"""
ui/device_panel.py  —  Left sidebar: device list with status indicators.
"""

from PyQt6.QtWidgets import (
    QWidget, QVBoxLayout, QHBoxLayout, QLabel,
    QPushButton, QScrollArea, QFrame, QSizePolicy,
)
from PyQt6.QtCore import Qt, pyqtSignal, QTimer
from devices.base_device import DeviceStatus
from devices.device_registry import DeviceRegistry
from core.acquisition import AcquisitionEngine


_STATUS_STYLE = {
    DeviceStatus.CONNECTED:    "color:#22c55e;",
    DeviceStatus.SIMULATED:    "color:#3b82f6;",
    DeviceStatus.DISCONNECTED: "color:#475569;",
    DeviceStatus.CONNECTING:   "color:#f59e0b;",
    DeviceStatus.ERROR:        "color:#ef4444;",
}
_STATUS_LABEL = {
    DeviceStatus.CONNECTED:    "CONNECTED",
    DeviceStatus.SIMULATED:    "SIMULATED",
    DeviceStatus.DISCONNECTED: "OFFLINE",
    DeviceStatus.CONNECTING:   "CONNECTING",
    DeviceStatus.ERROR:        "ERROR",
}


class DeviceCard(QFrame):
    config_requested = pyqtSignal(str)

    def __init__(self, device):
        super().__init__()
        self.device = device
        self.setObjectName("deviceCard")
        self._build()

    def _build(self):
        layout = QVBoxLayout(self)
        layout.setContentsMargins(10, 10, 10, 10)
        layout.setSpacing(5)

        # Header row: icon + name + status dot
        hdr = QHBoxLayout()
        icon_lbl = QLabel(self.device.info.icon)
        icon_lbl.setObjectName("deviceIcon")
        hdr.addWidget(icon_lbl)

        name_lbl = QLabel(self.device.info.name)
        name_lbl.setObjectName("deviceName")
        hdr.addWidget(name_lbl, 1)

        self._dot = QLabel("●")
        self._dot.setStyleSheet(_STATUS_STYLE.get(self.device.status, "color:#475569;") + " font-size:10px;")
        hdr.addWidget(self._dot)
        layout.addLayout(hdr)

        # Device ID
        id_lbl = QLabel(self.device.info.device_id)
        id_lbl.setObjectName("deviceSub")
        layout.addWidget(id_lbl)

        # Status text
        self._status_lbl = QLabel(_STATUS_LABEL.get(self.device.status, "UNKNOWN"))
        style = _STATUS_STYLE.get(self.device.status, "color:#475569;")
        self._status_lbl.setStyleSheet(
            style + " font-family:'IBM Plex Mono',monospace; font-size:10px; font-weight:700; letter-spacing:1px;"
        )
        layout.addWidget(self._status_lbl)

        # Channel count
        n = sum(1 for c in self.device.info.channels if c.enabled)
        ch_lbl = QLabel(f"{n} ch  ·  {self.device.info.device_type}")
        ch_lbl.setObjectName("deviceChannelCount")
        layout.addWidget(ch_lbl)

        # Config button
        cfg = QPushButton("Configure")
        cfg.setObjectName("configButton")
        cfg.clicked.connect(lambda: self.config_requested.emit(self.device.info.device_id))
        layout.addWidget(cfg)

    def refresh(self):
        dot_style   = _STATUS_STYLE.get(self.device.status, "color:#475569;") + " font-size:10px;"
        label_style = _STATUS_STYLE.get(self.device.status, "color:#475569;") + \
                      " font-family:'IBM Plex Mono',monospace; font-size:10px; font-weight:700; letter-spacing:1px;"
        self._dot.setStyleSheet(dot_style)
        self._status_lbl.setText(_STATUS_LABEL.get(self.device.status, "UNKNOWN"))
        self._status_lbl.setStyleSheet(label_style)


class DevicePanel(QWidget):
    config_requested = pyqtSignal(str)

    def __init__(self, registry: DeviceRegistry, engine: AcquisitionEngine):
        super().__init__()
        self.registry = registry
        self.engine   = engine
        self._cards   = {}
        self._build()

        # Refresh status every 2 s
        self._timer = QTimer(self)
        self._timer.setInterval(2000)
        self._timer.timeout.connect(self._refresh_status)
        self._timer.start()

    def _build(self):
        layout = QVBoxLayout(self)
        layout.setContentsMargins(0, 0, 0, 0)
        layout.setSpacing(0)

        hdr = QLabel("  DEVICES")
        hdr.setObjectName("panelHeader")
        hdr.setMinimumHeight(28)
        layout.addWidget(hdr)

        scroll = QScrollArea()
        scroll.setObjectName("deviceScroll")
        scroll.setWidgetResizable(True)
        scroll.setHorizontalScrollBarPolicy(Qt.ScrollBarPolicy.ScrollBarAlwaysOff)

        self._container = QWidget()
        self._inner = QVBoxLayout(self._container)
        self._inner.setContentsMargins(8, 8, 8, 8)
        self._inner.setSpacing(8)
        self._inner.addStretch()

        scroll.setWidget(self._container)
        layout.addWidget(scroll)

    def refresh(self):
        for card in self._cards.values():
            self._inner.removeWidget(card)
            card.deleteLater()
        self._cards.clear()

        for dev in self.registry.all_instances():
            card = DeviceCard(dev)
            card.config_requested.connect(self.config_requested.emit)
            self._inner.insertWidget(self._inner.count() - 1, card)
            self._cards[dev.info.device_id] = card

    def _refresh_status(self):
        for dev_id, card in self._cards.items():
            card.refresh()