import uuid
from sqlalchemy import Column, String, Text, DateTime, Integer, Float, ForeignKey, Index, create_engine, Boolean
from sqlalchemy.dialects.postgresql import UUID
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import sessionmaker
from datetime import datetime
from app.config import settings

Base = declarative_base()


class User(Base):
    __tablename__ = "users"

    id = Column(UUID(as_uuid=True), primary_key=True, default=uuid.uuid4)
    email = Column(String(255), unique=True, nullable=False, index=True)
    hashed_password = Column(String(255), nullable=False)
    is_active = Column(Boolean, default=True)
    created_at = Column(DateTime, default=datetime.utcnow)


class Document(Base):
    __tablename__ = "documents"

    id = Column(UUID(as_uuid=True), primary_key=True, default=uuid.uuid4)
    source = Column(String(50), nullable=False)
    ext_id = Column(String(200), nullable=True)
    title = Column(Text, nullable=False)
    url = Column(Text, nullable=True)
    lang = Column(String(2), nullable=True)
    minio_key = Column(Text, nullable=True)
    indexed_at = Column(DateTime, default=datetime.utcnow)


class Fingerprint(Base):
    __tablename__ = "fingerprints"

    id = Column(UUID(as_uuid=True), primary_key=True, default=uuid.uuid4)
    doc_id = Column(UUID(as_uuid=True), ForeignKey("documents.id"), nullable=False)
    hash = Column(String(64), nullable=False)   # xxhash hex string
    position = Column(Integer, nullable=True)


Index("ix_fingerprints_hash", Fingerprint.hash)
Index("ix_fingerprints_doc_id", Fingerprint.doc_id)


class AnalysisTask(Base):
    __tablename__ = "analysis_tasks"

    id = Column(UUID(as_uuid=True), primary_key=True, default=uuid.uuid4)
    user_id = Column(UUID(as_uuid=True), ForeignKey("users.id"), nullable=True)
    status = Column(String(20), default="pending")
    overall_similarity = Column(Float, nullable=True)
    source_text = Column(Text, nullable=True)
    created_at = Column(DateTime, default=datetime.utcnow)
    completed_at = Column(DateTime, nullable=True)


class Match(Base):
    __tablename__ = "matches"

    id = Column(UUID(as_uuid=True), primary_key=True, default=uuid.uuid4)
    task_id = Column(UUID(as_uuid=True), ForeignKey("analysis_tasks.id"), nullable=False)
    doc_id = Column(UUID(as_uuid=True), ForeignKey("documents.id"), nullable=True)
    similarity = Column(Float, nullable=False)
    method = Column(String(20), nullable=False)
    fragment_start = Column(Integer, nullable=True)
    fragment_end = Column(Integer, nullable=True)
    fragment_text = Column(Text, nullable=True)


engine = create_engine(settings.DATABASE_URL, echo=False)
SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)


def get_db():
    db = SessionLocal()
    try:
        yield db
    finally:
        db.close()