added metadata dataclass

modules/datatypes/metadata.py

@@ -0,0 +1,157 @@
+from dataclasses import dataclass
+from typing import List, Optional, Any, Dict, TypeVar, Callable, Type, cast
+
+T = TypeVar("T")
+
+
+def from_int(x: Any) -> int:
+    assert isinstance(x, int) and not isinstance(x, bool)
+    return x
+
+
+def from_str(x: Any) -> str:
+    assert isinstance(x, str)
+    return x
+
+
+def from_list(f: Callable[[Any], T], x: Any) -> List[T]:
+    assert isinstance(x, list)
+    return [f(y) for y in x]
+
+
+def from_none(x: Any) -> Any:
+    assert x is None
+    return x
+
+
+def from_union(fs, x):
+    for f in fs:
+        try:
+            return f(x)
+        except AssertionError:
+            pass
+    assert False
+
+
+def to_class(c: Type[T], x: Any) -> dict:
+    assert isinstance(x, c)
+    return cast(Any, x).to_dict()
+
+
+def from_dict(f: Callable[[Any], T], x: Any) -> Dict[str, T]:
+    assert isinstance(x, dict)
+    return {k: f(v) for (k, v) in x.items()}
+
+
+def from_native_dict(f: Callable[[Any], T], x: Any) -> Dict[Any, T]:
+    assert isinstance(x, dict)
+    return x
+
+
+@dataclass
+class ImageMetadata:
+    w: Optional[int]
+    h: Optional[int]
+    tags: List[str]
+    exifdata: Optional[Dict[str, Any]]
+    xmp: Optional[Dict[str, Any]]
+    src: str
+    msrc: str
+    name: str
+    title: str
+    tiff: Optional[str] = None
+    raw: Optional[str] = None
+
+    @staticmethod
+    def from_dict(obj: Any) -> "ImageMetadata":
+        assert isinstance(obj, dict)
+        w = from_union([from_int, from_none], obj.get("w"))
+        h = from_union([from_int, from_none], obj.get("h"))
+        tags = from_list(from_str, obj.get("tags"))
+        exifdata = from_union([from_native_dict, from_none], obj.get("exifdata"))
+        xmp = from_union([from_native_dict, from_none], obj.get("xmp"))
+        src = from_str(obj.get("src"))
+        msrc = from_str(obj.get("msrc"))
+        name = from_str(obj.get("name"))
+        title = from_str(obj.get("title"))
+        tiff = from_union([from_str, from_none], obj.get("tiff"))
+        raw = from_union([from_str, from_none], obj.get("raw"))
+        return ImageMetadata(w, h, tags, exifdata, xmp, src, msrc, name, title, tiff, raw)
+
+    def to_dict(self) -> dict:
+        result: dict = {}
+        if self.w is not None:
+            result["w"] = from_union([from_int, from_none], self.w)
+        if self.h is not None:
+            result["h"] = from_union([from_int, from_none], self.h)
+        result["tags"] = from_list(from_str, self.tags)
+        result["src"] = from_str(self.src)
+        result["msrc"] = from_str(self.msrc)
+        result["name"] = from_str(self.name)
+        result["title"] = from_str(self.title)
+        if self.tiff is not None:
+            result["tiff"] = from_union([from_str, from_none], self.tiff)
+        if self.raw is not None:
+            result["raw"] = from_union([from_str, from_none], self.raw)
+        if self.exifdata is not None:
+            result["exifdata"] = from_union([lambda x: from_native_dict(dict, x), from_none], self.exifdata)
+        if self.xmp is not None:
+            result["xmp"] = from_union([lambda x: from_native_dict(dict, x), from_none], self.xmp)
+        return result
+
+
+@dataclass
+class SubfolderMetadata:
+    url: str
+    name: str
+    metadata: Optional[str] = None
+    thumb: Optional[str] = None
+
+    @staticmethod
+    def from_dict(obj: Any) -> "SubfolderMetadata":
+        assert isinstance(obj, dict)
+        url = from_str(obj.get("url"))
+        name = from_str(obj.get("name"))
+        metadata = from_union([from_none, from_str], obj.get("metadata"))
+        thumb = from_union([from_none, from_str], obj.get("thumb"))
+        return SubfolderMetadata(url, name, metadata, thumb)
+
+    def to_dict(self) -> dict:
+        result: dict = {}
+        result["url"] = from_str(self.url)
+        result["name"] = from_str(self.name)
+        result["metadata"] = from_union([from_none, from_str], self.metadata)
+        result["thumb"] = from_union([from_none, from_str], self.thumb)
+        return result
+
+
+@dataclass
+class Metadata:
+    images: Dict[str, ImageMetadata]
+    subfolders: Optional[List[SubfolderMetadata]] = None
+
+    @staticmethod
+    def from_dict(obj: Any) -> "Metadata":
+        assert isinstance(obj, dict)
+        images = from_dict(ImageMetadata.from_dict, obj.get("images"))
+        subfolders = from_union([lambda x: from_list(SubfolderMetadata.from_dict, x), from_none], obj.get("subfolders"))
+        return Metadata(images, subfolders)
+
+    def to_dict(self) -> dict:
+        result: dict = {}
+        result["images"] = from_dict(lambda x: to_class(ImageMetadata, x), self.images)
+        if self.subfolders is not None:
+            result["subfolders"] = from_union([lambda x: from_list(lambda x: to_class(SubfolderMetadata, x), x), from_none], self.subfolders)
+        return result
+
+    def sort(self, reverse=False) -> "Metadata":
+        self.images = {key: self.images[key] for key in sorted(self.images, reverse=reverse)}
+        return self
+
+
+def top_level_from_dict(s: Any) -> Metadata:
+    return Metadata.from_dict(s)
+
+
+def top_level_to_dict(x: Metadata) -> Any:
+    return to_class(Metadata, x)