feat(marketing): add product of the day badge (#17)

fluxer_marketing/src/fluxer_marketing.gleam

@@ -47,11 +47,21 @@ pub fn main() {
       rpc_secret: cfg.gateway_rpc_secret,
     ))
 
-  let badge_cache = badge_proxy.start_cache()
+  let badge_featured_cache =
+    badge_proxy.start_cache(badge_proxy.product_hunt_featured_url)
+  let badge_top_post_cache =
+    badge_proxy.start_cache(badge_proxy.product_hunt_top_post_url)
 
   let assert Ok(_) =
     wisp_mist.handler(
-      handle_request(_, i18n_db, cfg, slots_cache, badge_cache),
+      handle_request(
+        _,
+        i18n_db,
+        cfg,
+        slots_cache,
+        badge_featured_cache,
+        badge_top_post_cache,
+      ),
       cfg.secret_key_base,
     )
     |> mist.new
@@ -67,7 +77,8 @@ fn handle_request(
   i18n_db,
   cfg: config.Config,
   slots_cache: visionary_slots.Cache,
-  badge_cache: badge_proxy.Cache,
+  badge_featured_cache: badge_proxy.Cache,
+  badge_top_post_cache: badge_proxy.Cache,
 ) -> wisp.Response {
   let locale = get_request_locale(req)
 
@@ -100,7 +111,8 @@ fn handle_request(
       release_channel: cfg.release_channel,
       visionary_slots: visionary_slots.current(slots_cache),
       metrics_endpoint: cfg.metrics_endpoint,
-      badge_cache: badge_cache,
+      badge_featured_cache: badge_featured_cache,
+      badge_top_post_cache: badge_top_post_cache,
     )
 
   use <- wisp.log_request(req)

fluxer_marketing/src/fluxer_marketing/badge_proxy.gleam

@@ -21,7 +21,9 @@ import gleam/httpc
 import gleam/option.{type Option}
 import wisp.{type Response}
 
-const product_hunt_url = "https://api.producthunt.com/widgets/embed-image/v1/featured.svg?post_id=1057558&theme=light"
+pub const product_hunt_featured_url = "https://api.producthunt.com/widgets/embed-image/v1/featured.svg?post_id=1057558&theme=light"
+
+pub const product_hunt_top_post_url = "https://api.producthunt.com/widgets/embed-image/v1/top-post-badge.svg?post_id=1057558&theme=light&period=daily&t=1767529639613"
 
 const stale_after_ms = 300_000
 
@@ -46,45 +48,46 @@ type State {
   State(cache: Option(CacheEntry), is_refreshing: Bool)
 }
 
-pub fn start_cache() -> Cache {
+pub fn start_cache(url: String) -> Cache {
   let started = process.new_subject()
-  let _ = process.spawn_unlinked(fn() { run(started) })
+  let _ = process.spawn_unlinked(fn() { run(started, url) })
 
   let assert Ok(subject) = process.receive(started, within: 1000)
   Cache(subject: subject)
 }
 
-fn run(started: process.Subject(process.Subject(ServerMessage))) {
+fn run(started: process.Subject(process.Subject(ServerMessage)), url: String) {
   let subject = process.new_subject()
   process.send(started, subject)
 
   let initial = State(cache: option.None, is_refreshing: False)
-  loop(subject, initial)
+  loop(subject, url, initial)
 }
 
-fn loop(subject: process.Subject(ServerMessage), state: State) {
+fn loop(subject: process.Subject(ServerMessage), url: String, state: State) {
   let new_state = case process.receive(subject, within: stale_after_ms) {
-    Ok(Get(reply_to)) -> handle_get(subject, reply_to, state)
+    Ok(Get(reply_to)) -> handle_get(subject, reply_to, url, state)
 
     Ok(RefreshDone(fetched_at, svg)) ->
       handle_refresh_done(fetched_at, svg, state)
 
