#include "../include/cache_files.hpp"
#include <spdlog/spdlog.h>
#include "../include/information.hpp"
#include <fstream>

namespace fs = std::filesystem;

gemini::CacheFiles::CacheFiles(const std::filesystem::path &folder, const Information &infos) : information(infos) {
	if (!fs::is_directory(folder)) {
		spdlog::error("Path {} is not a folder", folder.string());
		throw std::runtime_error("Stopped in cache files constructor, see log.");
	}
	std::size_t global_cache = 0;
	for (const auto &iterator : fs::directory_iterator(folder, fs::directory_options::follow_directory_symlink)) {
		// Each time it finds a file, it is going to load it in memory and check if infos.cache_size is reached in terms of size.
		if (!iterator.is_regular_file())
			continue;
		const std::size_t file_size = [&]() -> std::size_t {
			std::ifstream in(iterator.path());
			const std::size_t begin = in.tellg();
			in.seekg(0, std::ios::end);
			return static_cast<std::size_t>(in.tellg()) - begin;
		}();
		global_cache += file_size;

		if (global_cache > infos.cache_size)
			break;

		// I want to have the filename and not the whole path to be stored (less characters, less memory used).
		const std::string filename = [&]() -> std::string {
			const auto path = iterator.path().string();
			const std::size_t pos = path.rfind('/');
			return iterator.path().string().substr(pos != std::string::npos ? pos + 1 : pos);
		}();

		if (files.insert(filename.empty() ? iterator.path().string() : filename).second)
			spdlog::warn("File {} could not be registered", iterator.path().string());

		std::ifstream file{ iterator.path() };
		if (!content.emplace(filename.empty() ? iterator.path().string() : filename,
							 std::string{ std::istreambuf_iterator<char>(file), std::istreambuf_iterator<char>() }).second)
			spdlog::warn("File {} could not be loaded in cache", iterator.path().string());
	}
}