#include "core/system/director.hpp"

#include <SDL3/SDL.h>

#include <algorithm>
#include <cstdio>
#include <memory>
#include <utility>

#include "core/rendering/screen.hpp"
#include "core/scene/scene.hpp"
#include "core/system/event_buffer.hpp"
#include "game/scenes/black_scene.hpp"

Director::Director() {
    if (!SDL_Init(0)) {
        std::fprintf(stderr, "SDL_Init failed: %s\n", SDL_GetError());
    }

    Screen::init();

    current_scene_ = std::make_unique<BlackScene>();
    last_ticks_ms_ = SDL_GetTicks();
}

Director::~Director() {
    current_scene_.reset();
    Screen::destroy();
    SDL_Quit();
}

void Director::processEvents() {
    const bool QUIT_REQUESTED = std::ranges::any_of(
        EventBuffer::events,
        [](const SDL_Event& event) { return event.type == SDL_EVENT_QUIT; });
    if (QUIT_REQUESTED) { current_scene_.reset(); }
}

void Director::switchSceneIfRequested() {
    if (!current_scene_) { return; }
    if (auto next = current_scene_->nextScene()) {
        current_scene_ = std::move(next);
    }
}

auto Director::iterate() -> SDL_AppResult {
    processEvents();

    if (!current_scene_) {
        EventBuffer::events.clear();
        return SDL_APP_SUCCESS;
    }

    const std::uint64_t NOW_MS = SDL_GetTicks();
    int delta_ms = static_cast<int>(NOW_MS - last_ticks_ms_);
    delta_ms = std::max(delta_ms, 0);
    last_ticks_ms_ = NOW_MS;

    current_scene_->update(delta_ms);
    current_scene_->render();

    if (current_scene_->wantsQuit()) {
        EventBuffer::events.clear();
        return SDL_APP_SUCCESS;
    }

    switchSceneIfRequested();

    EventBuffer::events.clear();
    return SDL_APP_CONTINUE;
}