import { mkdtempSync, rmSync, writeFileSync } from "node:fs";
import { tmpdir } from "node:os";
import path from "node:path";

import { buildProgram } from "../src/cli.js";

type RunCliOptions = {
  args: string[];
  cwd?: string;
  env?: NodeJS.ProcessEnv;
  fetchImpl?: typeof fetch;
};

class MemoryWriter {
  private readonly chunks: string[] = [];

  write(chunk: string | Uint8Array) {
    this.chunks.push(typeof chunk === "string" ? chunk : Buffer.from(chunk).toString("utf8"));
    return true;
  }

  toString() {
    return this.chunks.join("");
  }
}

export async function runCli(options: RunCliOptions) {
  const stdout = new MemoryWriter();
  const stderr = new MemoryWriter();
  const program = buildProgram({
    cwd: options.cwd,
    env: options.env,
    fetchImpl: options.fetchImpl,
    stdout,
    stderr,
  });

  await program.parseAsync(options.args, { from: "user" });

  return {
    stdout: stdout.toString(),
    stderr: stderr.toString(),
  };
}

export function createTempWorkspace() {
  const cwd = mkdtempSync(path.join(tmpdir(), "atlassian-skill-"));

  return {
    cwd,
    cleanup() {
      rmSync(cwd, { recursive: true, force: true });
    },
    write(relativePath: string, contents: string) {
      const target = path.join(cwd, relativePath);
      writeFileSync(target, contents, "utf8");
      return target;
    },
  };
}

export function jsonResponse(payload: unknown, init?: ResponseInit) {
  return new Response(JSON.stringify(payload), {
    status: init?.status ?? 200,
    statusText: init?.statusText,
    headers: {
      "content-type": "application/json",
      ...(init?.headers ?? {}),
    },
  });
}