-    Error(_) -> maybe_refresh_in_background(subject, state)
+    Error(_) -> maybe_refresh_in_background(subject, url, state)
   }
 
-  loop(subject, new_state)
+  loop(subject, url, new_state)
 }
 
 fn handle_get(
   subject: process.Subject(ServerMessage),
   reply_to: process.Subject(Option(String)),
+  url: String,
   state: State,
 ) -> State {
   let now = monotonic_time_ms()
 
   case state.cache {
     option.None -> {
-      let svg = fetch_badge_svg()
+      let svg = fetch_badge_svg(url)
       process.send(reply_to, svg)
 
       let new_cache = case svg {
@@ -103,7 +106,7 @@ fn handle_get(
 
       case is_stale && !state.is_refreshing {
         True -> {
-          spawn_refresh(subject)
+          spawn_refresh(subject, url)
           State(..state, is_refreshing: True)
         }
         False -> state
@@ -128,13 +131,14 @@ fn handle_refresh_done(
 
 fn maybe_refresh_in_background(
   subject: process.Subject(ServerMessage),
+  url: String,
   state: State,
 ) -> State {
   let now = monotonic_time_ms()
 
   case state.cache, state.is_refreshing {
     option.Some(entry), False if now - entry.fetched_at > stale_after_ms -> {
-      spawn_refresh(subject)
+      spawn_refresh(subject, url)
       State(..state, is_refreshing: True)
     }
 
@@ -142,11 +146,11 @@ fn maybe_refresh_in_background(
   }
 }
 
-fn spawn_refresh(subject: process.Subject(ServerMessage)) {
+fn spawn_refresh(subject: process.Subject(ServerMessage), url: String) {
   let _ =
     process.spawn_unlinked(fn() {
       let fetched_at = monotonic_time_ms()
-      let svg = fetch_badge_svg()
+      let svg = fetch_badge_svg(url)
       process.send(subject, RefreshDone(fetched_at, svg))
     })
 
@@ -185,8 +189,8 @@ pub fn product_hunt(cache: Cache) -> Response {
   }
 }
 
-fn fetch_badge_svg() -> Option(String) {
-  let assert Ok(req0) = request.to(product_hunt_url)
+fn fetch_badge_svg(url: String) -> Option(String) {
+  let assert Ok(req0) = request.to(url)
   let req =
     req0
     |> request.prepend_header("accept", "image/svg+xml")

fluxer_marketing/src/fluxer_marketing/components/hero.gleam

@@ -84,27 +84,59 @@ pub fn render(ctx: Context) -> Element(a) {
           ],
         ),
         hackernews_banner.render(ctx),
-        html.div([attribute.class("mt-6 flex justify-center")], [
-          html.a(
-            [
-              attribute.href(
-                "https://www.producthunt.com/products/fluxer?embed=true&utm_source=badge-featured&utm_medium=badge&utm_campaign=badge-fluxer",
-              ),
-              attribute.target("_blank"),
-              attribute.attribute("rel", "noopener noreferrer"),
-            ],
-            [
-              html.img([
-                attribute.alt(
-                  "Fluxer - Open-source Discord-like instant messaging & VoIP platform | Product Hunt",
+        html.div(
+          [
+            attribute.class(
+              "mt-6 flex flex-wrap items-center justify-center gap-4",
+            ),
+          ],
+          [
+            html.a(
+              [
+                attribute.href(
+                  "https://www.producthunt.com/products/fluxer?embed=true&utm_source=badge-featured&utm_medium=badge&utm_campaign=badge-fluxer",
                 ),
-                attribute.attribute("width", "250"),
-                attribute.attribute("height", "54"),
-                attribute.src(prepend_base_path(ctx, "/api/badges/product-hunt")),
-              ]),
-            ],
-          ),
-        ]),
+                attribute.target("_blank"),
+                attribute.attribute("rel", "noopener noreferrer"),
+              ],
+              [
+                html.img([
+                  attribute.alt(
+                    "Fluxer - Open-source Discord-like instant messaging & VoIP platform | Product Hunt",
+                  ),
+                  attribute.attribute("width", "250"),
+                  attribute.attribute("height", "54"),
+                  attribute.src(prepend_base_path(
+                    ctx,
+                    "/api/badges/product-hunt",
+                  )),
+                ]),
+              ],
+            ),
+            html.a(
+              [
+                attribute.href(
+                  "https://www.producthunt.com/products/fluxer?embed=true&utm_source=badge-top-post-badge&utm_medium=badge&utm_campaign=badge-fluxer",
+                ),
+                attribute.target("_blank"),
+                attribute.attribute("rel", "noopener noreferrer"),
+              ],
+              [
+                html.img([
+                  attribute.alt(
+                    "Fluxer - Open-source Discord-like instant messaging & VoIP platform | Product Hunt Top Post",
+                  ),
+                  attribute.attribute("width", "250"),
+                  attribute.attribute("height", "54"),
+                  attribute.src(prepend_base_path(
+                    ctx,
+                    "/api/badges/product-hunt-top-post",
+                  )),
+                ]),
+              ],
+            ),
+          ],
+        ),
       ]),
       html.div(
         [

