"""
数据库模型定义
"""
from datetime import datetime, timezone
from typing import Optional, List
from sqlalchemy import Column, String, Integer, DateTime, Boolean, Text, ForeignKey, JSON
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import relationship

Base = declarative_base()


def utc_now():
    """返回当前 UTC 时间（带时区信息）"""
    return datetime.now(timezone.utc)


class User(Base):
    """用户表"""
    __tablename__ = "users"

    id = Column(String, primary_key=True)
    phone = Column(String, unique=True, nullable=False, index=True)  # 手机号（唯一，必填）
    password_hash = Column(String, nullable=False)  # 密码哈希
    email = Column(String, unique=True, nullable=True)  # 邮箱（可选）
    openid = Column(String, unique=True, nullable=True)  # 微信 OpenID（可选）
    nickname = Column(String, nullable=False)
    avatar_url = Column(String, nullable=True)
    subscription_type = Column(String, default="free")  # free, premium
    created_at = Column(DateTime(timezone=True), default=utc_now)

    # Relationships
    conversations = relationship("Conversation", back_populates="user")
    chapters = relationship("Chapter", back_populates="user")
    books = relationship("Book", back_populates="user")
    memoir_state = relationship("MemoirState", back_populates="user", uselist=False, cascade="all, delete-orphan")
    refresh_tokens = relationship("RefreshToken", back_populates="user", cascade="all, delete-orphan")


class Conversation(Base):
    """对话会话表"""
    __tablename__ = "conversations"

    id = Column(String, primary_key=True)
    user_id = Column(String, ForeignKey("users.id"), nullable=False)
    started_at = Column(DateTime(timezone=True), default=utc_now)
    ended_at = Column(DateTime(timezone=True), nullable=True)
    duration_seconds = Column(Integer, default=0)
    summary = Column(Text, nullable=True)
    status = Column(String, default="active")  # active, ended, processing
    current_topic = Column(String, nullable=True)
    conversation_stage = Column(String, nullable=True)  # childhood, education, career, family, beliefs, summary

    # Relationships
    user = relationship("User", back_populates="conversations")
    segments = relationship("Segment", back_populates="conversation", cascade="all, delete-orphan")


class Segment(Base):
    """对话段落表"""
    __tablename__ = "segments"

    id = Column(String, primary_key=True)
    conversation_id = Column(String, ForeignKey("conversations.id"), nullable=False)
    audio_url = Column(String, nullable=True)
    transcript_text = Column(Text, nullable=False)
    created_at = Column(DateTime(timezone=True), default=utc_now)
    processed = Column(Boolean, default=False)
    topic_category = Column(String, nullable=True)
    agent_response = Column(Text, nullable=True)

    # Relationships
    conversation = relationship("Conversation", back_populates="segments")


class Chapter(Base):
    """章节表"""
    __tablename__ = "chapters"

    id = Column(String, primary_key=True)
    user_id = Column(String, ForeignKey("users.id"), nullable=False)
    title = Column(String, nullable=False)
    content = Column(Text, nullable=False)
    order_index = Column(Integer, nullable=False)
    status = Column(String, default="draft")  # draft, completed
    images = Column(JSON, nullable=True)  # 图片 URL 列表
    updated_at = Column(DateTime(timezone=True), default=utc_now, onupdate=utc_now)
    category = Column(String, nullable=True)  # 章节分类
    is_new = Column(Boolean, default=True)  # 是否为新内容（未读）
    source_segments = Column(JSON, nullable=True)  # 来源 segment IDs 列表

    # Relationships
    user = relationship("User", back_populates="chapters")


class Book(Base):
    """回忆录表"""
    __tablename__ = "books"

    id = Column(String, primary_key=True)
    user_id = Column(String, ForeignKey("users.id"), nullable=False)
    title = Column(String, nullable=False)
    total_pages = Column(Integer, default=0)
    total_words = Column(Integer, default=0)
    cover_image_url = Column(String, nullable=True)
    updated_at = Column(DateTime(timezone=True), default=utc_now, onupdate=utc_now)
    has_update = Column(Boolean, default=False)  # 是否有新内容
    last_update_chapter_id = Column(String, nullable=True)  # 最近更新的章节 ID

    # Relationships
    user = relationship("User", back_populates="books")


class MemoirState(Base):
    """回忆录状态表 - 对话 Agent 与后台 Agent 共享"""
    __tablename__ = "memoir_states"

    id = Column(String, primary_key=True)
    user_id = Column(String, ForeignKey("users.id"), unique=True, nullable=False)
    stage_order = Column(JSON, default=list)  # 阶段顺序
    current_stage = Column(String, default="childhood")  # 当前阶段
    covered_stages = Column(JSON, default=list)  # 已完成阶段列表
    slots = Column(JSON, nullable=False)  # 各阶段 slot 信息
    updated_at = Column(DateTime(timezone=True), default=utc_now, onupdate=utc_now)

    # Relationships
    user = relationship("User", back_populates="memoir_state")


class RefreshToken(Base):
    """刷新令牌表"""
    __tablename__ = "refresh_tokens"

    id = Column(String, primary_key=True)
    user_id = Column(String, ForeignKey("users.id"), nullable=False, index=True)
    token = Column(String, unique=True, nullable=False, index=True)  # 刷新令牌（唯一）
    expires_at = Column(DateTime(timezone=True), nullable=False)  # 过期时间（30天后）
    created_at = Column(DateTime(timezone=True), default=utc_now)
    is_revoked = Column(Boolean, default=False)  # 是否已撤销

    # Relationships
    user = relationship("User", back_populates="refresh_tokens")