"""
数据库模型定义
使用 SQLModel 定义所有表结构
"""
from datetime import datetime, date
from typing import Optional
from sqlmodel import SQLModel, Field, Relationship, Column
from sqlalchemy import Numeric
from decimal import Decimal


# ==================== 用户表 ====================
class User(SQLModel, table=True):
    """用户表"""
    __tablename__ = "users"
    
    id: Optional[int] = Field(default=None, primary_key=True)
    username: str = Field(max_length=50, unique=True, index=True)
    email: Optional[str] = Field(default=None, max_length=100, unique=True, index=True)
    hashed_password: str
    created_at: datetime = Field(default_factory=datetime.now)


# ==================== 待办事项表 ====================
class Todo(SQLModel, table=True):
    """待办事项表"""
    __tablename__ = "todos"
    
    id: Optional[int] = Field(default=None, primary_key=True)
    title: str = Field(max_length=200)
    done: bool = Field(default=False)
    created_at: datetime = Field(default_factory=datetime.now)
    user_id: int = Field(foreign_key="users.id", index=True)
    
    # 关系（可选，用于ORM查询）
    user: Optional[User] = Relationship()


# ==================== 博客文章表 ====================
class Post(SQLModel, table=True):
    """博客文章表"""
    __tablename__ = "posts"
    
    id: Optional[int] = Field(default=None, primary_key=True)
    title: str = Field(max_length=200)
    slug: str = Field(max_length=200, index=True)
    content: str  # 支持 Markdown
    created_at: datetime = Field(default_factory=datetime.now)
    updated_at: Optional[datetime] = Field(default=None)
    user_id: int = Field(foreign_key="users.id", index=True)
    
    # 关系
    user: Optional[User] = Relationship()


# ==================== 记账记录表 ====================
class Transaction(SQLModel, table=True):
    """记账记录表"""
    __tablename__ = "transactions"
    
    id: Optional[int] = Field(default=None, primary_key=True)
    amount: Decimal = Field(sa_column=Column(Numeric(10, 2)))  # 正数为收入，负数为支出
    category: str = Field(max_length=50)
    description: Optional[str] = Field(default=None, max_length=200)
    date: date
    user_id: int = Field(foreign_key="users.id", index=True)
    
    # 关系
    user: Optional[User] = Relationship()


# ==================== 媒体-标签关联表（多对多）====================
class MediaTag(SQLModel, table=True):
    """媒体-标签关联表"""
    __tablename__ = "media_tags"
    
    media_id: int = Field(foreign_key="media.id", primary_key=True)
    tag_id: int = Field(foreign_key="tags.id", primary_key=True)


# ==================== 书影音收藏表 ====================
class Media(SQLModel, table=True):
    """书影音收藏表"""
    __tablename__ = "media"
    
    id: Optional[int] = Field(default=None, primary_key=True)
    title: str = Field(max_length=200)
    media_type: str = Field(max_length=20)  # book / movie / music
    rating: Optional[float] = Field(default=None, ge=0.0, le=5.0)
    comment: Optional[str] = Field(default=None)
    external_id: Optional[str] = Field(default=None, max_length=100)  # ISBN、IMDb ID等
    cover_url: Optional[str] = Field(default=None, max_length=300)
    created_at: datetime = Field(default_factory=datetime.now)
    user_id: int = Field(foreign_key="users.id", index=True)
    
    # 关系
    user: Optional[User] = Relationship()
    tags: list["Tag"] = Relationship(back_populates="media", link_model=MediaTag)


# ==================== 媒体标签表 ====================
class Tag(SQLModel, table=True):
    """媒体标签表"""
    __tablename__ = "tags"
    
    id: Optional[int] = Field(default=None, primary_key=True)
    name: str = Field(max_length=50, unique=True, index=True)
    
    # 关系
    media: list[Media] = Relationship(back_populates="tags", link_model=MediaTag)


# ==================== 聊天消息表 ====================
class ChatMessage(SQLModel, table=True):
    """聊天消息表"""
    __tablename__ = "chat_messages"
    
    id: Optional[int] = Field(default=None, primary_key=True)
    content: str
    sent_at: datetime = Field(default_factory=datetime.now)
    user_id: int = Field(foreign_key="users.id", index=True)
    room: str = Field(max_length=50, default="main", index=True)
    
    # 关系
    user: Optional[User] = Relationship()


# ==================== 文件上传记录表 ====================
class Upload(SQLModel, table=True):
    """文件上传记录表"""
    __tablename__ = "uploads"
    
    id: Optional[int] = Field(default=None, primary_key=True)
    filename: str = Field(max_length=200)
    stored_path: str = Field(max_length=300)
    file_size: int  # 字节数
    mime_type: str = Field(max_length=100)
    uploaded_at: datetime = Field(default_factory=datetime.now)
    expires_at: Optional[datetime] = Field(default=None)
    user_id: int = Field(foreign_key="users.id", index=True)
    
    # 关系
    user: Optional[User] = Relationship()