"""Embedded offscreen 3D mesh viewport for the Qt dashboard."""

from __future__ import annotations

from pipeline.frame import FingerFrameView
from viz.offscreen_mesh import OffscreenFingerMeshRenderer

from ..layout import DashboardLayout, LAYOUT
from .qt_pixmap import ndarray_to_pixmap
from .image_panel import ImagePanel


class MeshViewportWidget(ImagePanel):
    """Render the finger mesh offscreen in a square 1:1 viewport."""

    def __init__(self, parent=None, *, layout: DashboardLayout = LAYOUT):
        self._layout = layout
        self._renderer: OffscreenFingerMeshRenderer | None = None
        self._mesh_map = "depth"
        self._threshold = 0.0
        self._enable_3d = True
        slot = layout.top_slot("mesh")
        super().__init__(
            title=layout.mesh_panel_title,
            object_name="meshViewport",
            default_side=min(slot.width_px, slot.height_px),
            parent=parent,
        )

    def configure(self, pipeline) -> None:
        self._mesh_map = pipeline.config.mesh_map
        self._threshold = pipeline.config.flow_threshold
        self._enable_3d = pipeline.config.enable_3d and pipeline.uv_mesh is not None
        if self._renderer is not None:
            self._renderer.close()
            self._renderer = None
        if not self._enable_3d:
            self.label.setText(
                "3D mesh disabled" if not pipeline.config.enable_3d else "3D mesh unavailable"
            )
            self.set_source_pixmap(None)
            return
        self.label.setText("")
        self._init_renderer(pipeline)

    def _init_renderer(self, pipeline) -> None:
        if not self._enable_3d or pipeline.uv_mesh is None:
            return
        side = self.side_length
        self._renderer = OffscreenFingerMeshRenderer(
            pipeline.uv_mesh,
            width=side,
            height=side,
            threshold=self._threshold,
            color_mode=self._mesh_map,
            world_to_cam=pipeline.world_to_cam,
            lookat=pipeline.mesh_lookat,
        )

    def on_side_length_changed(self, side: int) -> None:
        if self._renderer is not None:
            self._renderer.resize(side, side)

    def update_frame(self, frame: FingerFrameView) -> None:
        if not self._enable_3d or self._renderer is None:
            return
        rgb = self._renderer.render(
            flow=frame.flow,
            scalar_map=frame.depth_map,
            centroid=frame.centroid,
            centroid_found=frame.centroid_found,
            fnormal=frame.fnormal,
        )
        self.set_source_pixmap(ndarray_to_pixmap(rgb, bgr=False))

    def close_renderer(self) -> None:
        if self._renderer is not None:
            self._renderer.close()
            self._renderer = None