export function byId<T extends HTMLElement = HTMLElement>(id: string): T {
  const node = document.getElementById(id);
  if (!node) throw new Error(`missing #${id}`);
  return node as T;
}

export function node<K extends keyof HTMLElementTagNameMap>(
  tag: K,
  className?: string,
  text?: string,
): HTMLElementTagNameMap[K] {
  const element = document.createElement(tag);
  if (className) element.className = className;
  if (text !== undefined) element.textContent = text;
  return element;
}

export function clear(element: HTMLElement): void {
  element.replaceChildren();
}

export function groupDigits(amount: number): string {
  const negative = amount < 0;
  const digits = String(Math.abs(Math.trunc(amount)));
  let grouped = "";
  for (let index = 0; index < digits.length; index += 1) {
    if (index > 0 && (digits.length - index) % 3 === 0) grouped += "\u2009";
    grouped += digits[index];
  }
  return negative ? `-${grouped}` : grouped;
}

export function money(amount: number | null | undefined): string {
  if (amount === null || amount === undefined || Number.isNaN(amount)) return "— Kr";
  return `${groupDigits(amount)} Kr`;
}

export function signedMoney(amount: number): string {
  return `${amount < 0 ? "-" : "+"}${money(Math.abs(amount))}`;
}

export function toast(text: string, tone: "info" | "good" | "bad" = "info"): void {
  const root = document.getElementById("toasts");
  if (!root || !text) return;
  const item = node("div", `toast ${tone}`, text);
  root.append(item);
  window.setTimeout(() => {
    item.style.opacity = "0";
    item.style.transition = "opacity 220ms ease";
    window.setTimeout(() => item.remove(), 240);
  }, 4200);
  while (root.children.length > 4) root.firstElementChild?.remove();
}

export function toneFor(text: string): "info" | "good" | "bad" {
  const lowered = text.toLowerCase();
  if (
    text.startsWith("ERROR") ||
    lowered.includes("failed") ||
    lowered.includes("lost") ||
    lowered.includes("invalid") ||
    lowered.includes("forfeit")
  ) {
    return "bad";
  }
  if (
    text.startsWith("Logged in") ||
    text.startsWith("Account created") ||
    lowered.includes("won") ||
    lowered.includes("cashed")
  ) {
    return "good";
  }
  return "info";
}

export async function sha256Hex(text: string): Promise<string> {
  const bytes = new TextEncoder().encode(text);
  const digest = await crypto.subtle.digest("SHA-256", bytes);
  return [...new Uint8Array(digest)]
    .map((byte) => byte.toString(16).padStart(2, "0"))
    .join("");
}

export function shortHash(hash: string, keep = 10): string {
  if (hash.length <= keep * 2) return hash;
  return `${hash.slice(0, keep)}…${hash.slice(-keep)}`;
}

export function formatTime(raw: string): string {
  // SQLite stores `YYYY-MM-DD HH:MM:SS` in UTC.
  const parsed = Date.parse(raw.includes("T") ? raw : raw.replace(" ", "T") + "Z");
  if (Number.isNaN(parsed)) return raw;
  return new Date(parsed).toLocaleString();
}

export function cardFace(card: string): { rank: string; suit: string; red: boolean } {
  if (card === "?" || !card) return { rank: "?", suit: "", red: false };
  const suit = card.slice(-1);
  const rank = card.slice(0, -1);
  const glyph =
    suit === "C" ? "♣" : suit === "D" ? "♦" : suit === "H" ? "♥" : suit === "S" ? "♠" : suit;
  return { rank, suit: glyph, red: suit === "D" || suit === "H" };
}