import { ZodError } from "zod";

// ── Action Result Type ───────────────────────────────────────────────

export type ActionResult<T = Record<string, unknown>> =
  { ok: true; data?: T } | { ok: false; error: string; fieldErrors?: Record<string, string[]> };

// ── Helper to build results ──────────────────────────────────────────

export function actionOk<T = Record<string, unknown>>(data?: T): ActionResult<T> {
  return { ok: true, data: data ?? ({} as T) };
}

export function actionError(message: string): ActionResult<never> {
  return { ok: false, error: message };
}

// ── Throwable error ──────────────────────────────────────────────────

export class ActionError extends Error {
  constructor(message: string) {
    super(message);
    this.name = "ActionError";
  }
}

// ── Error handler ────────────────────────────────────────────────────

export function handleActionError(error: unknown): ActionResult<never> {
  if (error instanceof ZodError) {
    return {
      ok: false,
      error: "Validation failed",
      fieldErrors: error.flatten().fieldErrors as Record<string, string[]>,
    };
  }
  if (error instanceof Error && error.name === "ActionError") {
    return { ok: false, error: error.message };
  }
  // Prisma P2025
  if (
    error instanceof Error &&
    error.constructor.name === "PrismaClientKnownRequestError" &&
    (error as Error & { code?: string }).code === "P2025"
  ) {
    return { ok: false, error: "Not found" };
  }
  console.error("[Action error]", error);
  return { ok: false, error: "Internal server error" };
}