from PyQt5.QtCore import QTimer
from PyQt5.QtWidgets import QAction
from qgis.core import Qgis, QgsProject
from qgis.gui import QgisInterface

from .api_client import ApiClient
from .layer_manager import LocationLayerManager
from .notification_server import NotificationServer

_RETRY_INTERVAL_MS = 30_000  # 30 seconds between automatic retries
_API_BASE_URL = "http://localhost:22650"
_NOTIF_PORT = 22651


class BAPEBridgePlugin:
    """Main QGIS plugin class.

    Wires together ApiClient, LocationLayerManager and NotificationServer.
    Provides a checkable toolbar button to toggle the layer on/off.
    """

    def __init__(self, iface: QgisInterface):
        self._iface = iface
        self._active = False

        self._layer_manager: LocationLayerManager | None = None
        self._notif_server: NotificationServer | None = None

        self._toggle_action: QAction | None = None

        # Timer drives periodic retry when the initial API call fails.
        self._retry_timer = QTimer()
        self._retry_timer.setInterval(_RETRY_INTERVAL_MS)
        self._retry_timer.timeout.connect(self._retry_load)

        QgsProject.instance().cleared.connect(self._on_project_cleared)

    # ------------------------------------------------------------------
    # QGIS plugin lifecycle
    # ------------------------------------------------------------------

    def initGui(self) -> None:
        """Add entry to the Layer menu."""
        self._toggle_action = QAction("BAPE Bridge", self._iface.mainWindow())
        self._toggle_action.setCheckable(True)
        self._toggle_action.setToolTip("Enable / disable the BAPE Bridge layer")
        self._toggle_action.triggered.connect(self._on_toggle)
        self._iface.addPluginToLayerMenu("BAPE Bridge", self._toggle_action)

    def unload(self) -> None:
        """Clean up when the plugin is disabled or QGIS closes."""
        self._deactivate()
        self._iface.removePluginFromLayerMenu("BAPE Bridge", self._toggle_action)

    # ------------------------------------------------------------------
    # Toggle on / off
    # ------------------------------------------------------------------

    def _on_toggle(self, checked: bool) -> None:
        if checked:
            self._activate()
        else:
            self._deactivate()

    def _activate(self) -> None:
        if self._active:
            return

        api_client = ApiClient(_API_BASE_URL)
        self._layer_manager = LocationLayerManager(api_client)

        # Create the layer structure (always succeeds).  Initial feature load
        # may fail if the API is not yet reachable; we surface a message and
        # start the retry timer in that case.
        try:
            self._layer_manager.create_layer()
        except Exception:
            self._retry_timer.start()

        # Start the notification server regardless; the layer may be empty
        # but the server should be ready to receive reload calls.
        self._notif_server = NotificationServer(
            self._on_reload_requested,
            self._on_clear_requested,
            port=_NOTIF_PORT,
        )
        try:
            self._notif_server.start()
        except RuntimeError as exc:
            self._iface.messageBar().pushMessage(
                "BAPE Bridge",
                f"Notification server error: {exc}",
                level=Qgis.Critical,
                duration=0,
            )

        self._active = True

    def _deactivate(self) -> None:
        if not self._active:
            return

        self._retry_timer.stop()

        if self._notif_server is not None:
            self._notif_server.stop()
            self._notif_server = None

        if self._layer_manager is not None:
            self._layer_manager.remove_layer()
            self._layer_manager = None

        self._active = False

        if self._toggle_action is not None:
            self._toggle_action.setChecked(False)

    # ------------------------------------------------------------------
    # Reload handling
    # ------------------------------------------------------------------

    def _on_reload_requested(self) -> None:
        """Called (in the main Qt thread) when POST /reload arrives."""
        if self._layer_manager is None:
            return

        success = self._layer_manager.reload_layer()
        if not success:
            pass  # layer name already shows 🔴

    def _on_clear_requested(self) -> None:
        """Called (in the main Qt thread) when POST /clear arrives."""
        if self._layer_manager is None:
            return
        self._layer_manager.clear_layer()

    def _retry_load(self) -> None:
        """Periodic retry: stop the timer once features load successfully."""
        if self._layer_manager is None:
            self._retry_timer.stop()
            return

        if self._layer_manager.reload_layer():
            self._retry_timer.stop()

    def _on_project_cleared(self) -> None:
        """Called when QGIS clears the project (open new/different project).

        The C++ layer objects are already deleted by this point, so we must
        not touch them — just drop references and reset state.
        """
        self._retry_timer.stop()

        if self._notif_server is not None:
            self._notif_server.stop()
            self._notif_server = None

        if self._layer_manager is not None:
            self._layer_manager.layer = None
            self._layer_manager = None

        self._active = False

        if self._toggle_action is not None:
            self._toggle_action.setChecked(False)