Add Linkki broadcast image

linkki-tiedotus/webapp/config.py

@@ -0,0 +1,57 @@
+import json
+import os
+from dataclasses import dataclass
+from pathlib import Path
+
+
+DEFAULT_TIMEZONE = "UTC"
+DEFAULT_POLL_SECONDS = 60
+
+
+class ConfigFileError(RuntimeError):
+    def __init__(self, path: Path, message: str):
+        super().__init__(f"{path}: {message}")
+        self.path = path
+        self.message = message
+
+
+@dataclass(frozen=True)
+class WebAppConfig:
+    data_dir: Path
+    posts_dir: Path
+    config_dir: Path
+    users_file: Path
+    timezone: str
+    session_secret: str
+    scheduler_poll_seconds: int
+
+
+def load_webapp_config() -> WebAppConfig:
+    data_dir = Path(os.environ.get("LINKKI_DATA_DIR", "data")).resolve()
+    config_dir = data_dir / "config"
+    posts_dir = data_dir / "posts"
+    config_dir.mkdir(parents=True, exist_ok=True)
+    posts_dir.mkdir(parents=True, exist_ok=True)
+
+    config_path = config_dir / "app_config.json"
+    config_data: dict[str, object] = {}
+    if config_path.exists():
+        try:
+            config_data = json.loads(config_path.read_text(encoding="utf-8"))
+        except json.JSONDecodeError as error:
+            raise ConfigFileError(config_path, f"Invalid JSON: {error.msg}") from error
+
+    timezone = str(config_data.get("timezone", DEFAULT_TIMEZONE))
+    session_secret = str(config_data.get("session_secret", "change-me"))
+    poll_seconds = int(config_data.get("scheduler_poll_seconds", DEFAULT_POLL_SECONDS))
+    users_filename = str(config_data.get("users_file", "users.json"))
+
+    return WebAppConfig(
+        data_dir=data_dir,
+        posts_dir=posts_dir,
+        config_dir=config_dir,
+        users_file=config_dir / users_filename,
+        timezone=timezone,
+        session_secret=session_secret,
+        scheduler_poll_seconds=poll_seconds,
+    )