"""
Apollo BPSK Subcarrier Demodulator — convenience wrapper.

Hierarchical block combining subcarrier_extract + bpsk_demod into a single
block for the common case of extracting and demodulating the 1.024 MHz PCM
subcarrier from the PM demodulator output.

This resolves the naming used in __init__.py and provides a simple
"float in, bytes out" interface.

Reference: IMPLEMENTATION_SPEC.md section 4.2
"""

from gnuradio import gr

from apollo.bpsk_demod import bpsk_demod
from apollo.constants import PCM_BPF_BW_HZ, PCM_HIGH_BIT_RATE, PCM_SUBCARRIER_HZ
from apollo.subcarrier_extract import subcarrier_extract


class bpsk_subcarrier_demod(gr.hier_block2):
    """Combined subcarrier extraction + BPSK demodulation.

    Inputs:
        float — PM demodulator output (composite subcarrier signal)

    Outputs:
        byte — recovered NRZ bits (0 or 1)
    """

    def __init__(
        self,
        subcarrier_freq: float = PCM_SUBCARRIER_HZ,
        bandwidth: float = PCM_BPF_BW_HZ,
        bit_rate: float = PCM_HIGH_BIT_RATE,
        sample_rate: float = 5_120_000,
        decimation: int = 1,
        loop_bw: float = 0.045,
    ):
        gr.hier_block2.__init__(
            self,
            "apollo_bpsk_subcarrier_demod",
            gr.io_signature(1, 1, gr.sizeof_float),
            gr.io_signature(1, 1, gr.sizeof_char),
        )

        # Subcarrier extraction: bandpass + translate to baseband
        self.extract = subcarrier_extract(
            center_freq=subcarrier_freq,
            bandwidth=bandwidth,
            sample_rate=sample_rate,
            decimation=decimation,
        )

        # BPSK demodulation: carrier recovery + symbol sync + slicer
        output_rate = sample_rate / decimation
        self.demod = bpsk_demod(
            symbol_rate=bit_rate,
            sample_rate=output_rate,
            loop_bw=loop_bw,
        )

        # Connect: float input → extract → demod → byte output
        self.connect(self, self.extract, self.demod, self)