fluxer_marketing/src/fluxer_marketing/router.gleam

@@ -51,7 +51,10 @@ pub fn handle_request(req: Request, ctx: Context) -> Response {
     ["_debug", "geoip"] -> handle_geoip_debug(req, ctx)
 
     ["api", "badges", "product-hunt"] ->
-      badge_proxy.product_hunt(ctx.badge_cache)
+      badge_proxy.product_hunt(ctx.badge_featured_cache)
+
+    ["api", "badges", "product-hunt-top-post"] ->
+      badge_proxy.product_hunt(ctx.badge_top_post_cache)
 
     ["robots.txt"] -> handle_robots_txt()
     ["sitemap.xml"] -> handle_sitemap(ctx)

fluxer_marketing/src/fluxer_marketing/visionary_slots.gleam

@@ -22,6 +22,7 @@ import gleam/http/request
 import gleam/httpc
 import gleam/int
 import gleam/json
+import gleam/option
 import gleam/result
 import gleam/string
 import wisp
@@ -40,9 +41,10 @@ pub opaque type Cache {
 
 type ServerMessage {
   Get(process.Subject(VisionarySlots))
+  RefreshDone(fetched_at: Int, slots: option.Option(VisionarySlots))
 }
 
-const refresh_interval_ms = 300_000
+const stale_after_ms = 300_000
 
 const receive_timeout_ms = 200
 
@@ -60,30 +62,124 @@ pub fn start(settings: Settings) -> Cache {
   Cache(name: name)
 }
 
+type CacheEntry {
+  CacheEntry(slots: VisionarySlots, fetched_at: Int)
+}
+
+type State {
+  State(cache: option.Option(CacheEntry), is_refreshing: Bool)
+}
+
 fn run(name: process.Name(ServerMessage), settings: Settings) {
   let _ = process.register(process.self(), name)
   let subject = process.named_subject(name)
-  let initial = fetch_slots(settings) |> result.unwrap(default_slots())
-  loop(subject, settings, initial)
+  let initial_slots = fetch_slots(settings) |> result.unwrap(default_slots())
+  let now = monotonic_time_ms()
+  let initial_state =
+    State(
+      cache: option.Some(CacheEntry(slots: initial_slots, fetched_at: now)),
+      is_refreshing: False,
+    )
+
+  loop(subject, settings, initial_state)
 }
 
