from http import HTTPStatus
from io import BytesIO
from typing import Any

from aws_lambda_powertools import Logger
from aws_lambda_powertools.event_handler.api_gateway import Router
from aws_lambda_powertools.event_handler.exceptions import (
    BadRequestError,
    NotFoundError,
)
from layercake.dateutils import now
from layercake.dynamodb import DynamoDBPersistenceLayer, KeyPair
from pydantic import UUID4, BaseModel

from api_gateway import JSONResponse
from boto3clients import dynamodb_client, s3_client
from config import BUCKET_NAME, COURSE_TABLE
from form_data import parse

logger = Logger(__name__)
router = Router()
dyn = DynamoDBPersistenceLayer(COURSE_TABLE, dynamodb_client)


@router.get('/<course_id>')
def get_course(course_id: str):
    return dyn.collection.get_item(
        KeyPair(course_id, '0'),
        exc_cls=NotFoundError,
    )


class Cert(BaseModel):
    exp_interval: int | None = None
    s3_uri: str | None = None

    def model_dump(self, **kwargs) -> dict[str, Any]:
        return super().model_dump(exclude_none=True, **kwargs)


class Course(BaseModel):
    id: UUID4
    name: str
    access_period: int
    cert: Cert
    rawfile: bytes | None = None


@router.put('/<course_id>')
def edit_course(course_id: str):
    event = router.current_event

    if not event.decoded_body:
        raise BadRequestError('Invalid request body')

    body = BytesIO(event.decoded_body.encode())
    course = Course.model_validate(
        {'id': course_id, 'cert': {}} | parse(event.headers, body),
    )
    now_ = now()

    if course.rawfile:
        object_key = f'certs/{course_id}.html'
        course.cert.s3_uri = f's3://{BUCKET_NAME}/{object_key}'

        s3_client.put_object(
            Bucket=BUCKET_NAME,
            Key=object_key,
            Body=course.rawfile,
            ContentType='text/html',
        )

    with dyn.transact_writer() as transact:
        transact.update(
            key=KeyPair(str(course.id), '0'),
            update_expr='SET #name = :name, access_period = :access_period, \
                        cert = :cert, updated_at = :updated_at',
            expr_attr_names={
                '#name': 'name',
            },
            expr_attr_values={
                ':name': course.name,
                ':cert': course.cert.model_dump(),
                ':access_period': course.access_period,
                ':updated_at': now_,
            },
            cond_expr='attribute_exists(sk)',
            exc_cls=BadRequestError,
        )

    return JSONResponse(HTTPStatus.NO_CONTENT)