Fix broken currency API (#71)

* Fix broken currency API * Adds freecurrencyapi python package * Fix more stuff
michaelhball · Apr 3, 2024 · 8c14a28 · 8c14a28
1 parent a5b705c
commit 8c14a28
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Showing 5 changed files with 66 additions and 190 deletions.
diff --git a/discogs_alert/util/currency.py b/discogs_alert/util/currency.py
@@ -1,37 +1,50 @@
+import json
 import os
-from typing import Dict, Union
+import pathlib
+from datetime import datetime
+from typing import Dict
 
-import requests
+import freecurrencyapi
 
 from discogs_alert.util.constants import CURRENCY_CHOICES
-from discogs_alert.util.system import time_cache
 
-CurrencyRates = Dict[str, Union[int, float]]
+# Dict containing currency conversions for all currencies with respect to a given base currency
+CurrencyRates = Dict[str, float]
+
+# Directory in which to store weekly CurrencyRates JSON caches
+CACHE_DIR = pathlib.Path(__file__).parent.parent.parent.resolve() / ".currency_cache"
 
 
 class InvalidCurrencyException(Exception):
     ...
 
 
-@time_cache(seconds=86400)
 def get_currency_rates(base_currency: str) -> CurrencyRates:
-    """Get live currency exchange rates (from one base currency). Cached for one day at a time, per currency.
+    """
+    Get live currency exchange rates (from one base currency). Cached for one week at a time, per currency (to avoid
+    API limits, and because small fluctuations in currency rates are really not important).
 
     Args:
-        base_currency: one of the 3-character currency identifiers from above.
+        base_currency: one of the valid 3-character currency identifiers.
 
     Returns: a dict containing exchange rates _to_ all major currencies _from_ the given base currency
     """
 
     if base_currency not in CURRENCY_CHOICES:
         raise InvalidCurrencyException(f"{base_currency} is not a supported currency (see `discogs_alert/types.py`).")
 
-    access_key = os.getenv("DA_CURRENCY_TOKEN")
-    return (
-        requests.get(f"http://api.exchangerate.host/live?access_key={access_key}&source={base_currency}")
-        .json()
-        .get("quotes")
-    )
+    # See whether we've already cached currency rates for the current week
+    now = datetime.now().isocalendar()
+    cache_file = f"{CACHE_DIR}/{now.year}-{now.week}-{base_currency}"
+    if os.path.exists(cache_file):
+        return json.load(pathlib.Path(cache_file).open("r"))
+
+    # Else query & cache them before returning
+    client = freecurrencyapi.Client(os.getenv("DA_CURRENCY_TOKEN"))
+    currency_rates = client.latest(base_currency="EUR")["data"]
+    json.dump(currency_rates, pathlib.Path(cache_file).open("w"))
+
+    return currency_rates
 
 
 def convert_currency(value: float, old_currency: str, new_currency: str) -> float:
@@ -46,6 +59,6 @@ def convert_currency(value: float, old_currency: str, new_currency: str) -> floa
     """
 
     try:
-        return float(value) / get_currency_rates(new_currency)[f"{new_currency}{old_currency}"]
+        return float(value) / get_currency_rates(new_currency)[old_currency]
     except KeyError:
         raise InvalidCurrencyException(f"{old_currency} is not a supported currency (see `discogs_alert/types.py`)")
diff --git a/pyproject.toml b/pyproject.toml
@@ -16,6 +16,7 @@ beautifulsoup4 = "^4.11.2"
 click = "^8.1.3"
 dacite = "^1.8.0"
 fake-useragent = "^1.1.1"
+freecurrencyapi = "^0.1.0"
 pre-commit = "^2.20.0"
 requests = "^2.28.2"
 ruff = "^0.0.253"

