feat: add read_file tool for agent with line range and 50KB size limit support

Co-authored-by: jxxghp <51039935+jxxghp@users.noreply.github.com>
Agent-Logs-Url: https://github.com/jxxghp/MoviePilot/sessions/615dcf93-c017-4d3f-a96f-5cdad426b9a4

app/agent/tools/factory.py

@@ -43,6 +43,7 @@ from app.agent.tools.impl.transfer_file import TransferFileTool
 from app.agent.tools.impl.execute_command import ExecuteCommandTool
 from app.agent.tools.impl.edit_file import EditFileTool
 from app.agent.tools.impl.write_file import WriteFileTool
+from app.agent.tools.impl.read_file import ReadFileTool
 from app.core.plugin import PluginManager
 from app.log import logger
 from .base import MoviePilotTool
@@ -104,7 +105,8 @@ class MoviePilotToolFactory:
             RunWorkflowTool,
             ExecuteCommandTool,
             EditFileTool,
-            WriteFileTool
+            WriteFileTool,
+            ReadFileTool
         ]
         # 创建内置工具
         for ToolClass in tool_definitions:

app/agent/tools/impl/read_file.py

@@ -0,0 +1,81 @@
+"""文件读取工具"""
+
+from pathlib import Path
+from typing import Optional, Type
+
+from anyio import Path as AsyncPath
+from pydantic import BaseModel, Field
+
+from app.agent.tools.base import MoviePilotTool
+from app.log import logger
+
+# 最大读取大小 50KB
+MAX_READ_SIZE = 50 * 1024
+
+
+class ReadFileInput(BaseModel):
+    """Input parameters for read file tool"""
+    file_path: str = Field(..., description="The absolute path of the file to read")
+    start_line: Optional[int] = Field(None, description="The starting line number (1-based, inclusive). If not provided, reading starts from the beginning of the file.")
+    end_line: Optional[int] = Field(None, description="The ending line number (1-based, inclusive). If not provided, reading goes until the end of the file.")
+
+
+class ReadFileTool(MoviePilotTool):
+    name: str = "read_file"
+    description: str = "Read the content of a text file. Supports reading by line range. Each read is limited to 50KB; content exceeding this limit will be truncated."
+    args_schema: Type[BaseModel] = ReadFileInput
+
+    def get_tool_message(self, **kwargs) -> Optional[str]:
+        """根据参数生成友好的提示消息"""
+        file_path = kwargs.get("file_path", "")
+        file_name = Path(file_path).name if file_path else "未知文件"
+        return f"正在读取文件: {file_name}"
+
+    async def run(self, file_path: str, start_line: Optional[int] = None,
+                  end_line: Optional[int] = None, **kwargs) -> str:
+        logger.info(f"执行工具: {self.name}, 参数: file_path={file_path}, start_line={start_line}, end_line={end_line}")
+
+        try:
+            path = AsyncPath(file_path)
+
+            if not await path.exists():
+                return f"错误：文件 {file_path} 不存在"
+
+            if not await path.is_file():
+                return f"错误：{file_path} 不是一个文件"
+
+            content = await path.read_text(encoding="utf-8")
+            truncated = False
+
+            if start_line is not None or end_line is not None:
+                lines = content.splitlines(keepends=True)
+                total_lines = len(lines)
+
+                # 将行号转换为索引（1-based -> 0-based）
+                s = (start_line - 1) if start_line and start_line >= 1 else 0
+                e = end_line if end_line and end_line >= 1 else total_lines
+
+                # 确保范围有效
+                s = max(0, min(s, total_lines))
+                e = max(s, min(e, total_lines))
+
+                content = "".join(lines[s:e])
+
+            # 检查大小限制
+            content_bytes = content.encode("utf-8")
+            if len(content_bytes) > MAX_READ_SIZE:
+                content = content_bytes[:MAX_READ_SIZE].decode("utf-8", errors="ignore")
+                truncated = True
+
+            if truncated:
+                return f"{content}\n\n[警告：文件内容已超过50KB限制，以上内容已被截断。请使用 start_line/end_line 参数分段读取。]"
+
+            return content
+
+        except PermissionError:
+            return f"错误：没有权限读取 {file_path}"
+        except UnicodeDecodeError:
+            return f"错误：{file_path} 不是文本文件，无法读取"
+        except Exception as e:
+            logger.error(f"读取文件 {file_path} 时发生错误: {str(e)}", exc_info=True)
+            return f"操作失败: {str(e)}"