"""
ui/alarm_panel.py  —  Alarm event log.
"""

from datetime import datetime
from PyQt6.QtWidgets import (
    QWidget, QVBoxLayout, QHBoxLayout, QLabel,
    QScrollArea, QFrame, QPushButton,
)
from PyQt6.QtCore import Qt


class AlarmRow(QFrame):
    def __init__(self, dev_id: str, ch_id: str, value: float, kind: str):
        super().__init__()
        self.setObjectName("alarmEntry")
        color  = "#ef4444" if kind == "high" else "#f59e0b"
        arrow  = "▲" if kind == "high" else "▼"
        self.setStyleSheet(f"QFrame#alarmEntry {{ border-left: 3px solid {color}; }}")

        ts_str = datetime.now().strftime("%H:%M:%S.%f")[:11]
        layout = QHBoxLayout(self)
        layout.setContentsMargins(8, 3, 8, 3)

        msg = QLabel(f"{arrow}  {dev_id}  /  {ch_id}   =  {value:.4f}   [{kind.upper()}]")
        msg.setObjectName("alarmMsg")
        ts  = QLabel(ts_str)
        ts.setObjectName("alarmTs")

        layout.addWidget(msg, 1)
        layout.addWidget(ts)


class AlarmPanel(QWidget):
    def __init__(self):
        super().__init__()
        self._count = 0
        self._build()

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

        hdr_w   = QWidget()
        hdr_w.setObjectName("alarmHeaderWidget")
        hdr_lay = QHBoxLayout(hdr_w)
        hdr_lay.setContentsMargins(0, 0, 4, 0)
        hdr = QLabel("  ALARMS")
        hdr.setObjectName("panelHeader")
        hdr.setMinimumHeight(28)
        hdr_lay.addWidget(hdr, 1)
        clr = QPushButton("Clear")
        clr.setObjectName("clearAlarmsBtn")
        clr.clicked.connect(self.clear)
        hdr_lay.addWidget(clr)
        layout.addWidget(hdr_w)

        self._scroll = QScrollArea()
        self._scroll.setWidgetResizable(True)
        self._container = QWidget()
        self._inner = QVBoxLayout(self._container)
        self._inner.setContentsMargins(4, 4, 4, 4)
        self._inner.setSpacing(2)
        self._inner.addStretch()
        self._scroll.setWidget(self._container)
        layout.addWidget(self._scroll)

    def add_alarm(self, dev_id: str, ch_id: str, value: float, kind: str):
        row = AlarmRow(dev_id, ch_id, value, kind)
        self._inner.insertWidget(0, row)
        self._count += 1
        # Cap at 300 entries
        if self._count > 300:
            item = self._inner.takeAt(self._inner.count() - 2)
            if item and item.widget():
                item.widget().deleteLater()
            self._count -= 1

    def clear(self):
        while self._inner.count() > 1:
            item = self._inner.takeAt(0)
            if item and item.widget():
                item.widget().deleteLater()
        self._count = 0