diff --git a/tests/data/currency_rates.json b/tests/data/currency_rates.json
@@ -1,170 +1,35 @@
 {
-    "EURAED": 4.00965,
-    "EURAFN": 75.018901,
-    "EURALL": 103.920772,
-    "EURAMD": 437.476958,
-    "EURANG": 1.957849,
-    "EURAOA": 903.570398,
-    "EURARS": 384.006996,
-    "EURAUD": 1.676099,
-    "EURAWG": 1.964957,
-    "EURAZN": 1.860127,
-    "EURBAM": 1.95525,
-    "EURBBD": 2.193383,
-    "EURBDT": 120.306163,
-    "EURBGN": 1.95964,
-    "EURBHD": 0.409685,
-    "EURBIF": 3087.531618,
-    "EURBMD": 1.091643,
-    "EURBND": 1.460289,
-    "EURBOB": 7.506889,
-    "EURBRL": 5.355496,
-    "EURBSD": 1.086294,
-    "EURBTC": 2.9743319e-05,
-    "EURBTN": 90.447761,
-    "EURBWP": 14.571902,
-    "EURBYN": 3.578494,
-    "EURBYR": 21396.202226,
-    "EURBZD": 2.189684,
-    "EURCAD": 1.497898,
-    "EURCDF": 2866.654836,
-    "EURCHF": 0.966941,
-    "EURCLF": 0.034535,
-    "EURCLP": 952.921987,
-    "EURCNY": 7.871514,
-    "EURCOP": 4439.651329,
-    "EURCRC": 577.337621,
-    "EURCUC": 1.091643,
-    "EURCUP": 28.928539,
-    "EURCVE": 110.233996,
-    "EURCZK": 24.489537,
-    "EURDJF": 193.415601,
-    "EURDKK": 7.458764,
-    "EURDOP": 61.692649,
-    "EURDZD": 146.66446,
-    "EUREGP": 33.594451,
-    "EURERN": 16.374645,
-    "EURETB": 60.756612,
-    "EURFJD": 2.498666,
-    "EURFKP": 0.878435,
-    "EURGBP": 0.876329,
-    "EURGEL": 2.942022,
-    "EURGGP": 0.878435,
-    "EURGHS": 12.989347,
-    "EURGIP": 0.878435,
-    "EURGMD": 73.413415,
-    "EURGNF": 9334.374667,
-    "EURGTQ": 8.505608,
-    "EURGYD": 227.276078,
-    "EURHKD": 8.511814,
-    "EURHNL": 26.831454,
-    "EURHRK": 7.68688,
-    "EURHTG": 144.149457,
-    "EURHUF": 379.215358,
-    "EURIDR": 16837.828673,
-    "EURILS": 4.05755,
-    "EURIMP": 0.878435,
-    "EURINR": 90.924854,
-    "EURIQD": 1423.099747,
-    "EURIRR": 46135.565218,
-    "EURISK": 152.895936,
-    "EURJEP": 0.878435,
-    "EURJMD": 169.282389,
-    "EURJOD": 0.774307,
-    "EURJPY": 163.238875,
-    "EURKES": 165.443468,
-    "EURKGS": 97.293557,
-    "EURKHR": 4475.741179,
-    "EURKMF": 495.196586,
-    "EURKPW": 982.491758,
-    "EURKRW": 1415.184533,
-    "EURKWD": 0.336543,
-    "EURKYD": 0.905245,
-    "EURKZT": 504.048234,
-    "EURLAK": 22526.664279,
-    "EURLBP": 16327.407846,
-    "EURLKR": 356.339778,
-    "EURLRD": 205.065549,
-    "EURLSL": 20.053898,
-    "EURLTL": 3.223338,
-    "EURLVL": 0.660324,
-    "EURLYD": 5.26352,
-    "EURMAD": 11.017801,
-    "EURMDL": 19.374551,
-    "EURMGA": 4920.616056,
-    "EURMKD": 61.597675,
-    "EURMMK": 2281.258386,
-    "EURMNT": 3763.112256,
-    "EURMOP": 8.726346,
-    "EURMRO": 389.716353,
-    "EURMUR": 48.207367,
-    "EURMVR": 16.866297,
-    "EURMWK": 1828.685674,
-    "EURMXN": 18.807484,
-    "EURMYR": 5.100706,
-    "EURMZN": 69.046364,
-    "EURNAD": 20.053893,
-    "EURNGN": 917.024173,
-    "EURNIO": 39.758818,
-    "EURNOK": 11.783075,
-    "EURNPR": 144.716298,
-    "EURNZD": 1.820619,
-    "EUROMR": 0.420217,
-    "EURPAB": 1.086294,
-    "EURPEN": 4.201418,
-    "EURPGK": 4.103846,
-    "EURPHP": 60.474296,
-    "EURPKR": 311.230565,
-    "EURPLN": 4.386266,
-    "EURPYG": 8072.72951,
-    "EURQAR": 3.974714,
-    "EURRON": 4.977678,
-    "EURRSD": 117.207035,
-    "EURRUB": 97.538707,
-    "EURRWF": 1339.823169,
-    "EURSAR": 4.094218,
-    "EURSBD": 9.191265,
-    "EURSCR": 14.320772,
-    "EURSDG": 656.077796,
-    "EURSEK": 11.564833,
-    "EURSGD": 1.467391,
-    "EURSHP": 1.328257,
-    "EURSLE": 24.490293,
-    "EURSLL": 21559.949041,
-    "EURSOS": 623.328506,
-    "EURSRD": 41.640763,
-    "EURSTD": 22594.805475,
-    "EURSYP": 14193.347758,
-    "EURSZL": 19.885407,
-    "EURTHB": 38.639253,
-    "EURTJS": 11.884357,
-    "EURTMT": 3.82075,
-    "EURTND": 3.399926,
-    "EURTOP": 2.600335,
-    "EURTRY": 31.307888,
-    "EURTTD": 7.376925,
-    "EURTWD": 34.659341,
-    "EURTZS": 2713.636778,
-    "EURUAH": 39.236265,
-    "EURUGX": 4105.845213,
-    "EURUSD": 1.091643,
-    "EURUYU": 43.147864,
-    "EURUZS": 13340.247998,
-    "EURVEF": 3861416.594396,
-    "EURVES": 38.607661,
-    "EURVND": 26488.716684,
-    "EURVUV": 132.260957,
-    "EURWST": 3.025362,
-    "EURXAF": 655.772561,
-    "EURXAG": 0.04601,
-    "EURXAU": 0.000551,
-    "EURXCD": 2.95022,
-    "EURXDR": 0.820169,
-    "EURXOF": 655.772561,
-    "EURXPF": 120.572363,
-    "EURYER": 273.351325,
-    "EURZAR": 20.024193,
-    "EURZMK": 9826.100628,
-    "EURZMW": 25.229904,
-    "EURZWL": 351.508591
+    "AUD": 1.6531610671,
+    "BGN": 1.9534088731,
+    "BRL": 5.4463221665,
+    "CAD": 1.4607323679,
+    "CHF": 0.9777059811,
+    "CNY": 7.7831235548,
+    "CZK": 25.2860762526,
+    "DKK": 7.4581583276,
+    "EUR": 1,
+    "GBP": 0.8562951521,
+    "HKD": 8.4285193519,
+    "HRK": 7.2489608558,
+    "HUF": 394.6315722182,
+    "IDR": 17104.5927655074,
+    "ILS": 4.0040174185,
+    "INR": 89.707252332,
+    "ISK": 150.2225196915,
+    "JPY": 163.1774310922,
+    "KRW": 1453.1252724105,
+    "MXN": 17.8313310647,
+    "MYR": 5.1151212505,
+    "NOK": 11.6666884565,
+    "NZD": 1.8037695252,
+    "PHP": 60.6137415547,
+    "PLN": 4.2891976903,
+    "RON": 4.9694668363,
+    "RUB": 99.5478026609,
+    "SEK": 11.5633284985,
+    "SGD": 1.4553042291,
+    "THB": 39.440724367,
+    "TRY": 34.4129784754,
+    "USD": 1.0770057964,
+    "ZAR": 20.2104575408
 }
diff --git a/tests/test_entities.py b/tests/test_entities.py
@@ -9,23 +9,22 @@ def test_conditions_satisfied():
 
