intercept/utils/sdr/airspy.py

"""
Airspy command builder implementation.

Uses SoapySDR-based tools for FM demodulation and signal capture.
Airspy R2/Mini supports 24 MHz to 1.8 GHz frequency range.
Airspy HF+ supports 9 kHz - 31 MHz and 60-260 MHz.
"""

from __future__ import annotations

from utils.dependencies import get_tool_path

from .base import CommandBuilder, SDRCapabilities, SDRDevice, SDRType


class AirspyCommandBuilder(CommandBuilder):
    """Airspy command builder using SoapySDR tools."""

    # Airspy R2/Mini capabilities (most common)
    # HF+ has different range but same interface
    CAPABILITIES = SDRCapabilities(
        sdr_type=SDRType.AIRSPY,
        freq_min_mhz=24.0,  # 24 MHz (HF+ goes lower)
        freq_max_mhz=1800.0,  # 1.8 GHz
        gain_min=0.0,
        gain_max=45.0,  # LNA (0-15) + Mixer (0-15) + VGA (0-15)
        sample_rates=[2500000, 3000000, 6000000, 10000000],
        supports_bias_t=True,
        supports_ppm=False,  # Airspy has TCXO, no PPM needed
        tx_capable=False,
    )

    def _build_device_string(self, device: SDRDevice) -> str:
        """Build SoapySDR device string for Airspy."""
        driver = device.driver if device.driver in ("airspy", "airspyhf") else "airspy"
        if device.serial and device.serial != "N/A":
            return f"driver={driver},serial={device.serial}"
        return f"driver={driver}"

    def _format_gain(self, gain: float) -> str:
        """
        Format gain string for Airspy.

        Airspy has three gain stages:
        - LNA: 0-15 dB
        - Mixer: 0-15 dB
        - VGA: 0-15 dB

        This distributes the requested gain across stages.
        """
        if gain <= 15:
            return f"LNA={int(gain)},MIX=0,VGA=0"
        elif gain <= 30:
            return f"LNA=15,MIX={int(gain - 15)},VGA=0"
        else:
            vga = min(15, int(gain - 30))
            return f"LNA=15,MIX=15,VGA={vga}"

    def build_fm_demod_command(
        self,
        device: SDRDevice,
        frequency_mhz: float,
        sample_rate: int = 22050,
        gain: float | None = None,
        ppm: int | None = None,
        modulation: str = "fm",
        squelch: int | None = None,
        bias_t: bool = False,
    ) -> list[str]:
        """
        Build SoapySDR rx_fm command for FM demodulation.

        For pager decoding with Airspy.
        """
        device_str = self._build_device_string(device)

        rx_fm_path = get_tool_path("rx_fm") or "rx_fm"
        cmd = [
            rx_fm_path,
            "-d",
            device_str,
            "-f",
            f"{frequency_mhz}M",
            "-M",
            modulation,
            "-s",
            str(sample_rate),
        ]

        if gain is not None and gain > 0:
            cmd.extend(["-g", self._format_gain(gain)])

        if squelch is not None and squelch > 0:
            cmd.extend(["-l", str(squelch)])

        if bias_t:
            cmd.extend(["-T"])

        # Output to stdout
        cmd.append("-")

        return cmd

    def build_adsb_command(self, device: SDRDevice, gain: float | None = None, bias_t: bool = False) -> list[str]:
        """
        Build dump1090/readsb command with SoapySDR support for ADS-B decoding.

        Uses readsb which has better SoapySDR support.
        """
        device_str = self._build_device_string(device)

        cmd = ["readsb", "--net", "--device-type", "soapysdr", "--device", device_str, "--quiet"]

        if gain is not None:
            cmd.extend(["--gain", str(int(gain))])

        if bias_t:
            cmd.extend(["--enable-bias-t"])

        return cmd

    def build_ism_command(
        self,
        device: SDRDevice,
        frequency_mhz: float = 433.92,
        gain: float | None = None,
        ppm: int | None = None,
        bias_t: bool = False,
    ) -> list[str]:
        """
        Build rtl_433 command with SoapySDR support for ISM band decoding.

        rtl_433 has native SoapySDR support via -d flag.
        """
        device_str = self._build_device_string(device)

        cmd = ["rtl_433", "-d", device_str, "-f", f"{frequency_mhz}M", "-F", "json"]

        if gain is not None and gain > 0:
            cmd.extend(["-g", str(int(gain))])

        if bias_t:
            cmd.extend(["-T"])

        return cmd

    def build_ais_command(
        self,
        device: SDRDevice,
        gain: float | None = None,
        bias_t: bool = False,
        tcp_port: int = 10110,
        udp_host: str | None = None,
        udp_port: int | None = None,
    ) -> list[str]:
        """
        Build AIS-catcher command for AIS vessel tracking with Airspy.

        Uses AIS-catcher with SoapySDR support.
        """
        device_str = self._build_device_string(device)

        cmd = [
            "AIS-catcher",
            "-d",
            f"soapysdr -d {device_str}",
            "-S",
            str(tcp_port),
            "-o",
            "5",
            "-q",
        ]

        if gain is not None and gain > 0:
            cmd.extend(["-gr", "tuner", str(int(gain))])

        if bias_t:
            cmd.extend(["-gr", "biastee", "1"])

        if udp_host and udp_port:
            cmd.extend(["-u", udp_host, str(udp_port)])

        return cmd

    def build_iq_capture_command(
        self,
        device: SDRDevice,
        frequency_mhz: float,
        sample_rate: int = 2048000,
        gain: float | None = None,
        ppm: int | None = None,
        bias_t: bool = False,
        output_format: str = "cu8",
    ) -> list[str]:
        """
        Build rx_sdr command for raw I/Q capture with Airspy.

        Outputs unsigned 8-bit I/Q pairs to stdout for waterfall display.
        """
        device_str = self._build_device_string(device)
        freq_hz = int(frequency_mhz * 1e6)

        rx_sdr_path = get_tool_path("rx_sdr") or "rx_sdr"
        cmd = [
            rx_sdr_path,
            "-d",
            device_str,
            "-f",
            str(freq_hz),
            "-s",
            str(sample_rate),
            "-F",
            "CU8",
        ]

        if gain is not None and gain > 0:
            cmd.extend(["-g", self._format_gain(gain)])

        if bias_t:
            cmd.append("-T")

        # Output to stdout
        cmd.append("-")

        return cmd

    def get_capabilities(self) -> SDRCapabilities:
        """Return Airspy capabilities."""
        return self.CAPABILITIES

    @classmethod
    def get_sdr_type(cls) -> SDRType:
        """Return SDR type."""
        return SDRType.AIRSPY