add(backend): possibility to delete paste

paste/db.py

@@ -26,9 +26,10 @@ def check_content_exist(key: str) -> bool:
     return db.exists(key)
 
 
-def insert_content_db(url_id: str, expiration: int, content: str) -> None:
+def insert_content_db(url_id: str, expiration: int, content: str, secret: str) -> None:
     """
 
+    :param secret: Secret key for delete url
     :param url_id: key for access to content.
     :param expiration: Content expiration in second.
     :param content: Paste content
@@ -36,7 +37,9 @@ def insert_content_db(url_id: str, expiration: int, content: str) -> None:
     """
     if not check_content_exist(url_id):
         db = connect_redis()
-        db.set(url_id, content)
+        data = {"content": content, "secret": secret}
+        for key, key_content in data.items():
+            db.hset(url_id, key, key_content)
         db.expire(url_id, expiration)
     else:
         logging.error(f"Key : {url_id} already exist") # noqa: G004

paste/home.py

@@ -1,6 +1,8 @@
 """Manage view and create paste."""
+
 from flask import (
     Blueprint,
+    abort,
     flash,
     redirect,
     render_template,
@@ -10,22 +12,24 @@ from flask import (
 from werkzeug import Response
 
 from paste.db import check_content_exist, connect_redis, insert_content_db
-from paste.utils import generate_id
+from paste.utils import generate_id, generate_secret
 
 home = Blueprint("home", __name__, url_prefix="/")
 
 
-def create_paste(content: str, time:int) -> str:
+def create_paste(content: str, time: int) -> dict[str, str]:
     """
     Create paste in DB.
+    :param time: Expiration time in second
     :param content: Content to add in redis.
-    :return: None.
+    :return: A dict with url_id and delete secret.
     """
+    secret = generate_secret()
     url_id = generate_id()
     while check_content_exist(url_id):
         url_id = generate_id()
-    insert_content_db(url_id, time, content)
+    insert_content_db(url_id, time, content, secret)
-    return url_id
+    return {"url_id": url_id, "secret": secret}
 
 
 @home.route("/")
@@ -47,11 +51,28 @@ def create() -> Response:
     time = request.form.get("time")
     time = 86400 if time == "" else int(time)
 
-    url_id = create_paste(content, time)
+    flash_data = create_paste(content, time)
-    flash(f"{request.host_url}{url_id}")
+    flash(flash_data["url_id"], category="create")
+    flash(flash_data["secret"], category="create")
     return redirect(url_for("home.homepage"))
 
 
+@home.route("/delete/<path:path>")
+def delete_paste(path: str) -> Response:
+    """
+    Delete a paste
+    :param path: path fetched from url
+    :return: forbidden (403) or homepage.
+    """
+    db = connect_redis()
+    secret = request.args.get("secret")
+    if db.hget(path, "secret") == secret:
+        db.delete(path)
+        flash(path, category="delete")
+        return redirect(url_for("home.homepage"))
+    return abort(403)
+
+
 @home.route("/<path:path>")
 def get_content(path: str) -> str:
     """
@@ -60,5 +81,9 @@ def get_content(path: str) -> str:
     :return: Paste content.
     """
     db = connect_redis()
-    flash(db.get(path))
+    data = db.hgetall(path)
+    if check_content_exist(path):
+        flash(data["content"])
         return render_template("content.html.j2")
+
+    return abort(404)

paste/templates/home.html.j2

@@ -4,8 +4,18 @@
     <input id="time" name="time">
     <input type="submit">
 </form>
-{% with messages = get_flashed_messages() %}
+{% with messages = get_flashed_messages(category_filter=["create"]) %}
-    {% if messages %}
+    {% if messages[0] %}
-        <p>Paste available at : <a href="{{ messages[0] }}">{{ messages[0] }}</a></p>
+        <p>Paste available at : <a href="{{ request.base_url }}{{ messages[0] }}">{{ messages[0] }}</a></p>
+    {% endif %}
+    {% if messages[1] %}
+        <p>You can delete paste with : <a href="{{ request.base_url }}delete/{{ messages[0] }}?secret={{ messages[1] }}">delete</a></p>
     {% endif %}
 {% endwith %}
+
+{% with messages = get_flashed_messages(category_filter=["delete"]) %}
+    {% if messages[0] %}
+        <p>Paste {{ messages[0] }} deleted </p>
+    {% endif %}
+{% endwith %}
+

paste/utils.py

@@ -1,6 +1,7 @@
 # ruff: noqa: S311
 """Shared utils function."""
 import random
+import secrets
 import string
 
 from paste import config
@@ -15,3 +16,11 @@ def generate_id() -> str:
         random.choices(string.ascii_letters + string.digits,
                        k=config.URL_LENGTH)
     )
+
+
+def generate_secret() -> str:
+    """
+    Generate hex secret for delete paste.
+    :return: The secret.
+    """
+    return secrets.token_hex()