from pydantic import BaseModel, PositiveInt, computed_field, field_validator
from .TabSchema import TabSchema
import datetime
import re


class RequestSchema(BaseModel):
    username: str
    expiry: PositiveInt = 1
    tab: TabSchema = TabSchema()

    @field_validator('username')
    def validate_username(cls, value):
        if not re.fullmatch(r'[a-zA-Z0-9_-]{4,16}', value):
            raise ValueError("Invalid username format")
        return value
    
    @computed_field(return_type=PositiveInt)
    def validated_expiry(self):
        if self.expiry > 10**5:
            try:
                expiry_datetime = datetime.datetime.utcfromtimestamp(self.expiry)
                if expiry_datetime <= datetime.datetime.utcnow():
                    raise ValueError("Expiry timestamp must be in the future")
                return self.expiry
            except ValueError:
                raise ValueError("Invalid timestamp format")
        else:
            if self.expiry != 0:
                now = datetime.datetime.utcnow()
                return int((now + datetime.timedelta(days=self.expiry)).timestamp())
            else:
                return 0