"""
地图缩放策略模块。支持 5 种缩放模式。
"""
from qgis.core import (
    QgsPointXY, QgsGeometry, QgsRectangle,
    QgsCoordinateTransform, QgsCoordinateReferenceSystem,
)

from app.config.paths import get_logger

logger = get_logger("qgis.zoom")

ZOOM_RULES = {
    "11": "pan_to_center",
    "12": "by_layer",
    "13": "layer_intersect",
    "14": "center_distance",
    "15": "layer_merged",
}


class MapZoom:
    def __init__(self, project, layout, map_item):
        self.project = project
        self.layout = layout
        self.map_item = map_item

    def execute(self, rule: str, data: dict) -> None:
        """执行缩放操作"""
        method_name = ZOOM_RULES.get(rule, "pan_to_center")
        method = getattr(self, method_name)
        logger.info(f"缩放: {method_name}, 参数: {data}")
        method(data)

    def _make_transform(self, source_crs=None) -> QgsCoordinateTransform:
        qct = QgsCoordinateTransform()
        qct.setDestinationCrs(self.map_item.crs())
        qct.setSourceCrs(
            source_crs if source_crs
            else QgsCoordinateReferenceSystem("EPSG:4326")
        )
        return qct

    def pan_to_center(self, data: dict) -> None:
        qct = self._make_transform()
        point = QgsPointXY(float(data["X"]), float(data["Y"]))
        geom = QgsGeometry.fromWkt(point.asWkt())
        geom.transform(qct, QgsCoordinateTransform.ForwardTransform)
        center = geom.asPoint()
        qr = QgsRectangle.fromCenterAndSize(
            center, self.map_item.extent().width(), self.map_item.extent().height()
        )
        self.map_item.zoomToExtent(qr)

    def center_distance(self, data: dict) -> None:
        qct = self._make_transform()
        point = QgsPointXY(float(data["X"]), float(data["Y"]))
        geom = QgsGeometry.fromWkt(point.asWkt())
        geom.transform(qct, QgsCoordinateTransform.ForwardTransform)
        box = geom.buffer(float(data["value"]) / 1000, 100).boundingBox()
        self.map_item.zoomToExtent(box.buffered(box.width() * 0.1))

    def by_layer(self, data: dict) -> None:
        layers = self.project.mapLayersByName(data["value"])
        if not layers:
            logger.warning(f"图层不存在: {data['value']}")
            return
        layer = layers[0]
        if layer.featureCount() == 0:
            self.pan_to_center(data)
            return
        qct = self._make_transform(layer.crs())
        geom = QgsGeometry.fromWkt(layer.extent().asWktPolygon())
        geom.transform(qct, QgsCoordinateTransform.ForwardTransform)
        box = geom.boundingBox()
        self.map_item.zoomToExtent(box.buffered(box.width() * 0.1))

    def layer_merged(self, data: dict) -> None:
        names = data["value"].split(",")
        combined = None
        for name in names:
            layers = self.project.mapLayersByName(name.strip())
            if not layers:
                continue
            layer = layers[0]
            qct = self._make_transform(layer.crs())
            geom = QgsGeometry.fromWkt(layer.extent().asWktPolygon())
            geom.transform(qct, QgsCoordinateTransform.ForwardTransform)
            box = geom.boundingBox()
            if combined is None:
                combined = box
            else:
                combined.combineExtentWith(box)
        if combined:
            self.map_item.zoomToExtent(combined.buffered(combined.width() * 0.1))

    def layer_intersect(self, data: dict) -> None:
        names = data["value"].split(",")
        intersection = None
        for name in names:
            layers = self.project.mapLayersByName(name.strip())
            if not layers:
                continue
            layer = layers[0]
            qct = self._make_transform(layer.crs())
            layer.selectAll()
            geom = None
            for fid in layer.selectedFeatureIds():
                if geom is None:
                    geom = layer.getGeometry(fid)
                else:
                    geom = geom.combine(layer.getGeometry(fid))
            if geom:
                qgm = QgsGeometry.fromWkt(geom.asWkt())
                qgm.transform(qct, QgsCoordinateTransform.ForwardTransform)
                box = qgm.boundingBox()
                if intersection is None:
                    intersection = box
                else:
                    intersection = intersection.intersection(box)
        if intersection:
            bbox = intersection.boundingBox()
            self.map_item.zoomToExtent(bbox.buffered(bbox.width() * 0.1))