 fn loop(
   subject: process.Subject(ServerMessage),
   settings: Settings,
-  state: VisionarySlots,
+  state: State,
 ) {
-  case process.receive(subject, within: refresh_interval_ms) {
-    Ok(Get(reply_to)) -> {
-      process.send(reply_to, state)
-      loop(subject, settings, state)
+  let new_state = case process.receive(subject, within: stale_after_ms) {
+    Ok(Get(reply_to)) -> handle_get(subject, reply_to, settings, state)
+
+    Ok(RefreshDone(fetched_at, slots)) ->
+      handle_refresh_done(fetched_at, slots, state)
+
+    Error(_) -> maybe_refresh_in_background(subject, settings, state)
+  }
+
+  loop(subject, settings, new_state)
+}
+
+fn handle_get(
+  subject: process.Subject(ServerMessage),
+  reply_to: process.Subject(VisionarySlots),
+  settings: Settings,
+  state: State,
+) -> State {
+  let now = monotonic_time_ms()
+
+  case state.cache {
+    option.None -> {
+      let slots = fetch_slots(settings) |> result.unwrap(default_slots())
+      process.send(reply_to, slots)
+
+      let entry = CacheEntry(slots: slots, fetched_at: now)
+
+      State(cache: option.Some(entry), is_refreshing: False)
     }
-    Error(_) -> {
-      let updated = fetch_slots(settings) |> result.unwrap(state)
-      loop(subject, settings, updated)
+
+    option.Some(entry) -> {
+      let is_stale = now - entry.fetched_at > stale_after_ms
+      process.send(reply_to, entry.slots)
+
+      case is_stale && !state.is_refreshing {
+        True -> {
+          spawn_refresh(subject, settings)
+          State(..state, is_refreshing: True)
+        }
+        False -> state
+      }
     }
   }
 }
 
+fn handle_refresh_done(
+  fetched_at: Int,
+  slots: option.Option(VisionarySlots),
+  state: State,
+) -> State {
+  let new_cache = case slots {
+    option.Some(data) ->
+      option.Some(CacheEntry(slots: data, fetched_at: fetched_at))
+    option.None -> state.cache
+  }
+
+  State(cache: new_cache, is_refreshing: False)
+}
+
+fn maybe_refresh_in_background(
+  subject: process.Subject(ServerMessage),
+  settings: Settings,
+  state: State,
+) -> State {
+  let now = monotonic_time_ms()
+
+  case state.cache, state.is_refreshing {
+    option.Some(entry), False if now - entry.fetched_at > stale_after_ms -> {
+      spawn_refresh(subject, settings)
+      State(..state, is_refreshing: True)
+    }
+
+    _, _ -> state
+  }
+}
+
+fn spawn_refresh(subject: process.Subject(ServerMessage), settings: Settings) {
+  let _ =
+    process.spawn_unlinked(fn() {
+      let fetched_at = monotonic_time_ms()
+      let result = fetch_slots(settings)
+      let payload = case result {
+        Ok(slots) -> option.Some(slots)
+        Error(_) -> option.None
+      }
+      process.send(subject, RefreshDone(fetched_at, payload))
+    })
+
+  Nil
+}
+
 pub fn current(cache: Cache) -> VisionarySlots {
   let subject = process.named_subject(cache.name)
   let reply_to = process.new_subject()
@@ -368,3 +464,14 @@ fn rpc_url(api_host: String) -> String {
 fn default_slots() -> VisionarySlots {
   VisionarySlots(total: 0, bought: 0, remaining: 0)
 }
+
+type TimeUnit {
+  Millisecond
+}
+
+@external(erlang, "erlang", "monotonic_time")
+fn erlang_monotonic_time(unit: TimeUnit) -> Int
+
+fn monotonic_time_ms() -> Int {
+  erlang_monotonic_time(Millisecond)
+}

fluxer_marketing/src/fluxer_marketing/web.gleam

@@ -56,7 +56,8 @@ pub type Context {
     release_channel: String,
     visionary_slots: VisionarySlots,
     metrics_endpoint: Option(String),
-    badge_cache: badge_proxy.Cache,
+    badge_featured_cache: badge_proxy.Cache,
+    badge_top_post_cache: badge_proxy.Cache,
   )
 }