from PyQt6.QtWidgets import QPlainTextEdit
from PyQt6.QtGui import QFont
from PyQt6.QtCore import pyqtSignal


class TerminalWidget(QPlainTextEdit):
    line_appended = pyqtSignal(str)

    def __init__(self, parent=None):
        super().__init__(parent)
        self.setReadOnly(True)
        font = QFont()
        font.setFamily("Courier New")
        font.setPointSize(11)
        font.setWeight(QFont.Weight.Bold)
        self.setFont(font)
        self.setStyleSheet("""
            QPlainTextEdit {
                background-color: #0a0e27;
                color: #0fff50;
                border: 3px solid #0fff50;
                border-radius: 8px;
                padding: 10px;
                font-family: 'Courier New', 'Consolas', monospace;
                font-size: 11pt;
                font-weight: bold;
            }
        """)
        self.line_appended.connect(self._append_on_main_thread)
        self._observer = None
        self._topics = []
        self._callbacks = []

    def _append_on_main_thread(self, text):
        self.appendPlainText(text)

    def bind_observer(self, observer, topics):
        self._observer = observer
        self._topics = list(topics)
        for topic in self._topics:
            cb = lambda event, t=topic: self.line_appended.emit(self._format_event(t, event))
            observer.subscribe(topic, cb)
            self._callbacks.append((topic, cb))

    def _format_event(self, topic, event):
        subject = getattr(event, 'subject', None)
        if subject is None:
            return f"[{topic}]"
        return f"[{topic}] {subject}"

    def append(self, text):
        self.line_appended.emit(str(text))