zenith-backend / app /services /simplified_database.py
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fix(backend): fix port and health check robustness
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"""
Simplified Database Service
Removes complexity and improves maintainability
"""
from typing import Any, Optional, TypeVar
from fastapi import HTTPException
from sqlalchemy import text
from core.database import get_db
from core.models.base import Base
GenericModel = TypeVar("GenericModel", bound=Base)
class DatabaseService:
"""Simplified database service with common patterns"""
def __init__(self):
self.db_session = get_db
self._connection = None
self.is_connected = False
async def initialize(self):
"""Initialize database connection"""
try:
# For this simplified version, we'll simulate connection
self.is_connected = True
print("Database service initialized (simplified)")
except Exception as e:
print(f"Database initialization error: {e}")
self.is_connected = False
async def create(self, model_data: dict[str, Any], model_class: type[GenericModel]) -> GenericModel:
"""Create database record"""
try:
with self.db_session() as session:
db_model = model_class(**model_data)
session.add(db_model)
session.commit()
session.refresh(db_model)
return db_model
except Exception as e:
session.rollback()
raise HTTPException(status_code=500, detail=f"Failed to create {model_class.__name__}: {str(e)}")
async def get_by_id(self, model_class: type[GenericModel], record_id: str) -> Optional[GenericModel]:
"""Get record by ID"""
try:
with self.db_session() as session:
return session.query(model_class).filter(model_class.id == record_id).first()
except Exception as e:
print(f"Database error: {e}")
return None
async def get_all(
self, model_class: type[GenericModel], filters: dict[str, Any] = None, pagination: dict[str, Any] = None
) -> list[GenericModel]:
"""Get all records with optional filters and pagination"""
try:
with self.db_session() as session:
query = session.query(model_class)
# Apply filters
if filters:
for key, value in filters.items():
if hasattr(model_class, key):
query = query.filter(getattr(model_class, key) == value)
# Apply pagination
if pagination:
page = pagination.get("page", 1)
per_page = pagination.get("per_page", 100)
offset = (page - 1) * per_page
query = query.offset(offset).limit(per_page)
return query.all()
except Exception as e:
print(f"Database error: {e}")
return []
async def update(
self, model_class: type[GenericModel], record_id: str, update_data: dict[str, Any]
) -> Optional[GenericModel]:
"""Update record by ID"""
try:
with self.db_session() as session:
db_model = session.query(model_class).filter(model_class.id == record_id).first()
if db_model:
for key, value in update_data.items():
if hasattr(db_model, key):
setattr(db_model, key, value)
session.commit()
session.refresh(db_model)
return db_model
except Exception as e:
session.rollback()
print(f"Database update error: {e}")
return None
async def delete(self, model_class: type[GenericModel], record_id: str) -> bool:
"""Delete record by ID"""
try:
with self.db_session() as session:
db_model = session.query(model_class).filter(model_class.id == record_id).first()
if db_model:
session.delete(db_model)
session.commit()
return True
return False
except Exception as e:
session.rollback()
print(f"Database delete error: {e}")
return False
async def execute_query(self, query: str, params: tuple = None) -> list[dict[str, Any]]:
"""Execute raw SQL query"""
try:
with self.db_session() as session:
result = session.execute(text(query), params or ())
# Convert to dict format
columns = result.keys()
return [dict(zip(columns, row)) for row in result.fetchall()]
except Exception as e:
print(f"Query execution error: {e}")
return []
async def execute_insert(self, query: str, params: tuple = None) -> Optional[str]:
"""Execute insert query and return ID"""
try:
with self.db_session() as session:
result = session.execute(text(query), params or ())
session.commit()
return str(result.lastrowid) if hasattr(result, "lastrowid") else None
except Exception as e:
session.rollback()
print(f"Insert execution error: {e}")
return None
async def count(self, model_class: type[GenericModel], filters: dict[str, Any] = None) -> int:
"""Count records with optional filters"""
try:
with self.db_session() as session:
query = session.query(model_class)
# Apply filters
if filters:
for key, value in filters.items():
if hasattr(model_class, key):
query = query.filter(getattr(model_class, key) == value)
return query.count()
except Exception as e:
print(f"Database count error: {e}")
return 0
# Helper functions for common database patterns
def apply_pagination(query, page: int, per_page: int):
"""Apply pagination to SQLAlchemy query"""
offset = (page - 1) * per_page
return query.offset(offset).limit(per_page)
def build_safe_where_clause(filters: dict[str, Any], allowed_columns: list[str]) -> str:
"""Build safe WHERE clause from filters"""
if not filters:
return "1=1"
conditions = []
for key, value in filters.items():
if key not in allowed_columns:
raise ValueError(f"Unsafe column name: {key}")
if isinstance(value, str):
conditions.append(f"{key} = '{value}'")
elif isinstance(value, list):
placeholders = ", ".join(["%s"] * len(value))
conditions.append(f"{key} IN ({placeholders})")
else:
conditions.append(f"{key} = {value}")
return " AND ".join(conditions)