import { t } from "structural";
import { fileTracker } from "../file-tracker.ts";
import { ToolError, attemptUntrackedRead, ToolDef } from "../common.ts";
import { Transport } from "../../transports/transport-common.ts";

// Construct the intersection manually, since OpenAI and Anthropic can't handle top-level allOf(...)
const DiffParts = {
  search: t.str.comment(`
    The search string to replace. Must EXACTLY match the text you intend to replace, including
    whitespace, punctuation, etc. Make sure to give a few lines of context above and below so you
    don't accidentally replace a different matching substring in the same file.
  `),
  replace: t.str.comment("The string you want to insert into the file"),
}
const ArgumentsSchema = t.subtype({
  filePath: t.str.comment("The path to the file"),
  ...DiffParts,
}).comment("Applies a search/replace edit to a file. This should be your default tool to edit existing files.");
const DiffEdit = t.subtype(DiffParts);

const Schema = t.subtype({
  name: t.value("edit"),
  arguments: ArgumentsSchema,
});

export default {
  Schema, ArgumentsSchema, validate, DiffEdit,
  async run(signal, transport, call) {
    const { filePath } = call.tool.arguments;
    const diff = call.tool.arguments;
    await fileTracker.assertCanEdit(transport, signal, filePath);

    const file = await attemptUntrackedRead(transport, signal, filePath);
    const replaced = runEdit({
      path: filePath,
      file, diff,
    });
    await fileTracker.write(transport, signal, filePath, replaced);
    return {
      content: "",
    };
  },
} satisfies ToolDef<t.GetType<typeof Schema>> & {
  DiffEdit: typeof DiffEdit,
};

async function validate(signal: AbortSignal, transport: Transport, toolCall: t.GetType<typeof Schema>) {
  await fileTracker.assertCanEdit(transport, signal, toolCall.arguments.filePath);
  const file = await attemptUntrackedRead(transport, signal, toolCall.arguments.filePath);
  return validateDiff({ file, diff: toolCall.arguments, path: toolCall.arguments.filePath });
}

function runEdit({ path, file, diff }: {
  path: string,
  file: string,
  diff: t.GetType<typeof ArgumentsSchema>,
}): string {
  validateDiff({ path, file, diff });
  return file.replace(diff.search, diff.replace);
}

function validateDiff({ path, file, diff }: {
  path: string,
  file: string,
  diff: t.GetType<typeof ArgumentsSchema>,
}) {
  if(!file.includes(diff.search)) {
    throw new ToolError(`
Could not find search string in file ${path}: ${diff.search}
This is likely an error in your formatting. The search string must EXACTLY match, including
whitespace and punctuation.
`.trim());
  }
  return null;
}