use fmt;
use io;

use gpt;
use volume;

export fn header(vol: str, args: []str) void = {
	const vol = volume::openvol(vol);
	const vol = match (gpt::from(vol)) {
	case let g: *gpt::gpt =>
		yield g;
	case gpt::nogpt =>
		fmt::fatalf("gpt.header: disk {} does not have valid gpt", args[0]);
	case =>
		fmt::fatalf("gpt.header: could not access disk {}", args[0]);
	};
	defer gpt::finish(vol);

	const header = vol.primary.header;

	fmt::printfln("revision: \t\t{}", header.revision)!;
	fmt::printfln("header_size: \t\t{}", header.header_size)!;
	fmt::printfln("header_crc32: \t\t{}", header.header_crc32)!;
	fmt::printfln("header_lba: \t\t{}", header.header_lba)!;
	fmt::printfln("backup_header_lba: \t{}", header.backup_header_lba)!;
	fmt::printfln("first_lba: \t\t{}", header.first_lba)!;
	fmt::printfln("last_lba: \t\t{}", header.last_lba)!;
	fmt::printfln("disk_guid: \t\t[{},{}]", header.disk_guid[0], header.disk_guid[1])!;
	fmt::printfln("entries_lba: \t\t{}", header.entries_lba)!;
	fmt::printfln("entries_len: \t\t{}", header.entries_len)!;
	fmt::printfln("entry_size: \t\t{}", header.entry_size)!;
	fmt::printfln("entries_crc32: \t\t{}", header.entries_crc32)!;
	
	const primary_valid = gpt::header_crc32(header) == header.header_crc32 && gpt::entries_crc32(vol.primary.entries) == header.entries_crc32;
	const backup_valid = gpt::header_crc32(vol.backup.header) == vol.backup.header.header_crc32 && gpt::entries_crc32(vol.backup.entries) == vol.backup.header.entries_crc32;

	fmt::printfln("primary_sane: \t\t{}", primary_valid)!;
	fmt::printfln("backup_sane: \t\t{}", backup_valid)!;
};