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


class MsgA3Payload(ctypes.Structure):
    """Message A3: Graphic Settings - improved mapping (best-effort).

    This structure maps common multiword fields to dedicated ctypes where
    evident in the ICD (lat/long pairs, semicircles). Remaining words are
    kept as uint16 placeholders to preserve word count (32 words total).
    """
    _pack_ = 1
    _fields_ = [
        ("graphic_order", ctypes.c_uint16),           # A3-01
        ("time_to_go", ctypes.c_uint16),              # A3-02 (single-word)
        ("wp1_lat", LatLong),                         # A3-03/04
        ("wp1_long", LatLong),                        # A3-05/06
        ("wp2_lat", LatLong),                         # A3-07/08
        ("wp2_long", LatLong),                        # A3-09/10
        ("wp3_lat", LatLong),                         # A3-11/12
        ("wp3_long", LatLong),                        # A3-13/14
        ("intercept_fd_x", Semicircle),               # A3-15
        ("intercept_fd_y", Semicircle),               # A3-16
        ("intercept_zone_r_min", ctypes.c_uint16),    # A3-17
        ("intercept_zone_r_max", ctypes.c_uint16),    # A3-18
        ("no_escape_zone_r_max", ctypes.c_uint16),    # A3-19
    ] + [(f"word_{i:02d}", ctypes.c_uint16) for i in range(20, 33)]

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