from datetime import datetime

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

from app.db import Base


class Conversation(Base):
    __tablename__ = "conversations"

    id: Mapped[int] = mapped_column(primary_key=True)
    user_id: Mapped[int] = mapped_column(ForeignKey("users.id"), index=True)
    title: Mapped[str] = mapped_column(String(255), default="新会话")
    adp_conversation_id: Mapped[str | None] = mapped_column(String(120))
    created_at: Mapped[datetime] = mapped_column(DateTime, default=datetime.utcnow)
    last_message_at: Mapped[datetime | None] = mapped_column(DateTime)

    messages: Mapped[list["Message"]] = relationship(back_populates="conversation")


class Message(Base):
    __tablename__ = "messages"

    id: Mapped[int] = mapped_column(primary_key=True)
    conversation_id: Mapped[int] = mapped_column(ForeignKey("conversations.id"), index=True)
    user_id: Mapped[int] = mapped_column(ForeignKey("users.id"), index=True)
    question: Mapped[str] = mapped_column(Text)
    answer: Mapped[str | None] = mapped_column(Text)
    status: Mapped[str] = mapped_column(String(30), default="pending", index=True)
    latency_ms: Mapped[int | None] = mapped_column(Integer)
    token_usage: Mapped[int] = mapped_column(Integer, default=0)
    pu_usage: Mapped[int] = mapped_column(Integer, default=0)
    model_conversation_id: Mapped[str | None] = mapped_column(String(120))
    created_at: Mapped[datetime] = mapped_column(DateTime, default=datetime.utcnow)

    conversation: Mapped[Conversation] = relationship(back_populates="messages")
    references: Mapped[list["MessageReference"]] = relationship(back_populates="message")


class MessageReference(Base):
    __tablename__ = "message_references"

    id: Mapped[int] = mapped_column(primary_key=True)
    message_id: Mapped[int] = mapped_column(ForeignKey("messages.id"), index=True)
    document_id: Mapped[int | None] = mapped_column(ForeignKey("documents.id"))
    source_title: Mapped[str] = mapped_column(String(255))
    snippet: Mapped[str | None] = mapped_column(Text)
    page_no: Mapped[str | None] = mapped_column(String(40))
    section: Mapped[str | None] = mapped_column(String(120))
    source_url: Mapped[str | None] = mapped_column(String(500))

    message: Mapped[Message] = relationship(back_populates="references")


class Attachment(Base):
    __tablename__ = "attachments"

    id: Mapped[int] = mapped_column(primary_key=True)
    user_id: Mapped[int] = mapped_column(ForeignKey("users.id"), index=True)
    message_id: Mapped[int | None] = mapped_column(ForeignKey("messages.id"))
    file_type: Mapped[str] = mapped_column(String(80))
    storage_key: Mapped[str] = mapped_column(String(255))
    remote_url: Mapped[str | None] = mapped_column(String(1000))
    original_name: Mapped[str | None] = mapped_column(String(255))
    expire_at: Mapped[datetime | None] = mapped_column(DateTime)
    created_at: Mapped[datetime] = mapped_column(DateTime, default=datetime.utcnow)


class Feedback(Base):
    __tablename__ = "feedback"

    id: Mapped[int] = mapped_column(primary_key=True)
    message_id: Mapped[int] = mapped_column(ForeignKey("messages.id"), index=True)
    user_id: Mapped[int] = mapped_column(ForeignKey("users.id"), index=True)
    rating: Mapped[str] = mapped_column(String(20))
    comment: Mapped[str | None] = mapped_column(Text)
    created_at: Mapped[datetime] = mapped_column(DateTime, default=datetime.utcnow)