xian_algorithm_new/app/services/qgis/map_service.py

"""
地图生成主流程控制器。
协调模板加载、图层过滤、缩放、文本更新、导出。
"""
import os
import time

from qgis.core import QgsProject, QgsDataSourceUri

from app.config.paths import get_logger
from app.config.qgis_mappings import TABLE_RENAMES, SCHEMA_REPLACEMENTS
from .template_cache import TemplateCache
from .template_modifier import TemplateModifier
from .layer_filter import LayerFilter
from .map_exporter import MapExporter
from app.utils.map_zoom import MapZoom
from app.config.paths import get_logger

logger = get_logger("qgis.service")

# 全局模板缓存（跨请求复用）
template_cache = TemplateCache()


class MapService:
    def __init__(self, config: dict):
        self.config = config

    def generate(self, model: dict) -> str:
        """
        执行完整的地图生成流程。

        Args:
            model: 包含地图参数的字典

        Returns:
            地图名称
        """
        t_start = time.time()
        template_path = model["path"]
        project = QgsProject.instance()
        is_cache_hit = template_cache.is_loaded(template_path)

        # 加载/恢复模板
        if is_cache_hit:
            logger.info(f"[缓存命中] {os.path.basename(template_path)}")
            project, texts, extent = template_cache.restore_template(template_path)
            template_cache.reset_project_state(project, texts, extent)
        else:
            logger.info(f"[首次加载] {os.path.basename(template_path)}")
            # 直接读原始模板，不做文件级修改（避免 ZIP 兼容性问题）
            project.read(template_path)

        # 更新图层连接 + GPKG/SRID/表名修正（仅首次加载）
        if not is_cache_hit:
            self._update_db_connections(project)

        # 图层过滤
        LayerFilter().apply(project, model)

        # 地图缩放
        layout = project.layoutManager().layoutByName(model["mapLayout"])
        if layout is None:
            available = [l.name() for l in project.layoutManager().layouts()]
            raise RuntimeError(
                f"模板中未找到布局 '{model['mapLayout']}'，可用布局：{available}"
            )

        map_item = layout.itemById("Map")
        zoom = MapZoom(project, layout, map_item)
        zoom.execute(model["zoomRule"], {
            "X": model["centerX"],
            "Y": model["centerY"],
            "value": model["zoomValue"],
        })

        # 文本更新 + 比例尺 + 导出
        exporter = MapExporter(self.config, layout)
        exporter.update_texts(model)
        exporter.update_scale_bar()
        exporter.export(model["outFile"])

        elapsed = time.time() - t_start
        logger.info(
            f"{'[缓存命中]' if is_cache_hit else '[首次加载]'} "
            f"导出完成: {model['name']}，耗时 {elapsed:.1f}s"
        )
        return model["name"]

    def _update_db_connections(self, project: QgsProject) -> None:
        """更新图层连接 + SRID修正 + GPKG静态层替换"""
        db_config = self.config["db"]
        override = self.config.get("template_override", {})
        actual_schema = override.get("actual", {}).get("schema", "qgis")
        static_config = self.config.get("static_layers", {})
        static_enabled = static_config.get("enabled", False)
        gpkg_dir = static_config.get("gpkg_dir", "")
        static_layers_map = static_config.get("layers", {})

        static_count = 0

        for layer in project.mapLayers().values():
            provider = layer.providerType()

            # GPKG 静态层替换：postgres 表 → 本地 GPKG 文件
            if provider == "postgres" and static_enabled:
                uri_str = layer.dataProvider().uri().uri()
                for name, info in static_layers_map.items():
                    table_key = info["table"]
                    schema, table = table_key.split(".", 1)
                    if f'table="{schema}"."{table}"' in uri_str:
                        gpkg_path = os.path.join(gpkg_dir, info["file"]).replace("\\", "/")
                        layer.setDataSource(gpkg_path, name, "ogr")
                        static_count += 1
                        logger.debug(f"静态图层 {name} → GPKG")
                        break
                else:
                    # 没匹配到静态层，继续处理为 postgres
                    self._fix_postgres_layer(layer, db_config, actual_schema)
                continue

            if provider == "ogr":
                static_count += 1
                continue

            if provider == "postgres":
                self._fix_postgres_layer(layer, db_config, actual_schema)

        if static_count:
            logger.info(f"静态底图已本地化: {static_count} 个图层")

    @staticmethod
    def _fix_postgres_layer(layer, db_config, actual_schema):
        """修正单个 PostgreSQL 图层的连接参数"""
        try:
            uri = layer.dataProvider().uri()
            uri.setConnection(
                db_config["host"],
                str(db_config["port"]),
                db_config["database"],
                db_config["username"],
                db_config["password"],
            )
            # Schema 替换
            uri_str = uri.uri()
            for old_schema in SCHEMA_REPLACEMENTS:
                if f'table="{old_schema}".' in uri_str:
                    uri_str = uri_str.replace(
                        f'table="{old_schema}".',
                        f'table="{actual_schema}".',
                    )
                    uri = QgsDataSourceUri(uri_str)
                    break
            # 表名映射
            uri_str = uri.uri()
            for old_name, new_name in TABLE_RENAMES.items():
                full_old = f'table="{actual_schema}"."{old_name}"'
                full_new = f'table="{actual_schema}"."{new_name}"'
                if full_old in uri_str:
                    uri_str = uri_str.replace(full_old, full_new)
                    uri = QgsDataSourceUri(uri_str)
            # SRID 修正
            uri_str = uri.uri()
            if " srid=0 " in uri_str:
                uri_str = uri_str.replace(" srid=0 ", " srid=4326 ")
                uri = QgsDataSourceUri(uri_str)

            layer.setDataSource(uri.uri(), layer.name(), "postgres")

            if layer.isValid():
                fc = layer.featureCount()
                logger.info(f"图层 {layer.name()} 连接更新成功 ({fc} features)")
            else:
                logger.error(f"图层 {layer.name()} 更新后仍无效")
        except Exception as e:
            logger.error(f"更新图层 {layer.name()} 连接失败: {e}")