#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""
数据库管理器 - 支持新的 data 数据结构
提供数据库操作的封装接口
"""

import sqlite3
import json
from pathlib import Path
from typing import Dict, List, Optional, Tuple
import logging

logger = logging.getLogger(__name__)


class DatabaseManager:
    """数据库管理器类"""
    
    def __init__(self, db_path: str = 'books.db'):
        """
        初始化数据库管理器
        
        Args:
            db_path: 数据库文件路径
        """
        self.db_path = db_path
        self.conn = None
        self._connect()
    
    def _connect(self):
        """连接数据库"""
        try:
            self.conn = sqlite3.connect(self.db_path, check_same_thread=False)
            self.conn.row_factory = sqlite3.Row  # 使用字典形式返回结果
            logger.info(f"数据库连接成功: {self.db_path}")
        except Exception as e:
            logger.error(f"数据库连接失败: {e}")
            raise
    
    def close(self):
        """关闭数据库连接"""
        if self.conn:
            self.conn.close()
            logger.info("数据库连接已关闭")
    
    def _dict_from_row(self, row) -> Dict:
        """将SQLite Row对象转换为字典"""
        if row is None:
            return None
        return dict(zip(row.keys(), row))
    
    # ==================== 书籍相关操作 ====================
    
    def get_all_books(self) -> List[Dict]:
        """
        获取所有书籍列表
        
        Returns:
            书籍列表
        """
        cursor = self.conn.cursor()
        cursor.execute('''
            SELECT 
                market_book_id, market_book_name, market_book_cover,
                max_page, market_classify_name, grade_id, reel_id,
                create_date, source_dir
            FROM books
            ORDER BY grade_id, reel_id, market_book_id
        ''')
        
        books = []
        for row in cursor.fetchall():
            books.append(self._dict_from_row(row))
        
        return books
    
    def get_book_by_id(self, book_id: int) -> Optional[Dict]:
        """
        根据ID获取书籍详情
        
        Args:
            book_id: 书籍ID
            
        Returns:
            书籍信息字典，如果不存在返回None
        """
        cursor = self.conn.cursor()
        cursor.execute('''
            SELECT * FROM books WHERE market_book_id = ?
        ''', (book_id,))
        
        row = cursor.fetchone()
        return self._dict_from_row(row)
    
    def get_books_by_grade(self, grade_id: int) -> List[Dict]:
        """
        根据年级获取书籍列表
        
        Args:
            grade_id: 年级ID
            
        Returns:
            书籍列表
        """
        cursor = self.conn.cursor()
        cursor.execute('''
            SELECT 
                market_book_id, market_book_name, market_book_cover,
                max_page, market_classify_name, reel_id
            FROM books
            WHERE grade_id = ?
            ORDER BY reel_id, market_book_id
        ''', (grade_id,))
        
        books = []
        for row in cursor.fetchall():
            books.append(self._dict_from_row(row))
        
        return books
    
    # ==================== 页面相关操作 ====================
    
    def get_book_pages(self, book_id: int) -> List[Dict]:
        """
        获取书籍的所有页面列表（目录）
        
        Args:
            book_id: 书籍ID
            
        Returns:
            页面列表
        """
        cursor = self.conn.cursor()
        cursor.execute('''
            SELECT page_id, page_number, origin_img_url, encrypt_img_url
            FROM pages
            WHERE book_id = ?
            ORDER BY page_number
        ''', (book_id,))
        
        pages = []
        for row in cursor.fetchall():
            pages.append(self._dict_from_row(row))
        
        return pages
    
    def get_page_by_number(self, book_id: int, page_number: int) -> Optional[Dict]:
        """
        根据页码获取页面信息（不含片段）
        
        Args:
            book_id: 书籍ID
            page_number: 页码
            
        Returns:
            页面信息字典
        """
        cursor = self.conn.cursor()
        cursor.execute('''
            SELECT * FROM pages
            WHERE book_id = ? AND page_number = ?
        ''', (book_id, page_number))
        
        row = cursor.fetchone()
        return self._dict_from_row(row)
    
    def get_page_content(self, book_id: int, page_number: int) -> Optional[Dict]:
        """
        获取页面的完整内容（含片段）
        
        Args:
            book_id: 书籍ID
            page_number: 页码
            
        Returns:
            包含pieces的完整页面数据
        """
        # 获取页面基本信息
        page = self.get_page_by_number(book_id, page_number)
        if not page:
            return None
        
        # 获取页面片段
        cursor = self.conn.cursor()
        cursor.execute('''
            SELECT 
                piece_id, original, translation,
                origin_sound_url, encrypt_sound_url, duration,
                coordinate_x, coordinate_y, coordinate_width, coordinate_height,
                is_evaluated, show_translation, rich_original, rich_translation
            FROM pieces
            WHERE page_id = ?
            ORDER BY piece_order
        ''', (page['page_id'],))
        
        pieces = []
        for row in cursor.fetchall():
            piece = self._dict_from_row(row)
            # 构建coordinate对象
            piece['coordinate'] = {
                'x': piece.pop('coordinate_x'),
                'y': piece.pop('coordinate_y'),
                'width': piece.pop('coordinate_width'),
                'height': piece.pop('coordinate_height')
            }
            pieces.append(piece)
        
        # 将pieces添加到page中
        page['pieces'] = pieces
        page['piece_count'] = len(pieces)
        
        return page
    
    # ==================== 目录相关操作 ====================
    
    def get_book_catalog(self, book_id: int) -> List[Dict]:
        """
        获取书籍目录结构
        