 
 def test_convert_listing_price_currency(mock_currency_rates, rates: da_currency.CurrencyRates):
-
     # full listing price
     lp1 = da_entities.ListingPrice("GBP", 10, shipping=da_entities.ShippingPrice("GBP", 5))
     lp1_target = da_entities.ListingPrice(
-        "EUR", 10 / rates["EURGBP"], shipping=da_entities.ShippingPrice("EUR", 5 / rates["EURGBP"])
+        "EUR", 10 / rates["GBP"], shipping=da_entities.ShippingPrice("EUR", 5 / rates["GBP"])
     )
     assert lp1.convert_currency("EUR") == lp1_target
 
     # no shipping
     lp2 = da_entities.ListingPrice("GBP", 10, shipping=None)
-    lp2_target = da_entities.ListingPrice("EUR", 10 / rates["EURGBP"], shipping=None)
+    lp2_target = da_entities.ListingPrice("EUR", 10 / rates["GBP"], shipping=None)
     assert lp2.convert_currency("EUR") == lp2_target
 
     # different currencies
     lp3 = da_entities.ListingPrice("GBP", 10, shipping=da_entities.ShippingPrice("AUD", 5))
     lp3_target = da_entities.ListingPrice(
-        "EUR", 10 / rates["EURGBP"], shipping=da_entities.ShippingPrice("EUR", 5 / rates["EURAUD"])
+        "EUR", 10 / rates["GBP"], shipping=da_entities.ShippingPrice("EUR", 5 / rates["AUD"])
     )
     assert lp3.convert_currency("EUR") == lp3_target
 

diff --git a/tests/util/test_currency.py b/tests/util/test_currency.py
@@ -5,7 +5,6 @@
 
 @pytest.mark.online
 def test_get_currency_rates():
-
     # test that the URL works for all supported currencies (requires internet connection)
     for currency in dac.CURRENCY_CHOICES:
         rates = da_currency.get_currency_rates(currency)
@@ -22,13 +21,12 @@ def test_get_currency_rates():
 
 
 def test_convert_currency(mock_currency_rates, rates: da_currency.CurrencyRates):
-
     # make sure our monkeypatch worked
     assert da_currency.get_currency_rates("SGD") == da_currency.get_currency_rates("EUR")
 
     # make sure the currency conversion is working correctly
-    assert da_currency.convert_currency(1, "GBP", "EUR") == 1 / rates.get("EURGBP")
-    assert da_currency.convert_currency(1, "CHF", "EUR") == 1 / rates.get("EURCHF")
+    assert da_currency.convert_currency(1, "GBP", "EUR") == 1 / rates.get("GBP")
+    assert da_currency.convert_currency(1, "CHF", "EUR") == 1 / rates.get("CHF")
 
     # make sure invalid currencies are handled
     with pytest.raises(da_currency.InvalidCurrencyException):