# ===================== Importing FastAPI necessary packages =============
from fastapi import (
    FastAPI,
    HTTPException,
    status,
    Request,
)
from fastapi.staticfiles import StaticFiles
from src.dependecies import authenticate_user
from src.routers.routers import router
from src.routers.post import post
from src.routers.history_find import history_find
from src.routers.post_save import post_save
from src.routers.history import history

import base64
import binascii

from fastapi.middleware.cors import CORSMiddleware

# ------------------ FastAPI variable ----------------------------------
app = FastAPI()

app.mount("/post", StaticFiles(directory="post"), name="post")

origins = ["*"]

app.add_middleware(
    CORSMiddleware,
    allow_origins=origins,
    allow_credentials=True,
    allow_methods=["*"],
    allow_headers=["*"],
)


# ================ Authentication Middleware =======================
# ----------- Here authentication is based on basic scheme,
# ----------- another authentication, based on bearer scheme, is used throughout
# ---------- the application (as decribed in FastAPI oficial documentation)
@app.middleware("http")
async def authenticate(request: Request, call_next):

    # -------------------- Authentication basic scheme -----------------------------
    if "Authorization" in request.headers:
        auth = request.headers["Authorization"]
        try:
            scheme, credentials = auth.split()
            if scheme.lower() == 'basic':
                decoded = base64.b64decode(credentials).decode("ascii")
                username, _, password = decoded.partition(":")
                request.state.user = await authenticate_user(username, password)
        except (ValueError, UnicodeDecodeError, binascii.Error):
            raise HTTPException(
                status_code=status.HTTP_401_UNAUTHORIZED,
                detail="Invalid basic auth credentials"
            )

    response = await call_next(request)
    return response

# ================= Routers inclusion from src directory ===============
app.include_router(post)
app.include_router(router)
app.include_router(history_find)
app.include_router(post_save)
app.include_router(history)