bring back reactions

app/routes/api.py

@@ -1,10 +1,21 @@
 from flask import Blueprint, request
 from ..auth import is_logged_in, hard_login_required, get_active_user
 from ..lib.babycode import babycode_to_html
-from ..models import APIRateLimits
+from ..models import APIRateLimits, Posts, Threads, Reactions
+from ..constants import REACTION_EMOJI
 
 bp = Blueprint('api', __name__, url_prefix='/api/')
 
+@bp.before_request
+def ensure_json():
+    if request.method == 'POST':
+        if not request.is_json:
+           return {'error': 'unsupported media type'}, 415
+        elif not request.content_length:
+            return {'error': 'body expected'}, 400
+        elif not isinstance(request.json, dict):
+            return {'error': 'body must be an object'}, 400
+
 @bp.post('/babycode-preview/')
 @hard_login_required
 def babycode_preview():
@@ -31,3 +42,48 @@ def whoami():
         'username': user.username,
         'display_name': user.display_name,
     }
+
+@bp.post('/toggle-reaction/')
+@hard_login_required
+def toggle_reaction():
+    user = get_active_user()
+    emoji = request.json.get('reaction')
+    if emoji not in REACTION_EMOJI:
+        return {'error': f'invalid reaction string, given: {emoji}'}, 400
+
+    post_id = request.json.get('post', -1)
+    post = Posts.find({'id': post_id})
+    if not post:
+        return {'error': 'post not found'}, 404
+
+    thread = Threads.find({'id': post.thread_id})
+
+    if not user.can_post_to_thread_or_topic(thread):
+        return {'error': 'thread is locked'}, 403
+
+    reaction_obj = {
+        'user_id': int(user.id),
+        'post_id': int(post_id),
+        'reaction_text': emoji,
+    }
+    r = Reactions.find(reaction_obj)
+    if r:
+        # remove
+        r.delete()
+        return {'status': 'ok', 'added': False}
+    else:
+        # add
+        r = Reactions.create(reaction_obj)
+        return {'status': 'ok', 'added': True}
+
+@bp.get('/thread-permission/<int:thread_id>')
+def thread_permission(thread_id):
+    user = get_active_user()
+    if not user:
+        return {'can_post': False}
+
+    thread = Threads.find({'id': thread_id})
+    if not thread:
+        return {'can_post': False}
+
+    return {'can_post': user.can_post_to_thread_or_topic(thread)}