# occupation_resolver_tkinter.py
import logging
import subprocess
import os
from tkinter import messagebox

logger = logging.getLogger(__name__)


class OccupationResolver:
    """设备占用解除类 - Tkinter 版本"""
    
    def __init__(self, shell_executor_func, mount_info_getter_func):
        self.shell_executor_func = shell_executor_func
        self.mount_info_getter_func = mount_info_getter_func
        
    def resolve_occupation(self, device_path: str) -> bool:
        """处理设备占用问题"""
        logger.info(f"开始处理设备 {device_path} 的占用问题。")
        
        # 1. 获取挂载点
        mount_point = self.mount_info_getter_func(device_path)
        
        # 2. 如果设备已挂载，尝试卸载
        if mount_point:
            logger.info(f"设备 {device_path} 已挂载在 {mount_point}。检查是否有嵌套挂载...")
            
            # 卸载嵌套挂载点
            if not self._unmount_nested_mounts(mount_point):
                messagebox.showerror("错误", f"未能卸载设备 {device_path} 下的所有嵌套挂载点。")
                # 嵌套挂载卸载失败，可能是被进程占用，继续检查进程
            else:
                # 嵌套挂载卸载成功，尝试卸载设备本身
                if self._unmount_device(device_path):
                    messagebox.showinfo("成功", f"设备 {device_path} 及其所有挂载点已成功卸载。")
                    return True
                # 设备卸载失败，可能是被进程占用，继续检查进程
                logger.warning(f"设备 {device_path} 卸载失败，可能存在进程占用。")
        else:
            logger.info(f"设备 {device_path} 当前未挂载。")
            
        # 3. 检查是否有进程占用设备（无论是否已挂载，都检查进程占用）
        if self._is_device_busy(device_path):
            return self._kill_processes_using_device(device_path)
            
        # 4. 如果之前有挂载点但卸载失败，且没有进程占用，说明是其他原因
        if mount_point:
            messagebox.showwarning("警告", 
                f"设备 {device_path} 卸载失败，但未检测到进程占用。\n"
                f"可能是其他原因导致，请检查日志。")
            return False
            
        # 5. 无任何占用
        messagebox.showinfo("信息", f"设备 {device_path} 未被任何进程占用。")
        return True
        
    def _unmount_nested_mounts(self, mount_point: str) -> bool:
        """卸载指定挂载点下的所有嵌套挂载"""
        logger.info(f"尝试卸载 {mount_point} 下的所有嵌套挂载点。")
        
        try:
            with open('/proc/mounts', 'r') as f:
                mounts = f.readlines()
                
            nested_mounts = []
            for line in mounts:
                parts = line.split()
                if len(parts) >= 2:
                    mp = parts[1]
                    if mp.startswith(mount_point + '/') or mp == mount_point:
                        nested_mounts.append(mp)
                        
            # 按深度排序，先卸载深层挂载
            nested_mounts.sort(key=lambda x: x.count('/'), reverse=True)
            
            for nm in nested_mounts:
                logger.info(f"尝试卸载嵌套挂载点: {nm}")
                success, _, _ = self.shell_executor_func(
                    ["umount", nm],
                    f"卸载嵌套挂载点 {nm} 失败",
                    show_dialog=False
                )
                if not success:
                    logger.warning(f"卸载嵌套挂载点 {nm} 失败，但将继续尝试其他挂载点。")
                    
            return True
        except Exception as e:
            logger.error(f"卸载嵌套挂载点时发生错误: {e}")
            return False
            
    def _unmount_device(self, device_path: str) -> bool:
        """卸载设备"""
        logger.info(f"尝试卸载设备 {device_path}。")
        success, _, stderr = self.shell_executor_func(
            ["umount", device_path],
            f"卸载设备 {device_path} 失败",
            show_dialog=False
        )
        if success:
            logger.info(f"设备 {device_path} 已成功卸载。")
            return True
        else:
            # 检查是否是因为设备已经未挂载
            if "未挂载" in stderr or "not mounted" in stderr.lower():
                logger.info(f"设备 {device_path} 已经处于未挂载状态。")
                return True
            logger.error(f"卸载设备 {device_path} 失败: {stderr}")
            return False
            
    def _is_device_busy(self, device_path: str) -> bool:
        """检查设备是否被进程占用"""
        logger.info(f"检查设备 {device_path} 是否被进程占用。")
        
        # 尝试使用 lsof
        try:
            result = subprocess.run(
                ["sudo", "lsof", device_path],
                capture_output=True, text=True, timeout=10
            )
            if result.returncode == 0 and result.stdout.strip():
                logger.info(f"设备 {device_path} 被以下进程占用:\n{result.stdout}")
                return True
        except Exception as e:
            logger.debug(f"lsof 检查失败: {e}")
            
        # 尝试使用 fuser
        try:
            result = subprocess.run(
                ["sudo", "fuser", device_path],
                capture_output=True, text=True, timeout=10
            )
            if result.returncode == 0 and result.stdout.strip():
                logger.info(f"设备 {device_path} 被以下进程占用: {result.stdout.strip()}")
                return True
        except Exception as e:
            logger.debug(f"fuser 检查失败: {e}")
            
        return False
        
    def _kill_processes_using_device(self, device_path: str) -> bool:
        """终止占用设备的进程"""
        logger.info(f"尝试终止占用设备 {device_path} 的进程。")
        
        if messagebox.askyesno("确认终止进程",
                               f"设备 {device_path} 当前被进程占用。\n"
                               "是否终止这些进程？",
                               default=messagebox.NO):
            try:
                # 使用 fuser -k 终止进程
                result = subprocess.run(
                    ["sudo", "fuser", "-k", device_path],
                    capture_output=True, text=True, timeout=10
                )
                
                if result.returncode == 0 or result.returncode == 1:  # 1 表示没有进程被终止
                    messagebox.showinfo("成功", f"已尝试终止占用设备 {device_path} 的所有进程。")
                    
                    # 再次尝试卸载
                    if self._unmount_device(device_path):
                        messagebox.showinfo("成功", f"设备 {device_path} 已成功卸载。")
                        return True
                    else:
                        # 设备可能已经没有挂载
                        mount_point = self.mount_info_getter_func(device_path)
                        if not mount_point:
                            messagebox.showinfo("成功", f"设备 {device_path} 已成功卸载。")
                            return True
                        messagebox.showwarning("警告", f"进程已终止，但未能成功卸载设备 {device_path}。可能仍有其他问题。")
                        return False
                else:
                    messagebox.showerror("错误", f"未能终止占用设备 {device_path} 的进程。")
                    return False
            except Exception as e:
                logger.error(f"终止进程时发生错误: {e}")
                messagebox.showerror("错误", f"终止进程时发生错误: {e}")
                return False
        else:
            messagebox.showinfo("信息", f"已取消终止占用设备 {device_path} 的进程。")
            return False