/**
 * 文件 AI SDK tools。
 *
 * 关键点（中文）
 * - 模型看到独立的 read/write/edit 工具，不需要构造 shell 命令。
 * - 工具只负责 schema 与 action 转发，文件语义由 FileActionRuntime 统一实现。
 */

import path from "node:path";
import { tool } from "ai";
import type { ActionResult } from "@/types/action/ActionResult.js";
import type {
  EditFileToolInput,
  EditFileToolResult,
  FileToolRunner,
  FileToolSet,
  ReadFileToolInput,
  ReadFileToolResult,
  WriteFileToolInput,
  WriteFileToolResult,
} from "@/types/workspace/FileTool.js";
import {
  edit_file_tool_input_schema,
  read_file_tool_input_schema,
  write_file_tool_input_schema,
} from "@/workspace/tool/FileToolSchemas.js";

/** 创建 Workspace 持有的结构化文件工具。 */
export function create_file_tools(runner: FileToolRunner): FileToolSet {
  const read = tool({
    description:
      "Read a project file instead of using cat or sed. For a chat attachment, use the file part's url (the .downcity/... storage path) as path; filename is only the user's display name and is not a project path. Images and PDFs are attached to the next model step as local file parts. Text output is limited to 500 lines and 256KB by default; use offset and limit to continue. Other binary files return metadata only.",
    inputSchema: read_file_tool_input_schema,
    execute: async (
      input: ReadFileToolInput,
    ): Promise<ActionResult<ReadFileToolResult>> => {
      const output = await runner.run_file_action({
        action: "read",
        input,
      }) as ReadFileToolResult;
      const messages: ActionResult<ReadFileToolResult>["messages"] = [];
      if (
        output.success &&
        (output.type === "image" || output.mime_type === "application/pdf")
      ) {
        messages.push({
          role: "user",
          parts: [{
            type: "file",
            url: output.file_path,
            mediaType: output.mime_type || "application/octet-stream",
            filename: path.basename(output.file_path),
          }],
        });
      }
      return { output, messages };
    },
  });

  const write = tool({
    description:
      "Create a new UTF-8 text file or atomically replace an existing file when overwrite=true. Parent directories are created automatically. Use edit for partial changes.",
    inputSchema: write_file_tool_input_schema,
    execute: async (
      input: WriteFileToolInput,
    ): Promise<ActionResult<WriteFileToolResult>> => {
      const output = await runner.run_file_action({
        action: "write",
        input,
      }) as WriteFileToolResult;
      return { output, messages: [] };
    },
  });

  const edit = tool({
    description:
      "Atomically edit one text file using exact replacements. Every edits[].old_text must match exactly once in the original file, and edit regions must not overlap. Combine separate changes to one file in a single call.",
    inputSchema: edit_file_tool_input_schema,
    execute: async (
      input: EditFileToolInput,
    ): Promise<ActionResult<EditFileToolResult>> => {
      const output = await runner.run_file_action({
        action: "edit",
        input,
      }) as EditFileToolResult;
      return { output, messages: [] };
    },
  });

  return { read, write, edit };
}