Merge pull request #348 from openclimatefix/fix/crude-dev-without-db

Add dummy db class; update README

README.md

@@ -38,7 +38,12 @@ cd src && uvicorn main:app --reload
 
 You may need to run the following additional installation `pip install git+https://github.com/SheffieldSolar/PV_Live-API#pvlive_api` for `pvlive-api`, as in the Dockerfile.
 
-## Docker
+> If you don't have a local database set up, you can leave the `DB_URL` string empty (default not set) and the API will still run and return routes such as `http://localhost:8000/` for API info and any other non-DB routes with DB dependencies e.g. session/caching commented out.
+>
+> You will not be able to access any routes using the DB client / database, but for local development of new routes this should work for now, until we reinstate dynamic fake data as a dependable dev tool.
+
+## [ Docker ]
+### 🛑 Currently non-functional, needs updating to migrate database to match datamodel
 
 1. Make sure docker is installed on your system.
 2. Use `docker-compose up`
@@ -62,7 +67,7 @@ as Actions when code is pushed to GitHub.
 You can run the formatters and linters locally. To do that:
 
 1. [Install pre-commit](https://pre-commit.com/#install)
-2. Check the install worked via `pre-commit --version`
+2. Check the install worked via `pre-commit --v`
 3. Install the git hooks script via `pre-commit install`
 
 # Deployment

src/database.py

@@ -1,5 +1,6 @@
 """ Functions to read from the database and format """
 
+import abc
 import os
 from datetime import datetime, timedelta, timezone
 from typing import List, Optional, Union
@@ -44,7 +45,64 @@
 )
 from utils import filter_forecast_values, floor_30_minutes_dt, get_start_datetime
 
-db_conn = DatabaseConnection(url=os.getenv("DB_URL", "not_set"))
+
+class BaseDBConnection(abc.ABC):
+    """This is a base class for database connections with one static method get_connection().
+
+    Methods
+    -------
+    get_connection : static method
+        It gets the database connection. If a valid Postgresql database URL is set in
+        the "DB_URL" environment variable, get_connection returns an instance
+        of DatabaseConnection(). If not, it returns an instance of the DummyDBConnection.
+    """
+
+    @staticmethod
+    def get_connection():
+        """
+        Get the database connection.
+        """
+        db_url = os.getenv("DB_URL")
+        if db_url and db_url.find("postgresql") != -1:
+            return DatabaseConnection(url=db_url)
+        else:
+            return DummyDBConnection()
+
+
+class DummyDBConnection(BaseDBConnection):
+    """The DummyDBConnection serves as a placeholder database connection
+
+    This might be useful when a valid Postgresql
+    database connection is not available. in testing or development environments.
+    Feel free to improve on this implementation and submit a pull request!
+    A better example can be found in the [india-api](
+    https://github.com/openclimatefix/india-api/blob/f4e3b776194290d78e1c9702b792cbb88edf4b90/src/india_api/cmd/main.py#L12
+    ) repository.
+
+    It inherits from the BaseDBConnection class and implements the methods accordingly.
+
+    Methods
+    ----------
+    get_session:
+        Returns None for now, but should mock the session if possible,
+        if we keep the current DB/datamodel implementation.
+    """
+
+    def __init__(self):
+        """Initializes the DummyDBConnection"""
+        pass
+
+    def get_session(self):
+        """Returns None for now, but mock the session if we keep the current implementation."""
+        return None
+
+
+def get_db_connection() -> BaseDBConnection:
+    """Return either the datamodel connection or a dummy connection"""
+    return BaseDBConnection.get_connection()
+
+
+db_conn = get_db_connection()
 
 logger = structlog.stdlib.get_logger()
 

src/national.py

@@ -189,3 +189,28 @@ def get_national_pvlive(
     return get_truth_values_for_a_specific_gsp_from_database(
         session=session, gsp_id=0, regime=regime
     )
+
+
+@router.get(
+    "/bmrs",
+    response_model=dict,
+    # dependencies=[Depends(get_auth_implicit_scheme())],
+    summary="Get BMRS Forecast",
+)
+# @cache_response
+@limiter.limit(f"{N_CALLS_PER_HOUR}/hour")
+def get_bmrs_forecast(
+    request: Request,
+    # session: Session = Depends(get_session),
+    # user: Auth0User = Security(get_user()),
+) -> dict:
+    """
+
+    This route returns the most recent BMRS forecast for each _target_time_.
+
+    #### Parameters
+
+    """
+    logger.debug("Get bmrs forecast")
+
+    return {"message": "This route is not yet implemented. Please check back later."}