"""
Photo Model — ORM + Pydantic Schemas

ORM:     Photo (SQLAlchemy table: photos)
Schemas: PhotoCreate, PhotoResponse
"""

import uuid
from datetime import datetime
from typing import Optional

from sqlalchemy import String, Text, BigInteger, DateTime, ForeignKey, func
from sqlalchemy.dialects.postgresql import UUID
from sqlalchemy.orm import Mapped, mapped_column, relationship

from pydantic import BaseModel, Field, ConfigDict

from models.base import Base


# ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
# ORM Model
# ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

class Photo(Base):
    """SQLAlchemy ORM model for the 'photos' table."""

    __tablename__ = "photos"

    id: Mapped[uuid.UUID] = mapped_column(
        UUID(as_uuid=True), primary_key=True, default=uuid.uuid4
    )
    visit_id: Mapped[uuid.UUID] = mapped_column(
        UUID(as_uuid=True),
        ForeignKey("visits.id", ondelete="CASCADE"),
        nullable=False,
    )
    checklist_id: Mapped[Optional[uuid.UUID]] = mapped_column(
        UUID(as_uuid=True),
        ForeignKey("checklists.id", ondelete="SET NULL"),
        nullable=True,
    )
    assessment_id: Mapped[Optional[uuid.UUID]] = mapped_column(
        UUID(as_uuid=True),
        ForeignKey("assessments.id", ondelete="SET NULL"),
        nullable=True,
        comment="Linked assessment item (for per-item photo gallery)"
    )
    file_path: Mapped[str] = mapped_column(String(500), nullable=False)
    file_name: Mapped[str] = mapped_column(String(255), nullable=False)
    file_size: Mapped[Optional[int]] = mapped_column(BigInteger, nullable=True)
    mime_type: Mapped[Optional[str]] = mapped_column(String(100), nullable=True)
    caption: Mapped[Optional[str]] = mapped_column(Text, nullable=True)
    uploaded_at: Mapped[datetime] = mapped_column(
        DateTime, server_default=func.now()
    )
    created_at: Mapped[datetime] = mapped_column(
        DateTime, server_default=func.now()
    )

    # Relationships
    visit = relationship("Visit", back_populates="photos")
    checklist = relationship("Checklist", back_populates="photos", foreign_keys=[checklist_id])
    assessment = relationship("Assessment", back_populates="photos", foreign_keys=[assessment_id])

    def __repr__(self) -> str:
        return f"<Photo(id={self.id}, file='{self.file_name}')>"


# ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
# Pydantic Schemas
# ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

class PhotoCreate(BaseModel):
    """Schema for photo upload metadata."""
    checklist_id: Optional[uuid.UUID] = Field(
        None, description="Optional linked checklist item"
    )
    assessment_id: Optional[uuid.UUID] = Field(
        None, description="Optional linked assessment item (per-item photo)"
    )
    caption: Optional[str] = Field(None, description="Photo caption")


class PhotoResponse(BaseModel):
    """Schema for a single photo in API responses."""
    model_config = ConfigDict(from_attributes=True)

    id: uuid.UUID
    visit_id: uuid.UUID
    checklist_id: Optional[uuid.UUID]
    assessment_id: Optional[uuid.UUID]
    file_path: str
    file_name: str
    file_size: Optional[int]
    mime_type: Optional[str]
    caption: Optional[str]
    uploaded_at: datetime
    created_at: datetime