# Copyright (c) 2023 Anthropic
# Copyright (c) 2025 ByteDance Ltd. and/or its affiliates.
# Copyright (c) 2025 Beijing Tokens Infinity Technology Co., Ltd. and/or its affiliates.
# SPDX-License-Identifier: MIT
#
# This file has been modified by Beijing Tokens Infinity Technology Co., Ltd. and/or its affiliates. on 27 Oct 2025
#
# Original file was released under MIT License, with the full license text
# available at https://github.com/anthropics/anthropic-quickstarts/blob/main/LICENSE
# and https://github.com/bytedance/trae-agent/blob/main/LICENSE
#
# This modified file is released under the same license.


import os
from pathlib import Path
import tempfile
from typing import Optional, override
import shlex

from src.tools.base import (
    Tool,
    ToolCallArguments,
    ToolError,
    ToolExecResult,
    ToolParameter,
    STR_REPLACE_BASED_EDIT_TOOL_NAME,
)
from src.tools.run import maybe_truncate, run
from src.tools.executor import Executor
from src.managers.log.logger import Logger
from typing import Dict, Any
from traceback import format_exc

EditToolSubCommands = [
    "view",
    "create",
    "str_replace",
    "insert",
]
SNIPPET_LINES: int = 4


class TextEditorTool(Tool):
    """Tool to replace a string in a file."""

    def __init__(
        self,
        model_provider: str | None = None,
        executor: Executor | None = None,
        logger: Logger | None = None,
        config: Dict[str, Any] | None = None,
    ) -> None:
        super().__init__(model_provider, logger, config)
        self.executor = executor

    @override
    def get_model_provider(self) -> str | None:
        return self._model_provider

    @override
    def get_name(self) -> str:
        return STR_REPLACE_BASED_EDIT_TOOL_NAME

    @override
    def get_description(self) -> str:

        return """This tool provides capabilities for viewing, creating and editing files
* This tool is stateless. No context is retained between individual command invocations.
* Content Examination `view`:
** For a file: Executing `view` on a file path will output the file's full content with sequential line numbers prefixed (using cat -n).
** For a directory: Executing view on a directory path will recursively list all non-hidden items, displaying contents up to two directory levels deep.

* File Creation `create`:
** The `create` operation is strictly prohibited if a file already exists at the specified `path`. 
** Mandatory Pre-action: You must explicitly remove any existing file at the target `path` before proceeding with the creation of a new file.

* Output Handling:
** Should the output generated by a `command` exceed a certain length threshold, it will be automatically shortened and clearly marked with the indicator: <response clipped>.

* String Replacement `str_replace` Operational Rules:
** Precision Targeting: The `old_str` parameter must be an exact, character-for-character match of one or more complete lines from the source file. Special attention must be paid to invisible characters like spaces and tabs.
** Match Uniqueness: The replacement will be canceled if the specified `old_str` pattern is not absolutely unique within the file. To ensure a single match, expand the `old_str` scope to include sufficient preceding or following context lines.
** Content Insertion: The `new_str` parameter defines the complete set of lines that will be inserted into the file, directly replacing the content matched by `old_str`.
"""

    @override
    def get_parameters(self) -> list[ToolParameter]:
        """Get the parameters for the str_replace_based_edit_tool."""
        return [
            ToolParameter(
                name="command",
                type="string",
                description=f"Operation to execute. Supported commands: {', '.join(EditToolSubCommands)}.",
                required=True,
                enum=EditToolSubCommands,
            ),
            ToolParameter(
                name="file_text",
                type="string",
                description="Required for `create` command. Specifies the textual content for the new file.",
                required=False,
            ),
            ToolParameter(
                name="insert_line",
                type="integer",
                description="Required for `insert` command. The line number AFTER which the `new_str` will be inserted.",
                required=False,
            ),
            ToolParameter(
                name="new_str",
                type="string",
                description="For `str_replace`: the replacement text (optional, defaults to empty). For `insert`: the text to insert (required).",
                required=False,
            ),
            ToolParameter(
                name="old_str",
                type="string",
                description="Required for `str_replace` command. The exact text segment in the file to be replaced.",
                required=False,
            ),
            ToolParameter(
                name="path",
                type="string",
                description="Absolute filesystem path to the target file or directory. Example: `/workspace/script.py` or `/workspace`.",
                required=True,
            ),
            ToolParameter(
                name="view_range",
                type="array",
                description="Optional for `view` command on files. Defines the line range to display. Examples: `[5, 10]` shows lines 5-10; `[15, -1]` shows from line 15 to EOF. Line numbering starts at 1.",
                items={"type": "integer"},
                required=False,
            ),
        ]

