from datetime import datetime, time, timezone
from typing import Dict, Optional
from uuid import UUID

from pydantic import BaseModel, Field, field_validator


class EventBase(BaseModel):
    title: str = Field(..., min_length=1, max_length=200)
    description: Optional[str] = None
    location_name: Optional[str] = None
    location_address: Optional[str] = None
    location_url: Optional[str] = None
    event_date: datetime
    event_start_time: Optional[time] = None
    event_end_time: Optional[time] = None
    timezone: str
    rsvp_deadline: Optional[datetime] = None
    is_public: bool = False
    access_code: Optional[str] = None
    theme_id: Optional[UUID] = None
    custom_theme_settings: Optional[Dict] = None
    additional_info: Optional[Dict] = None
    is_active: bool = True
    rsvp_enabled: bool = True
    gift_registry_enabled: bool = True
    updates_enabled: bool = True
    max_guests_per_invitation: Optional[int] = Field(None, ge=1)
    contact_email: Optional[str] = None
    contact_phone: Optional[str] = None

    @field_validator('timezone')
    def validate_timezone(cls, v):
        from zoneinfo import ZoneInfo
        try:
            ZoneInfo(v)
            return v
        except Exception:
            raise ValueError("Invalid timezone")

    @field_validator('event_date')
    def validate_event_date(cls, v):
        if not v.tzinfo:
            v =  v.replace(tzinfo=timezone.utc)
        now = datetime.now(tz=timezone.utc)
        if v < now:
            raise ValueError("Event date cannot be in the past")
        return v

    @field_validator('rsvp_deadline')
    def validate_rsvp_deadline(cls, v, values):
        if v:
            if not v.tzinfo:
                raise ValueError("RSVP deadline must be timezone-aware")
            if 'event_date' in values.data:
                if v > values.data['event_date']:
                    raise ValueError("RSVP deadline must be before event date")
        return v


class EventCreate(EventBase):
    slug: str = Field(..., min_length=1, pattern="^[a-z0-9-]+$")


class EventUpdate(EventBase):
    title: Optional[str] = None
    event_date: Optional[datetime] = None
    timezone: Optional[str] = None
    slug: Optional[str] = Field(None, min_length=1, pattern="^[a-z0-9-]+$")


class EventInDBBase(EventBase):
    id: UUID
    created_by: UUID
    created_at: datetime
    updated_at: datetime
    slug: str

    class Config:
        from_attributes = True


class EventResponse(EventInDBBase):
    @field_validator('event_date')
    def validate_datetime(cls, v):
        if v.tzinfo is None:
           v.event_date =  v.event_date.replace(tzinfo=timezone.utc)
        return v



class Event(EventInDBBase):
    pass