Add timezone selector

Cargo.toml

@@ -60,6 +60,7 @@ time = { version = "0.3.31", features = ["serde"] }
 tokio = { version = "1.35.1", features = ["full"], optional = true }
 tower-http = { version = "0.5.1", features = ["fs"], optional = true }
 tz-rs = "0.6.14"
+tzdb = "0.6.1"
 uuid = { version = "1.7.0", features = ["v7"], optional = true }
 
 [build-dependencies]

src/http.rs

@@ -86,8 +86,13 @@ pub fn router() -> Result<Router> {
     Ok(router)
 }
 
+#[derive(Serialize)]
+struct IndexHtml<'a> {
+   timezones: &'a[&'a str],
+}
+
 async fn get_index(State(state): State<Arc<AppState<'_>>>) -> Result<Response, Response> {
-    let data: HashMap<String, String> = HashMap::new();
+    let data = IndexHtml { timezones: tzdb::TZ_NAMES };
     let body = state
         .handlebars
         .render("index", &data)

templates/index.hbs

@@ -50,6 +50,14 @@ https://waifu-calendar.fly.dev/ics?username=Owldown
           AniList username
         <input id="username-field" name="username" autocomplete="username" type="text" minlength="2" maxlength="64" pattern="^[^\s]*$" required />
         </label>
+        <label>
+            Time zone
+            <select "tz-select" name="tz">
+                {{#each timezones}}
+                    <option>{{this}}</option>
+                {{/each}}
+            </select>
+        </label>
         <button type="submit" formaction="/cal">View Calendar</button>
         <button type="submit" formaction="/ics">Download ICS</button>
       </form>