Implemented methods to fetch a list of available problems and the problem description.

JavaScript no longer parses pythonic problem descriptions, instead they are loaded by server and JSONized.

6 files changed, 188 insertions, 56 deletions

diff --git a/client/__init__.py b/client/__init__.py
index 8781a96..1ac18cd 100644
--- a/client/__init__.py
+++ b/client/__init__.py
@@ -9,18 +9,28 @@ class CodeqManager(multiprocessing.managers.BaseManager):
 
 CodeqManager.register('PrologSession')
 CodeqManager.register('UserSession')
-CodeqManager.register('get_session_by_id')
-CodeqManager.register('get_or_create_session')
-CodeqManager.register('authenticate_and_create_session')
+#CodeqManager.register('get_session_by_id')
+#CodeqManager.register('get_or_create_session')
+#CodeqManager.register('authenticate_and_create_session')
+#CodeqManager.register('list_problems_in_groups')
+CodeqManager.register('Codeq')
 
 m = CodeqManager(address=('localhost', 16231), authkey=b'c0d3q3y')
 m.connect()
+codeq = m.Codeq()
 
 def get_session_by_id(sid):
-    return m.get_session_by_id(sid)
+#    return m.get_session_by_id(sid)
+    return codeq.get_session_by_id(sid)
 
 def get_or_create_session(uid, username, sid=None):
-    return m.get_or_create_session(uid, username, sid)
+#    return m.get_or_create_session(uid, username, sid)
+    return codeq.get_or_create_session(uid, username, sid)
 
 def authenticate_and_create_session(username, password):
-    return m.authenticate_and_create_session(username, password)
+#    return m.authenticate_and_create_session(username, password)
+    return codeq.authenticate_and_create_session(username, password)
+
+def list_problems_in_groups(language):
+#    return m.list_problems_in_groups(language)
+    return codeq.list_problems_in_groups(language)
diff --git a/server/__init__.py b/server/__init__.py
index f2c73b7..9f2469d 100644
--- a/server/__init__.py
+++ b/server/__init__.py
@@ -3,8 +3,28 @@
 import multiprocessing.managers
 from . import user_session
 from . import prolog_session
+import server.problems
 
-__all__ = ['user_session']
+__all__ = ['user_session', 'prolog_session', 'problems', 'start']
+
+class Codeq(object):
+    _method_to_typeid_ = {
+        'get_session_by_id': 'UserSession',
+        'get_or_create_session': 'UserSession',
+        'authenticate_and_create_session': 'UserSession'
+    }
+
+    def get_session_by_id(self, sid):
+        return user_session.get_session_by_id(sid)
+
+    def get_or_create_session(self, uid, username, sid=None):
+        return user_session.get_or_create_session(uid, username, sid)
+
+    def authenticate_and_create_session(self, username, password):
+        return user_session.authenticate_and_create_session(username, password)
+
+    def list_problems_in_groups(self, language):
+        return server.problems.list_problems_in_groups(language)
 
 class CodeqManager(multiprocessing.managers.BaseManager):
     pass
@@ -14,9 +34,11 @@ class UserSessionProxy(multiprocessing.managers.BaseProxy):
 
 CodeqManager.register('PrologSession')
 CodeqManager.register('UserSession', proxytype=UserSessionProxy)
-CodeqManager.register('get_session_by_id', callable=user_session.get_session_by_id, proxytype=UserSessionProxy)
-CodeqManager.register('get_or_create_session', callable=user_session.get_or_create_session, proxytype=UserSessionProxy)
-CodeqManager.register('authenticate_and_create_session', callable=user_session.authenticate_and_create_session, proxytype=UserSessionProxy)
+#CodeqManager.register('get_session_by_id', callable=user_session.get_session_by_id, proxytype=UserSessionProxy)
+#CodeqManager.register('get_or_create_session', callable=user_session.get_or_create_session, proxytype=UserSessionProxy)
+#CodeqManager.register('authenticate_and_create_session', callable=user_session.authenticate_and_create_session, proxytype=UserSessionProxy)
+#CodeqManager.register('list_problems_in_groups', callable=server.problems.list_problems_in_groups)
+CodeqManager.register('Codeq', callable=Codeq, method_to_typeid=Codeq._method_to_typeid_)
 
 def start():
     m = CodeqManager(address=('localhost', 16231), authkey=b'c0d3q3y')
diff --git a/server/problems.py b/server/problems.py
index 7fb2606..bce72fe 100644
--- a/server/problems.py
+++ b/server/problems.py
@@ -3,6 +3,7 @@
 import sys
 import importlib.machinery
 import threading
+from db import get_connection, return_connection
 
 #sys.path.append('/home/aless/job/codeq/source/codeq-problems/')
 _path_prefix = '/home/aless/job/codeq/source/codeq-problems/'
@@ -45,7 +46,6 @@ def load_problems(language, tuples, tail_module):
     modules = []
     for problem_group, problem in tuples:
         mod = '{0}.problems.{1}.{2}.{3}'.format(language, problem_group, problem, tail_module)
-        print('importing {}'.format(mod))
         modules.append(load_module(mod))
     return modules
 
@@ -81,3 +81,29 @@ def solutions_for_problems(language, tuples):
             if f:
                 facts.add(f)
     return '\n'.join(facts) + '\n' + '\n'.join(solutions)
+
+def list_problems_in_groups(language):
+    conn = get_connection()
+    try:
+        cur = conn.cursor()
+        try:
+            cur.arraysize = 1000
+            cur.execute("select g.identifier, g.name, p.identifier, p.name from problem p inner join problem_group g on g.id = p.problem_group_id where p.language_id = (select id from language where identifier = %s) order by g.identifier, p.identifier", (language,))
+            result = []
+            previous_group_name = ''
+            current_sublist = None
+            row = cur.fetchone()
+            while row:
+                current_group_name = row[0]
+                if previous_group_name != current_group_name:
+                    current_sublist = []
+                    result.append({'identifier': current_group_name, 'name': row[1], 'problems': current_sublist})
+                    previous_group_name = current_group_name
+                current_sublist.append({'identifier': row[2], 'name': row[3]})
+                row = cur.fetchone()
+            return result
+        finally:
+            cur.close()
+    finally:
+        conn.commit()
+        return_connection(conn)
diff --git a/server/prolog_session.py b/server/prolog_session.py
index e00afd8..c21d929 100644
--- a/server/prolog_session.py
+++ b/server/prolog_session.py
@@ -86,7 +86,7 @@ class PrologSession(object):
             prolog.engine.stop(self._engine_id)
             self._engine_id = None
 
-    def run_for_user(self, user_id, language, problem_group, problem, program, query):
+    def run_for_user(self, user_id, problem_id, program, query):
         """A "shorthand" method to start a Prolog session, load correct solutions of all user's solved
         problems and the given program, and ask a query.
         """
@@ -94,10 +94,12 @@ class PrologSession(object):
         try:
             cur = conn.cursor()
             try:
-                cur.execute('select l.id, p.id from problem p inner join problem_group g on g.id = p.problem_group_id inner join language l on l.id = p.language_id where l.identifier = %s and g.identifier = %s and p.identifier = %s', (language, problem_group, problem))
+                cur.execute('select l.id, l.identifier, g.identifier, p.identifier from problem p inner join problem_group g on g.id = p.problem_group_id inner join language l on l.id = p.language_id where p.id = %s', (problem_id,))
                 row = cur.fetchone()
                 language_id = row[0]
-                problem_id = row[1]
+                language = row[1]
+                problem_group = row[2]
+                problem = row[3]
                 cur.execute('select g.identifier, p.identifier from solution s inner join problem p on p.id = s.problem_id inner join problem_group g on g.id = p.problem_group_id where s.codeq_user_id = %s and s.done = True and s.problem_id != %s and p.language_id = %s', (user_id, problem_id, language_id))
                 solved_problems = cur.fetchall()
             finally:
diff --git a/server/user_session.py b/server/user_session.py
index b12d6f1..bb4179d 100644
--- a/server/user_session.py
+++ b/server/user_session.py
@@ -6,6 +6,7 @@ import hashlib
 import base64
 import random
 from . import prolog_session
+from . import problems
 import db
 from errors.session import NoSuchSession, AuthenticationFailed
 
@@ -51,6 +52,33 @@ class UserSession(object):
                 self.prolog_session = prolog_session.PrologSession()  # lazy init
             return self.prolog_session
 
