import base64
from urllib.parse import parse_qs, urlencode

from pydantic import BaseModel, Field, field_validator


class RequestHeaders(BaseModel):
    request_signature: str = Field(validation_alias="x-twilio-signature")
    host: str
    scheme: str = Field(validation_alias="x-forwarded-proto")


class Event(BaseModel):
    headers: RequestHeaders
    params: dict[str, str] | None = Field(
        default=None, validation_alias="queryStringParameters"
    )
    path: str
    body: dict[str, str]

    @field_validator("body", mode="before")
    def decode_body(cls, body: str) -> dict[str, str]:
        decoded_body = base64.b64decode(body).decode()
        body_dict = parse_qs(decoded_body, keep_blank_values=True)
        body_dict_prepared = {k: v[0] for k, v in body_dict.items()}
        return body_dict_prepared

    @property
    def request_full_uri(self) -> str:
        return (
            f"{self.headers.scheme}://{self.headers.host}{self.path}{self.request_qs}"
        )

    @property
    def request_qs(self) -> str:
        if not self.params:
            return ""
        return f"?{urlencode(sorted(self.params.items()))}"