//
// Window.cpp
// gui
//
// Created by Bob Polis at 2020-10-14
// Copyright (c) 2020 SwiftCoder. All rights reserved.
//

#include <SDL2/SDL_image.h>
#include <cmath>
#include "Window.hpp"

using namespace sc::gui;

Window::Window(const char* title) : _path {title} {
    SDL_Window* win = SDL_CreateWindow(title,
                                     SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED,
                                     900, 540,
                                     SDL_WINDOW_RESIZABLE);
    _w.reset(win);
    _r.reset(SDL_CreateRenderer(win, -1, 0));
}

void Window::set_size(int w, int h) {
    SDL_SetWindowSize(_w.get(), w, h);
}

void Window::update() const {
    SDL_RenderClear(_r.get());
    SDL_RenderCopy(_r.get(), _t.get(), nullptr, nullptr);
    SDL_RenderPresent(_r.get());
}

void Window::load_image() {
    // load image from file into surface
    SDL_Surface* loaded = IMG_Load(_path.c_str());
    if (!loaded) throw std::runtime_error(IMG_GetError());
    std::unique_ptr<SDL_Surface, void(*)(SDL_Surface*)> loaded_ {loaded, SDL_FreeSurface};

    // create texture from surface
    _t.reset(SDL_CreateTextureFromSurface(_r.get(), loaded));

    // query texture for properties, like image size
    Uint32 format;
    int access;
    int w, h;
    int result = SDL_QueryTexture(_t.get(), &format, &access, &w, &h);
    if (result != 0) throw std::runtime_error(SDL_GetError());

    // get screen size, to scale down if image is too big
    SDL_DisplayMode dm;
    SDL_GetCurrentDisplayMode(0, &dm);
    if (dm.w < w || dm.h < h) {
        double screen_ratio {static_cast<double>(dm.w) / dm.h};
        double image_ratio {static_cast<double>(w) / h};
        const int safety {100}; // room for window and desktop adornments
        if (screen_ratio > image_ratio) { // screen relatively less high than image
            h = dm.h - safety;
            w = static_cast<int>(round(image_ratio * h));
        } else { // screen relatively less wide than image
            w = dm.w - safety;
            h = static_cast<int>(round(w / image_ratio));
        }
    }
    set_size(w, h);
}