Add unified DepoFetcher interface

fin_depo/data.py

@@ -3,6 +3,7 @@ import dataclasses
 import datetime
 from collections.abc import Iterable, Mapping
 from decimal import Decimal
+from typing import TypeVar
 
 import enforce_typing
 from fin_defs import Asset
@@ -69,3 +70,23 @@ class DepoGroup(Depo):
             summed += nested_depo.get_amount_of_asset(asset)
             del nested_depo
         return summed
+
+T = TypeVar('T')
+
+class DepoFetcher(abc.ABC):
+    """Base `Depo` fetcher interface.
+
+    Used to get depository information for specific websites/backends.
+    """
+
+    @abc.abstractmethod
+    def get_depo(self) -> Depo:
+        """Fetches the `Depo`s available for the fetcher, possibly as
+        a `DepoGroup`.
+        """
+
+    def assert_param(self, param_name: str, param_type: type[T], param_value: T) -> T:
+        if not isinstance(param_value, param_type):
+            msg = f'{self} expected {param_name} parameter of type {param_type}, but got: {param_value}'
+            raise TypeError(msg)
+        return param_value

fin_depo/defi_kraken.py

@@ -7,12 +7,12 @@ from decimal import Decimal
 import fin_defs
 import krakenex
 
-from .data import Depo, DepoSingle
+from .data import Depo, DepoSingle, DepoFetcher
 
 logger = logging.getLogger(__name__)
 
 
-class KrakenDepoFetcher:
+class KrakenDepoFetcher(DepoFetcher):
     """Depository fetcher for [Kraken](https://www.kraken.com), the online crypto currency exchange.
 
     Requirements for use:
@@ -27,6 +27,8 @@ class KrakenDepoFetcher:
     """
 
     def __init__(self, kraken_key: str, kraken_secret: str):
+        self.assert_param('kraken_key', str, kraken_key)
+        self.assert_param('kraken_secret', str, kraken_secret)
         assert kraken_key is not None, 'Missing kraken_key'
         assert kraken_secret is not None, 'Missing kraken_secret'
         self.client = krakenex.API(

fin_depo/defi_kucoin.py

@@ -7,13 +7,13 @@ from decimal import Decimal
 import fin_defs
 import kucoin.client
 
-from .data import DepoGroup, DepoSingle
+from .data import DepoGroup, DepoSingle, DepoFetcher
 
 logger = logging.getLogger(__name__)
 
 
-class KucoinDepoFetcher:
-    """Depository fetcher for [Kucoin](https://www.kucoin.com), the online crypto currency exchange.
+class KucoinDepoFetcher(DepoFetcher):
+    """`Depo` fetcher for [Kucoin](https://www.kucoin.com), the online crypto currency exchange.
 
     Requirements for use:
     - Account on [Kucoin](https://www.kucoin.com).
@@ -27,9 +27,9 @@ class KucoinDepoFetcher:
     """
 
     def __init__(self, kucoin_key: str, kucoin_secret: str, kucoin_pass: str):
-        assert kucoin_key is not None, 'Missing kucoin_key'
-        assert kucoin_secret is not None, 'Missing kucoin_secret'
-        assert kucoin_pass is not None, 'Missing kucoin_pass'
+        self.assert_param('kucoin_key', str, kucoin_key)
+        self.assert_param('kucoin_secret', str, kucoin_secret)
+        self.assert_param('kucoin_pass', str, kucoin_pass)
         self.client = kucoin.client.Client(
             kucoin_key,
             kucoin_secret,

fin_depo/defi_partisia_blockchain.py

@@ -2,6 +2,7 @@
 
 import dataclasses
 import datetime
+import requests
 import email.utils
 import json
 import logging
@@ -12,7 +13,7 @@ import fin_defs
 import requests
 from frozendict import frozendict
 
-from .data import DepoGroup, DepoSingle
+from .data import DepoGroup, DepoSingle, DepoFetcher
 
 logger = logging.getLogger(__name__)
 
