#include <string>
#include <vector>

#include "gfx/types.h"
#include "ui/ui_renderer.h"
#include "ui/login_screen.h"

LoginScreen::LoginScreen(int screen_width, int screen_height) 
    : _screen_width(screen_width), _screen_height(screen_height) {}

LoginScreen::~LoginScreen(void) {}

void LoginScreen::update(float dt) {
  /* TODO: */
}

void LoginScreen::render(const RenderContext& context) const {
  UIRenderer* ui_renderer = context.ui_renderer;

  /* Colours. */
  const Color text_color          = { 0.8f,   0.8f,   0.8f  };
  const Color inactive_box_color  = { 0.1f,   0.1f,   0.15f };
  const Color active_box_color    = { 0.15f,  0.15f,  0.2f  };
  const Color warning_color       = { 0.7f,   0.3f,   0.3f  };

  /* Layout. */
  const int box_width   = 300;
  const int box_height  = 30;
  const int center_x    = (_screen_width - box_width) / 2;
  const int start_y     = _screen_height / 2 - 100;

  const Rect username_rect = { center_x, start_y+40,  box_width, box_height };
  const Rect password_rect = { center_x, start_y+100, box_width, box_height };
  const Rect hostname_rect = { center_x, start_y+160, box_width, box_height };

  ui_renderer->begin_shapes();
  ui_renderer->begin_text();

  /* Draw title. */
  const char* title = _is_new_account ? "Create Account" : "Login";
  float title_width = ui_renderer->get_text_renderer()->get_text_width(title, 1.0f);
  ui_renderer->render_text(title, (_screen_width-title_width)/2, start_y, text_color);

  /* Draw input boxes and labels. */
  /* Username */
  ui_renderer->render_text("Username", username_rect.x, username_rect.y-5, text_color);
  ui_renderer->draw_rect(username_rect.x, username_rect.y, username_rect.w, username_rect.h,
                         _active_field == 0 ? active_box_color : inactive_box_color);
  ui_renderer->render_text(_username_input.c_str(), username_rect.x+10, username_rect.y+20, text_color);
  if(_active_field == 0 && context.show_cursor) {
    float cursor_x = username_rect.x + 10 +
      ui_renderer->get_text_renderer()->get_text_width(_username_input.c_str(), 1.0f);
    ui_renderer->draw_rect((int)cursor_x, username_rect.y+5, 2, 20, text_color);
  }

  /* Password. */
  ui_renderer->render_text("Password", password_rect.x, password_rect.y-5, text_color);
  ui_renderer->draw_rect(password_rect.x, password_rect.y, password_rect.w, password_rect.h,
                         _active_field == 1 ? active_box_color : inactive_box_color);
  ui_renderer->render_text(_password_input.c_str(), password_rect.x+10, password_rect.y+20, text_color);
  if(_active_field == 1 && context.show_cursor) {
    float cursor_x = password_rect.x + 10 +
      ui_renderer->get_text_renderer()->get_text_width(_password_input.c_str(), 1.0f);
    ui_renderer->draw_rect((int)cursor_x, password_rect.y+5, 2, 20, text_color);
  }

  /* Hostname (only for new account). */
  if(_is_new_account) {
    ui_renderer->render_text("Hostname", hostname_rect.x, hostname_rect.y-5, text_color);
    ui_renderer->draw_rect(hostname_rect.x, hostname_rect.y, hostname_rect.w, hostname_rect.h,
                           _active_field == 2 ? active_box_color : inactive_box_color);
    ui_renderer->render_text(_hostname_input.c_str(), hostname_rect.x+10, hostname_rect.y+20, text_color);
    if(_active_field == 2 && context.show_cursor) {
      float cursor_x = hostname_rect.x + 10 +
        ui_renderer->get_text_renderer()->get_text_width(_hostname_input.c_str(), 1.0f);
      ui_renderer->draw_rect((int)cursor_x, hostname_rect.y+5, 2, 20, text_color);
    }
  }

  /* Draw the security warning. */
  const char* warning_title = "Security Warning";
  float warning_title_width = ui_renderer->get_text_renderer()->get_text_width(warning_title, 1.0f);
  ui_renderer->render_text(warning_title, (_screen_width-warning_title_width)/2,
                           _screen_height-120, warning_color);
  const std::vector<std::string> warning_lines = {
    "Passwords in Bettola are stored in plain text by design.",
    "Players, can, and will attempt to obtain your password.",
    "DO NOT use a password you have used for any other game or service.",
    "Use a unique, throwaway password for this game only!"
  };
  for(size_t i = 0; i < warning_lines.size(); ++i) {
    const std::string& line = warning_lines[i];
    float line_width = ui_renderer->get_text_renderer()->get_text_width(line.c_str(), 1.0f);
    ui_renderer->render_text(line.c_str(), (_screen_width-line_width)/2, 
                             _screen_height-100+(i*20), warning_color);
  }

  ui_renderer->flush_shapes();
  ui_renderer->flush_text();
}

void LoginScreen::handle_event(const SDL_Event* event) {
  if(event->type == SDL_EVENT_TEXT_INPUT) {
    /* Append character to active input string. */
    switch(_active_field) {
      case 0: _username_input += event->text.text; break;
      case 1: _password_input += event->text.text; break;
      case 2: if(_is_new_account) { _hostname_input += event->text.text; } break;
    }
  } else if(event->type == SDL_EVENT_KEY_DOWN) {
    if(event->key.key == SDLK_BACKSPACE) {
      /* Handle backspace. */
      switch(_active_field) {
        case 0: if(!_username_input.empty()) { _username_input.pop_back(); } break;
        case 1: if(!_password_input.empty()) { _password_input.pop_back(); } break;
        case 2: if(_is_new_account && !_hostname_input.empty()) {
          _hostname_input.pop_back();
        }
        break;
      }
    } else if(event->key.key == SDLK_TAB) {
      /* Tab to switch fields. */
      int num_fields = _is_new_account ? 3 : 2;
      _active_field = (_active_field+1) % num_fields;
    } else if(event->key.key == SDLK_RETURN) {
      _login_attempted = true;
    }
  } else if(event->type == SDL_EVENT_MOUSE_BUTTON_DOWN) {
    /* Handle mouse clicks. */
    int mouse_x = event->button.x;
    int mouse_y = event->button.y;

    /* Recalculate rects to check for clicks. */
    const int box_width = 300;
    const int start_y = _screen_height / 2 - 100;
    const int center_x = (_screen_width - box_width) / 2;

    const Rect username_rect = { center_x, start_y+40,  box_width, 30 };
    const Rect password_rect = { center_x, start_y+100, box_width, 30 };
    const Rect hostname_rect = { center_x, start_y+160, box_width, 30 };

    if(mouse_y >= username_rect.y && mouse_y <= username_rect.y + username_rect.h)
      _active_field = 0;
    else if(mouse_y >= password_rect.y && mouse_y <= password_rect.y + password_rect.h)
      _active_field = 1;
    else if(_is_new_account && (mouse_y >= hostname_rect.y && mouse_y <= hostname_rect.y + hostname_rect.h))
      _active_field = 2;
  }
}