    @override
    async def execute(self, arguments: ToolCallArguments) -> ToolExecResult:
        """Execute the str_replace_editor tool."""
        command = str(arguments["command"]) if "command" in arguments else None
        if command is None:
            return ToolExecResult(
                error=f"No command provided for the {self.get_name()} tool",
                error_code=-1,
            )
        path = str(arguments["path"]) if "path" in arguments else None
        if path is None:
            return ToolExecResult(
                error=f"No path provided for the {self.get_name()} tool", error_code=-1
            )
        _path = Path(path)
        try:
            self.validate_path(command, _path)
            match command:
                case "view":
                    return await self._view_handler(arguments, _path)
                case "create":
                    return self._create_handler(arguments, _path)
                case "str_replace":
                    return self._str_replace_handler(arguments, _path)
                case "insert":
                    return self._insert_handler(arguments, _path)
                case _:
                    return ToolExecResult(
                        error=f"Unrecognized command {command}. The allowed commands for the {self.name} tool are: {', '.join(EditToolSubCommands)}",
                        error_code=-1,
                    )
        except ToolError as e:
            return ToolExecResult(error=str(e), error_code=-1)

    def validate_path(self, command: str, path: Path):
        """Validate the path for the str_replace_editor tool."""
        if not path.is_absolute():
            suggested_path = Path("/") / path
            raise ToolError(
                f"The path {path} is not an absolute path, it should start with `/`. Maybe you meant {suggested_path}?"
            )
        # Check if path exists
        if not path.exists() and command != "create":
            raise ToolError(
                f"The path {path} does not exist. Please provide a valid path."
            )
        if path.exists() and command == "create":
            raise ToolError(
                f"File already exists at: {path}. Cannot overwrite files using command `create`."
            )
        # Check if the path points to a directory
        if path.is_dir() and command != "view":
            raise ToolError(
                f"The path {path} is a directory and only the `view` command can be used on directories"
            )

    async def _view(
        self, path: Path, view_range: list[int] | None = None
    ) -> ToolExecResult:
        """Implement the view command"""
        if path.is_dir():
            if view_range:
                raise ToolError(
                    "The `view_range` parameter is not allowed when `path` points to a directory."
                )

            return_code, stdout, stderr = await run(
                rf"find {path} -maxdepth 2 -not -path '*/\.*'"
            )
            if not stderr:
                stdout = f"Here's the files and directories up to 2 levels deep in {path}, excluding hidden items:\n{stdout}\n"
            return ToolExecResult(error_code=return_code, output=stdout, error=stderr)

        file_content = self.read_file(path)
        init_line = 1
        if view_range:
            if len(view_range) != 2 or not all(
                isinstance(i, int) for i in view_range
            ):  # pyright: ignore[reportUnnecessaryIsInstance]
                raise ToolError(
                    "Invalid `view_range`. It should be a list of two integers."
                )
            file_lines = file_content.split("\n")
            n_lines_file = len(file_lines)
            init_line, final_line = view_range
            if init_line < 1 or init_line > n_lines_file:
                raise ToolError(
                    f"Invalid `view_range`: {view_range}. Its first element `{init_line}` should be within the range of lines of the file: {[1, n_lines_file]}"
                )
            if final_line > n_lines_file:
                raise ToolError(
                    f"Invalid `view_range`: {view_range}. Its second element `{final_line}` should be smaller than the number of lines in the file: `{n_lines_file}`"
                )
            if final_line != -1 and final_line < init_line:
                raise ToolError(
                    f"Invalid `view_range`: {view_range}. Its second element `{final_line}` should be larger or equal than its first `{init_line}`"
                )

            if final_line == -1:
                file_content = "\n".join(file_lines[init_line - 1 :])
            else:
                file_content = "\n".join(file_lines[init_line - 1 : final_line])

        return ToolExecResult(
            output=self._make_output(file_content, str(path), init_line=init_line)
        )

    def _view_container(
        self, path: Path, view_range: list[int] | None = None
    ) -> ToolExecResult:
        """Implement the view command"""
        if path.is_dir():
            raise ToolError("The `path` parameter is not allowed be a directory.")