@@ -138,7 +139,7 @@ BYOC_ASSETS = {
 }
 
 
-class PartisiaBlockchainAccountDepoFetcher:
+class PartisiaBlockchainAccountDepoFetcher(DepoFetcher):
     """Depository fetcher for individual [Partisia
     Blockchain](https://partisiablockchain.com/) accounts, including [MPC](https://partisiablockchain.gitlab.io/documentation/pbc-fundamentals/mpc-token-model-and-account-elements.html) and
     [Bring-Your-Own-Coin](https://partisiablockchain.gitlab.io/documentation/pbc-fundamentals/byoc/introduction-to-byoc.html).
@@ -150,9 +151,9 @@ class PartisiaBlockchainAccountDepoFetcher:
     depo.
     """
 
-    def __init__(self, session, blockchain_address: str):
-        assert session is not None, 'missing session'
-        assert blockchain_address is not None, 'missing blockchain_address'
+    def __init__(self, session: requests.Session, blockchain_address: str):
+        self.assert_param('session', requests.Session, session)
+        self.assert_param('blockchain_address', str, blockchain_address)
 
         self.client = PbcClient(session)
         self.blockchain_address = blockchain_address

fin_depo/investbank_nordnet.py

@@ -11,12 +11,13 @@ I am grateful for his pioneering work.
 
 import datetime
 import logging
+import requests
 from decimal import Decimal
 
 import fin_defs
 from frozendict import frozendict
 
-from .data import Depo, DepoGroup, DepoSingle
+from .data import Depo, DepoGroup, DepoSingle, DepoFetcher
 
 logger = logging.getLogger(__name__)
 
@@ -41,7 +42,7 @@ def asset_from_instrument_json(json) -> fin_defs.Asset | None:
 
 EMPTY_DICT: dict[str,str | int] = frozendict()
 
-class NordnetDepoFetcher:
+class NordnetDepoFetcher(DepoFetcher):
     """Depository fetcher for [Nordnet](https://nordnet.dk), the online investment bank.
 
     Requirements for use:
@@ -57,23 +58,14 @@ class NordnetDepoFetcher:
     `Depo`, with all of them nested under a "Nordnet" nested depository.
     """
 
-    def __init__(self, session, username: str, password: str):
-        self.session = session
-        self.username = username
-        self.password = password
+    def __init__(self, session: requests.Session, username: str, password: str):
+
+        self.session = self.assert_param('session', requests.Session, session)
+        self.username: str = self.assert_param('username', str, username)
+        self.password: str = self.assert_param('password', str, password)
         self.is_logged_in = False
 
-        if self.session is None:
-            msg = 'Session argument is missing'
-            raise TypeError(msg)
-        if self.username is not None:
-            msg = 'Username argument s missing'
-            raise TypeError(msg)
-        if self.password is not None:
-            msg = 'Password argument is missing'
-            raise TypeError(msg)
-
-    def get_json(self, url: str, params: dict[str, str | int] = EMPTY_DICT)-> dict:
+    def _get_json(self, url: str, params: dict[str, str | int] = EMPTY_DICT)-> dict:
         if not url.startswith(API_ROOT):
             msg = f'Given url must be located below API ROOT: {url}'
             raise ValueError(msg)
@@ -115,7 +107,7 @@ class NordnetDepoFetcher:
             tz=datetime.UTC,
         )  # TODO: Use info from json requests
 
-        json_accounts = self.get_json(API_ACCOUNTS)
+        json_accounts = self._get_json(API_ACCOUNTS)
 
         nested: list[Depo] = []
         for json_account in json_accounts:
@@ -125,7 +117,7 @@ class NordnetDepoFetcher:
 
             # Determine amount of usable currency stored on Nordnet
             if True:
-                json_account_info = self.get_json(
+                json_account_info = self._get_json(
                     API_ACCOUNT_INFO.format(accid=account_id),
                 )
                 asset = fin_defs.FiatCurrency(
@@ -136,7 +128,7 @@ class NordnetDepoFetcher:
                 del asset, amount
 
             # Determine positions on Nordnet
-            json_account_positions = self.get_json(
+            json_account_positions = self._get_json(
                 API_ACCOUNT_POSITIONS.format(accid=account_id),
             )
             for pos in json_account_positions: