From 15965187572b4fa3758d7a277d708c49b7e9d997 Mon Sep 17 00:00:00 2001
From: Xevion <xevioni@yandex.com>
Date: Thu, 27 Aug 2020 01:31:52 -0500
Subject: [PATCH] basic arithmetic, API & questions organization, ID generation

---
 server/api.py        | 31 +++++++++++++++++++++
 server/arithmetic.py | 66 ++++++++++++++++++++++++++++++++++++++++++++
 server/helpers.py    |  6 ++++
 server/questions.py  |  6 ++++
 4 files changed, 109 insertions(+)
 create mode 100644 server/api.py
 create mode 100644 server/arithmetic.py
 create mode 100644 server/helpers.py
 create mode 100644 server/questions.py

diff --git a/server/api.py b/server/api.py
new file mode 100644
index 0000000..5b799d9
--- /dev/null
+++ b/server/api.py
@@ -0,0 +1,31 @@
+from flask import current_app, jsonify, request
+
+from server import questions
+from server.helpers import generate_id
+
+# Stores active questions in memory for checking answers.
+# Keys represent random question IDs. Values are Question objects.
+active_questions = {}
+
+categories = {
+    'arithmetic': questions.get_arithmetic
+}
+
+
+@current_app.route('/api/<category>/new')
+def new_question(category: str):
+    q_id = None
+    while q_id in active_questions.keys() or q_id is None:
+        q_id = generate_id(5)
+
+    active_questions[q_id] = categories[category]()()
+
+    return jsonify(active_questions[q_id])
+
+
+@current_app.route('/api/<category>/check')
+def check_question(category: str):
+    if 'id' not in request.args.keys():
+        return jsonify({'error': ''}), 400
+
+    return jsonify({'answer': active_questions.get(request.args[id])})
diff --git a/server/arithmetic.py b/server/arithmetic.py
new file mode 100644
index 0000000..5467d8d
--- /dev/null
+++ b/server/arithmetic.py
@@ -0,0 +1,66 @@
+"""
+arithmetic.py
+
+Organizes all questions related to basic arithmetic, i.e. the four primary mathematical operations.
+Also includes arithmetic related to exponents (positive and negative), fractions and more.
+"""
+import inspect
+import random
+
+
+def addition():
+    a, b = random.randint(6, 70), random.randint(6, 70)
+    return {
+        'type': inspect.stack()[0][3],
+        'question': f'{a} + {b}',
+        'answer': a + b
+    }
+
+
+def subtraction():
+    a, b = random.randint(6, 70), random.randint(6, 70)
+    return {
+        'type': inspect.stack()[0][3],
+        'question': f'{a} - {b}',
+        'answer': a - b
+    }
+
+
+def multiplication():
+    a = random.randint(2, 18)
+    b = random.randint(2, 26 - a)
+    return {
+        'type': inspect.stack()[0][3],
+        'question': f'{a} x {b}',
+        'answer': a * b
+    }
+
+
+def division():
+    a = random.randint(2, 18)
+    b = random.randint(2, 26 - a)
+    return {
+        'type': inspect.stack()[0][3],
+        'question': f'{a * b} ÷ {b}',
+        'answer': a
+    }
+
+
+def simplify_fraction():
+    a = random.randint(1, 12)
+    b = random.randint(2, 20 - a)
+
+    # Multiply by even/odd to
+    c, d = a, b
+    while c + d <= 15:
+        multiplier = random.randint(2, 3)
+        c, d = c * multiplier, d * multiplier
+
+    return {
+        'type': inspect.stack()[0][3],
+        'question': f'Simplify. \\frac{{{c}}}{{{d}}}',
+        'answer': f'{c}/{d}'
+    }
+
+
+questions = [addition, subtraction, multiplication, division, simplify_fraction]
diff --git a/server/helpers.py b/server/helpers.py
new file mode 100644
index 0000000..c2bf620
--- /dev/null
+++ b/server/helpers.py
@@ -0,0 +1,6 @@
+import random
+import string
+
+
+def generate_id(length: int):
+    return ''.join(random.choices(string.ascii_letters, k=length))
diff --git a/server/questions.py b/server/questions.py
new file mode 100644
index 0000000..1a86a91
--- /dev/null
+++ b/server/questions.py
@@ -0,0 +1,6 @@
+import random
+from server import arithmetic
+
+
+def get_arithmetic():
+    return random.choice(arithmetic.questions)