Add support for latest in query string

src/hexdocs.gleam

@@ -49,6 +49,8 @@ fn update(model: Model, msg: Msg) {
     msg.ApiReturnedPackages(response) -> api_returned_packages(model, response)
     msg.ApiReturnedTypesenseSearch(response) ->
       api_returned_typesense_search(model, response)
+    msg.ApiReturnedInitialLatestPackages(versions) ->
+      api_returned_initial_latest_packages(model, versions)
 
     msg.DocumentChangedLocation(location:) ->
       model.update_route(model, location)
@@ -161,6 +163,18 @@ fn api_returned_typesense_search(model: Model, response: Loss(decode.Dynamic)) {
   |> result.unwrap(#(model, effect.none()))
 }
 
+fn api_returned_initial_latest_packages(
+  model: Model,
+  versions: Loss(List(hexpm.Package)),
+) -> #(Model, Effect(a)) {
+  case versions {
+    Error(_) -> #(model, toast.error("Server error. Retry later."))
+    Ok(versions) ->
+      model.add_packages_versions(model, versions)
+      |> model.replace_search_packages
+  }
+}
+
 fn document_registered_event_listener(model: Model, unsubscriber: fn() -> Nil) {
   let dom_click_unsubscriber = Some(unsubscriber)
   Model(..model, dom_click_unsubscriber:)

src/hexdocs/data/model.gleam

@@ -229,14 +229,44 @@ pub fn update_route(model: Model, route: uri.Uri) {
       case string.is_empty(q) {
         True -> #(set_search_results(model, #(-1, [])), effect.none())
         False -> {
+          let latest = list.filter(packages, fn(p) { p.1 == "latest" })
           Model(..model, search_input: q, search_packages_filters: packages)
-          |> pair.new(effects.typesense_search(q, packages))
+          |> pair.new({
+            case latest {
+              [] -> effects.typesense_search(q, packages)
+              latest -> {
+                latest
+                |> list.map(pair.first)
+                |> effects.initial_latest_packages
+              }
+            }
+          })
         }
       }
     }
   }
 }
 
+pub fn replace_search_packages(model: Model) {
+  let model =
+    Model(..model, search_packages_filters: {
+      use #(package, version) <- list.map(model.search_packages_filters)
+      use <- bool.guard(when: version != "latest", return: #(package, version))
+      case dict.get(model.packages_versions, package) {
+        Error(_) -> #(package, version)
+        Ok(versions) -> {
+          case versions.releases {
+            [] -> #(package, version)
+            [release, ..] -> #(package, release.version)
+          }
+        }
+      }
+    })
+  route.Search(q: model.search_input, packages: model.search_packages_filters)
+  |> route.replace
+  |> pair.new(model, _)
+}
+
 pub fn select_autocomplete_option(model: Model, package: String) {
   case model.autocomplete, model.route {
     None, _ -> model

src/hexdocs/data/model/route.gleam

@@ -47,6 +47,11 @@ pub fn push(route: Route) {
   modem.push(route.path, route.query, route.fragment)
 }
 
+pub fn replace(route: Route) {
+  let route = to_uri(route)
+  modem.replace(route.path, route.query, route.fragment)
+}
+
 fn create_query(
   query: List(#(String, String)),
   packages: List(#(String, String)),

src/hexdocs/data/model/version.gleam

@@ -1,7 +1,7 @@
 import gleam/option.{type Option, None, Some}
 import gleam/regexp
 
-const version_regexp = "^#([a-zA-Z_0-9]+)(:(([0-9]+|\\.){1,5}))?"
+const version_regexp = "^#([a-zA-Z_0-9]+)(:((([0-9]+|\\.){1,5})|latest))?"
 
 pub fn match_package(word: String) -> Result(#(String, Option(String)), Nil) {
   let regexp = version_search()

src/hexdocs/data/msg.gleam

@@ -9,6 +9,7 @@ pub type Msg {
   ApiReturnedPackages(Loss(String))
   ApiReturnedTypesenseSearch(Loss(Dynamic))
   ApiReturnedPackagesVersions(packages: Loss(List(hexpm.Package)))
+  ApiReturnedInitialLatestPackages(versions: Loss(List(hexpm.Package)))
 
   // Application messages.
   DocumentChangedLocation(location: uri.Uri)

src/hexdocs/effects.gleam

@@ -2,6 +2,8 @@ import browser/document
 import gleam/function
 import gleam/http/response.{type Response}
 import gleam/javascript/promise
+import gleam/list
+import gleam/result
 import hexdocs/data/msg
 import hexdocs/loss.{type Loss}
 import hexdocs/services/hex
@@ -24,6 +26,27 @@ pub fn package_versions(package: String) {
   dispatch(msg.ApiReturnedPackageVersions(response:))
 }
 
+pub fn initial_latest_packages(packages: List(String)) {
+  use dispatch <- effect.from()
+  use _ <- function.tap(Nil)
+  use response <- promise.map({
+    promise.await_list({
+      use package <- list.map(packages)
+      hex.package_versions(package)
+    })
+  })
+  let versions = case result.all(response) {
+    Error(error) -> Error(error)
+    Ok(response) -> {
+      case list.any(response, fn(r) { r.status != 200 }) {
+        True -> Error(loss.HttpError)
+        False -> Ok(list.map(response, fn(r) { r.body }))
+      }
+    }
+  }
+  dispatch(msg.ApiReturnedInitialLatestPackages(versions:))
+}
+
 pub fn subscribe_blurred_search() {
   use dispatch <- effect.from()
   document.add_listener(fn() { dispatch(msg.UserBlurredSearch) })

src/hexdocs/view/search.gleam

@@ -253,7 +253,11 @@ pub fn search(model: Model) {
                               "self-stretch justify-start text-slate-700 dark:text-slate-400 text-sm font-normal leading-none",
                             ),
                           ],
-                          [html.text(version)],
+                          // You can add any loader you want here.
+                          case version {
+                            "latest" -> [html.text("Loading…")]
+                            version -> [html.text(version)]
+                          },
                         ),
                       ],
                     ),