big upgrade UwU

sticker_downloader/config.py

@@ -0,0 +1,88 @@
+"""Download settings and file-type handling."""
+
+from __future__ import annotations
+
+from dataclasses import dataclass, field
+from pathlib import Path
+
+from sticker_downloader.errors import InvalidFileType
+
+STATIC = "webp"
+ANIMATED = "tgs"
+VIDEO = "webm"
+THUMBNAIL = "png"
+
+#: Every type the downloader knows how to save, in a stable display order.
+ALL_FILE_TYPES: tuple[str, ...] = (STATIC, ANIMATED, VIDEO, THUMBNAIL)
+
+FILE_TYPE_HELP: dict[str, str] = {
+    STATIC: "static stickers",
+    ANIMATED: "animated stickers (Lottie)",
+    VIDEO: "video stickers",
+    THUMBNAIL: "PNG thumbnails",
+}
+
+DEFAULT_OUTPUT_DIR = Path("downloads")
+DEFAULT_URL_FILE = Path("urls.txt")
+DEFAULT_CONCURRENCY = 8
+DEFAULT_RETRIES = 3
+METADATA_FILE_NAME = "pack.json"
+PACK_THUMBNAIL_STEM = "_pack_thumbnail"
+
+
+@dataclass(frozen=True)
+class DownloadConfig:
+    """Everything that shapes a download run."""
+
+    file_types: frozenset[str] = field(default_factory=lambda: frozenset(ALL_FILE_TYPES))
+    output_dir: Path = DEFAULT_OUTPUT_DIR
+    concurrency: int = DEFAULT_CONCURRENCY
+    retries: int = DEFAULT_RETRIES
+    overwrite: bool = False
+    write_metadata: bool = True
+    pack_thumbnail: bool = True
+    emoji_names: bool = False
+    dry_run: bool = False
+
+    def __post_init__(self) -> None:
+        unknown = sorted(self.file_types - set(ALL_FILE_TYPES))
+        if unknown:
+            raise InvalidFileType(f"unknown file type(s): {', '.join(unknown)}")
+        if not self.file_types:
+            raise InvalidFileType("at least one file type is required")
+        if self.concurrency < 1:
+            raise ValueError("concurrency must be at least 1")
+        if self.retries < 1:
+            raise ValueError("retries must be at least 1")
+
+    @property
+    def sorted_file_types(self) -> list[str]:
+        """The requested types in canonical order, for stable output."""
+        return [file_type for file_type in ALL_FILE_TYPES if file_type in self.file_types]
+
+    def wants(self, file_type: str) -> bool:
+        return file_type in self.file_types
+
+
+def parse_file_types(raw: str | None) -> frozenset[str]:
+    """Turn user input such as ``"webp, png"``, ``"all"`` or ``""`` into a type set.
+
+    Empty input and ``"all"`` both mean "every supported type", matching what the
+    interactive prompt advertises.
+    """
+    text = (raw or "").strip().lower()
+    if not text or text == "all":
+        return frozenset(ALL_FILE_TYPES)
+
+    requested = [part.strip().lstrip(".") for part in text.replace(" ", ",").split(",")]
+    selected = {part for part in requested if part}
+    if not selected:
+        raise InvalidFileType("no file types given")
+
+    unknown = sorted(selected - set(ALL_FILE_TYPES))
+    if unknown:
+        raise InvalidFileType(
+            f"unknown file type(s): {', '.join(unknown)}. "
+            f"Supported: {', '.join(ALL_FILE_TYPES)}, or 'all'."
+        )
+    return frozenset(selected)