use fmt;
use os;
use io;
use fs;
use strings;
use errors;
use rt;
use getopt;

use cmd;
use mbr;
use gpt;
use sector;


export fn convert(args: []str) void = {
	let nombr = false;
	let notranslation = false;
	let nohybrid = false;

	const c = getopt::parse(args,
		('m', "do not overwrite the MBR bootstrap"),
		('t', "do not translate partitions to GPT"),
		('H', "do not create a hybrid MBR"),
		"disk file"
	);
	defer getopt::finish(&c);

	for (let i = 0z; i < len(c.opts); i += 1) {
		const opt = c.opts[i];
		switch (opt.0) {
		case 'm' => nombr = true;
		case 't' => notranslation = true;
		case 'H' => nohybrid = true;
		};
	};

	if (len(c.args) < 1)
		fmt::fatalf("gpt.convert: need a disk file");

	let sourcefd = match (os::open(c.args[0], fs::flags::RDONLY)) {
	case let f: io::file =>
		yield f;
	case => fmt::fatalf("gpt.convert: could not open file {}", args[1]);
	};
	defer io::close(sourcefd)!;

	const source = mbr::from(sourcefd)!;
	defer mbr::finish(source);

	let fd = cmd::openfile();
	defer io::close(fd)!;

	let vol = cmd::opengpt(fd);
	defer {
		vol.mbr.entries[3] = mbr::entry {
			part_type = 0xEE,
			lba_begin = 0,
			length = -1: u32,
			...
		};

		gpt::chksums(vol);
		gpt::commit(vol)!;
		gpt::finish(vol);
	};

	if (!nombr)
		rt::memcpy(vol.mbr, source.bootsector, size(mbr::bootsector));

	if (notranslation)
		return;

	for (let i = 0z; i < 4; i += 1) {
		const entry = &source.bootsector.entries[i];
		if (entry.lba_begin == 0 && entry.length == 0)
			continue;

		const reader = mbr::partstream_reader(source, entry)!;
		const partlength = entry.length;

		const part = match (gpt::allocate(vol, partlength)) {
		case let e: *gpt::entry =>
			yield e;
		case =>
			fmt::errorfln("gpt.convert: could not allocate size needed for MBR partition {}", i)!;
			continue;
		};

		const writer = gpt::partstream_writer(vol, part)!;

		io::copy(&writer, &reader)!;

		if (!nohybrid) {
			vol.mbr.entries[i].lba_begin = part.lba_begin: u32;
			vol.mbr.entries[i].length = (part.lba_end - part.lba_begin + 1): u32;
		};
	};
};