| 1 | "use client"; |
| 2 | |
| 3 | /** |
| 4 | * <ThemeToggle> — a compact Auto / Light / Dark control for the date strip. |
| 5 | * |
| 6 | * Dark mode is scoped to the /docs routes (see globals.css `.docs-theme`), |
| 7 | * so the toggle only renders while on a docs route — showing it site-wide |
| 8 | * would be a control that appears to do nothing on the marketing pages. |
| 9 | * |
| 10 | * "auto" removes the attribute and follows prefers-color-scheme; "light" and |
| 11 | * "dark" force the choice via `data-theme` on <html>. The choice persists to |
| 12 | * localStorage and is re-applied before paint by the inline script in the |
| 13 | * locale layout, so there is no theme flash on reload. |
| 14 | */ |
| 15 | |
| 16 | import { useEffect, useState } from "react"; |
| 17 | import { usePathname } from "next/navigation"; |
| 18 | import { fill } from "@/lib/i18n/dictionaries"; |
| 19 | |
| 20 | type Mode = "auto" | "light" | "dark"; |
| 21 | const ORDER: Mode[] = ["auto", "light", "dark"]; |
| 22 | const KEY = "cw-theme"; |
| 23 | |
| 24 | function apply(mode: Mode) { |
| 25 | const el = document.documentElement; |
| 26 | if (mode === "auto") el.removeAttribute("data-theme"); |
| 27 | else el.setAttribute("data-theme", mode); |
| 28 | } |
| 29 | |
| 30 | export function ThemeToggle({ |
| 31 | autoLabel, |
| 32 | lightLabel, |
| 33 | darkLabel, |
| 34 | ariaTemplate, |
| 35 | titleLabel, |
| 36 | }: { |
| 37 | autoLabel: string; |
| 38 | lightLabel: string; |
| 39 | darkLabel: string; |
| 40 | /** "Docs theme: {mode} (click to cycle)" — interpolated with fill(). */ |
| 41 | ariaTemplate: string; |
| 42 | titleLabel: string; |
| 43 | }) { |
| 44 | const pathname = usePathname(); |
| 45 | const [mode, setMode] = useState<Mode>("auto"); |
| 46 | const [mounted, setMounted] = useState(false); |
| 47 | |
| 48 | useEffect(() => { |
| 49 | setMounted(true); |
| 50 | const stored = (typeof localStorage !== "undefined" && localStorage.getItem(KEY)) as Mode | null; |
| 51 | if (stored && ORDER.includes(stored)) setMode(stored); |
| 52 | }, []); |
| 53 | |
| 54 | const onDocs = /^\/[a-z]{2}\/docs(\/|$)/.test(pathname) || pathname.includes("/docs"); |
| 55 | if (!onDocs) return null; |
| 56 | |
| 57 | const cycle = () => { |
| 58 | const next = ORDER[(ORDER.indexOf(mode) + 1) % ORDER.length]; |
| 59 | setMode(next); |
| 60 | try { |
| 61 | localStorage.setItem(KEY, next); |
| 62 | } catch { |
| 63 | /* private mode / storage disabled — the choice just won't persist */ |
| 64 | } |
| 65 | apply(next); |
| 66 | }; |
| 67 | |
| 68 | const labels: Record<Mode, string> = { |
| 69 | auto: autoLabel, |
| 70 | light: lightLabel, |
| 71 | dark: darkLabel, |
| 72 | }; |
| 73 | const glyph: Record<Mode, string> = { auto: "◐", light: "☀", dark: "☾" }; |
| 74 | |
| 75 | return ( |
| 76 | <button |
| 77 | type="button" |
| 78 | onClick={cycle} |
| 79 | className="inline-flex items-center gap-1.5 px-1.5 py-0.5 hairline-l hairline-r hairline-t hairline-b hover:text-indigo transition-colors" |
| 80 | aria-label={fill(ariaTemplate, { mode: labels[mode] })} |
| 81 | title={titleLabel} |
| 82 | suppressHydrationWarning |
| 83 | > |
| 84 | <span aria-hidden>{mounted ? glyph[mode] : glyph.auto}</span> |
| 85 | <span className="hidden sm:inline" suppressHydrationWarning> |
| 86 | {mounted ? labels[mode] : labels.auto} |
| 87 | </span> |
| 88 | </button> |
| 89 | ); |
| 90 | } |
| 91 |