from datetime import datetime, timedelta

import secrets as secrets_mod

from fastapi import APIRouter, Depends, HTTPException, Request, status
from sqlalchemy.orm import Session

from auth import (
    create_access_token,
    get_current_user,
    hash_password,
    require_admin,
    verify_password,
)
from database import get_db
from models import Invitation, User
from ratelimit import change_password_limiter, login_limiter, rate_limit, register_limiter
from schemas import (
    InvitationCreate,
    InvitationResponse,
    PasswordChange,
    TokenResponse,
    UserCreate,
    UserLogin,
    UserResponse,
)

router = APIRouter(prefix="/api/auth", tags=["auth"])

INVITATION_EXPIRY_DAYS = 7


@router.post("/register", response_model=TokenResponse)
@rate_limit(register_limiter)
def register(request: Request, data: UserCreate, db: Session = Depends(get_db)):
    invite = (
        db.query(Invitation)
        .filter(
            Invitation.token == data.invite_token,
            Invitation.used_by.is_(None),
        )
        .first()
    )
    if not invite:
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail="Invitation invalide ou déjà utilisée",
        )

    if invite.expires_at and invite.expires_at < datetime.utcnow():
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail="Invitation expirée",
        )

    if db.query(User).filter(
        (User.username == data.username) | (User.email == data.email)
    ).first():
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail="Un compte avec ces informations existe déjà",
        )

    user = User(
        username=data.username,
        email=data.email,
        hashed_password=hash_password(data.password),
    )
    db.add(user)
    db.flush()

    invite.used_by = user.id
    invite.used_at = datetime.utcnow()
    db.flush()

    db.commit()
    db.refresh(user)

    token = create_access_token({"sub": str(user.id), "token_version": user.token_version})
    return TokenResponse(
        access_token=token,
        user=UserResponse.model_validate(user),
    )


@router.post("/login", response_model=TokenResponse)
@rate_limit(login_limiter)
def login(request: Request, data: UserLogin, db: Session = Depends(get_db)):
    user = db.query(User).filter(User.username == data.username).first()
    if not user or not verify_password(data.password, user.hashed_password):
        raise HTTPException(
            status_code=status.HTTP_401_UNAUTHORIZED,
            detail="Identifiants incorrects",
        )

    token = create_access_token({"sub": str(user.id), "token_version": user.token_version})
    return TokenResponse(
        access_token=token,
        user=UserResponse.model_validate(user),
    )


@router.get("/me", response_model=UserResponse)
def me(user: User = Depends(get_current_user)):
    return UserResponse.model_validate(user)


@router.post("/change-password")
@rate_limit(change_password_limiter)
def change_password(
    request: Request,
    data: PasswordChange,
    user: User = Depends(get_current_user),
    db: Session = Depends(get_db),
):
    if not verify_password(data.current_password, user.hashed_password):
        raise HTTPException(
            status_code=status.HTTP_400_BAD_REQUEST,
            detail="Mot de passe actuel incorrect",
        )
    user.hashed_password = hash_password(data.new_password)
    user.token_version += 1
    db.commit()
    return {"detail": "Mot de passe modifié"}


@router.post("/logout")
def logout(user: User = Depends(get_current_user), db: Session = Depends(get_db)):
    user.token_version += 1
    db.commit()
    return {"detail": "Déconnexion réussie"}


@router.post("/invitations", response_model=InvitationResponse)
def create_invitation(
    admin: User = Depends(require_admin),
    db: Session = Depends(get_db),
):
    invitation = Invitation(
        token=secrets_mod.token_urlsafe(32),
        created_by=admin.id,
        expires_at=datetime.utcnow() + timedelta(days=INVITATION_EXPIRY_DAYS),
    )
    db.add(invitation)
    db.commit()
    db.refresh(invitation)
    return InvitationResponse.model_validate(invitation)


@router.get("/invitations", response_model=list[InvitationResponse])
def list_invitations(
    admin: User = Depends(require_admin),
    db: Session = Depends(get_db),
):
    invitations = (
        db.query(Invitation)
        .filter(Invitation.created_by == admin.id)
        .order_by(Invitation.created_at.desc())
        .all()
    )
    return [InvitationResponse.model_validate(i) for i in invitations]