#include <base/io/MemoryStream.hpp>
#include <cstring>

namespace dmtools::io {
	MemoryStream::MemoryStream(u8* memory, usize size) {
		beg = memory;
		cur = beg;
		end = memory + size;
		this->size = size;
	}

	MemoryStream::~MemoryStream() {
	}

	StreamDiff MemoryStream::ReadSome(u8* buffer, usize length) {
		if(Eof())
			return -1;
		memcpy(&buffer[0], cur, length);
		cur += length;
		return length;
	}

	StreamDiff MemoryStream::WriteSome(const u8* buffer, usize length) {
		return -1;
	};

	StreamDiff MemoryStream::Seek(StreamDiff where, StreamSeekDirection dir) {
		using enum StreamSeekDirection;
		auto last = Tell();
		switch(dir) {
			case Beg:
				cur = beg + where;
				break;
			case Cur:
				cur += where;
				break;
			case End: // TODO
				cur = end;
				break;
		}
		return last;
	}

	StreamDiff MemoryStream::Tell() const {
		return (cur - beg);
	}

	bool MemoryStream::Ok() const {
		return !Eof();
	}

	bool MemoryStream::Eof() const {
		return cur == end;
	};

} // namespace dmtools::io