Create new log by posting to /log/new

Fulfils part of leedshackspace#3
Returns 201 CREATED for a successful log insertion, and tries to return
a sane error message (for debugging client side) when there is a
problem, as well as an appropriate HTTP status code.

Author: adnbr

app/views.py

@@ -8,6 +8,7 @@
 from playhouse import shortcuts
 import json
 import logging
+import datetime
 
 #Shamelessly taken from http://flask.pocoo.org/snippets/45/ - works well
 def request_wants_json():
@@ -241,5 +242,66 @@ def checkvalid(machine, card):
     else:
         return("no result!")
     '''
+'''
+LOGGING
+'''
+
+@app.route('/log/new', methods=['POST'])
+def logusage():
+    try:
+        # Force parsing as JSON even if content header is
+        # incorrect, because we don't accept anything else.
+        json = request.get_json(force=True)
+    except Exception as ex:
+        # Return a bad request if we aren't getting our JSON.
+        # This could happen if the content type isn't set properly or if the JSON
+        # is particularly malformed such that it can't even be
+        print ("Bad JSON request.")
+        print(ex)
+        return "{\"error\":\"Bad JSON\"}", 400 # 400 BAD REQUEST
+
+    try:
+        log = Log()
+        log.endtime = datetime.datetime.now()
+        log.starttime = log.endtime - datetime.timedelta(seconds=int(json["elapsed"]))
+        log.machineuid = json["machineuid"]
+
+        # Check that the machine UID exists and is associated with a machine.
+        machineQuery = Machine.select().where(Machine.machineuid == log.machineuid)
+        if machineQuery.exists() is False:
+            print ("Bad request, Machine UID doesn't exist.")
+            return "{\"error\":\"Machine UID doesn't exist\"}", 400 # 400 BAD REQUEST
+
+        # Check that the Card UID exists and is associated with a user UID. This is what
+        # we need to associate the log request with.
+        log.useruid = User.select(User.useruid).where(User.carduid == json["carduid"]).limit(1)
+        if log.useruid is None:
+            print ("Bad request, Card UID doesn't exist.")
+            return "{\"error\":\"Card UID doesn't exist\"}", 400 # 400 BAD REQUEST
+
+        # If we're debugging the App it would probably be nice to see all the json
+        # and also to save it in the database for future lookup.
+        # Otherwise store a readable note of seconds used.
+        if app.debug is True:
+            print(json)
+            log.notes = json
+        else:
+            log.notes = json["elapsed"] + "s used"
+
+    except (TypeError, ValueError) as ex:
+        print ("TypeError or ValueError when populating new log from JSON.")
+        print (json)
+        print (ex)
+        return "{\"error\":\"Bad JSON - bad value type or a value conversion error occurred.\"}", 400 # 400 BAD REQUEST
+
+    try:
+        log.save()
+    except Exception as ex:
+        # Had a problem saving the data to the database,
+        # so return an internal server error.
+        print("Error creating log in database.")
+        print(ex)
+        return "0", 500 # 500 SERVER ERROR
 
-#@app.route('/induct')
+    # Return created response
+    return "1", 201 # 201 CREATED