"""
devices/base_device.py

Abstract base class for all DAQ I/O modules.
Every device plugin must subclass BaseDevice and implement the required methods.
"""

from abc import ABC, abstractmethod
from dataclasses import dataclass, field
from typing import Any, Dict, List, Optional
from enum import Enum


class DeviceStatus(Enum):
    DISCONNECTED = "disconnected"
    CONNECTING   = "connecting"
    CONNECTED    = "connected"
    ERROR        = "error"
    SIMULATED    = "simulated"


@dataclass
class SignalConfig:
    """Configuration for a single physical Signal — one I/O stream coming
    off a Device (e.g. an Arduino analog pin, a digital line). Contrast
    with a Channel (core/signal_processor.py), which takes one or more
    Signals and applies math/filters to produce a new derived stream."""
    signal_id:   str
    name:        str
    unit:        str            = ""
    min_value:   float          = 0.0
    max_value:   float          = 100.0
    enabled:     bool           = True
    color:       str            = "#00d4ff"
    writable:    bool           = False  # True if this signal accepts write_channel() calls
    extra:       Dict[str, Any] = field(default_factory=dict)


@dataclass
class DeviceInfo:
    """Metadata describing a device module."""
    device_id:   str
    name:        str
    device_type: str            # "arduino" | "serial" | "nidaqmx" | ...
    description: str            = ""
    manufacturer: str           = ""
    model:       str            = ""
    version:     str            = "1.0.0"
    icon:        str            = "⚙"
    signals:     List[SignalConfig] = field(default_factory=list)


class BaseDevice(ABC):
    """
    Abstract base for all DAQ device plugins.

    To create a new module:
      1. Subclass BaseDevice
      2. Implement all @abstractmethod methods
      3. Drop the file in devices/  — DeviceRegistry auto-discovers it
    """

    def __init__(self, device_info: DeviceInfo):
        self.info   = device_info
        self.status = DeviceStatus.DISCONNECTED
        self._callbacks: List[Any] = []

    # ── Required interface ──────────────────────────────────────────────

    @abstractmethod
    def connect(self) -> bool:
        """Open connection. Returns True on success."""

    @abstractmethod
    def disconnect(self) -> None:
        """Close connection and release resources."""

    @abstractmethod
    def read_channels(self) -> Dict[str, float]:
        """Return {signal_id: value} for all enabled signals."""

    @abstractmethod
    def write_channel(self, channel_id: str, value: Any) -> bool:
        """Write value to an output channel. Returns True on success."""

    @abstractmethod
    def get_config_widget(self):
        """Return a QWidget with device-specific configuration controls."""

    # ── Shared helpers ──────────────────────────────────────────────────

    def add_data_callback(self, cb) -> None:
        self._callbacks.append(cb)

    def _emit(self, channel_id: str, value: float, timestamp: float) -> None:
        for cb in self._callbacks:
            try:
                cb(self.info.device_id, channel_id, value, timestamp)
            except Exception:
                pass

    def get_signal(self, signal_id: str) -> Optional[SignalConfig]:
        return next((s for s in self.info.signals if s.signal_id == signal_id), None)

    def __repr__(self):
        return f"<{self.__class__.__name__} id={self.info.device_id} status={self.status.value}>"


def merge_signal_metadata(old_signals: List[SignalConfig], new_signals: List[SignalConfig]) -> List[SignalConfig]:
    """Reapply user-customized Signal metadata (name/unit/enabled/color) onto a
    freshly rebuilt signal list, keyed by signal_id. Mirrors exactly the fields
    ProfileManager treats as user overrides (core/profile.py capture/apply) so
    identity set at profile-load time survives a later device reconfigure too —
    otherwise a device's own reconfigure()/remap_pins() rebuilding info.signals
    from scratch silently resets names back to hardware defaults. Signal ids
    not present in old_signals (new pins) keep their fresh defaults; ids no
    longer in new_signals (removed pins) are simply dropped."""
    old_by_id = {s.signal_id: s for s in old_signals}
    for sig in new_signals:
        old = old_by_id.get(sig.signal_id)
        if old is not None:
            sig.name, sig.unit, sig.enabled, sig.color = old.name, old.unit, old.enabled, old.color
    return new_signals