io :: import "@std/io"
process :: import "@std/process"

hide read_ok func(_ ?@mut anyopaque, _ io.Handle, buffer []mut u8) usize ! io.ReadError {
	if buffer.len == 0 {
		return 0
	}
	buffer[0] = 'o'
	if buffer.len == 1 {
		return 1
	}
	buffer[1] = 'k'
	return 2
}

hide read_too_much func(_ ?@mut anyopaque, _ io.Handle, buffer []mut u8) usize ! io.ReadError {
	return buffer.len + 1
}

hide read_eof func(_ ?@mut anyopaque, _ io.Handle, _ []mut u8) usize ! io.ReadError {
	return 0
}

hide write_short func(_ ?@mut anyopaque, _ io.Handle, bytes []u8) usize ! io.WriteError {
	if bytes.len > 2 {
		return 2
	}
	return bytes.len
}

hide write_none func(_ ?@mut anyopaque, _ io.Handle, _ []u8) usize ! io.WriteError {
	return 0
}

hide write_too_much func(_ ?@mut anyopaque, _ io.Handle, bytes []u8) usize ! io.WriteError {
	return bytes.len + 1
}

ok_reader func() io.Reader {
	return io.Reader {
		context = null,
		handle = io.Handle {file_desc = 0},
		read = read_ok,
	}
}

bad_reader func() io.Reader {
	return io.Reader {
		context = null,
		handle = io.Handle {file_desc = 0},
		read = read_too_much,
	}
}

eof_reader func() io.Reader {
	return io.Reader {
		context = null,
		handle = io.Handle {file_desc = 0},
		read = read_eof,
	}
}

short_writer func() io.Writer {
	return io.Writer {
		context = null,
		handle = io.Handle {file_desc = 0},
		write = write_short,
	}
}

none_writer func() io.Writer {
	return io.Writer {
		context = null,
		handle = io.Handle {file_desc = 0},
		write = write_none,
	}
}

bad_writer func() io.Writer {
	return io.Writer {
		context = null,
		handle = io.Handle {file_desc = 0},
		write = write_too_much,
	}
}

rejects_bad_read func() bool {
	buffer [1]mut u8 := [0]
	_ = io.read(bad_reader(), buffer[..]) catch |err| {
		return err == .read_failed
	}
	return false
}

rejects_no_progress func() bool {
	io.print(none_writer(), "{s}", {"x",}) catch |err| {
		return err == .no_progress
	}
	return false
}

rejects_bad_write func() bool {
	_ = io.write(bad_writer(), "x") catch |err| {
		return err == .write_failed
	}
	return false
}

main func(init process.Init) i32 {
	system io.Io :: init.io
	buffer [2]mut u8 := [0, 0]
	count usize :: io.read(ok_reader(), buffer[..]) catch 0
	if count != 2 or buffer[0] != 'o' or buffer[1] != 'k' {
		return 1
	}
	eof usize :: io.read(eof_reader(), buffer[..]) catch 1
	empty_read usize :: io.read(bad_reader(), buffer[0..0]) catch 1
	empty_write usize :: io.write(bad_writer(), "") catch 1
	if eof != 0 or empty_read != 0 or empty_write != 0 {
		return 5
	}
	io.print(short_writer(), "{s}{d}", {"partial", 37}) catch |_| {
		return 2
	}
	if !rejects_bad_read() or !rejects_no_progress() or !rejects_bad_write() {
		return 3
	}
	io.print(io.stdout(system), "io-ok {d} {{bro}}\n", {37,}) catch |_| {
		return 4
	}
	io.print(io.stdout(system), "bounds={d}/{d} {d}/{d} {d}/{d} {d}/{d} {d}/{d} {d}/{d} {d}/{d} {d}/{d} {d}/{d} {d}/{d} {d}/{d} {d}/{d} {d}/{d} {d}/{d}\n", {
		minval!(i8), maxval!(u8),
		minval!(i16), maxval!(u16),
		minval!(i32), maxval!(u32),
		minval!(i64), maxval!(u64),
		minval!(isize), maxval!(usize),
		minval!(c_char), maxval!(c_char),
		minval!(c_schar), maxval!(c_uchar),
		minval!(c_short), maxval!(c_ushort),
		minval!(c_int), maxval!(c_uint),
		minval!(c_long), maxval!(c_ulong),
		minval!(c_longlong), maxval!(c_ulonglong),
		0, 0,
		1, 1,
		-1, 1,
	}) catch |_| {
		return 6
	}
	return 0
}