"""
模板 XML 修改模块。在 project.read() 之前：
1. 替换 PostgreSQL 连接参数（host/port/dbname/schema）
2. 将静态底图的 datasource 替换为本地 GeoPackage 路径
"""
import os
import re
import zipfile
import tempfile

from app.config.paths import get_logger

logger = get_logger("qgis.modifier")


class TemplateModifier:
    def __init__(self, config: dict):
        self.config = config
        self._static_map = self._build_static_map()

    def _build_static_map(self) -> dict[str, str]:
        """构建 table_key → gpkg_abs_path 的映射"""
        sl = self.config.get("static_layers")
        if not sl or not sl.get("enabled", False):
            return {}

        gpkg_dir = sl["gpkg_dir"]
        mapping = {}
        for info in sl["layers"].values():
            schema, table = info["table"].split(".", 1)
            xml_key = f'table="{schema}"."{table}"'
            gpkg_path = os.path.join(gpkg_dir, info["file"]).replace("\\", "/")
            mapping[xml_key] = gpkg_path
        return mapping

    def modify(self, template_path: str) -> str:
        """修改模板文件，返回修改后的临时 .qgz 路径"""
        override = self.config.get("template_override")
        has_override = override and override.get("enabled", False)
        has_static = bool(self._static_map)

        if not has_override and not has_static:
            return template_path

        orig = override["original"] if has_override else None
        actual = override["actual"] if has_override else None

        try:
            tmp = tempfile.NamedTemporaryFile(
                suffix=".qgz", delete=False,
                dir=os.path.dirname(template_path),
            )
            tmp_path = tmp.name
            tmp.close()

            datasource_re = re.compile(r"(<datasource>)(.*?)(</datasource>)", re.DOTALL)
            table_re = re.compile(r'table="(\w+)"\."(\w+)"')

            with zipfile.ZipFile(template_path, "r") as zin, \
                 zipfile.ZipFile(tmp_path, "w", zipfile.ZIP_DEFLATED) as zout:

                for item in zin.infolist():
                    data = zin.read(item.filename)

                    if item.filename.endswith(".qgs"):
                        content = data.decode("utf-8")

                        # 替换 host/port/dbname/schema
                        if orig and actual:
                            content = re.sub(
                                rf"(host\s*=\s*['\"])({re.escape(orig['host'])})(['\"])",
                                rf"\g<1>{actual['host']}\3",
                                content,
                            )
                            content = re.sub(
                                rf"(port\s*=\s*['\"])({re.escape(str(orig['port']))})(['\"])",
                                rf"\g<1>{actual['port']}\3",
                                content,
                            )
                            content = re.sub(
                                rf"(dbname\s*=\s*['\"])({re.escape(orig['dbname'])})(['\"])",
                                rf"\g<1>{actual['dbname']}\3",
                                content,
                            )
                            content = content.replace(
                                f'table="{orig["schema"]}".',
                                f'table="{actual["schema"]}".',
                            )

                        # 替换静态底图 datasource
                        if self._static_map:
                            def _replace(m):
                                tbl = table_re.search(m.group(2))
                                if tbl:
                                    key = f'table="{tbl.group(1)}"."{tbl.group(2)}"'
                                    if key in self._static_map:
                                        return f"{m.group(1)}{self._static_map[key]}{m.group(3)}"
                                return m.group(0)

                            content = datasource_re.sub(_replace, content)

                        data = content.encode("utf-8")

                    zout.writestr(item, data)

            logger.info(f"模板已修改并写入: {tmp_path}")
            return tmp_path

        except Exception as e:
            logger.error(f"模板修改失败，将使用原始模板: {e}")
            return template_path