use jsonschema instead of custom type validations

requirements.txt

@@ -12,3 +12,4 @@ PYQT5==5.9
 scikit-learn==0.19.0
 scipy==0.19.1
 stockstats==0.2.0
+jsonschema==2.6.0

utils.py

@@ -1,102 +1,82 @@
 import json
 import logging
-from typing import List
 
+from jsonschema import validate
 from wrapt import synchronized
-from bittrex.bittrex import Bittrex
 
 logger = logging.getLogger(__name__)
 
 _cur_conf = None
 
 
+# Required json-schema for user specified config
+_conf_schema = {
+    'type': 'object',
+    'properties': {
+        'max_open_trades': {'type': 'integer'},
+        'stake_currency': {'type': 'string'},
+        'stake_amount': {'type': 'number'},
+        'dry_run': {'type': 'boolean'},
+        'minimal_roi': {
+            'type': 'object',
+            'patternProperties': {
+                '^[0-9.]+$': {'type': 'number'}
+            },
+            'minProperties': 1
+        },
+        'poloniex': {'$ref': '#/definitions/exchange'},
+        'bittrex': {'$ref': '#/definitions/exchange'},
+        'telegram': {
+            'type': 'object',
+            'properties': {
+                'enabled': {'type': 'boolean'},
+                'token': {'type': 'string'},
+                'chat_id': {'type': 'string'},
+            },
+            'required': ['enabled', 'token', 'chat_id']
+        }
+    },
+    'definitions': {
+        'exchange': {
+            'type': 'object',
+            'properties': {
+                'enabled': {'type': 'boolean'},
+                'key': {'type': 'string'},
+                'secret': {'type': 'string'},
+                'pair_whitelist': {
+                    'type': 'array',
+                    'items': {'type': 'string'},
+                    'uniqueItems': True
+                }
+            },
+            'required': ['enabled', 'key', 'secret', 'pair_whitelist']
+        }
+    },
+    'anyOf': [
+        {'required': ['poloniex']},
+        {'required': ['bittrex']}
+    ],
+    'required': [
+        'max_open_trades',
+        'stake_currency',
+        'stake_amount',
+        'dry_run',
+        'minimal_roi',
+        'telegram'
+    ]
+}
+
+
 @synchronized
 def get_conf(filename: str='config.json') -> dict:
     """
-    Loads the config into memory and returns the instance of it
+    Loads the config into memory validates it
+    and returns the singleton instance
     :return: dict
     """
     global _cur_conf
     if not _cur_conf:
         with open(filename) as file:
             _cur_conf = json.load(file)
-            validate_conf(_cur_conf)
+            validate(_cur_conf, _conf_schema)
     return _cur_conf
-
-
-def validate_conf(conf: dict) -> None:
-    """
-    Validates if the minimal possible config is provided
-    :param conf: config as dict
-    :return: None, raises ValueError if something is wrong
-    """
-    if not isinstance(conf.get('max_open_trades'), int):
-        raise ValueError('max_open_trades must be a int')
-    if not isinstance(conf.get('stake_currency'), str):
-        raise ValueError('stake_currency must be a str')
-    if not isinstance(conf.get('stake_amount'), float):
-        raise ValueError('stake_amount  must be a float')
-    if not isinstance(conf.get('dry_run'), bool):
-        raise ValueError('dry_run must be a boolean')
-    if not isinstance(conf.get('minimal_roi'), dict):
-        raise ValueError('minimal_roi must be a dict')
-
-    for index, (minutes, threshold) in enumerate(conf.get('minimal_roi').items()):
-        if not isinstance(minutes, str):
-            raise ValueError('minimal_roi[{}].key must be a string'.format(index))
-        if not isinstance(threshold, float):
-            raise ValueError('minimal_roi[{}].value must be a float'.format(index))
-
-    if conf.get('telegram'):
-        telegram = conf.get('telegram')
-        if not isinstance(telegram.get('token'), str):
-            raise ValueError('telegram.token must be a string')
-        if not isinstance(telegram.get('chat_id'), str):
-            raise ValueError('telegram.chat_id must be a string')
-
-    if conf.get('poloniex'):
-        poloniex = conf.get('poloniex')
-        if not isinstance(poloniex.get('key'), str):
-            raise ValueError('poloniex.key must be a string')
-        if not isinstance(poloniex.get('secret'), str):
-            raise ValueError('poloniex.secret must be a string')
-        if not isinstance(poloniex.get('pair_whitelist'), list):
-            raise ValueError('poloniex.pair_whitelist must be a list')
-        if poloniex.get('enabled', False):
-            raise ValueError('poloniex is currently not implemented')
-            #if not poloniex.get('pair_whitelist'):
-            #    raise ValueError('poloniex.pair_whitelist must contain some pairs')
-
-    if conf.get('bittrex'):
-        bittrex = conf.get('bittrex')
-        if not isinstance(bittrex.get('key'), str):
-            raise ValueError('bittrex.key must be a string')
-        if not isinstance(bittrex.get('secret'), str):
-            raise ValueError('bittrex.secret must be a string')
-        if not isinstance(bittrex.get('pair_whitelist'), list):
-            raise ValueError('bittrex.pair_whitelist must be a list')
-        if bittrex.get('enabled', False):
-            if not bittrex.get('pair_whitelist'):
-                raise ValueError('bittrex.pair_whitelist must contain some pairs')
-            validate_bittrex_pairs(bittrex.get('pair_whitelist'))
-
-    if conf.get('poloniex', {}).get('enabled', False) \
-            and conf.get('bittrex', {}).get('enabled', False):
-        raise ValueError('Cannot use poloniex and bittrex at the same time')
-
-    logger.info('Config is valid ...')
-
-
-def validate_bittrex_pairs(pairs: List[str]) -> None:
-    """
-    Validates if all given pairs exist on bittrex
-    :param pairs: list of str
-    :return: None
-    """
-    data = Bittrex(None, None).get_markets()
-    if not data['success']:
-        raise RuntimeError('BITTREX: {}'.format(data['message']))
-    available_markets = [market['MarketName'].replace('-', '_')for market in data['result']]
-    for pair in pairs:
-        if pair not in available_markets:
-            raise ValueError('Invalid pair: {}'.format(pair))