many changes

xexe/cli.py

@@ -66,12 +66,14 @@ def xe_healthcheck():
     "--currencies", default=",".join([]), show_default=True, type=click.STRING
 )
 @click.option("--dry-run", is_flag=True)
+@click.option("--ignore-warnings", is_flag=True)
 @click.option("--output", type=click.STRING, required=True)
 def get_rates(
     start_date: Union[str, datetime.datetime, datetime.date],
     end_date: Union[str, datetime.datetime, datetime.date],
     currencies: Union[None, str],
     dry_run: bool,
+    ignore_warnings: bool,
     output: pathlib.Path,
 ):
     get_rates_inputs = handle_get_rates_inputs(
@@ -79,6 +81,7 @@ def get_rates(
         end_date=end_date,
         currencies=currencies,
         dry_run=dry_run,
+        ignore_warnings=ignore_warnings,
         output=output,
     )
     logger.info("Starting get-rates process.")

xexe/inputs_handling.py

@@ -16,6 +16,7 @@ def handle_get_rates_inputs(
     end_date: Union[datetime.datetime, datetime.date],
     currencies: Union[None, str],
     dry_run: bool,
+    ignore_warnings: bool,
     output: Union[str, pathlib.Path],
 ):
     logger.info("Handling inputs.")
@@ -31,7 +32,8 @@ def handle_get_rates_inputs(
         tmp = {Currency(currency_code) for currency_code in currencies}
         currencies = tmp
 
-    if currencies is None:
+    if currencies is None or currencies == "":
+        logger.info("No currency list passed. Running for default currencies.")
         currencies = DEFAULT_CURRENCIES
 
     # The Path constructor is idempotent, so this works equally fine if output
@@ -44,6 +46,7 @@ def handle_get_rates_inputs(
         "date_range": date_range,
         "currencies": currencies,
         "dry_run": dry_run,
+        "ignore_warnings": ignore_warnings,
         "output": output,
     }
 

xexe/processes.py

@@ -56,16 +56,23 @@ def run_get_rates(
     date_range: DateRange,
     currencies: List[Currency],
     dry_run: bool,
+    ignore_warnings: bool,
     output: pathlib.Path,
 ) -> None:
     logger.info("Getting rates")
 
-    process_state = GetRatesProcessState(output=output, dry_run=dry_run)
+    process_state = GetRatesProcessState(
+        output=output, dry_run=dry_run, ignore_warnings=ignore_warnings
+    )
 
     rates = obtain_rates_from_source(
-        process_state, date_range=date_range, currencies=currencies
+        process_state,
+        date_range=date_range,
+        currencies=currencies,
     )
+    logger.info("Rates obtained.")
     write_rates_to_output(process_state, rates)
+    logger.info("Rates written to output.")
 
 
 def obtain_rates_from_source(
@@ -77,6 +84,21 @@ def obtain_rates_from_source(
         date_range=date_range, currencies=currencies
     )
 
+    large_api_call_planned = (
+        rates_fetcher.is_production_grade and len(currency_and_date_combinations) > 100
+    )
+    if large_api_call_planned and not process_state.ignore_warnings:
+        user_confirmation_string = "i understand"
+        user_response = input(
+            f"WARNING: you are about to execute a large call {len(currency_and_date_combinations)} to a metered API. Type '{user_confirmation_string}' to move forward."
+        )
+        if user_response != user_confirmation_string:
+            raise Exception("Execution aborted.")
+
+    logger.debug(
+        f"We are looking for the following rate combinations: {currency_and_date_combinations}"
+    )
+
     rates = ExchangeRates()
     for combination in currency_and_date_combinations:
         try:
@@ -97,13 +119,15 @@ def obtain_rates_from_source(
 
 def write_rates_to_output(process_state, rates):
     rates_writer = process_state.get_writer()
+    logger.info("Attempting writing rates to output.")
     rates_writer.write_rates(rates)
 
 
 class GetRatesProcessState:
-    def __init__(self, output: str, dry_run: bool) -> None:
+    def __init__(self, output: str, dry_run: bool, ignore_warnings: bool) -> None:
         self.writer = self._select_writer(output)
         self.fetcher = self._select_fetcher(dry_run)
+        self.ignore_warnings = ignore_warnings
 
     @staticmethod
     def _select_writer(output: str) -> CSVRateWriter:
@@ -115,12 +139,14 @@ class GetRatesProcessState:
         raise ValueError(f"Don't know how to handle passed output: {output}")
 
     @staticmethod
-    def _select_fetcher(dry_run: bool) -> str:
+    def _select_fetcher(dry_run: bool) -> RateFetcher:
         if dry_run:
-            return MockRateFetcher
+            logger.info("Dry-run activated. Running against MockRateFetcher.")
+            return MockRateFetcher()
 
         if not dry_run:
-            return XERateFetcher
+            logger.info("Real run active. Running against XE.com's API.")
+            return XERateFetcher()
 
     def get_fetcher(self) -> RateFetcher:
         return self.fetcher

xexe/rate_fetching.py

@@ -10,6 +10,9 @@ from xexe.exchange_rates import ExchangeRate
 
 
 class RateFetcher(ABC):
+
+    is_production_grade = False
+
     @abstractmethod
     def fetch_rate(
         self, from_currency: Currency, to_currency: Currency, rate_date: datetime.date
@@ -19,6 +22,8 @@ class RateFetcher(ABC):
 
 class MockRateFetcher(RateFetcher):
 
+    is_production_grade = False
+
     def __init__(self) -> None:
         super().__init__()
 
@@ -36,6 +41,8 @@ class MockRateFetcher(RateFetcher):
 
 class XERateFetcher(RateFetcher):
 
+    is_production_grade = True
+
     def __init__(self) -> None:
         super().__init__()
         self.xe_client = XecdClient(

xexe/rate_writing.py

@@ -18,8 +18,8 @@ class CSVRateWriter(RateWriter):
         self.output_file_path = output_file_path
 
     def write_rates(self, rates: ExchangeRates) -> None:
-        with open(self.output_file_path, mode="w", newline="") as csvfile:
-            csv_writer = csv.writer(csvfile)
+        with open(self.output_file_path, mode="w") as csv_file:
+            csv_writer = csv.writer(csv_file)
             csv_writer.writerow(["from_currency", "to_currency", "rate", "rate_date"])
 
             # Write the exchange rate data