feat: refactor db calls to url service

app/services/__init__.py

@@ -1 +1 @@
-from .encoder import encoder
+from .url_service import UrlService

app/services/encoder.py

@@ -1,27 +0,0 @@
-from app.config import settings
-from hashids import Hashids
-
-class ShortCodeEncoder:
-    def __init__(self, salt=None, alphabet=None, min_length=6):
-        self.salt = salt or settings.hashids_salt
-        self.alphabet = alphabet or settings.encoder_alphabet
-
-        self.hashids = Hashids(salt=self.salt, min_length=min_length, alphabet=self.alphabet)
-        self.min_length = min_length
-
-    def encode(self, id: int) -> str:
-        return self.hashids.encode(id)
-
-    def decode(self, shortcode: str) -> int:
-        decoded = self.hashids.decode(shortcode)
-        return decoded[0] if decoded else None
-
-    def is_valid(self, shortcode: str) -> bool:
-        if len(shortcode) < self.min_length:
-            return False
-        if any(char not in self.alphabet for char in shortcode):
-            return False
-        return True
-
-# Singleton instance of encoder
-encoder = ShortCodeEncoder()

app/services/url_service.py

@@ -0,0 +1,36 @@
+from sqlalchemy import select, insert
+from sqlalchemy.exc import IntegrityError
+
+from app.utils import encoder
+from app.models import Url
+from app.exceptions import ShortcodeConflict, ShortcodeNotFound
+
+class UrlService:
+    def __init__(self, db):
+        self.db = db
+
+    async def get_url_by_shortcode(self, shortcode: str) -> str:
+        query = select(Url.url).where(Url.shortcode == shortcode)
+        result = await self.db.fetch_val(query)
+
+        if result is None:
+            raise ShortcodeNotFound(f"Shortcode '{shortcode}' not found")
+
+        return result
+
+    async def generate_shortcode_and_save(self, url: str):
+        try:
+            # Get the next ID from the sequence
+            next_id = await self.db.fetch_val("SELECT nextval('urls_id_seq')")
+            shortcode = encoder.encode(next_id)
+
+            # Insert the new URL entry
+            insert_stmt = insert(Url).values(id=next_id, url=url, shortcode=shortcode)
+            await self.db.execute(insert_stmt)
+
+            return {"shortcode": shortcode, "url": url}
+
+        except IntegrityError as e:
+            if 'shortcode' in str(e):
+                raise ShortcodeConflict(f"Shortcode '{shortcode}' already in use") from None
+            raise