
  run_systems();

  while($window.isOpen()) {
    render_scene();

    if(handle_events()) {
      run_systems();
    }
    std::this_thread::sleep_for(10ms);
  }

  return 0;
}