#include "memoryimagecache.h"

#include <algorithm>
#include <Log.h>

MemoryImageCache::MemoryImageCache(size_t maxsize) : maxsize(maxsize) {}

void MemoryImageCache::addImage(QPixmap img, const QString& title, int type) {
	auto it = std::find_if(cache.begin(), cache.end(), getImageMatcher(title, type));
	if(it == cache.end()) {
		// insert new
		cache.push_back({time(0), img, title, type});
		cleanUp();
		return;
	}

	// update old
	it->lastaccessed = time(0);
	it->imageref = img;
}

QPixmap MemoryImageCache::getImage(const QString& title, int type) {
	auto it = std::find_if(cache.begin(), cache.end(), getImageMatcher(title, type));
	if(it == cache.end()) {
		return {};
	}
	it->lastaccessed = time(0);
	return it->imageref;
}

void MemoryImageCache::cleanUp() {
	if(cache.size() < maxsize) return;

	auto oldest = std::min_element(cache.begin(), cache.end());

	cache.erase(oldest);
}

bool MemoryImageCache::CachedImage::operator<(const MemoryImageCache::CachedImage& other) const {
	return lastaccessed < other.lastaccessed;
}

std::function<bool(const MemoryImageCache::CachedImage&)> MemoryImageCache::getImageMatcher(const QString& title, int type) {
	return [title, type](const MemoryImageCache::CachedImage& img) -> bool {
		return img.type == type && img.title == title;
	};
}