#include "asset_io.h"

#include <godot_cpp/classes/file_access.hpp>

#include "platform/PackBackend.h"

#include <cstring>
#include <string>
#include <vector>

using namespace godot;

namespace mtgodot {

namespace {
bool pack_name(const String &path, std::string &name) {
	if (!path.begins_with(PACK_SCHEME)) {
		return false;
	}
	name = path.substr(String(PACK_SCHEME).length()).utf8().get_data();
	return true;
}
} // namespace

PackedByteArray read_file(const String &path) {
	if (path.is_empty()) {
		return PackedByteArray();
	}
	std::string name;
	if (pack_name(path, name)) {
		std::vector<uint8_t> bytes;
		PackedByteArray out;
		if (mtpack40250::read(name, bytes)) {
			out.resize((int64_t)bytes.size());
			if (!bytes.empty()) {
				std::memcpy(out.ptrw(), bytes.data(), bytes.size());
			}
		}
		return out;
	}
	// FileAccess::get_file_as_bytes handles res:// / user:// / absolute OS paths.
	return FileAccess::get_file_as_bytes(path);
}

bool file_exists(const String &path) {
	std::string name;
	if (pack_name(path, name)) {
		return mtpack40250::exists(name);
	}
	return !path.is_empty() && FileAccess::file_exists(path);
}

Image dds_from_file(const String &path) {
	PackedByteArray b = read_file(path);
	if (b.is_empty()) {
		return Image{};
	}
	return load_dds(b.ptr(), (size_t)b.size());
}

std::optional<gr2::File> gr2_from_file(const String &path, gr2::LoadError *err) {
	PackedByteArray b = read_file(path);
	if (b.is_empty()) {
		if (err) {
			*err = {"open", std::string("cannot read ") + path.utf8().get_data()};
		}
		return std::nullopt;
	}
	return gr2::File::load(b.ptr(), (size_t)b.size(), err);
}

} // namespace mtgodot