import { mkdtemp, writeFile } from "node:fs/promises";
import { tmpdir } from "node:os";
import { join } from "node:path";
import {
  DEFAULT_MAX_BYTES,
  DEFAULT_MAX_LINES,
  formatSize,
  type TruncationOptions,
  truncateHead,
} from "@earendil-works/pi-coding-agent";

export interface WorkspaceOutput {
  text: string;
  truncated: boolean;
  fullOutputPath?: string;
}

export function buildRipgrepArgs(
  pattern: string,
  roots: readonly string[],
  glob?: string,
): string[] {
  return [...(glob ? ["--glob", glob] : []), "-e", pattern, "--", ...roots];
}

export function resolveRipgrepOutput(result: {
  stdout: string;
  stderr: string;
  code: number;
}): string {
  if (result.code === 1) return "No matches found.";
  if (result.code !== 0) {
    throw new Error(
      `ripgrep failed: ${result.stderr.trim() || `exit code ${result.code}`}`,
    );
  }
  return result.stdout || "No matches found.";
}

export async function truncateWorkspaceOutput(
  output: string,
  options: TruncationOptions = {
    maxLines: DEFAULT_MAX_LINES,
    maxBytes: DEFAULT_MAX_BYTES,
  },
): Promise<WorkspaceOutput> {
  const t = truncateHead(output, options);
  if (!t.truncated) return { text: t.content, truncated: false };

  const fullOutputPath = join(
    await mkdtemp(join(tmpdir(), "pi-workspace-search-")),
    "output.txt",
  );
  await writeFile(fullOutputPath, output, "utf8");
  const notice =
    `\n\n[Output truncated: showing ${t.outputLines} of ${t.totalLines} lines ` +
    `(${formatSize(t.outputBytes)} of ${formatSize(t.totalBytes)}). ` +
    `Full output saved to: ${fullOutputPath}]`;
  return { text: t.content + notice, truncated: true, fullOutputPath };
}