        file_content = self.container_read_file(path)
        init_line = 1
        make_out_max_lines = None
        if view_range:
            if len(view_range) != 2 or not all(
                isinstance(i, int) for i in view_range
            ):  # pyright: ignore[reportUnnecessaryIsInstance]
                raise ToolError(
                    "Invalid `view_range`. It should be a list of two integers."
                )
            file_lines = file_content.split("\n")
            n_lines_file = len(file_lines)
            init_line, final_line = view_range
            # Initial line must start from 1, initial line cannot be greater than max line of file
            if init_line < 1 or init_line > n_lines_file:
                raise ToolError(
                    f"Invalid `view_range`: {view_range}. Its first element `{init_line}` should be within the range of lines of the file: {[1, n_lines_file]}"
                )
            # When the end line takes effect, the end line cannot be less than the start line.
            if final_line != -1 and final_line < init_line:
                raise ToolError(
                    f"Invalid `view_range`: {view_range}. Its second element `{final_line}` should be larger or equal than its first `{init_line}`"
                )

            if final_line == -1:
                file_content = "\n".join(file_lines[init_line - 1 :])
            elif final_line > n_lines_file:
                file_content = "\n".join(file_lines[init_line - 1 : n_lines_file])
                make_out_max_lines = n_lines_file
                pass
            else:
                file_content = "\n".join(file_lines[init_line - 1 : final_line])

        return ToolExecResult(
            output=self._make_output(
                file_content,
                str(path),
                init_line=init_line,
                max_lines=make_out_max_lines,
            )
        )

    def str_replace(
        self, path: Path, old_str: str, new_str: str | None
    ) -> ToolExecResult:
        """Implement the str_replace command, which replaces old_str with new_str in the file content"""
        # Read the file content
        file_content = self.read_file(path).expandtabs()
        old_str = old_str.expandtabs()
        new_str = new_str.expandtabs() if new_str is not None else ""

        # Check if old_str is unique in the file
        occurrences = file_content.count(old_str)
        if occurrences == 0:
            raise ToolError(
                f"No replacement was performed, old_str `{old_str}` did not appear verbatim in {path}."
            )
        elif occurrences > 1:
            file_content_lines = file_content.split("\n")
            lines = [
                idx + 1
                for idx, line in enumerate(file_content_lines)
                if old_str in line
            ]
            raise ToolError(
                f"No replacement was performed. Multiple occurrences of old_str `{old_str}` in lines {lines}. Please ensure it is unique"
            )

        # Replace old_str with new_str
        new_file_content = file_content.replace(old_str, new_str)

        # Write the new content to the file
        self.write_file(path, new_file_content)

        # Create a snippet of the edited section
        replacement_line = file_content.split(old_str)[0].count("\n")
        start_line = max(0, replacement_line - SNIPPET_LINES)
        end_line = replacement_line + SNIPPET_LINES + new_str.count("\n")
        snippet = "\n".join(new_file_content.split("\n")[start_line : end_line + 1])

        # Prepare the success message
        success_msg = f"The file {path} has been edited. "
        success_msg += self._make_output(
            snippet, f"a snippet of {path}", start_line + 1
        )
        success_msg += "Review the changes and make sure they are as expected. Edit the file again if necessary."

        return ToolExecResult(
            output=success_msg,
        )

    def _insert(self, path: Path, insert_line: int, new_str: str) -> ToolExecResult:
        """Implement the insert command, which inserts new_str at the specified line in the file content."""
        file_text = self.read_file(path).expandtabs()
        new_str = new_str.expandtabs()
        file_text_lines = file_text.split("\n")
        n_lines_file = len(file_text_lines)

        if insert_line < 0 or insert_line > n_lines_file:
            raise ToolError(
                f"Invalid `insert_line` parameter: {insert_line}. It should be within the range of lines of the file: {[0, n_lines_file]}"
            )

        new_str_lines = new_str.split("\n")
        new_file_text_lines = (
            file_text_lines[:insert_line]
            + new_str_lines
            + file_text_lines[insert_line:]
        )
        snippet_lines = (
            file_text_lines[max(0, insert_line - SNIPPET_LINES) : insert_line]
            + new_str_lines
            + file_text_lines[insert_line : insert_line + SNIPPET_LINES]
        )

