export const SERVER_JOB_RESOURCE_BUDGET_SCHEMA = 1;
export const SERVER_JOB_RESOURCE_LIMITS = Object.freeze({
  cpuMs: 60_000,
  memoryBytes: 512 * 1024 * 1024,
  processCount: 1,
  fileCount: 1_024,
  wallMs: 300_000,
  outputBytes: 512 * 1024 * 1024,
});

const fields = Object.keys(SERVER_JOB_RESOURCE_LIMITS);

function integer(value, field, minimum = 0) {
  if (!Number.isSafeInteger(value) || value < minimum || value > SERVER_JOB_RESOURCE_LIMITS[field]) throw new Error(`SERVER_JOB_BUDGET_EXCEEDED: ${field} is outside the enforced budget`);
  return value;
}

export function parseServerJobResourceBudget(value) {
  if (!value || value.schemaVersion !== SERVER_JOB_RESOURCE_BUDGET_SCHEMA || typeof value !== "object") throw new Error("SERVER_JOB_BUDGET_INVALID: schema is unsupported");
  if (Object.keys(value).some((key) => key !== "schemaVersion" && !fields.includes(key))) throw new Error("SERVER_JOB_BUDGET_INVALID: undeclared budget field");
  return Object.freeze({ schemaVersion: SERVER_JOB_RESOURCE_BUDGET_SCHEMA, ...Object.fromEntries(fields.map((field) => [field, integer(value[field], field)])) });
}

export function createServerJobResourceReceipt(budgetValue, usageValue, status = "SUCCEEDED") {
  const budget = parseServerJobResourceBudget(budgetValue);
  if (!usageValue || typeof usageValue !== "object") throw new Error("SERVER_JOB_BUDGET_INVALID: usage is invalid");
  const usage = Object.freeze(Object.fromEntries(fields.map((field) => [field, integer(usageValue[field], field)])));
  const exceeded = fields.filter((field) => usage[field] > budget[field]);
  if (exceeded.length > 0) throw new Error(`SERVER_JOB_BUDGET_EXCEEDED: ${exceeded.join(",")}`);
  if (!["SUCCEEDED", "FAILED", "CANCELLED"].includes(status)) throw new Error("SERVER_JOB_BUDGET_INVALID: status is unsupported");
  return Object.freeze({ schemaVersion: SERVER_JOB_RESOURCE_BUDGET_SCHEMA, status, budget, usage, enforced: true, exceeded: [] });
}