import json
import os
from pathlib import Path
from typing import Union
from qwen_agent.tools.base import BaseTool, register_tool

# 从环境变量读取，如果读不到则默认为当前目录下的 memory.json
# 使用 .resolve() 自动处理相对路径转绝对路径的逻辑
MEMORY_FILE = Path(os.getenv('MEMORY_FILE_PATH', './memory.json')).resolve()

def _load_memory() -> list:
    """内部函数：安全加载记忆并强制转换为列表格式"""
    if not MEMORY_FILE.exists():
        return []
    try:
        content = MEMORY_FILE.read_text(encoding='utf-8').strip()
        if not content:
            return []
        data = json.loads(content)
        # 核心修复：如果读到的是字典或其他格式，强制转为列表
        if isinstance(data, list):
            return data
        return [] 
    except Exception:
        return []

def _save_memory(memories: list):
    """内部函数：安全保存"""
    try:
        MEMORY_FILE.parent.mkdir(parents=True, exist_ok=True)
        MEMORY_FILE.write_text(json.dumps(memories, ensure_ascii=False, indent=2), encoding='utf-8')
    except Exception as e:
        print(f"写入记忆文件失败: {e}")

@register_tool('manage_memory', allow_overwrite=True)
class MemoryTool(BaseTool):
    description = '长期记忆管理工具。支持 add (添加), list (查看), delete (删除索引)。'
    parameters = {
        'type': 'object',
        'properties': {
            'operation': {'type': 'string', 'description': '操作类型: add|list|delete'},
            'content': {'type': 'string', 'description': '记忆内容（仅add模式）'},
            'index': {'type': 'integer', 'description': '索引号（仅delete模式）'}
        },
        'required': ['operation'],
    }

    def call(self, params: Union[str, dict], **kwargs) -> str:
        params = self._verify_json_format_args(params)
        op = params['operation'].lower()
        memories = _load_memory()

        if op == 'add':
            content = params.get('content', '').strip()
            if not content:
                return "错误：内容不能为空。"
            memories.append(content)
            _save_memory(memories)
            return f"✅ 成功存入：『{content}』"

        elif op == 'list':
            if not memories:
                return "目前没有任何长期记忆。"
            return "记忆列表：\n" + "\n".join([f"[{i}] {m}" for i, m in enumerate(memories)])

        elif op == 'delete':
            idx = params.get('index')
            if idx is None or not (0 <= idx < len(memories)):
                return f"错误：索引 {idx} 无效。"
            removed = memories.pop(idx)
            _save_memory(memories)
            return f"🗑️ 已删除：『{removed}』"

        return f"不支持的操作: {op}"