        new_file_text = "\n".join(new_file_text_lines)
        snippet = "\n".join(snippet_lines)

        self.write_file(path, new_file_text)

        success_msg = f"The file {path} has been edited. "
        success_msg += self._make_output(
            snippet,
            "a snippet of the edited file",
            max(1, insert_line - SNIPPET_LINES + 1),
        )
        success_msg += "Review the changes and make sure they are as expected (correct indentation, no duplicate lines, etc). Edit the file again if necessary."
        return ToolExecResult(
            output=success_msg,
        )

    # Note: undo_edit method is not implemented in this version as it was removed

    def read_file(self, path: Path):
        """Read the content of a file from a given path; raise a ToolError if an error occurs."""
        try:
            return path.read_text()
        except Exception as e:
            if self.logger:
                self.logger.error(
                    f"In edit_tool, read_file command error, ran into {e} while trying to read {path}, traceback: {format_exc()}."
                )
            raise ToolError(f"Ran into {e} while trying to read {path}.") from None

    def write_file(self, path: Path, file: str):
        """Write the content of a file to a given path; raise a ToolError if an error occurs."""
        try:
            _ = path.write_text(file)
        except Exception as e:
            if self.logger:
                self.logger.error(
                    f"In edit_tool, write_file command error, ran into {e} while trying to write to {path}, traceback: {format_exc()}."
                )
            raise ToolError(f"Ran into {e} while trying to write to {path}.") from None

    def container_read_file(self, path: Path, session_id: str = "0") -> str:
        """Read the content of a file from a container using cat command."""
        if not self.executor:
            raise ToolError("No executor provided for container operations")

        try:
            # Check if session is alive and restart if needed
            if not self.executor.check_session(session_id):
                raise ToolError(
                    "Container session is not alive and could not be restarted"
                )

            # Use cat command to read file content
            command = f"cat {path}"
            # return_code, output = self.executor.execute(session_id, command)
            return_code, output = self.executor.execute_once(command)

            if return_code != 0:
                raise ToolError(
                    f"Failed to read file {path} from container. Exit code: {return_code}, Output: {output}"
                )

            # Clean the output by removing only the command echo, preserving file content exactly
            # lines = output.split("\n")
            # Remove the first line if it contains the command echo
            # if lines and f"cat {path}" in lines[0]:
            #     lines = lines[2:-1]
            final = output[:-1] if output.endswith("\n") else output

            # return "\n".join(lines)
            return final
        except Exception as e:
            if self.logger:
                self.logger.error(
                    f"In edit_tool, container_read_file command error, ran into {e} while trying to read {path} from container, traceback: {format_exc()}."
                )
            raise ToolError(
                f"Ran into {e} while trying to read {path} from container."
            ) from None

    def container_write_file(
        self, path: Path, content: str, session_id: str = "0"
    ) -> None:
        """Write content to a file in a container using cat with here document."""
        if not self.executor:
            raise ToolError("No executor provided for container operations")

        try:
            # Check if session is alive and restart if needed
            if not self.executor.check_session():
                raise ToolError(
                    "Container session is not alive and could not be restarted"
                )
            # 先创建目录
            return_code, output = self.executor.execute_once(f"mkdir -p {path.parent}")
            if return_code != 0:
                raise ToolError(
                    f"Failed to create dir {path.parent} in container. Exit code: {return_code}, Output: {output}"
                )

            with tempfile.NamedTemporaryFile(
                mode="w+", delete=False, encoding="utf-8"
            ) as temp_file:
                temp_file.write(content)
                temp_file_path = temp_file.name
            return_code, output = self.executor.cpfile_host_to_container(
                temp_file_path, path
            )
            os.remove(temp_file_path)

            if return_code != 0:
                raise ToolError(
                    f"Failed to write to file {path} in container. Exit code: {return_code}, Output: {output}"
                )

        except Exception as e:
            if self.logger:
                self.logger.error(
                    f"In edit_tool, container_write_file command error, ran into {e} while trying to write to {path} in container, traceback: {format_exc()}."
                )
            raise ToolError(
                f"Ran into {e} while trying to write to {path} in container."
            ) from None

    def container_str_replace(
        self, path: Path, old_str: str, new_str: str | None, session_id: str = "0"
    ) -> ToolExecResult:
        """Replace old_str with new_str in a file in a container using sed command."""
        if not self.executor:
            raise ToolError("No executor provided for container operations")

        try:
            # Check if session is alive and restart if needed
            if not self.executor.check_session():
                raise ToolError(
                    "Container session is not alive and could not be restarted"
                )

