From 7949e16195bc954efc050f4f7b379cfca2703adc Mon Sep 17 00:00:00 2001
From: Edward Betts <edward@4angle.com>
Date: Sun, 5 Nov 2023 12:27:40 +0000
Subject: [PATCH] Split currency rate code into own file

---
 agenda/__init__.py | 34 ++--------------------------------
 agenda/fx.py       | 42 ++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 44 insertions(+), 32 deletions(-)
 create mode 100644 agenda/fx.py

diff --git a/agenda/__init__.py b/agenda/__init__.py
index 122f056..07698d8 100644
--- a/agenda/__init__.py
+++ b/agenda/__init__.py
@@ -5,7 +5,6 @@ import os
 import typing
 import warnings
 from datetime import date, datetime, time, timedelta, timezone
-from decimal import Decimal
 from time import time as unixtime
 from typing import List
 
@@ -25,7 +24,7 @@ from dateutil.relativedelta import FR, relativedelta
 
 from agenda import thespacedevs
 
-from . import gwr, markets, waste_schedule
+from . import fx, gwr, markets, waste_schedule
 from .types import Event
 
 warnings.simplefilter(action="ignore", category=FutureWarning)
@@ -150,35 +149,6 @@ def get_next_bank_holiday(input_date: date) -> list[Event]:
     return hols
 
 
-def get_gbpusd() -> Decimal:
-    """Get the current value for GBPUSD, with caching."""
-    now = datetime.now()
-    now_str = now.strftime("%Y-%m-%d_%H:%M")
-    fx_dir = os.path.join(data_dir, "fx")
-    existing_data = os.listdir(fx_dir)
-    existing = [f for f in existing_data if f.endswith("_GBPUSD.json")]
-    if existing:
-        recent_filename = max(existing)
-        recent = datetime.strptime(recent_filename, "%Y-%m-%d_%H:%M_GBPUSD.json")
-        delta = now - recent
-
-    if existing and delta < timedelta(hours=6):
-        full = os.path.join(fx_dir, recent_filename)
-        data = json.load(open(full), parse_float=Decimal)
-        if "quotes" in data and "USDGBP" in data["quotes"]:
-            return typing.cast(Decimal, 1 / data["quotes"]["USDGBP"])
-
-    url = "http://api.exchangerate.host/live"
-    params = {"currencies": "GBP,USD", "access_key": access_key}
-
-    filename = f"{fx_dir}/{now_str}_GBPUSD.json"
-    r = requests.get(url, params=params)
-    open(filename, "w").write(r.text)
-    data = json.loads(r.text, parse_float=Decimal)
-
-    return typing.cast(Decimal, 1 / data["quotes"]["USDGBP"])
-
-
 def next_economist(input_date: date) -> date:
     """Next date that the Economist is published."""
     # Define the publication day (Thursday) and the day of the week of the input date
@@ -558,7 +528,7 @@ def get_data(now: datetime) -> typing.Mapping[str, str | object]:
 
     reply = {
         "now": now,
-        "gbpusd": get_gbpusd(),
+        "gbpusd": fx.get_gbpusd(config),
         "next_economist": next_economist(today),
         "bank_holiday": get_next_bank_holiday(today),
         "us_holiday": get_us_holidays(today),
diff --git a/agenda/fx.py b/agenda/fx.py
new file mode 100644
index 0000000..5d397e1
--- /dev/null
+++ b/agenda/fx.py
@@ -0,0 +1,42 @@
+"""Currency exchange rates."""
+
+import configparser
+import json
+import os
+import typing
+from datetime import datetime, timedelta
+from decimal import Decimal
+
+import requests
+
+
+def get_gbpusd(config: configparser.ConfigParser) -> Decimal:
+    """Get the current value for GBPUSD, with caching."""
+    access_key = config.get("exchangerate", "access_key")
+    data_dir = config.get("data", "dir")
+
+    now = datetime.now()
+    now_str = now.strftime("%Y-%m-%d_%H:%M")
+    fx_dir = os.path.join(data_dir, "fx")
+    existing_data = os.listdir(fx_dir)
+    existing = [f for f in existing_data if f.endswith("_GBPUSD.json")]
+    if existing:
+        recent_filename = max(existing)
+        recent = datetime.strptime(recent_filename, "%Y-%m-%d_%H:%M_GBPUSD.json")
+        delta = now - recent
+
+    if existing and delta < timedelta(hours=6):
+        full = os.path.join(fx_dir, recent_filename)
+        data = json.load(open(full), parse_float=Decimal)
+        if "quotes" in data and "USDGBP" in data["quotes"]:
+            return typing.cast(Decimal, 1 / data["quotes"]["USDGBP"])
+
+    url = "http://api.exchangerate.host/live"
+    params = {"currencies": "GBP,USD", "access_key": access_key}
+
+    filename = f"{fx_dir}/{now_str}_GBPUSD.json"
+    r = requests.get(url, params=params)
+    open(filename, "w").write(r.text)
+    data = json.loads(r.text, parse_float=Decimal)
+
+    return typing.cast(Decimal, 1 / data["quotes"]["USDGBP"])