+    def get_problem_data(self, language, problem_group, problem):
+        mod = problems.load_problem(language, problem_group, problem, 'en')
+        conn = db.get_connection()
+        try:
+            cur = conn.cursor()
+            try:
+                cur.execute("select l.id, l.name, g.id, g.name, p.id, p.name from problem p inner join language l on l.id = p.language_id inner join problem_group g on g.id = p.problem_group_id where l.identifier = %s and g.identifier = %s and p.identifier = %s", (language, problem_group, problem))
+                row = cur.fetchone()
+                problem_id = row[4]
+                result = {
+                    'language': {'id': row[0], 'identifier': language, 'name': row[1]},
+                    'problem_group': {'id': row[2], 'identifier': problem_group, 'name': row[3]},
+                    'problem': {'id': problem_id, 'identifier': problem, 'name': row[5], 'slug': mod.slug, 'description': mod.description, 'hint': mod.hint}
+                }
+                cur.execute("select content from solution where problem_id = %s and codeq_user_id = %s", (problem_id, self.uid))
+                row = cur.fetchone()
+                if row:
+                    result['solution'] = row[0]
+                else:
+                    result['solution'] = ''
+                return result
+            finally:
+                cur.close()
+        finally:
+            conn.commit()
+            db.return_connection(conn)
+
     def __del__(self):
         #  no locking needed if GC is removing us, as there cannot be any concurrent access by definition
         if hasattr(self, 'prolog_session') and (self.prolog_session is not None):
diff --git a/wsgi_server.py b/wsgi_server.py
index 0f70b40..9b3a51e 100644
--- a/wsgi_server.py
+++ b/wsgi_server.py
@@ -12,7 +12,15 @@ api = application = falcon.API()
 
 
 def get_json_payload(req, session_is_optional=False):
-    if not ((req.content_type == 'application/json') or (req.content_type == 'text/json')):
+    content_type_parts = req.content_type.split(';')
+    content_type = content_type_parts[0].strip()
+    encoding = 'utf-8'
+    if len(content_type_parts) > 1:
+        for part in content_type_parts[1:]:
+            subparts = part.strip().split('=')
+            if (len(subparts) == 2) and subparts[0] == 'charset':
+                encoding = subparts[1]
+    if not ((content_type == 'application/json') or (content_type == 'text/json')):
         raise falcon.HTTPUnsupportedMediaType('Unsupported content-type: {0}'.format(req.content_type))
     length = req.get_header('Content-Length')
     if length is None:
@@ -28,95 +36,121 @@ def get_json_payload(req, session_is_optional=False):
     except Exception as e:
         raise falcon.HTTPBadRequest('Error reading request', 'Error while reading the request body: {0}'.format(e.message))
     try:
-        js = json.loads(txt, encoding="utf-8")
+        js = json.loads(txt.decode(encoding=encoding, errors='replace'))
     except ValueError as e:
         raise falcon.HTTPBadRequest('Error parsing JSON payload', 'Error while parsing the request as JSON: {0}'.format(e.message))
     sid = js.get('sid')
     if sid is None:
         if session_is_optional:
-            return js
+            return js, None
         raise falcon.HTTPBadRequest('No Session', 'Request is missing a session-ID')
     del js['sid']
     try:
         session = client.get_session_by_id(sid)
     except NoSuchSession:
         if session_is_optional:
-            return js
+            return js, None
         raise falcon.HTTPBadRequest('Session Expired', 'This user session has expired. Please log-in again.')
-    req.context['session'] = session
-    return js
+    return js, session
 
 
-class Login(object):
+class CodeqService(object):
+    """Base class for all CodeQ services.
+     It only support the POST method and JSON data.
+     Handles JSON decoding and encoding, and session retrieval which can be optional.
+    """
+    session_is_optional = False
+
     def on_post(self, req, resp):
+        js, session = get_json_payload(req, self.session_is_optional)
+        resp.body = json.dumps(self.process(js, session))
         resp.cache_control = 'private, no-cache, no-store'
-        js = get_json_payload(req, True)
+        resp.content_type = 'application/json'
+        resp.status = falcon.HTTP_200
+
+    def process(self, js, session):
+        raise falcon.HTTPNotFound()
+
+class ProblemList(CodeqService):
+    session_is_optional = True
+
+    def process(self, js, session):
+        language = js.get('language')
+        if language is None:
+            return {'code': 1, 'message': 'Language was not provided'}
+        else:
+            return {'code': 0, 'message': 'ok', 'problems': client.list_problems_in_groups(language)}
+
+class Login(CodeqService):
+    session_is_optional = True
+
+    def process(self, js, old_session):
         username = js.get('username')
         password = js.get('password')
         if username is None:
-            response = {'code': 1, 'message': 'Username was not provided'}
+            return {'code': 1, 'message': 'Username was not provided'}
         elif password is None:
-            response = {'code': 2, 'message': 'Password was not provided'}
+            return {'code': 2, 'message': 'Password was not provided'}
         else:
             try:
                 session = client.authenticate_and_create_session(username, password)
             except AuthenticationFailed:
-                response = {'code': 3, 'message': 'Username or password do not match'}
+                return {'code': 3, 'message': 'Username or password do not match'}
             else:
-                response = {'code': 0, 'message': 'OK', 'sid':session.get_sid()}
-                old_session = req.context.get('session')
                 if old_session:
                     old_session.destroy()
-        resp.body = json.dumps(response)
-        resp.content_type = 'application/json'
-        resp.status = falcon.HTTP_200
+                return {'code': 0, 'message': 'OK', 'sid':session.get_sid()}
 
