import datetime
import os
import uuid

from dotenv import load_dotenv
from pgvector.sqlalchemy import Vector
from sqlalchemy import JSON, Column, ForeignKey, String, UniqueConstraint, Uuid
from sqlalchemy.dialects.postgresql import JSONB
from sqlalchemy.orm import Mapped, mapped_column, relationship

from .db import Base

load_dotenv()

DATABASE_TYPE = os.getenv("DATABASE_TYPE", 'postgres')

ColumnType = JSONB if DATABASE_TYPE == 'postgres' else JSON

class Session(Base):
    __tablename__ = "sessions"
    id: Mapped[uuid.UUID] = mapped_column(primary_key=True, index=True, default=uuid.uuid4)
    app_id: Mapped[str] = mapped_column(String(512), index=True)
    user_id: Mapped[str] = mapped_column(String(512), index=True)
    location_id: Mapped[str] = mapped_column(String(512), index=True)
    is_active: Mapped[bool] = mapped_column(default=True)
    h_metadata: Mapped[dict] = mapped_column("metadata", ColumnType, default={}) 
    created_at: Mapped[datetime.datetime] = mapped_column(default=datetime.datetime.utcnow)
    messages = relationship("Message", back_populates="session")

    def __repr__(self) -> str:
        return f"Session(id={self.id}, app_id={self.app_id}, user_id={self.user_id}, location_id={self.location_id}, is_active={self.is_active}, created_at={self.created_at}, h_metadata={self.h_metadata})"

class Message(Base):
    __tablename__ = "messages"
    id: Mapped[uuid.UUID] = mapped_column(primary_key=True, index=True, default=uuid.uuid4)
    session_id: Mapped[uuid.UUID] = mapped_column(ForeignKey("sessions.id"))
    is_user: Mapped[bool]
    content: Mapped[str]  = mapped_column(String(65535)) 

    created_at: Mapped[datetime.datetime] = mapped_column(default=datetime.datetime.utcnow)
    session = relationship("Session", back_populates="messages")
    metamessages = relationship("Metamessage", back_populates="message")
    def __repr__(self) -> str:
        return f"Message(id={self.id}, session_id={self.session_id}, is_user={self.is_user}, content={self.content[10:]})"

class Metamessage(Base):
    __tablename__ = "metamessages"
    id: Mapped[uuid.UUID] = mapped_column(primary_key=True, index=True, default=uuid.uuid4)
    metamessage_type: Mapped[str] = mapped_column(String(512), index=True) 
    content: Mapped[str] = mapped_column(String(65535)) 
    message_id = Column(Uuid, ForeignKey("messages.id"))

    message = relationship("Message", back_populates="metamessages")
    created_at: Mapped[datetime.datetime] = mapped_column(default=datetime.datetime.utcnow)

    def __repr__(self) -> str:
        return f"Metamessages(id={self.id}, message_id={self.message_id}, metamessage_type={self.metamessage_type}, content={self.content[10:]})"

class Collection(Base):
    __tablename__ = "collections"
    id: Mapped[uuid.UUID] = mapped_column(primary_key=True, index=True, default=uuid.uuid4)
    name: Mapped[str] = mapped_column(String(512), index=True)
    app_id: Mapped[str] = mapped_column(String(512), index=True)
    user_id: Mapped[str] = mapped_column(String(512), index=True)
    created_at: Mapped[datetime.datetime] = mapped_column(default=datetime.datetime.utcnow)
    documents = relationship("Document", back_populates="collection", cascade="all, delete, delete-orphan")

    __table_args__ = (
        UniqueConstraint('name', 'app_id', 'user_id', name="unique_name_app_user"),
    )

class Document(Base):
    __tablename__ = "documents"
    id: Mapped[uuid.UUID] = mapped_column(primary_key=True, index=True, default=uuid.uuid4)
    h_metadata: Mapped[dict] = mapped_column("metadata", ColumnType, default={})
    content: Mapped[str] = mapped_column(String(65535))
    embedding = mapped_column(Vector(1536))
    created_at: Mapped[datetime.datetime] = mapped_column(default=datetime.datetime.utcnow)
    
    collection_id = Column(Uuid, ForeignKey("collections.id"))
    collection = relationship("Collection", back_populates="documents")