import uuid
from datetime import datetime
from enum import Enum

from sqlalchemy import Boolean, DateTime, ForeignKey, String, Text
from sqlalchemy.orm import Mapped, mapped_column, relationship

from app.database import Base


def generate_uuid() -> str:
    return str(uuid.uuid4())


class ReasoningType(str, Enum):
    CHAIN = "chain"
    IDEA = "idea"
    CONTEXT = "context"
    REFLECTION = "reflection"


class Document(Base):
    __tablename__ = "documents"

    id: Mapped[str] = mapped_column(String(36), primary_key=True, default=generate_uuid)
    title: Mapped[str] = mapped_column(String(500), nullable=False)
    content: Mapped[str] = mapped_column(Text, nullable=False, default="")
    project_id: Mapped[str] = mapped_column(String(36), ForeignKey("projects.id", ondelete="CASCADE"), nullable=False)
    folder_id: Mapped[str | None] = mapped_column(String(36), ForeignKey("folders.id", ondelete="SET NULL"), nullable=True)
    path: Mapped[str] = mapped_column(Text, nullable=False)
    is_deleted: Mapped[bool] = mapped_column(Boolean, default=False, nullable=False)
    deleted_at: Mapped[datetime | None] = mapped_column(DateTime, nullable=True)
    deleted_by: Mapped[str | None] = mapped_column(String(36), nullable=True)
    created_at: Mapped[datetime] = mapped_column(DateTime, default=datetime.utcnow, nullable=False)
    updated_at: Mapped[datetime] = mapped_column(DateTime, default=datetime.utcnow, onupdate=datetime.utcnow, nullable=False)
    # Phase 2: Reasoning fields
    reasoning_type: Mapped[str | None] = mapped_column(String(20), nullable=True)
    confidence: Mapped[str | None] = mapped_column(String(10), nullable=True)  # Store as string to handle JSON serialization
    reasoning_steps: Mapped[str | None] = mapped_column(Text, nullable=True)  # JSON array as text
    model_source: Mapped[str | None] = mapped_column(String(100), nullable=True)
    tiptap_content: Mapped[str | None] = mapped_column(Text, nullable=True)  # JSON object as text
    # Phase 3: Link tracking
    outgoing_links: Mapped[str] = mapped_column(Text, nullable=False, default="[]")  # JSON array of document IDs
    backlinks_count: Mapped[int] = mapped_column(default=0, nullable=False)  # Cached count of incoming links