from datetime import datetime, timezone
from enum import Enum
from uuid import UUID

from pydantic import AnyHttpUrl, BaseModel, ConfigDict, Field, field_validator


def utc_now() -> datetime:
    return datetime.now(timezone.utc)


class MonitorState(str, Enum):
    UNKNOWN = "unknown"
    UP = "up"
    DOWN = "down"
    ERROR = "error"


class CurrentStatus(BaseModel):
    state: MonitorState = MonitorState.UNKNOWN
    checked_at: datetime | None = None
    latency_ms: float | None = Field(default=None, ge=0)
    http_status: int | None = Field(default=None, ge=100, le=599)
    error: str | None = Field(default=None, max_length=500)


class MonitorFields(BaseModel):
    model_config = ConfigDict(str_strip_whitespace=True)

    name: str = Field(min_length=1, max_length=100)
    target_url: AnyHttpUrl

    @field_validator("target_url")
    @classmethod
    def reject_credentials(cls, value: AnyHttpUrl) -> AnyHttpUrl:
        if value.username is not None or value.password is not None:
            raise ValueError("URL credentials are not allowed")
        return value


class MonitorCreate(MonitorFields):
    pass


class MonitorUpdate(MonitorFields):
    pass


class Monitor(MonitorFields):
    id: UUID
    created_at: datetime
    updated_at: datetime
    current_status: CurrentStatus


class Health(BaseModel):
    status: str