"""ctypes port of the shared wave generator RTU codec."""
import ctypes as C
from .signal_reconstruction import library

class WaveProtocol:
    def __init__(self, address=16):
        if not 1 <= address <= 247:
            raise ValueError("Адрес должен быть 1…247")
        self.address = address
        self.lib = library()
        p = C.POINTER(C.c_uint8)
        self.lib.set_wave_request.argtypes = [C.c_uint, C.c_uint, C.c_uint, C.c_uint, p, C.c_size_t]
        self.lib.set_wave_request.restype = C.c_size_t
        self.lib.set_wave_response.argtypes = [p, p, C.c_size_t, C.POINTER(C.c_uint16), C.c_size_t]
        self.lib.set_wave_response.restype = C.c_int
        self.lib.set_wave_block_request.argtypes = [C.c_uint, C.c_uint, C.POINTER(C.c_uint16), C.c_size_t, p, C.c_size_t]
        self.lib.set_wave_block_request.restype = C.c_size_t
        self.lib.set_wave_block_response.argtypes = [p, C.c_size_t, p, C.c_size_t, C.POINTER(C.c_uint16), C.c_size_t]
        self.lib.set_wave_block_response.restype = C.c_int

    def block_request(self, index, values=None, count=None):
        count = len(values) if values is not None else count
        if count is None or not 1 <= count <= 120:
            raise ValueError("Блок должен содержать 1…120 отсчётов")
        if values is not None and any(not 0 <= value <= 4095 for value in values):
            raise ValueError("Коды ЦАП должны быть 0…4095")
        samples = (C.c_uint16 * count)(*values) if values is not None else None
        output = (C.c_uint8 * 249)()
        size = self.lib.set_wave_block_request(self.address, index, samples, count, output, len(output))
        if not size:
            raise ValueError("Недопустимый блок генератора")
        return bytes(output[:size])

    def block_response(self, request, reply):
        words = (C.c_uint16 * 120)()
        code = self.lib.set_wave_block_response((C.c_uint8 * len(request)).from_buffer_copy(request), len(request),
            (C.c_uint8 * len(reply)).from_buffer_copy(reply), len(reply), words, len(words))
        if code == 0:
            return None
        if code < 0:
            raise ValueError(f"Неверный ответ блока генератора ({code})")
        return tuple(words[:code])

    def request(self, operation, index=0, value=0):
        output = (C.c_uint8 * 8)()
        if self.lib.set_wave_request(self.address, operation, index, value, output, 8) != 8:
            raise ValueError("Недопустимая команда генератора")
        return bytes(output)

    def response(self, request, reply):
        if len(request) != 8:
            raise ValueError("Неверный запрос")
        words = (C.c_uint16 * 8)()
        code = self.lib.set_wave_response((C.c_uint8 * 8).from_buffer_copy(request),
            (C.c_uint8 * len(reply)).from_buffer_copy(reply), len(reply), words, len(words))
        if code == 0:
            return None
        if code < 0:
            raise ValueError(f"Неверный ответ генератора или исключение устройства ({code})")
        return tuple(words[:code])

    @staticmethod
    def status(words, rate_high=0):
        if len(words) != 8 or words[0] != 0x5747 or words[1] not in (1, 2, 3):
            raise ValueError("Устройство не поддерживает генератор WG v1/v2/v3")
        return dict(version=words[1], running=bool(words[2]), rate=(rate_high << 16) | words[3], count=words[4],
                    received=words[5], ready=bool(words[6]), capacity=words[7])