#!/usr/bin/env python3
"""
图片存储方案迁移脚本
将图片从旧的层级目录结构迁移到新的扁平结构

旧结构: /{module}/{year}/{month}/{filename}
        /{module}/{year}/{month}/thumbnails/thumb_{filename}.jpg
新结构: /{filename}
        /thumbnails/{filename_stem}.jpg
"""

import os
import sys
import shutil
from pathlib import Path
from sqlalchemy import create_engine, text
from sqlalchemy.orm import sessionmaker, Session

# 添加项目路径
sys.path.insert(0, os.path.dirname(os.path.abspath(__file__)))

from app.config import get_settings

settings = get_settings()

# 数据库路径
DB_PATH = "./cms.db"
UPLOAD_DIR = Path(settings.UPLOAD_DIR)

def migrate_images():
    """迁移图片路径"""
    engine = create_engine(f"sqlite:///{DB_PATH}")
    SessionLocal = sessionmaker(bind=engine)
    db = SessionLocal()
    
    try:
        # 获取所有图片记录
        result = db.execute(text("SELECT id, file_path, thumb_path, filename FROM images"))
        images = result.fetchall()
        
        print(f"找到 {len(images)} 条图片记录需要迁移")
        
        migrated_count = 0
        skipped_count = 0
        error_count = 0
        
        for img in images:
            try:
                img_id = img[0]
                old_file_path = img[1]  # e.g., /news/2026/04/20260420_121931_b91c5d3a.jpg
                old_thumb_path = img[2]  # e.g., /news/2026/04/thumbnails/thumb_20260420_121931_b91c5d3a.jpg.jpg
                filename = img[3]  # e.g., 20260420_121931_b91c5d3a.jpg
                
                # 如果已经是新格式，跳过
                if old_file_path.startswith("/") and "/" not in old_file_path.lstrip("/"):
                    print(f"跳过 (已是新格式): {old_file_path}")
                    skipped_count += 1
                    continue
                
                # 新的路径格式
                new_file_path = f"/{filename}"
                new_thumb_path = f"/thumbnails/{Path(filename).stem}.jpg" if old_thumb_path else None
                
                # 物理文件路径
                old_file_full = UPLOAD_DIR / old_file_path.lstrip("/")
                new_file_full = UPLOAD_DIR / filename
                
                # 移动原图文件
                if old_file_full.exists() and old_file_full != new_file_full:
                    try:
                        shutil.move(str(old_file_full), str(new_file_full))
                        print(f"移动文件: {old_file_full} -> {new_file_full}")
                    except Exception as e:
                        print(f"移动文件失败 {old_file_full}: {e}")
                        error_count += 1
                        continue
                
                # 处理缩略图
                if old_thumb_path:
                    old_thumb_full = UPLOAD_DIR / old_thumb_path.lstrip("/")
                    new_thumb_full = UPLOAD_DIR / "thumbnails" / f"{Path(filename).stem}.jpg"
                    
                    if old_thumb_full.exists() and old_thumb_full != new_thumb_full:
                        try:
                            shutil.move(str(old_thumb_full), str(new_thumb_full))
                            print(f"移动缩略图: {old_thumb_full} -> {new_thumb_full}")
                        except Exception as e:
                            print(f"移动缩略图失败 {old_thumb_full}: {e}")
                
                # 更新数据库
                db.execute(
                    text("UPDATE images SET file_path = :new_path, thumb_path = :new_thumb WHERE id = :id"),
                    {"new_path": new_file_path, "new_thumb": new_thumb_path, "id": img_id}
                )
                
                migrated_count += 1
                print(f"迁移成功 ID={img_id}: {old_file_path} -> {new_file_path}")
                
            except Exception as e:
                print(f"迁移失败 ID={img_id}: {e}")
                error_count += 1
        
        db.commit()
        
        print("\n" + "="*60)
        print(f"迁移完成!")
        print(f"成功: {migrated_count}")
        print(f"跳过 (已是新格式): {skipped_count}")
        print(f"失败: {error_count}")
        print("="*60)
        
        # 清理空目录
        cleanup_empty_dirs(UPLOAD_DIR)
        
    except Exception as e:
        print(f"迁移过程出错: {e}")
        db.rollback()
    finally:
        db.close()


def cleanup_empty_dirs(root_dir: Path):
    """清理空目录"""
    removed_count = 0
    for dirpath, dirnames, filenames in os.walk(str(root_dir), topdown=False):
        dir_path = Path(dirpath)
        # 跳过根目录和 thumbnails 目录
        if dir_path == root_dir or dir_path.name == "thumbnails":
            continue
        
        # 检查是否为空
        try:
            if dir_path.exists() and not any(dir_path.iterdir()):
                dir_path.rmdir()
                print(f"删除空目录: {dir_path}")
                removed_count += 1
        except Exception as e:
            print(f"删除目录失败 {dir_path}: {e}")
    
    print(f"清理完成，共删除 {removed_count} 个空目录")


if __name__ == "__main__":
    print("图片存储方案迁移工具")
    print("="*60)
    print(f"数据库: {DB_PATH}")
    print(f"上传目录: {UPLOAD_DIR}")
    print("="*60)
    
    confirm = input("\n确定要开始迁移吗? (yes/no): ")
    if confirm.lower() == "yes":
        migrate_images()
    else:
        print("已取消迁移")