            # First, read the file to check if old_str exists
            file_content = self.container_read_file(path, session_id)

            # Check if old_str is unique in the file
            occurrences = file_content.count(old_str)
            if occurrences == 0:
                raise ToolError(
                    f"No replacement was performed, old_str `{old_str}` did not appear verbatim in {path}."
                )
            elif occurrences > 1:
                # Here the calculation is wrong, old_str could be a multi-line text, cannot calculate all locations through the code below
                # file_content_lines = file_content.split("\n")
                # lines = [
                #     idx + 1
                #     for idx, line in enumerate(file_content_lines)
                #     if old_str in line
                # ]
                raise ToolError(
                    f"No replacement was performed. Multiple occurrences of old_str `{old_str}`. Total occurrences: {occurrences}. Please ensure it is unique"
                )

            updated_content = file_content.replace(old_str, new_str)
            self.container_write_file(path=path, content=updated_content)

            # Read the file to show a snippet of the changes
            try:
                file_content = self.container_read_file(path, session_id)
                # Create a simple snippet showing the change
                lines = file_content.split("\n")
                snippet_lines = lines[: min(10, len(lines))]  # Show first 10 lines
                snippet = "\n".join(snippet_lines)

                success_msg = f"The file {path} has been edited in container. "
                success_msg += self._make_output(
                    snippet, f"a snippet of {path}", init_line=1
                )
                success_msg += "Review the changes and make sure they are as expected. Edit the file again if necessary."

                return ToolExecResult(output=success_msg)
            except Exception:
                # If we can't read the file for snippet, just return success
                return ToolExecResult(
                    output=f"Successfully replaced string in file {path} in container."
                )

        except Exception as e:
            if self.logger:
                self.logger.error(
                    f"In edit_tool, container_str_replace command error, ran into {e} while trying to replace string in {path} in container, traceback: {format_exc()}."
                )
            raise ToolError(
                f"Ran into {e} while trying to replace string in {path} in container."
            ) from None

    def container_insert(
        self, path: Path, insert_line: int, new_str: str, session_id: str = "0"
    ) -> ToolExecResult:
        if not self.executor:
            raise ToolError("No executor provided for container operations")

        try:
            if not self.executor.check_session():
                raise ToolError(
                    "Container session is not alive and could not be restarted"
                )

            file_content = self.container_read_file(path, session_id)
            file_text_lines = file_content.split("\n")
            n_lines_file = len(file_text_lines)

            if insert_line < 0 or insert_line > n_lines_file:
                raise ToolError(
                    f"Invalid `insert_line` parameter: {insert_line}. It should be within the range of lines of the file: {[0, n_lines_file]}"
                )

            new_str_lines = new_str.split("\n")
            new_file_text_lines = (
                file_text_lines[:insert_line]
                + new_str_lines
                + file_text_lines[insert_line:]
            )
            snippet_lines = (
                file_text_lines[max(0, insert_line - SNIPPET_LINES) : insert_line]
                + new_str_lines
                + file_text_lines[insert_line : insert_line + SNIPPET_LINES]
            )

            new_file_text = "\n".join(new_file_text_lines)
            snippet = "\n".join(snippet_lines)

            self.container_write_file(path, new_file_text, session_id)

            success_msg = f"The file {path} has been edited in container. "
            success_msg += self._make_output(
                snippet,
                "a snippet of the edited file",
                max(1, insert_line - SNIPPET_LINES + 1),
            )
            success_msg += "Review the changes and make sure they are as expected (correct indentation, no duplicate lines, etc). Edit the file again if necessary."
            return ToolExecResult(
                output=success_msg,
            )

        except Exception as e:
            if self.logger:
                self.logger.error(
                    f"In edit_tool, container_insert command error, ran into {e} while trying to insert content in {path} in container, traceback: {format_exc()}."
                )
            raise ToolError(
                f"Ran into {e} while trying to insert content in {path} in container."
            ) from None

