import { env } from "cloudflare:workers";
import { countD1, countD1Rows, timed } from "./perf";

type D1Value = string | number | null;

export function stmt(sql: string, ...params: D1Value[]): D1PreparedStatement {
  return env.DB.prepare(sql).bind(...params);
}

const count = (ms: number) => countD1(ms);

export async function first<T>(sql: string, ...params: D1Value[]): Promise<T | null> {
  return timed(count, () => stmt(sql, ...params).first<T>());
}

function rows(result: D1Result): void {
  countD1Rows(result.meta?.rows_read ?? 0, result.meta?.rows_written ?? 0);
}

export async function all<T>(sql: string, ...params: D1Value[]): Promise<T[]> {
  const result = await timed(count, () => stmt(sql, ...params).all<T>());
  rows(result);
  return result.results;
}

export async function run(sql: string, ...params: D1Value[]): Promise<D1Result> {
  const result = await timed(count, () => stmt(sql, ...params).run());
  rows(result);
  return result;
}

export async function batch(statements: D1PreparedStatement[]): Promise<D1Result[]> {
  if (statements.length === 0) return [];
  const results = await timed(count, () => env.DB.batch(statements));
  for (const result of results) rows(result);
  return results;
}

export function placeholders(count: number): string {
  return Array.from({ length: count }, () => "?").join(", ");
}

/** D1 allows at most 100 bound parameters per statement; keep IN-lists well below that. */
export const MAX_IN_LIST = 90;

export function chunks<T>(items: T[], size = MAX_IN_LIST): T[][] {
  const out: T[][] = [];
  for (let index = 0; index < items.length; index += size) out.push(items.slice(index, index + size));
  return out;
}