export type Theme = "light" | "dark"

export const STORAGE_KEY = "theme"

function getSystemTheme(): Theme {
    return window.matchMedia("(prefers-color-scheme: dark)").matches
        ? "dark"
        : "light"
}

export function getInitialTheme(): Theme {
    const stored = localStorage.getItem(STORAGE_KEY)
    if (stored === "light" || stored === "dark") {
        return stored
    }
    return getSystemTheme()
}

export function useTheme() {
    document.documentElement.dataset.theme = getInitialTheme()
}