-class Activity(object):
+class Activity(CodeqService):
     def on_get(self, req, resp):
         resp.body = '{}'
         resp.status = falcon.HTTP_200
 
-class Query(object):
-    def on_post(self, req, resp):
-        resp.cache_control = 'private, no-cache, no-store'
-        js = get_json_payload(req)
-        session = req.context['session']
+class Query(CodeqService):
+    def process(self, js, session):
         step = js.get('step')
         if step is None:
-            response = {'code': 1, 'message': '"step" is not set'}
+            return {'code': 1, 'message': '"step" is not set'}
         else:
             prolog = session.get_prolog()
             if step == 'run':
                 program = js.get('program')
                 query = js.get('query')
-                language = js.get('language')
-                problem_group = js.get('problem_group')
-                problem = js.get('problem')
+                problem_id = js.get('problem_id')
                 if program is None:
-                    response = {'code': 2, 'message': 'No program specified'}
+                    return {'code': 2, 'message': 'No program specified'}
                 elif query is None:
-                    response = {'code': 3, 'message': 'No query specified'}
-                elif language is None:
-                    response = {'code': 4, 'message': 'Language identifier not given'}
-                elif problem_group is None:
-                    response = {'code': 5, 'message': 'Problem group identifier not given'}
-                elif problem is None:
-                    response = {'code': 6, 'message': 'Problem identifier not given'}
+                    return {'code': 3, 'message': 'No query specified'}
+                elif problem_id is None:
+                    return {'code': 4, 'message': 'Problem ID not given'}
                 else:
-                    messages, status, have_more = prolog.run_for_user(session.get_uid(), language, problem_group, problem, program, query)
-                    response = {'code': 0, 'message': 'ok', 'terminal': {'messages': messages, 'status': status, 'have_more': have_more}}
+                    messages, status, have_more = prolog.run_for_user(session.get_uid(), problem_id, program, query)
+                    return {'code': 0, 'message': 'ok', 'terminal': {'messages': messages, 'status': status, 'have_more': have_more}}
             elif step == 'next':
                 messages, status, have_more = prolog.step()
-                response = {'code': 0, 'message': 'ok', 'terminal': {'messages': messages, 'status': status, 'have_more': have_more}}
+                return {'code': 0, 'message': 'ok', 'terminal': {'messages': messages, 'status': status, 'have_more': have_more}}
             elif step == 'end':
                 messages, status, have_more = prolog.end()
-                response = {'code': 0, 'message': 'ok', 'terminal': {'messages': messages, 'status': status, 'have_more': have_more}}
+                return {'code': 0, 'message': 'ok', 'terminal': {'messages': messages, 'status': status, 'have_more': have_more}}
             else:
-                response = {'code': 7, 'message': 'Unknown prolog step: {0}'.format(step)}
+                return {'code': 5, 'message': 'Unknown prolog step: {0}'.format(step)}
 
-        resp.body = json.dumps(response)
-        resp.content_type = 'application/json'
-        resp.status = falcon.HTTP_200
+class GetProblem(CodeqService):
+    def process(self, js, session):
+        language = js.get('language')
+        problem_group = js.get('problem_group')
+        problem = js.get('problem')
+        if language is None:
+            return {'code': 1, 'message': 'Language identifier not given'}
+        elif problem_group is None:
+            return {'code': 2, 'message': 'Problem group identifier not given'}
+        elif problem is None:
+            return {'code': 3, 'message': 'Problem identifier not given'}
+        else:
+            return {'code': 0, 'message': 'ok', 'data': session.get_problem_data(language, problem_group, problem)}
+
+problem_list = ProblemList()
+api.add_route('/list_problems', problem_list)
 
 login = Login()
 api.add_route('/login', login)
@@ -126,3 +160,13 @@ api.add_route('/activity', activity)
 
 query = Query()
 api.add_route('/query', query)
+
+get_problem = GetProblem()
+api.add_route('/get_problem', get_problem)
+
+if __name__ == '__main__':
+    import logging
+    from waitress import serve
+    logger = logging.getLogger('waitress')
+    logger.setLevel(logging.DEBUG)
+    serve(application, host='0.0.0.0', port=8082)