import { access, readFile } from "node:fs/promises";
import { join } from "node:path";

const COMMAND_START = /^(?:npm|pnpm|yarn|bun|node|npx|git|go|cargo|pytest|python3?|make|cmake|gradle|mvn|dotnet|ruby|bundle|composer)\b/i;

export function explicitAcceptanceCommands(objective: string): string[] {
  return [...objective.matchAll(/`([^`\r\n]+)`/g)].map((match) => match[1]?.trim() ?? "").filter((command) => COMMAND_START.test(command));
}

export function explicitAcceptanceCommand(objective: string): string | undefined {
  const commands = [...objective.matchAll(/(?:\bacceptance(?:\s+command)?)\s*:\s*`([^`\r\n]+)`/gi)].map((match) => match[1]?.trim()).filter((command): command is string => Boolean(command));
  if (commands.length > 1) throw new Error("Task must declare exactly one acceptance command");
  return commands[0];
}

async function exists(path: string): Promise<boolean> {
  return access(path).then(() => true, () => false);
}

export async function inferAcceptanceCommand(cwd: string, trusted = false): Promise<string | undefined> {
  if (!trusted) return undefined;
  try {
    const pkg = JSON.parse(await readFile(join(cwd, "package.json"), "utf8")) as { scripts?: Record<string, unknown> };
    const scripts = pkg.scripts ?? {};
    const runner = await exists(join(cwd, "bun.lock")) || await exists(join(cwd, "bun.lockb")) ? "bun"
      : await exists(join(cwd, "pnpm-lock.yaml")) ? "pnpm"
        : await exists(join(cwd, "yarn.lock")) ? "yarn" : "npm";
    if (typeof scripts.verify === "string") return `${runner} run verify`;
    if (typeof scripts.test === "string" && !scripts.test.includes("Error: no test specified")) return `${runner} test`;
  } catch {}
  if (await exists(join(cwd, "go.mod"))) return "go test ./...";
  if (await exists(join(cwd, "Cargo.toml"))) return "cargo test";
  if (await Promise.any(["pytest.ini", "pyproject.toml", "setup.cfg", "tox.ini"].map((file) => access(join(cwd, file)))).then(() => true, () => false)) return "pytest";
  return undefined;
}