fix: use lazy FTP connection initialization to avoid connecting on import

pysus/online_data/CIHA.py

@@ -12,8 +12,9 @@
 from pysus.ftp import CACHEPATH
 from pysus.ftp.databases.ciha import CIHA
 from pysus.ftp.utils import parse_UFs
+from pysus.online_data._lazy import _LazyDatabase
 
-ciha = CIHA().load()
+ciha = _LazyDatabase(CIHA)
 
 
 def get_available_years(

pysus/online_data/CNES.py

@@ -4,8 +4,9 @@
 from pysus.ftp import CACHEPATH
 from pysus.ftp.databases.cnes import CNES
 from pysus.ftp.utils import parse_UFs
+from pysus.online_data._lazy import _LazyDatabase
 
-cnes = CNES().load()
+cnes = _LazyDatabase(CNES)
 
 
 group_dict = {

pysus/online_data/IBGE.py

@@ -14,13 +14,14 @@
 import urllib3
 from pysus.data.local import ParquetSet
 from pysus.ftp.databases.ibge_datasus import IBGEDATASUS
+from pysus.online_data._lazy import _LazyDatabase
 
 # requests.packages.urllib3.util.ssl_.DEFAULT_CIPHERS = 'ALL:@SECLEVEL=1'
 
 
 APIBASE = "https://servicodados.ibge.gov.br/api/v3/"
 
-ibge = IBGEDATASUS().load()
+ibge = _LazyDatabase(IBGEDATASUS)
 
 
 def get_sidra_table(

pysus/online_data/PNI.py

@@ -7,8 +7,9 @@
 from pysus.ftp import CACHEPATH
 from pysus.ftp.databases.pni import PNI
 from pysus.ftp.utils import parse_UFs
+from pysus.online_data._lazy import _LazyDatabase
 
-pni = PNI().load()
+pni = _LazyDatabase(PNI)
 
 
 def get_available_years(group, states):

pysus/online_data/SIA.py

@@ -13,8 +13,9 @@
 from pysus.ftp import CACHEPATH
 from pysus.ftp.databases.sia import SIA
 from pysus.ftp.utils import parse_UFs
+from pysus.online_data._lazy import _LazyDatabase
 
-sia = SIA().load()
+sia = _LazyDatabase(SIA)
 
 
 group_dict: Dict[str, Tuple[str, int, int]] = {

pysus/online_data/SIH.py

@@ -10,8 +10,9 @@
 from pysus.ftp import CACHEPATH
 from pysus.ftp.databases.sih import SIH
 from pysus.ftp.utils import parse_UFs
+from pysus.online_data._lazy import _LazyDatabase
 
-sih = SIH().load()
+sih = _LazyDatabase(SIH)
 
 
 def get_available_years(

pysus/online_data/SIM.py

@@ -14,8 +14,9 @@
 from pysus.ftp import CACHEPATH
 from pysus.ftp.databases.sim import SIM
 from pysus.ftp.utils import parse_UFs
+from pysus.online_data._lazy import _LazyDatabase
 
-sim = SIM().load()
+sim = _LazyDatabase(SIM)
 
 
 def get_available_years(

pysus/online_data/SINAN.py

@@ -4,8 +4,9 @@
 import pandas as pd
 from pysus.ftp import CACHEPATH
 from pysus.ftp.databases.sinan import SINAN
+from pysus.online_data._lazy import _LazyDatabase
 
-sinan = SINAN().load()
+sinan = _LazyDatabase(SINAN)
 
 
 def list_diseases() -> dict:

pysus/online_data/SINASC.py

@@ -10,8 +10,9 @@
 from pysus.ftp import CACHEPATH
 from pysus.ftp.databases.sinasc import SINASC
 from pysus.ftp.utils import parse_UFs
+from pysus.online_data._lazy import _LazyDatabase
 
-sinasc = SINASC().load()
+sinasc = _LazyDatabase(SINASC)
 
 
 def get_available_years(group: str, states: Union[str, list[str]]) -> list:

pysus/online_data/_lazy.py

@@ -0,0 +1,44 @@
+"""
+Lazy database wrapper to defer FTP connections until first use.
+
+This avoids connecting to the FTP server on import, which can cause
+hangs and failures when the server is unavailable.
+"""
+
+from loguru import logger
+
+
+class _LazyDatabase:
+    """Base lazy wrapper that defers FTP connection until the database is
+    actually accessed. All attribute access is transparently proxied to
+    the underlying database instance.
+
+    Subclasses only need to override ``_ensure_loaded`` if custom
+    initialisation logic is required; the default implementation calls
+    ``db_class().load()`` with error handling for FTP failures.
+    """
+
+    def __init__(self, db_class):
+        # Use object.__setattr__ to avoid triggering __getattr__
+        object.__setattr__(self, "_db_class", db_class)
+        object.__setattr__(self, "_instance", None)
+
+    def _ensure_loaded(self):
+        if self._instance is None:
+            try:
+                instance = self._db_class().load()
+            except Exception as exc:
+                logger.error(
+                    "Failed to connect to FTP server for "
+                    f"{self._db_class.__name__}: {exc}"
+                )
+                raise ConnectionError(
+                    f"Could not load {self._db_class.__name__} database. "
+                    "The FTP server may be unavailable. "
+                    f"Original error: {exc}"
+                ) from exc
+            object.__setattr__(self, "_instance", instance)
+        return self._instance
+
+    def __getattr__(self, name):
+        return getattr(self._ensure_loaded(), name)