from aws_lambda_powertools.event_handler.api_gateway import (
    APIGatewayHttpResolver,
    Response,
)
from aws_lambda_powertools.event_handler.middlewares import (
    BaseMiddlewareHandler,
    NextMiddleware,
)
from aws_lambda_powertools.shared.functions import (
    extract_event_from_common_models,
)
from layercake.dateutils import now, ttl
from layercake.dynamodb import ComposeKey, DynamoDBCollection, KeyPair
from layercake.funcs import pick
from pydantic import UUID4, BaseModel, EmailStr, Field

from auth import AuthFlowType

LOG_RETENTION_DAYS = 365 * 2  # 2 years


class User(BaseModel):
    id: str
    name: str
    email: EmailStr


class CognitoUser(User):
    id: str = Field(alias='custom:user_id')
    email_verified: bool
    sub: UUID4


class AuthorizerMiddleware(BaseMiddlewareHandler):
    def handler(
        self,
        app: APIGatewayHttpResolver,
        next_middleware: NextMiddleware,
    ) -> Response:
        # Gets the Lambda authorizer associated with the current API Gateway event.
        # You can check the file `auth.py` for more details.
        context = app.current_event.request_context.authorizer.get_lambda
        auth_flow_type = context.get('auth_flow_type')

        if not auth_flow_type:
            return next_middleware(app)

        cls = {
            AuthFlowType.USER_AUTH: CognitoUser,
            AuthFlowType.API_AUTH: User,
        }.get(auth_flow_type)

        if cls:
            app.append_context(user=cls(**context['user']))

        return next_middleware(app)


class TenantMiddleware(BaseMiddlewareHandler):
    def handler(
        self,
        app: APIGatewayHttpResolver,
        next_middleware: NextMiddleware,
    ) -> Response:
        context = app.current_event.request_context.authorizer.get_lambda
        tenant = app.current_event.headers.get('x-tenant')
        auth_flow_type = context.get('auth_flow_type')

        match auth_flow_type, tenant:
            case AuthFlowType.API_AUTH, None:
                app.append_context(tenant=context['tenant'])
            case AuthFlowType.USER_AUTH, str():
                print(tenant)

        return next_middleware(app)


class AuditLogMiddleware(BaseMiddlewareHandler):
    """This middleware logs audit details for successful requests, storing user,
    action, and IP info with a specified retention period.

    Parameters
    ----------
    action : str
        The identifier for the audit log action.
    collect : DynamoDBCollection
        The collection instance used to persist the audit log data.
    audit_attrs : tuple of str, optional
        A tuple of attribute names to extract from the response body for logging.
        These represent the specific fields to include in the audit log.
    retention_days : int or None, optional
        The number of days the log is retained on the server.
        If None, no time-to-live (TTL) will be applied.
    """

    def __init__(
        self,
        action: str,
        /,
        collect: DynamoDBCollection,
        audit_attrs: tuple[str, ...] = (),
        retention_days: int | None = LOG_RETENTION_DAYS,
    ) -> None:
        self.action = action
        self.collect = collect
        self.audit_attrs = audit_attrs
        self.retention_days = retention_days

    def handler(
        self,
        app: APIGatewayHttpResolver,
        next_middleware: NextMiddleware,
    ) -> Response:
        user = app.context.get('user')
        req_context = app.current_event.request_context
        ip_addr = req_context.http.source_ip
        response = next_middleware(app)

        # Successful response
        # https://developer.mozilla.org/en-US/docs/Web/HTTP/Reference/Status#successful_responses
        if 200 <= response.status_code < 300 and user:
            now_ = now()
            data = (
                pick(self.audit_attrs, extract_event_from_common_models(response.body))
                if response.is_json()
                else None
            )
            retention_days = (
                ttl(start_dt=now_, days=self.retention_days)
                if self.retention_days
                else None
            )

            self.collect.put_item(
                key=KeyPair(
                    # Post-migration: remove `delimiter` from ComposeKey.
                    pk=ComposeKey(user.id, prefix='logs', delimiter=':'),
                    sk=now_.isoformat(),
                ),
                action=self.action,
                data=data,
                ip=ip_addr,
                ttl=retention_days,
            )

        return response