Migrate from Flask to FastAPI (#163)

* Migrate from Flask to FastAPI

 * FastAPI migration:
    - Use pydantic model classes as input parameters to the
      data/calculation classes.
    - Interface field names changed to constructor parameter names (for
      simplicity only during transition, should be updated in a followup
      PR).
    - Add basic interface requirements (e.g. some values > 0, etc.).
 * Update tests for new data format.
 * Python requirement down to 3.9 (TypeGuard no longer needed)
 * Makefile: Add helpful targets (e.g. development server with reload)

* Move API doc from README to pydantic model classes (swagger)

 * Link to swagger.io with own openapi.yml.
 * Commit openapi.json and check with pytest for changes so the
   documentation is always up-to-date.

* Streamline docker

* FastAPI: Run startup action on dev server

 * Fix config for /strompreis, endpoint still broken however.

* test_openapi: Compare against docs/.../openapi.json

* Move fastapi to server/ submodule

 * See #187 for new repository structure.

Makefile

@@ -1,5 +1,5 @@
 # Define the targets
-.PHONY: help venv pip install dist test test-full docker-run docs read-docs clean
+.PHONY: help venv pip install dist test test-full docker-run docker-build docs read-docs clean format run run-dev
 
 # Default target
 all: help
@@ -10,12 +10,14 @@ help:
 	@echo "  venv         - Set up a Python 3 virtual environment."
 	@echo "  pip          - Install dependencies from requirements.txt."
 	@echo "  pip-dev      - Install dependencies from requirements-dev.txt."
+	@echo "  format       - Format source code."
 	@echo "  install      - Install EOS in editable form (development mode) into virtual environment."
 	@echo "  docker-run   - Run entire setup on docker"
 	@echo "  docker-build - Rebuild docker image"
 	@echo "  docs         - Generate HTML documentation (in build/docs/html/)."
 	@echo "  read-docs    - Read HTML documentation in your browser."
-	@echo "  run          - Run flask_server in the virtual environment (needs install before)."
+	@echo "  run          - Run FastAPI server in the virtual environment (needs install before)."
+	@echo "  run-dev      - Run FastAPI development server in the virtual environment (automatically reloads)."
 	@echo "  dist         - Create distribution (in dist/)."
 	@echo "  clean        - Remove generated documentation, distribution and virtual environment."
 
@@ -66,8 +68,12 @@ clean:
 	@echo "Deletion complete."
 
 run:
-	@echo "Starting flask server, please wait..."
-	.venv/bin/python -m akkudoktoreosserver.flask_server
+	@echo "Starting FastAPI server, please wait..."
+	.venv/bin/python -m akkudoktoreos.server.fastapi_server
+
+run-dev:
+	@echo "Starting FastAPI development server, please wait..."
+	.venv/bin/fastapi dev src/akkudoktoreos/server/fastapi_server.py
 
 # Target to setup tests.
 test-setup: pip-dev
@@ -83,9 +89,13 @@ test-full:
 	@echo "Running all tests..."
 	.venv/bin/pytest --full-run
 
+# Target to format code.
+format:
+	pre-commit run --all-files
+
 # Run entire setup on docker
 docker-run:
 	@docker compose up --remove-orphans
 
 docker-build:
-	@docker compose build
+	@docker compose build --pull