import re
from pydantic import BaseModel, ConfigDict, Field, model_validator, field_validator
from datetime import datetime, date
from typing import Optional

_EMAIL_RE = re.compile(r'^[^@\s]+@[^@\s]+\.[^@\s]+$')


class PersonCreate(BaseModel):
    model_config = ConfigDict(extra="forbid")

    name: Optional[str] = Field(None, max_length=255)          # legacy fallback — auto-split into first/last if provided alone
    first_name: Optional[str] = Field(None, max_length=100)
    last_name: Optional[str] = Field(None, max_length=100)
    nickname: Optional[str] = Field(None, max_length=100)
    email: Optional[str] = Field(None, max_length=255)
    phone: Optional[str] = Field(None, max_length=50)
    mobile: Optional[str] = Field(None, max_length=50)
    address: Optional[str] = Field(None, max_length=2000)
    birthday: Optional[date] = None
    category: Optional[str] = Field(None, max_length=100)
    is_favourite: bool = False
    company: Optional[str] = Field(None, max_length=255)
    job_title: Optional[str] = Field(None, max_length=255)
    notes: Optional[str] = Field(None, max_length=5000)

    @model_validator(mode='after')
    def require_some_name(self) -> 'PersonCreate':
        if not any([
            self.name and self.name.strip(),
            self.first_name and self.first_name.strip(),
            self.last_name and self.last_name.strip(),
            self.nickname and self.nickname.strip(),
        ]):
            raise ValueError('At least one name field is required')
        return self

    @field_validator('email')
    @classmethod
    def validate_email(cls, v: str | None) -> str | None:
        if v and not _EMAIL_RE.match(v):
            raise ValueError('Invalid email address')
        return v


class PersonUpdate(BaseModel):
    model_config = ConfigDict(extra="forbid")

    # name is intentionally omitted — always computed from first/last/nickname
    first_name: Optional[str] = Field(None, max_length=100)
    last_name: Optional[str] = Field(None, max_length=100)
    nickname: Optional[str] = Field(None, max_length=100)
    email: Optional[str] = Field(None, max_length=255)
    phone: Optional[str] = Field(None, max_length=50)
    mobile: Optional[str] = Field(None, max_length=50)
    address: Optional[str] = Field(None, max_length=2000)
    birthday: Optional[date] = None
    category: Optional[str] = Field(None, max_length=100)
    is_favourite: Optional[bool] = None
    company: Optional[str] = Field(None, max_length=255)
    job_title: Optional[str] = Field(None, max_length=255)
    notes: Optional[str] = Field(None, max_length=5000)

    @field_validator('email')
    @classmethod
    def validate_email(cls, v: str | None) -> str | None:
        if v and not _EMAIL_RE.match(v):
            raise ValueError('Invalid email address')
        return v


class PersonResponse(BaseModel):
    id: int
    name: str
    first_name: Optional[str]
    last_name: Optional[str]
    nickname: Optional[str]
    email: Optional[str]
    phone: Optional[str]
    mobile: Optional[str]
    address: Optional[str]
    birthday: Optional[date]
    category: Optional[str]
    is_favourite: bool
    company: Optional[str]
    job_title: Optional[str]
    notes: Optional[str]
    linked_user_id: Optional[int] = None
    is_umbral_contact: bool = False
    shared_fields: Optional[dict] = None
    created_at: datetime
    updated_at: datetime

    model_config = ConfigDict(from_attributes=True)