merica/backend/app/main.py

"""
DLH Data Lakehouse - Dynamic Pipeline & Storage API
Modular Entrypoint with FastAPI
"""
import logging
from fastapi import FastAPI
from fastapi.middleware.cors import CORSMiddleware

from app.core.config import settings
from app.routers import api_v1_router, legacy_router
from app.schemas.pipeline import DeployRequest, DraftRequest
from app.schemas.connection import ConnectionTestRequest, CustomConnectionRequest
from app.services.pipeline_parser import parse_yaml_to_pipeline_dict
from app.services.metadb_service import save_connection_to_metadb
from app.services.dbt_service import sync_dbt_models_from_nodes

# Configure root logger
logging.basicConfig(
    level=logging.INFO,
    format="%(asctime)s [%(levelname)s] %(name)s: %(message)s"
)
logger = logging.getLogger(__name__)

# Module-level variable exports for backward compatibility with existing scripts
CONFIGS_DIR = settings.CONFIGS_DIR
UPLOADS_DIR = settings.UPLOADS_DIR
DOCS_DIR = settings.DOCS_DIR
DBT_DIR = settings.DBT_DIR

# FastAPI Application Factory / Instance
app = FastAPI(
    title=settings.PROJECT_NAME,
    version=settings.VERSION,
    description="Modular FastAPI Backend for MERICA Studio, Dynamic Lakehouse YAML Generation, and Airflow 3 DAG Bundles."
)

# CORS Setup
app.add_middleware(
    CORSMiddleware,
    allow_origins=settings.CORS_ORIGINS,
    allow_credentials=True,
    allow_methods=["*"],
    allow_headers=["*"],
)

# Mount RESTful v1 Router and Canvas v0.1 Backward Compatibility Router
app.include_router(api_v1_router)
app.include_router(legacy_router)


@app.api_route("/api/v1/health", methods=["GET", "HEAD"], tags=["System"], summary="System health check probe")
def health_check():
    """Health check probe endpoint."""
    return {
        "status": "ok",
        "service": settings.PROJECT_NAME,
        "version": settings.VERSION
    }

# Backward compatibility health check probes (hidden from OpenAPI schema)
@app.api_route("/health", methods=["GET", "HEAD"], include_in_schema=False)
@app.api_route("/api/health", methods=["GET", "HEAD"], include_in_schema=False)
def legacy_health_check():
    return health_check()


# Exported symbols for python imports
__all__ = [
    "app",
    "settings",
    "CONFIGS_DIR",
    "UPLOADS_DIR",
    "DOCS_DIR",
    "DBT_DIR",
    "parse_yaml_to_pipeline_dict",
    "save_connection_to_metadb",
    "sync_dbt_models_from_nodes",
    "DeployRequest",
    "DraftRequest",
    "ConnectionTestRequest",
    "CustomConnectionRequest",
]