"""
命令行界面模块
"""

import argparse
import sys
from typing import List
from .todo import Todo
from .storage import Storage


class CLI:
    """命令行界面类"""
    
    def __init__(self, storage_path: str = "todos.json"):
        self.storage = Storage(storage_path)
        self.todo = self.storage.load()
    
    def run(self, args: List[str] = None):
        """运行命令行界面"""
        parser = argparse.ArgumentParser(
            description="Todo List - 简单的待办事项管理工具",
            formatter_class=argparse.RawDescriptionHelpFormatter,
            epilog="""
示例:
  %(prog)s add "买菜"           # 添加待办事项
  %(prog)s list                 # 查看所有待办事项
  %(prog)s complete 1           # 标记ID为1的事项为完成
  %(prog)s delete 1             # 删除ID为1的事项
            """
        )
        
        subparsers = parser.add_subparsers(dest="command", help="可用命令")
        
        # add 命令
        parser_add = subparsers.add_parser("add", help="添加待办事项")
        parser_add.add_argument("title", help="待办事项标题")
        
        # list 命令
        parser_list = subparsers.add_parser("list", help="查看待办事项")
        parser_list.add_argument(
            "--filter", 
            choices=["all", "pending", "completed"],
            default="all",
            help="筛选条件 (默认: all)"
        )
        
        # complete 命令
        parser_complete = subparsers.add_parser("complete", help="标记为完成")
        parser_complete.add_argument("id", type=int, help="待办事项ID")
        
        # uncomplete 命令
        parser_uncomplete = subparsers.add_parser("uncomplete", help="标记为未完成")
        parser_uncomplete.add_argument("id", type=int, help="待办事项ID")
        
        # delete 命令
        parser_delete = subparsers.add_parser("delete", help="删除待办事项")
        parser_delete.add_argument("id", type=int, help="待办事项ID")
        
        # clear 命令
        parser_clear = subparsers.add_parser("clear", help="清除所有已完成的事项")
        
        # 解析参数
        parsed_args = parser.parse_args(args)
        
        if not parsed_args.command:
            parser.print_help()
            return
        
        # 执行命令
        try:
            if parsed_args.command == "add":
                self.cmd_add(parsed_args.title)
            elif parsed_args.command == "list":
                self.cmd_list(parsed_args.filter)
            elif parsed_args.command == "complete":
                self.cmd_complete(parsed_args.id)
            elif parsed_args.command == "uncomplete":
                self.cmd_uncomplete(parsed_args.id)
            elif parsed_args.command == "delete":
                self.cmd_delete(parsed_args.id)
            elif parsed_args.command == "clear":
                self.cmd_clear()
        except Exception as e:
            print(f"错误: {e}", file=sys.stderr)
            sys.exit(1)
    
    def cmd_add(self, title: str):
        """添加待办事项"""
        item = self.todo.add(title)
        self.storage.save(self.todo)
        print(f"✓ 已添加: {item.title} (ID: {item.id})")
    
    def cmd_list(self, filter_type: str = "all"):
        """列出待办事项"""
        if filter_type == "pending":
            items = self.todo.get_pending()
            title = "未完成的待办事项"
        elif filter_type == "completed":
            items = self.todo.get_completed()
            title = "已完成的待办事项"
        else:
            items = self.todo.get_all()
            title = "所有待办事项"
        
        if not items:
            print(f"{title}: 无")
            return
        
        print(f"\n{title}:")
        print("-" * 50)
        for item in items:
            status = "✓" if item.completed else " "
            print(f"[{status}] {item.id}. {item.title}")
            print(f"    创建时间: {item.created_at}")
        print("-" * 50)
        
        # 统计信息
        total = len(self.todo.get_all())
        completed = len(self.todo.get_completed())
        pending = len(self.todo.get_pending())
        print(f"总计: {total} | 已完成: {completed} | 未完成: {pending}")
    
    def cmd_complete(self, item_id: int):
        """标记为完成"""
        if self.todo.complete(item_id):
            self.storage.save(self.todo)
            item = self.todo.get_by_id(item_id)
            print(f"✓ 已完成: {item.title}")
        else:
            print(f"错误: 找不到ID为 {item_id} 的待办事项", file=sys.stderr)
            sys.exit(1)
    
    def cmd_uncomplete(self, item_id: int):
        """标记为未完成"""
        if self.todo.uncomplete(item_id):
            self.storage.save(self.todo)
            item = self.todo.get_by_id(item_id)
            print(f"○ 已标记为未完成: {item.title}")
        else:
            print(f"错误: 找不到ID为 {item_id} 的待办事项", file=sys.stderr)
            sys.exit(1)
    
    def cmd_delete(self, item_id: int):
        """删除待办事项"""
        item = self.todo.get_by_id(item_id)
        if item and self.todo.delete(item_id):
            self.storage.save(self.todo)
            print(f"✓ 已删除: {item.title}")
        else:
            print(f"错误: 找不到ID为 {item_id} 的待办事项", file=sys.stderr)
            sys.exit(1)
    
    def cmd_clear(self):
        """清除所有已完成的事项"""
        count = self.todo.clear_completed()
        self.storage.save(self.todo)
        print(f"✓ 已清除 {count} 个已完成的待办事项")