"""
ORM 模型定义

SQLite 数据库模型，使用 Text 存储 JSON 格式的向量。
"""

from __future__ import annotations

import json
from datetime import datetime
from typing import Any, Dict

from sqlalchemy import DateTime, Float, Integer, String, Text, func
from sqlalchemy.orm import DeclarativeBase, Mapped, mapped_column


class Base(DeclarativeBase):
    """所有 ORM 模型的基类"""
    pass


class TimestampMixin:
    """时间戳 Mixin"""

    created_at: Mapped[datetime] = mapped_column(
        DateTime, default=func.now(), comment="创建时间"
    )
    updated_at: Mapped[datetime] = mapped_column(
        DateTime, default=func.now(), onupdate=func.now(), comment="更新时间"
    )

    def to_dict(self) -> Dict[str, Any]:
        """将模型转为字典"""
        result = {}
        for col in self.__table__.columns:
            val = getattr(self, col.name)
            if isinstance(val, datetime):
                val = val.isoformat()
            result[col.name] = val
        return result


class KnowledgePage(Base, TimestampMixin):
    """知识页面"""
    __tablename__ = "knowledge_pages"

    id: Mapped[int] = mapped_column(Integer, primary_key=True, autoincrement=True)
    title: Mapped[str] = mapped_column(String(500), nullable=False, comment="页面标题")
    content: Mapped[str] = mapped_column(Text, nullable=False, comment="页面内容")
    source_file: Mapped[str | None] = mapped_column(String(500), nullable=True, comment="来源文件路径")
    page_number: Mapped[int | None] = mapped_column(Integer, nullable=True, comment="原文件页码")
    course_name: Mapped[str | None] = mapped_column(String(200), nullable=True, comment="课程名称")
    teacher_name: Mapped[str | None] = mapped_column(String(100), nullable=True, comment="讲师名称")
    live_date: Mapped[str | None] = mapped_column(String(20), nullable=True, comment="直播日期")
    metadata_json: Mapped[str | None] = mapped_column(Text, nullable=True, comment="额外元数据（JSON）")
    embedding: Mapped[str | None] = mapped_column(Text, nullable=True, comment="向量嵌入（JSON）")


class KnowledgeChunk(Base, TimestampMixin):
    """知识页面分块"""
    __tablename__ = "knowledge_chunks"

    id: Mapped[int] = mapped_column(Integer, primary_key=True, autoincrement=True)
    page_id: Mapped[int] = mapped_column(Integer, nullable=False, comment="关联页面 ID")
    chunk_index: Mapped[int] = mapped_column(Integer, nullable=False, comment="分块索引")
    content: Mapped[str] = mapped_column(Text, nullable=False, comment="分块内容")
    embedding: Mapped[str | None] = mapped_column(Text, nullable=True, comment="向量嵌入（JSON）")


class OCRImage(Base, TimestampMixin):
    """OCR 图片记录"""
    __tablename__ = "ocr_images"

    id: Mapped[int] = mapped_column(Integer, primary_key=True, autoincrement=True)
    file_path: Mapped[str] = mapped_column(String(500), nullable=False, comment="图片文件路径")
    original_filename: Mapped[str | None] = mapped_column(String(200), nullable=True, comment="原始文件名")
    ocr_text: Mapped[str | None] = mapped_column(Text, nullable=True, comment="OCR 识别文本")
    confidence: Mapped[float | None] = mapped_column(Float, nullable=True, comment="OCR 置信度")
    provider: Mapped[str | None] = mapped_column(String(50), nullable=True, comment="OCR 提供商")
    status: Mapped[str] = mapped_column(
        String(20), default="pending", comment="状态: pending/processing/completed/failed"
    )
    blocks: Mapped[str | None] = mapped_column(Text, nullable=True, comment="OCR 文本块（JSON）")

    @property
    def blocks_list(self) -> list[dict]:
        if self.blocks is None:
            return []
        return json.loads(self.blocks)

    @blocks_list.setter
    def blocks_list(self, value: list[dict]):
        self.blocks = json.dumps(value) if value else None


class WebsiteSettings(Base):
    """网站设置（单例）"""
    __tablename__ = "website_settings"

    key: Mapped[str] = mapped_column(String(100), primary_key=True, comment="设置键")
    value: Mapped[str | None] = mapped_column(Text, nullable=True, comment="设置值（JSON）")
    updated_at: Mapped[datetime] = mapped_column(
        DateTime, default=func.now(), onupdate=func.now(), comment="更新时间"
    )

    def to_dict(self) -> Dict[str, Any]:
        """将模型转为字典"""
        result = {}
        for col in self.__table__.columns:
            val = getattr(self, col.name)
            if isinstance(val, datetime):
                val = val.isoformat()
            result[col.name] = val
        return result