first sources: batman

src/storage.gleam

@@ -0,0 +1,69 @@
+import gleam/dict.{type Dict}
+import gleam/erlang/process
+import gleam/option.{type Option, None, Some}
+import gleam/otp/actor
+
+const max_requests_per_minute = 10
+
+pub type StorageState {
+  StorageState(pastes: Dict(String, String), rate_limits: Dict(String, Int))
+}
+
+pub type StorageMsg {
+  CreatePaste(key: String, content: String, reply: process.Subject(Bool))
+  GetPaste(key: String, reply: process.Subject(Option(String)))
+  PeekPaste(key: String, reply: process.Subject(Option(String)))
+  CheckRateLimit(ip: String, reply: process.Subject(Bool))
+  ResetRateLimits
+}
+
+pub fn handle_message(state: StorageState, msg: StorageMsg) {
+  case msg {
+    CreatePaste(key, content, reply) -> {
+      let new_state =
+        StorageState(dict.insert(state.pastes, key, content), state.rate_limits)
+      process.send(reply, True)
+      actor.continue(new_state)
+    }
+    PeekPaste(key, reply) -> {
+      let content = case dict.get(state.pastes, key) {
+        Ok(value) -> Some(value)
+        Error(_) -> None
+      }
+      process.send(reply, content)
+      actor.continue(state)
+    }
+    GetPaste(key, reply) -> {
+      let content = case dict.get(state.pastes, key) {
+        Ok(value) -> Some(value)
+        Error(_) -> None
+      }
+      let new_pastes = dict.delete(state.pastes, key)
+      let new_state = StorageState(new_pastes, state.rate_limits)
+      process.send(reply, content)
+      actor.continue(new_state)
+    }
+    CheckRateLimit(ip, reply) -> {
+      let current_count =
+        dict.get(state.rate_limits, ip)
+        |> option.from_result
+        |> option.unwrap(0)
+      let allowed = current_count < max_requests_per_minute
+      let new_limits = case allowed {
+        True -> dict.insert(state.rate_limits, ip, current_count + 1)
+        False -> state.rate_limits
+      }
+      process.send(reply, allowed)
+      actor.continue(StorageState(state.pastes, new_limits))
+    }
+    ResetRateLimits -> {
+      actor.continue(StorageState(state.pastes, dict.new()))
+    }
+  }
+}
+
+pub fn start() {
+  actor.new(StorageState(dict.new(), dict.new()))
+  |> actor.on_message(handle_message)
+  |> actor.start
+}