1 files changed, 85 insertions, 11 deletions
diff --git a/api.py b/api.py
index 41e361a..48e8f72 100644
--- a/api.py
+++ b/api.py
@@ -1,5 +1,20 @@
 import requests
 import json
+from datetime import date, date, datetime, timedelta
+
+# helper function to pull most recent chart data on failure
+def pull_last_from_file():
+    fd = open('last_chart_data.json', 'r')
+    d = json.loads(fd.read())
+    fd.close()
+    return d
+    
+def update_last_file(data):
+    fd = open('last_chart_data.json', 'w')
+    fd.truncate(0)
+    fd.write(json.dumps(data))
+    fd.close()
+
 """
 Given the parameters, 
 fetches the data for the corresponding chart using yahoo finance.
@@ -51,15 +66,74 @@ def fetch_chart_data(ticker, period='1y', interval='1d'):
     # save data to file in case necessary
     return data
 
-# helper function to pull most recent chart data on failure
-def pull_last_from_file():
-    fd = open('last_chart_data.json', 'r')
-    d = json.loads(fd.read())
-    fd.close()
-    return d
+"""
+Given the parameters, 
+fetches the data for the corresponding chart using yahoo finance.
+Cosumes period_length as a timedelta and period_end_date as a date
+If bad request, returns the previous chart.
+"""
+def fetch_chart_data_backtest(ticker='ADA-USD', interval='1m', period_end_date=None, period_length=None):
+    if period_end_date == None:
+        period_end_date = datetime.now()
+    if period_length == None:
+        period_length = timedelta(days=8)
     
-def update_last_file(data):
-    fd = open('last_chart_data.json', 'w')
-    fd.truncate(0)
-    fd.write(json.dumps(data))
-    fd.close()
-\ No newline at end of file
+    # cast to int to truncate the decimal
+    period2 = int(datetime.timestamp(period_end_date))
+    # find the first period via subtracting the period length
+    period1 = int(datetime.timestamp(period_end_date - period_length))
+
+    print(datetime.isoformat(datetime.fromtimestamp(period2)), datetime.isoformat(datetime.fromtimestamp(period1)))
+
+    params = {
+           'period1' : period1, # the start date (in epoch time)
+           'period2' : period2, # the end time (in epoch time)
+           'interval' : interval, # 1m, 2m, 5m, 15m, 30m, 60m, 90m, 1h, 4h, 1d, 5d, 1wk, 1mo, 3mo
+           'events' : 'div|split|earn', 
+           'includePrePost' : 'false',
+           'lang' : 'en-US',
+            'region' : 'US' }
+    headers = {'User-agent' : 'fin-backtesting-proj'}
+    r = requests.get("https://query2.finance.yahoo.com/v8/finance/chart/" + ticker, headers=headers, params=params)
+
+    print(r.url)
+    print("status_code:\t", r.status_code)
+
+    # decode the JSON response data into a Python object
+    try:
+        r.raise_for_status() # raises if error before parsing
+    except:
+        print(r.text)
+        last_data = pull_last_from_file()
+        last_data['error'] = True
+        return last_data
+    
+    data_obj = r.json()
+
+    # get the specific data we want
+    if 'timestamp' not in data_obj['chart']['result'][0]:
+        last_data = pull_last_from_file()
+        last_data['error'] = True
+        return last_data
+    timestamps = data_obj['chart']['result'][0]['timestamp']
+    close_prices = data_obj['chart']['result'][0]['indicators']['quote'][0]['close']
+    
+    # clean out null's and 0s from the data
+    i = 0
+    while i < len(timestamps):
+        if close_prices[i] == None or close_prices[i] == 0:
+            del close_prices[i]
+            del timestamps[i]
+            i -= 1
+        i += 1
+    
+    name = data_obj['chart']['result'][0]['meta']['longName']
+
+    data = {'timestamps': timestamps, 'prices': close_prices, 'name': name, 'error': False}
+    update_last_file(data)
+    # save data to file in case necessary
+    return data
+
+def test():
+    fetch_chart_data_backtest()
+test()
+\ No newline at end of file