from __future__ import annotations

from datetime import datetime
from enum import Enum

from passlib.context import CryptContext
from pydantic import BaseModel, validator
from sqlalchemy.exc import IntegrityError
from sqlalchemy.orm import Session

from . import models


class CertificateBase(BaseModel):
    expiry: datetime


class CertificateCreate(CertificateBase):
    owner_name: str
    dn_id: int


class Certificate(CertificateBase):
    id: int

    class Config:
        orm_mode = True


class UserCapability(Enum):
    admin = "admin"


class UserBase(BaseModel):
    name: str


class UserCreate(UserBase):
    password: str


class User(UserBase):
    certificates: list[Certificate]
    capabilities: list[UserCapability]

    class Config:
        orm_mode = True

    @validator("capabilities", pre=True)
    @classmethod
    def unify_capabilities(
        cls,
        value: list[models.UserCapability | str]
    ) -> list[UserCapability]:
        return [
            UserCapability(str(capability))
            for capability in value
        ]

    @classmethod
    def from_db(
        cls,
        db: Session,
        name: str,
    ) -> User | None:
        user = (db
                .query(models.User)
                .filter(models.User.name == name)
                .first())

        if user is None:
            return None

        return cls.from_orm(user)

    @classmethod
    def login(
        cls,
        db: Session,
        name: str,
        password: str,
        crypt_context: CryptContext,
    ) -> User | None:
        user = (db
                .query(models.User)
                .filter(models.User.name == name)
                .first())

        if user is None:
            # inexistent user, fake doing password verification
            crypt_context.dummy_verify()
            return None

        if not crypt_context.verify(password, user.password):
            # password hash mismatch
            return None

        return cls.from_orm(user)

    @classmethod
    def create(
        cls,
        db: Session,
        user: UserCreate,
        crypt_context: CryptContext,
    ) -> User | None:
        try:
            user = models.User(
                name=user.name,
                password=crypt_context.hash(user.password),
                capabilities=[models.UserCapability(capability="admin")],
            )

            db.add(user)
            db.commit()
            db.refresh(user)

            return cls.from_orm(user)

        except IntegrityError:
            pass


class DistinguishedNameBase(BaseModel):
    cn_only: bool
    country: str
    state: str
    city: str
    organization: str
    organizational_unit: str
    email: str
    common_name: str


class DistinguishedNameCreate(DistinguishedNameBase):
    pass


class DistinguishedName(DistinguishedNameBase):
    id: int
    certificates: list[Certificate]

    class Config:
        orm_mode = True