        Args:
            book_id: 书籍ID
            
        Returns:
            目录列表（树形结构）
        """
        cursor = self.conn.cursor()
        cursor.execute('''
            SELECT 
                catalog_id, catalog_name, catalog_name_cn,
                start_page, end_page, thumbnail, parent_id, sort
            FROM catalogs
            WHERE book_id = ?
            ORDER BY sort
        ''', (book_id,))
        
        catalogs = []
        for row in cursor.fetchall():
            catalogs.append(self._dict_from_row(row))
        
        # 构建树形结构
        catalog_dict = {cat['catalog_id']: dict(cat, children=[]) for cat in catalogs}
        tree = []
        
        for catalog in catalogs:
            cat_id = catalog['catalog_id']
            parent_id = catalog['parent_id']
            
            if parent_id == 0:
                tree.append(catalog_dict[cat_id])
            else:
                if parent_id in catalog_dict:
                    catalog_dict[parent_id]['children'].append(catalog_dict[cat_id])
        
        return tree
    
    # ==================== 搜索相关操作 ====================
    
    def search_content(self, book_id: int, keyword: str, limit: int = 20) -> List[Dict]:
        """
        在书籍中搜索内容（使用FTS全文搜索）
        
        Args:
            book_id: 书籍ID
            keyword: 搜索关键词
            limit: 返回结果数量限制
            
        Returns:
            搜索结果列表
        """
        cursor = self.conn.cursor()
        
        # 使用FTS5全文搜索
        sql = '''
            SELECT 
                p.page_number,
                pc.piece_id,
                pc.original,
                pc.translation,
                pc.origin_sound_url
            FROM pieces_fts
            JOIN pieces pc ON pieces_fts.rowid = pc.piece_id
            JOIN pages p ON pc.page_id = p.page_id
            WHERE p.book_id = ? 
            AND pieces_fts MATCH ?
            ORDER BY rank
            LIMIT ?
        '''
        
        cursor.execute(sql, (book_id, keyword, limit))
        
        results = []
        for row in cursor.fetchall():
            results.append(self._dict_from_row(row))
        
        return results
    
    def search_all_books(self, keyword: str, limit: int = 50) -> List[Dict]:
        """
        在所有书籍中搜索内容
        
        Args:
            keyword: 搜索关键词
            limit: 返回结果数量限制
            
        Returns:
            搜索结果列表（包含书籍信息）
        """
        cursor = self.conn.cursor()
        
        sql = '''
            SELECT 
                b.market_book_id,
                b.market_book_name,
                p.page_number,
                pc.piece_id,
                pc.original,
                pc.translation,
                pc.origin_sound_url
            FROM pieces_fts
            JOIN pieces pc ON pieces_fts.rowid = pc.piece_id
            JOIN pages p ON pc.page_id = p.page_id
            JOIN books b ON p.book_id = b.market_book_id
            WHERE pieces_fts MATCH ?
            ORDER BY rank
            LIMIT ?
        '''
        
        cursor.execute(sql, (keyword, limit))
        
        results = []
        for row in cursor.fetchall():
            results.append(self._dict_from_row(row))
        
        return results
    
    # ==================== 统计相关操作 ====================
    
    def get_book_statistics(self, book_id: int) -> Dict:
        """
        获取书籍统计信息
        
        Args:
            book_id: 书籍ID
            
        Returns:
            统计信息字典
        """
        cursor = self.conn.cursor()
        
        # 获取页面数
        cursor.execute('SELECT COUNT(*) FROM pages WHERE book_id = ?', (book_id,))
        page_count = cursor.fetchone()[0]
        
        # 获取片段数
        cursor.execute('''
            SELECT COUNT(*) FROM pieces 
            WHERE page_id IN (SELECT page_id FROM pages WHERE book_id = ?)
        ''', (book_id,))
        piece_count = cursor.fetchone()[0]
        
        # 获取有音频的片段数
        cursor.execute('''
            SELECT COUNT(*) FROM pieces 
            WHERE page_id IN (SELECT page_id FROM pages WHERE book_id = ?)
            AND (origin_sound_url != '' OR encrypt_sound_url != '')
        ''', (book_id,))
        audio_count = cursor.fetchone()[0]
        
        # 获取目录项数
        cursor.execute('SELECT COUNT(*) FROM catalogs WHERE book_id = ?', (book_id,))
        catalog_count = cursor.fetchone()[0]
        
        return {
            'book_id': book_id,
            'total_pages': page_count,
            'total_pieces': piece_count,
            'total_audio': audio_count,
            'total_catalogs': catalog_count
        }
    
    def get_overall_statistics(self) -> Dict:
        """
        获取整体统计信息
        
        Returns:
            整体统计信息字典
        """
        cursor = self.conn.cursor()
        
        cursor.execute('SELECT COUNT(*) FROM books')
        book_count = cursor.fetchone()[0]
        
        cursor.execute('SELECT COUNT(*) FROM pages')
        page_count = cursor.fetchone()[0]
        
        cursor.execute('SELECT COUNT(*) FROM pieces')
        piece_count = cursor.fetchone()[0]
        
        cursor.execute('SELECT COUNT(*) FROM catalogs')
        catalog_count = cursor.fetchone()[0]
        
        return {
            'total_books': book_count,
            'total_pages': page_count,
            'total_pieces': piece_count,
            'total_catalogs': catalog_count
        }


# 全局数据库实例
_db_instance = None


def get_db_instance(db_path: str = 'books.db') -> DatabaseManager:
    """
    获取数据库管理器单例
    
    Args:
        db_path: 数据库文件路径
        
    Returns:
        DatabaseManager实例
    """
    global _db_instance
    if _db_instance is None:
        _db_instance = DatabaseManager(db_path)
    return _db_instance


def close_db():
    """关闭全局数据库连接"""
    global _db_instance
    if _db_instance:
        _db_instance.close()
        _db_instance = None