    def _escape_sed(self, text: str) -> str:
        """Escape special characters in text for use with sed command."""
        # Escape sed special characters: / \ &
        escaped = text.replace("\\", "\\\\")  # Escape backslashes first
        escaped = escaped.replace("/", "\\/")  # Escape forward slashes
        escaped = escaped.replace("&", "\\&")  # Escape ampersands
        escaped = escaped.replace("\n", "\\n")  # Handle newlines
        escaped = escaped.replace("\t", "\\t")  # Handle tabs
        return escaped

    def _make_output(
        self,
        file_content: str,
        file_descriptor: str,
        init_line: int = 1,
        expand_tabs: bool = True,
        max_lines: Optional[int] = None,  # 文件最大行，如果不为None则在返回中提示
    ):
        """Generate output for the CLI based on the content of a file."""
        file_content = maybe_truncate(file_content)
        if expand_tabs:
            file_content = file_content.expandtabs()
        file_content = "\n".join(
            [
                f"{i + init_line:6}\t{line}"
                for i, line in enumerate(file_content.split("\n"))
            ]
        )
        if max_lines:
            return (
                f"Here's the result of running `cat -n` on {file_descriptor}(The file is only {max_lines} lines):\n"
                + file_content
                + "\n"
            )
        else:
            return (
                f"Here's the result of running `cat -n` on {file_descriptor}:\n"
                + file_content
                + "\n"
            )

    async def _view_handler(
        self, arguments: ToolCallArguments, _path: Path
    ) -> ToolExecResult:
        view_range = arguments.get("view_range", None)
        if view_range is None:
            return await self._view(_path, None)
        if not (
            isinstance(view_range, list) and all(isinstance(i, int) for i in view_range)
        ):
            return ToolExecResult(
                error="Parameter `view_range` should be a list of integers.",
                error_code=-1,
            )
        view_range_int: list[int] = [i for i in view_range if isinstance(i, int)]
        return await self._view(_path, view_range_int)

    def view_handler_container(
        self, arguments: ToolCallArguments, path: Path
    ) -> ToolExecResult:
        view_range = arguments.get("view_range", None)
        if view_range is None:
            return self._view_container(path, None)
        if not (
            isinstance(view_range, list) and all(isinstance(i, int) for i in view_range)
        ):
            return ToolExecResult(
                error="Parameter `view_range` should be a list of integers.",
                error_code=-1,
            )
        view_range_int: list[int] = [i for i in view_range if isinstance(i, int)]
        return self._view_container(path, view_range_int)

    def _create_handler(
        self, arguments: ToolCallArguments, _path: Path
    ) -> ToolExecResult:
        file_text = arguments.get("file_text", None)
        if not isinstance(file_text, str):
            return ToolExecResult(
                error="Parameter `file_text` is required and must be a string for command: create",
                error_code=-1,
            )
        self.write_file(_path, file_text)
        return ToolExecResult(output=f"File created successfully at: {_path}")

    def _str_replace_handler(
        self, arguments: ToolCallArguments, _path: Path
    ) -> ToolExecResult:
        old_str = arguments.get("old_str") if "old_str" in arguments else None
        if not isinstance(old_str, str):
            return ToolExecResult(
                error="Parameter `old_str` is required and should be a string for command: str_replace",
                error_code=-1,
            )
        new_str = arguments.get("new_str") if "new_str" in arguments else None
        if not (new_str is None or isinstance(new_str, str)):
            return ToolExecResult(
                error="Parameter `new_str` should be a string or null for command: str_replace",
                error_code=-1,
            )
        return self.str_replace(_path, old_str, new_str)

    def _insert_handler(
        self, arguments: ToolCallArguments, _path: Path
    ) -> ToolExecResult:
        insert_line = (
            arguments.get("insert_line") if "insert_line" in arguments else None
        )
        if not isinstance(insert_line, int):
            return ToolExecResult(
                error="Parameter `insert_line` is required and should be integer for command: insert",
                error_code=-1,
            )
        new_str_to_insert = arguments.get("new_str") if "new_str" in arguments else None
        if not isinstance(new_str_to_insert, str):
            return ToolExecResult(
                error="Parameter `new_str` is required for command: insert",
                error_code=-1,
            )
        return self._insert(_path, insert_line, new_str_to_insert)