cmdc

defmodule CMDC.Tool.EditFile do
  @moduledoc """
  通过精确字符串替换编辑文件（str_replace 模式）。

  使用 `old_string` 定位文件中唯一的目标片段并替换为 `new_string`。
  `old_string` 必须在文件中**唯一出现**；若有多处匹配则返回错误，要求提供更多上下文。

  - 有 Sandbox 时走 `sandbox.edit_file/4`
  - 无 Sandbox 时走 `CMDC.Sandbox.Local`

  ## 使用示例

      # 替换特定代码片段
      edit_file(path: "lib/app.ex",
        old_string: "def hello, do: :world",
        new_string: "def hello, do: :universe"
      )

      # 删除一段内容（new_string 为空字符串）
      edit_file(path: "lib/app.ex",
        old_string: "\\n  # TODO: remove this line",
        new_string: ""
      )
  """

  @behaviour CMDC.Tool

  alias CMDC.Sandbox.Local, as: SandboxLocal

  @impl true
  def name, do: "edit_file"

  @impl true
  def description,
    do:
      "Edit a file by replacing a unique string occurrence. " <>
        "old_string must appear exactly once in the file. " <>
        "Use read_file first to identify the exact string to replace."

  @impl true
  def meta(%{"path" => path}), do: "Edit #{path}"
  def meta(_), do: "Edit file"

  @impl true
  def parameters do
    %{
      "type" => "object",
      "properties" => %{
        "path" => %{
          "type" => "string",
          "description" => "Path to the file to edit (relative to working_dir or absolute)"
        },
        "old_string" => %{
          "type" => "string",
          "description" =>
            "The exact string to find and replace. Must appear exactly once in the file."
        },
        "new_string" => %{
          "type" => "string",
          "description" =>
            "The replacement string. Use empty string \"\" to delete the old_string."
        }
      },
      "required" => ["path", "old_string", "new_string"]
    }
  end

  @impl true
  def execute(
        %{"path" => path, "old_string" => old_string, "new_string" => new_string},
        %CMDC.Context{} = ctx
      ) do
    opts = [working_dir: ctx.working_dir]

    result =
      if ctx.sandbox do
        ctx.sandbox.edit_file(path, old_string, new_string, opts)
      else
        SandboxLocal.edit_file(path, old_string, new_string, opts)
      end

    case result do
      {:ok, _count} ->
        {:ok, "Edit applied to: #{path}"}

      {:error, :not_found} ->
        {:error,
         "old_string not found in #{path}. " <>
           "Use read_file to verify the exact content and try again."}

      {:error, :not_unique} ->
        {:error,
         "old_string appears multiple times in #{path}. " <>
           "Provide a longer, more unique string with surrounding context."}

      {:error, reason} ->
        {:error, reason}
    end
  end

  def execute(_args, _ctx),
    do: {:error, "Missing required parameters: path, old_string, and new_string"}
end