feat: add multi-chat routing and bill-specific dashboard countdown

src/blackout_notifier/config.py

@@ -1,8 +1,10 @@
 from __future__ import annotations
 
 import os
+from collections.abc import Mapping
 from dataclasses import dataclass
 from pathlib import Path
+from types import MappingProxyType
 
 from dotenv import load_dotenv
 
@@ -15,13 +17,16 @@ class ConfigurationError(ValueError):
 class Config:
     bargheman_token: str
     eitaayar_token: str
-    chat_id: str
-    bill_ids: tuple[str, ...]
+    bill_chat_ids: Mapping[str, tuple[str, ...]]
     state_file: Path
     lookahead_days: int = 5
     request_timeout_seconds: float = 15.0
     max_events_per_bill: int = 25
 
+    @property
+    def bill_ids(self) -> tuple[str, ...]:
+        return tuple(self.bill_chat_ids)
+
     @classmethod
     def from_env(cls) -> Config:
         load_dotenv(override=False)
@@ -29,20 +34,27 @@ class Config:
         values = {
             "BARGHEMAN_TOKEN": os.getenv("BARGHEMAN_TOKEN", "").strip(),
             "EITAAYAR_TOKEN": os.getenv("EITAAYAR_TOKEN", "").strip(),
-            "CHAT_ID": os.getenv("CHAT_ID", "").strip(),
         }
         missing = [name for name, value in values.items() if not value]
 
-        raw_bill_ids = os.getenv("BILL_IDS", "")
-        bill_ids = tuple(
-            dict.fromkeys(part.strip() for part in raw_bill_ids.split(",") if part.strip())
-        )
-        if not bill_ids:
-            missing.append("BILL_IDS")
-        elif invalid := [bill_id for bill_id in bill_ids if not bill_id.isdecimal()]:
-            raise ConfigurationError(
-                f"BILL_IDS must contain only decimal IDs: {', '.join(invalid)}"
+        raw_routes = os.getenv("BILL_CHAT_MAP", "").strip()
+        if raw_routes:
+            bill_chat_ids = _bill_chat_map(raw_routes)
+        else:
+            chat_id = os.getenv("CHAT_ID", "").strip()
+            raw_bill_ids = os.getenv("BILL_IDS", "")
+            bill_ids = tuple(
+                dict.fromkeys(part.strip() for part in raw_bill_ids.split(",") if part.strip())
             )
+            if not chat_id:
+                missing.append("CHAT_ID")
+            if not bill_ids:
+                missing.append("BILL_IDS")
+            elif invalid := [bill_id for bill_id in bill_ids if not bill_id.isdecimal()]:
+                raise ConfigurationError(
+                    f"BILL_IDS must contain only decimal IDs: {', '.join(invalid)}"
+                )
+            bill_chat_ids = {bill_id: (chat_id,) for bill_id in bill_ids}
 
         if missing:
             raise ConfigurationError(
@@ -52,8 +64,7 @@ class Config:
         return cls(
             bargheman_token=values["BARGHEMAN_TOKEN"],
             eitaayar_token=values["EITAAYAR_TOKEN"],
-            chat_id=values["CHAT_ID"],
-            bill_ids=bill_ids,
+            bill_chat_ids=MappingProxyType(bill_chat_ids),
             state_file=Path(os.getenv("STATE_FILE", "state/outages.json").strip()),
             lookahead_days=_integer_setting("LOOKAHEAD_DAYS", 5, minimum=1, maximum=30),
             request_timeout_seconds=_float_setting(
@@ -63,6 +74,36 @@ class Config:
         )
 
 
+def _bill_chat_map(raw_routes: str) -> dict[str, tuple[str, ...]]:
+    routes: dict[str, list[str]] = {}
+    malformed: list[str] = []
+    for raw_route in raw_routes.split(","):
+        route = raw_route.strip()
+        if not route:
+            continue
+        bill_id, separator, chat_id = route.partition(":")
+        bill_id = bill_id.strip()
+        chat_id = chat_id.strip()
+        if not separator or not bill_id or not chat_id:
+            malformed.append(route)
+            continue
+        if not bill_id.isdecimal():
+            raise ConfigurationError(
+                f"BILL_CHAT_MAP bill IDs must be decimal: {bill_id}"
+            )
+        chat_ids = routes.setdefault(bill_id, [])
+        if chat_id not in chat_ids:
+            chat_ids.append(chat_id)
+    if malformed:
+        raise ConfigurationError(
+            "BILL_CHAT_MAP entries must use BILL_ID:CHAT_ID format: "
+            + ", ".join(malformed)
+        )
+    if not routes:
+        raise ConfigurationError("BILL_CHAT_MAP must contain at least one route")
+    return {bill_id: tuple(chat_ids) for bill_id, chat_ids in routes.items()}
+
+
 def _integer_setting(name: str, default: int, *, minimum: int, maximum: int) -> int:
     raw_value = os.getenv(name, str(default)).strip()
     try: