1 files changed, 90 insertions, 0 deletions
diff --git a/www/assets/color-scheme.ts b/www/assets/color-scheme.ts
new file mode 100644
index 0000000..62a1b5c
--- /dev/null
+++ b/www/assets/color-scheme.ts
@@ -0,0 +1,90 @@
+const key = "color-scheme"
+
+type scheme = "dark" | "light" | null
+
+function createResetTimer(cleanup: () => void, timeout = 1) {
+  let tag = 0
+  return () => {
+    clearTimeout(tag)
+    tag = setTimeout(() => {
+      cleanup()
+    }, timeout * 1000)
+  }
+}
+
+let current = localStorage.getItem(key) as scheme
+
+let inited = false
+
+function createToast(duration: number = 1): (text: string) => void {
+  const toast = document.createElement("div")
+  toast.className = "toast"
+
+  const reset = createResetTimer(() => {
+      toast.remove()
+  }, duration)
+
+  return (text) => {
+    if (!toast.isConnected) {
+      document.body.appendChild(toast)
+    }
+    toast.textContent = text
+    reset()
+  }
+}
+
+const themeToast = createToast()
+
+function setTheme(value: scheme) {
+  let message = ""
+  current = value
+
+  if (value == null) {
+    const prefersDarkScheme = window.matchMedia("(prefers-color-scheme: dark)").matches
+    value = prefersDarkScheme ? "dark" : "light"
+    message = `theme: system(${value})`
+    localStorage.removeItem(key)
+  } else {
+    message = `theme: force(${value})`
+    localStorage.setItem(key, value)
+  }
+
+  document.body.dataset["theme"] = value
+
+  if (inited) {
+    themeToast(message)
+  }
+}
+
+setTheme(current)
+inited = true
+
+function next(scheme: scheme): scheme {
+  switch (scheme) {
+    case "dark":
+      return "light"
+    case "light":
+      return null
+    default:
+      return "dark"
+  }
+}
+
+window.addEventListener("load", () => {
+  const slogon = document.getElementById("slogan")!
+  let clicks: number = 0
+
+  const reset = createResetTimer(() => {
+    clicks = 0
+  })
+
+  slogon.addEventListener("click", () => {
+    reset()
+    clicks += 1
+    if (clicks === 3) {
+      setTheme(next(current))
+      clicks = 0
+    }
+  })
+})
+