from dotenv import load_dotenv

load_dotenv()

import logging
import os
import uvicorn
from contextlib import asynccontextmanager
from fastapi import FastAPI, Request, Response
from fastapi.middleware.cors import CORSMiddleware
from fastapi.responses import RedirectResponse
from app.api.routers.chat import chat_router
from app.api.routers.user import user_router
from app.settings import init_settings
from app.observability import init_observability
from fastapi.staticfiles import StaticFiles
from alembic.config import Config
from alembic import command


from app.engine.postgresdb import engine, Base, SessionLocal

logger = logging.getLogger("uvicorn")

# Create all tables in the database
Base.metadata.create_all(bind=engine)


def run_migrations():
    alembic_cfg = Config("alembic.ini")
    command.upgrade(alembic_cfg, "head")


@asynccontextmanager
async def lifespan(app_: FastAPI):
    logger.info("Starting up...")
    logger.info("Run 'alembic upgrade head' to apply migrations...")
    run_migrations()
    yield
    logger.info("Shutting down...")


app = FastAPI(lifespan=lifespan)


@app.middleware("http")
async def db_session_middleware(request: Request, call_next):
    response = Response("Internal server error", status_code=500)
    try:
        request.state.db = SessionLocal()
        response = await call_next(request)
    finally:
        request.state.db.close()
    return response


init_settings()
init_observability()

environment = os.getenv("ENVIRONMENT", "dev")  # Default to 'development' if not set

if environment == "dev":
    logger.warning("Running in development mode - allowing CORS for all origins")
    app.add_middleware(
        CORSMiddleware,
        allow_origins=["*"],
        allow_credentials=True,
        allow_methods=["*"],
        allow_headers=["*"],
    )

    # Redirect to documentation page when accessing base URL
    @app.get("/")
    async def redirect_to_docs():
        return RedirectResponse(url="/docs")


if os.path.exists("data"):
    app.mount("/api/data", StaticFiles(directory="data"), name="static")
app.include_router(chat_router, prefix="/api/chat")
app.include_router(user_router)


if __name__ == "__main__":
    app_host = os.getenv("APP_HOST", "0.0.0.0")
    app_port = int(os.getenv("APP_PORT", "8000"))
    reload = True if environment == "dev" else False

    uvicorn.run(app="main:app", host=app_host, port=app_port, reload=reload)