From 80fd49a98ad8177c164ba13dc7c5010a44a40330 Mon Sep 17 00:00:00 2001
From: Brett Smith <brettcsmith@brettcsmith.org>
Date: Sat, 16 May 2020 15:07:20 -0400
Subject: [PATCH] historical: Introduce --output-format option.

Beancount output will be added here.
---
 oxrlib/commands/historical.py | 16 +++++++++++++++-
 oxrlib/config.py              | 33 +++++++++++++++++++++++++--------
 tests/test_historical.py      |  2 +-
 3 files changed, 41 insertions(+), 10 deletions(-)

diff --git a/oxrlib/commands/historical.py b/oxrlib/commands/historical.py
index 3223f94..3f61594 100644
--- a/oxrlib/commands/historical.py
+++ b/oxrlib/commands/historical.py
@@ -6,6 +6,11 @@ import babel.numbers
 
 from .. import rate as oxrrate
 
+try:
+    import enum
+except ImportError:
+    import enum34 as enum
+
 class Formatter:
     def __init__(self, rate, signed_currencies=(), base_fmt='#,##0.###'):
         self.rate = rate
@@ -130,13 +135,22 @@ class LedgerFormatter(Formatter):
         )
 
 
+class Formats(enum.Enum):
+    RAW = Formatter
+    LEDGER = LedgerFormatter
+
+    @classmethod
+    def from_arg(cls, s):
+        return cls[s.upper()]
+
+
 def run(config, stdout, stderr):
     loaders = config.get_loaders()
     with loaders.historical(config.args.date, config.args.base) as rate_json:
         rate = oxrrate.Rate.from_json_file(rate_json)
     if loaders.should_cache():
         config.cache.save_rate(rate)
-    if config.args.ledger:
+    if config.args.output_format is Formats.LEDGER:
         formatter = LedgerFormatter(rate, config.args.signed_currencies,
                                     denomination=config.args.denomination)
     else:
diff --git a/oxrlib/config.py b/oxrlib/config.py
index f9d6e0e..5110ab1 100644
--- a/oxrlib/config.py
+++ b/oxrlib/config.py
@@ -10,6 +10,7 @@ import babel.dates
 import babel.numbers
 
 from . import cache, loaders
+from .commands import historical
 
 HOME_PATH = pathlib.Path(os.path.expanduser('~'))
 
@@ -97,22 +98,35 @@ class Configuration:
             command='historical',
             amount=None,
             from_currency=None,
-            ledger=None,
+            from_date=None,
+            to_currency=None,
+            output_format=None,
         )
         hist_parser.add_argument(
             '--base',
             metavar='CODE', type=currency_code,
             help="Base currency (default USD)",
         )
+        hist_parser.add_argument(
+            '--output-format',
+            type=historical.Formats.from_arg,
+            choices=[fmt.name.lower() for fmt in historical.Formats],
+            help="Output format. Choices are %(choices)s. Default `raw`.",
+        )
+        # --ledger and --no-ledger predate --output-format.
         hist_parser.add_argument(
             '--ledger', '-L',
-            action='store_true',
-            help="Output the rate or conversion in Ledger format",
+            action='store_const',
+            dest='output_format',
+            const=historical.Formats.LEDGER,
+            help=argparse.SUPPRESS,
         )
         hist_parser.add_argument(
             '--no-ledger',
-            action='store_false', dest='ledger',
-            help="Turn off an earlier --ledger setting",
+            action='store_const',
+            dest='output_format',
+            const=historical.Formats.RAW,
+            help=argparse.SUPPRESS,
         )
         hist_parser.add_argument(
             '--denomination',
@@ -213,7 +227,12 @@ class Configuration:
         pref_currency = self.args.denomination or self._user_currency(self.args.base)
         self._read_from_conffile('signed_currencies', 'Historical', pref_currency,
                                  currency_list, convert_fallback=True)
-        self._read_from_conffile('ledger', 'Historical', False, getter='getboolean')
+        self._read_from_conffile('output_format', 'Historical', None, historical.Formats.from_arg)
+        if self.args.output_format is None:
+            if self.conffile.getboolean('Historical', 'ledger', fallback=None):
+                self.args.output_format = historical.Formats.LEDGER
+            else:
+                self.args.output_format = historical.Formats.RAW
         raw_words = iter(getattr(self.args, 'word' + c) for c in '123456')
         words = iter(word for word in raw_words if word is not None)
         try:
@@ -229,8 +248,6 @@ class Configuration:
             self.args.from_currency = self._convert_or_error(currency_code, next_word)
         except StopIteration:
             pass
-        self.args.to_currency = None
-        self.args.from_date = None
         for next_word in words:
             next_lower = next_word.lower()
             if next_lower in self.CURRENCY_PREPOSITIONS:
diff --git a/tests/test_historical.py b/tests/test_historical.py
index 4f17a03..48d4bbc 100644
--- a/tests/test_historical.py
+++ b/tests/test_historical.py
@@ -58,7 +58,7 @@ def build_config(
         'amount': None if amount is None else decimal.Decimal(amount),
         'from_currency': from_currency,
         'to_currency': base if to_currency is None else to_currency,
-        'ledger': ledger,
+        'output_format': oxrhist.Formats['LEDGER' if ledger else 'RAW'],
         'signed_currencies': [base] if signed_currencies is None else signed_currencies,
         'denomination': denomination,
     })