import ctypes
from pymsc.lib1553.datatypes.common_extra import StatusWord, TimeTag
from pymsc.lib1553.datatypes.navigation import Semicircle, Velocity


class MsgB4Payload(ctypes.Structure):
    """Message B4: SPT Target - partial typed mapping.

    Maps status words, time tag, range and normalized position (X,Y,Z) and
    velocity fields where appropriate.
    """
    _pack_ = 1
    _fields_ = [
        ("track_validity_status_1", StatusWord),  # B4-01
        ("track_validity_status_2", StatusWord),  # B4-02
        ("time_tag", TimeTag),                    # B4-03 (two words)
        ("target_range", ctypes.c_uint16),       # B4-04
        ("norm_pos_x", Semicircle),               # B4-05
        ("norm_pos_y", Semicircle),               # B4-06
        ("norm_pos_z", Semicircle),               # B4-07
        ("target_range_rate", ctypes.c_uint16),   # B4-08
        ("target_velocity_mag", Velocity),        # B4-09
        ("target_velocity_x", Velocity),          # B4-10
        ("target_velocity_y", Velocity),          # B4-11
        ("target_velocity_z", Velocity),          # B4-12
    ] + [(f"word_{i:02d}", ctypes.c_uint16) for i in range(13, 33)]

    def __init__(self):
        super().__init__()