import ctypes
from pymsc.lib1553.datatypes.navigation import Semicircle
from pymsc.lib1553.datatypes.common_extra import LatLong


class MsgA7Payload(ctypes.Structure):
    """Message A7: Data Link Targets (Message#1) - partial typed mapping.

    We'll map the validity word and the first five targets (X, Y, ground track)
    to typed fields. Remaining words remain placeholders.
    """
    _pack_ = 1
    _fields_ = [
        ("dl_targets_validity", ctypes.c_uint16),  # A7-01
        # Target 01
        ("t1_pos_x", Semicircle),                   # A7-02
        ("t1_pos_y", Semicircle),                   # A7-03
        ("t1_gnd_track", Semicircle),               # A7-04
        # Target 02
        ("t2_pos_x", Semicircle),                   # A7-08 (approx mapping)
        ("t2_pos_y", Semicircle),
        ("t2_gnd_track", Semicircle),
        # Target 03
        ("t3_pos_x", Semicircle),
        ("t3_pos_y", Semicircle),
        ("t3_gnd_track", Semicircle),
        # Target 04
        ("t4_pos_x", Semicircle),
        ("t4_pos_y", Semicircle),
        ("t4_gnd_track", Semicircle),
        # Target 05
        ("t5_pos_x", Semicircle),
        ("t5_pos_y", Semicircle),
        ("t5_gnd_track", Semicircle),
    ] + [(f"word_{i:02d}", ctypes.c_uint16) for i in range(17, 33)]

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