from fastapi import FastAPI, Request
from fastapi.middleware.cors import CORSMiddleware
from contextlib import asynccontextmanager

from api.routers import chats
from api.routers import memory
from db.session import create_db_and_tables
from core.config import get_settings

import time

settings = get_settings()

@asynccontextmanager
async def lifespan(app: FastAPI):
    print(f"INFO:     Starting up {settings.APP_NAME} v{settings.APP_VERSION}...")
    await create_db_and_tables()
    print("INFO:     Database tables checked/created.")
    yield
    print(f"INFO:     Shutting down {settings.APP_NAME}...")

# FastAPI app instance
app = FastAPI(
    title=settings.APP_NAME,
    description=f"An API for interacting with {settings.APP_NAME}.",
    version=settings.APP_VERSION,
    lifespan=lifespan
)

# --- Middlewares ---

@app.middleware("http")
async def add_process_time_header(request: Request, call_next):
    start_time = time.time()
    response = await call_next(request)
    process_time = time.time() - start_time
    response.headers["X-Process-Time"] = str(process_time)
    print(f"INFO:     Request {request.method} {request.url.path} processed in {process_time:.4f} sec")
    return response

app.add_middleware(
    CORSMiddleware,
    allow_origins=[settings.FRONTEND_URL, "http://127.0.0.1:3000"],
    allow_credentials=True,
    allow_methods=["*"],
    allow_headers=["*"],
)

# --- Routers ---
app.include_router(chats.router, prefix="/api/chats", tags=["Chats & Messages"])
app.include_router(memory.router, prefix="/api/memories", tags=["Memory Management"])

# --- Root Endpoint ---
@app.get("/", tags=["Health"])
async def read_root():
    return {"status": "ok", "message": "Welcome to Makhfi AI API!"}