export type Mode = "dark" | "light";
export type Scheme = "midnight" | "forest" | "slate" | "youtube";

export const SCHEMES: { id: Scheme; name: string; swatch: string }[] = [
  { id: "midnight", name: "Midnight", swatch: "#6d8cff" },
  { id: "forest", name: "Forest", swatch: "#2dd4bf" },
  { id: "slate", name: "Slate", swatch: "#e8913c" },
  { id: "youtube", name: "YouTube", swatch: "#ff3b46" },
];

export interface ThemePrefs {
  mode: Mode;
  scheme: Scheme;
  fontScale: number;
}

export const DEFAULT_THEME: ThemePrefs = {
  mode: "dark",
  scheme: "midnight",
  fontScale: 1.06,
};

export function applyTheme(t: ThemePrefs): void {
  const el = document.documentElement;
  el.dataset.theme = t.mode;
  el.dataset.scheme = t.scheme;
  el.style.setProperty("--font-scale", String(t.fontScale));
}

const KEY = "subfeed.theme";

export function loadLocalTheme(): ThemePrefs {
  try {
    return { ...DEFAULT_THEME, ...JSON.parse(localStorage.getItem(KEY) || "{}") };
  } catch {
    return DEFAULT_THEME;
  }
}

export function saveLocalTheme(t: ThemePrefs): void {
  localStorage.setItem(KEY, JSON.stringify(t));
}