"""
Pydantic representation of database contents.
"""


from __future__ import annotations

from datetime import datetime
from enum import Enum
from typing import Any

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

from . import models

##########
# table: user_capabilities
##########


class UserCapability(Enum):
    admin = "admin"
    login = "login"
    issue = "issue"
    renew = "renew"

    def __repr__(self) -> str:
        return self.value

    @classmethod
    def from_value(cls, value) -> UserCapability:
        """
        Create UserCapability from various formats
        """

        if isinstance(value, cls):
            # value is already a UserCapability, use that
            return value

        elif isinstance(value, models.UserCapability):
            # create from db format
            return cls(value.capability)

        else:
            # create from string representation
            return cls(str(value))

    @property
    def model(self) -> models.UserCapability:
        return models.UserCapability(
            capability=self.value,
        )


##########
# table: users
##########


class UserBase(BaseModel):
    name: str

    country: str
    state: str
    city: str
    organization: str
    organizational_unit: str

    email: str

    capabilities: list[UserCapability] = []


class UserCreate(UserBase):
    password: str


class User(UserBase):
    devices: list[Device] = Field(
        default=[], repr=False
    )

    class Config:
        orm_mode = True

    @validator("capabilities", pre=True)
    @classmethod
    def unify_capabilities(cls, value: list[Any]) -> list[UserCapability]:
        """
        Import the capabilities from various formats
        """

        return [
            UserCapability.from_value(capability)
            for capability in value
        ]

    @classmethod
    def from_db(
        cls,
        db: Session,
        name: str,
    ) -> User | None:
        """
        Load user from database by name.
        """

        db_user = models.User(name=name)
        db.refresh(db_user)

        return cls.from_orm(db_user)

    @classmethod
    def create(
        cls,
        db: Session,
        user: UserCreate,
        crypt_context: CryptContext,
    ) -> User | None:
        """
        Create a new user in the database.
        """

        try:
            db_user = models.User(
                name=user.name,
                password=crypt_context.hash(user.password),
                capabilities=[
                    capability.model
                    for capability in user.capabilities
                ],
            )

            db.add(db_user)
            db.commit()
            db.refresh(db_user)

            return cls.from_orm(db_user)

        except IntegrityError:
            # user already existed
            pass

    def is_admin(self) -> bool:
        return UserCapability.admin in self.capabilities

    def authenticate(
        self,
        db: Session,
        password: str,
        crypt_context: CryptContext,
    ) -> User | None:
        """
        Authenticate with name/password against users in database.
        """

        db_user = models.User(name=self.name)
        db.refresh(db_user)

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

        if not crypt_context.verify(password, db_user.password):
            # password hash mismatch
            return False

        self.from_orm(db_user)

        return True

    def update(
        self,
        db: Session,
    ) -> None:
        """
        Update this user in the database.
        """

        db_user = models.User(name=self.name)
        db.refresh(db_user)

        for capability in db_user.capabilities:
            db.delete(capability)

        db_user.capabilities = [
            capability.model
            for capability in self.capabilities
        ]

        db.commit()

    def delete(
        self,
        db: Session,
    ) -> bool:
        """
        Delete this user from the database.
        """

        db_user = models.User(name=self.name)
        db.refresh(db_user)

        if db_user is None:
            # nonexistent user
            return False

        db.delete(db_user)
        db.commit()
        return True


##########
# table: devices
##########


class DeviceBase(BaseModel):
    name: str
    type: str
    expiry: datetime


class DeviceCreate(DeviceBase):
    owner_name: str


class Device(DeviceBase):
    class Config:
        orm_mode = True

    @classmethod
    def create(
        cls,
        db: Session,
        device: DeviceCreate,
    ) -> Device | None:
        """
        Create a new device in the database.
        """

        try:
            db_device = models.Device(
                owner_name=device.owner_name,

                name=device.name,
                type=device.type,
                expiry=device.expiry,
            )

            db.add(db_device)
            db.commit()
            db.refresh(db_device)

            return cls.from_orm(db_device)

        except IntegrityError:
            # device already existed
            pass

    def delete(
        self,
        db: Session,
    ) -> bool:
        """
        Delete this device from the database.
        """

        db_device = models.Device(
            # owner_name=
            name=self.name,
        )
        db.refresh(db_device)

        if db_device is None:
            # nonexistent device
            return False

        db.delete(db_device)
        db.commit()
        return True