scraper updates

lib/cobblemon_ui/tier_list_scraper.ex

@@ -1,22 +1,84 @@
 defmodule CobblemonUi.TierListScraper do
+  use GenServer
   require Logger
 
   @url "https://rankedboost.com/pokemon/tier-list/"
   @filename "pokemon_tier_list.json"
 
-  def output_file do
-    dir = System.get_env("CACHE_DIR", ".")
-    Path.join(dir, @filename)
+  # ---------------------------------------------------------------------------
+  # Client API
+  # ---------------------------------------------------------------------------
+
+  def start_link(_opts) do
+    GenServer.start_link(__MODULE__, [], name: __MODULE__)
   end
 
-  def run do
+  @doc "Returns the current tier list map (%{lowercase_name => tier})."
+  def get_tier_list do
+    GenServer.call(__MODULE__, :get_tier_list)
+  end
+
+  @doc "Triggers a background re-scrape from HTTP."
+  def refresh do
+    GenServer.cast(__MODULE__, :refresh)
+  end
+
+  # ---------------------------------------------------------------------------
+  # Server callbacks
+  # ---------------------------------------------------------------------------
+
+  @impl true
+  def init(_opts) do
+    tier_list = load_from_file()
+
+    if map_size(tier_list) == 0 do
+      Logger.info("[TierListScraper] No cached data found, scheduling HTTP fetch")
+      send(self(), :fetch)
+    else
+      Logger.info("[TierListScraper] Loaded #{map_size(tier_list)} pokemon from cache file")
+    end
+
+    {:ok, tier_list}
+  end
+
+  @impl true
+  def handle_call(:get_tier_list, _from, state) do
+    {:reply, state, state}
+  end
+
+  @impl true
+  def handle_cast(:refresh, state) do
+    Logger.info("[TierListScraper] Manual refresh requested")
+    send(self(), :fetch)
+    {:noreply, state}
+  end
+
+  @impl true
+  def handle_info(:fetch, state) do
     Logger.info("[TierListScraper] Starting scrape from #{@url}")
 
+    case run_scrape() do
+      {:ok, tier_list} ->
+        Logger.info("[TierListScraper] Updated state with #{map_size(tier_list)} pokemon")
+        {:noreply, tier_list}
+
+      {:error, reason} ->
+        Logger.error("[TierListScraper] Scrape failed, keeping existing state: #{inspect(reason)}")
+        {:noreply, state}
+    end
+  end
+
+  # ---------------------------------------------------------------------------
+  # Private scrape pipeline
+  # ---------------------------------------------------------------------------
+
+  defp run_scrape do
     with {:ok, html} <- fetch_page(),
          {:ok, pokemon} <- parse(html),
          :ok <- write_json(pokemon) do
+      tier_list = to_tier_map(pokemon)
       Logger.info("[TierListScraper] Successfully scraped and saved #{length(pokemon)} pokemon")
-      {:ok, pokemon}
+      {:ok, tier_list}
     else
       {:error, reason} = err ->
         Logger.error("[TierListScraper] Scrape failed: #{inspect(reason)}")
@@ -24,22 +86,25 @@ defmodule CobblemonUi.TierListScraper do
     end
   end
 
-  def fetch_page do
+  defp fetch_page do
     Logger.debug("[TierListScraper] Fetching #{@url}")
+
     case Req.get(@url, headers: [{"user-agent", "Mozilla/5.0 (compatible; CobblemonUI/1.0)"}]) do
       {:ok, %Req.Response{status: 200, body: body}} ->
         Logger.debug("[TierListScraper] Fetch OK, body size: #{byte_size(body)} bytes")
         {:ok, body}
+
       {:ok, %Req.Response{status: status}} ->
         Logger.warning("[TierListScraper] Unexpected HTTP status: #{status}")
         {:error, {:http_error, status}}
+
       {:error, err} ->
         Logger.error("[TierListScraper] HTTP request failed: #{inspect(err)}")
         {:error, err}
     end
   end
 
-  def parse(html) do
+  defp parse(html) do
     nodes = html |> Floki.parse_document!() |> Floki.find(".pokemon-tier")
     Logger.debug("[TierListScraper] Found #{length(nodes)} .pokemon-tier nodes")
 
@@ -47,6 +112,7 @@ defmodule CobblemonUi.TierListScraper do
       [] ->
         Logger.warning("[TierListScraper] No .pokemon-tier elements found — page structure may have changed or content is JS-rendered")
         {:error, :no_pokemon_found}
+
       _ ->
         pokemon = Enum.map(nodes, &extract_pokemon/1)
         valid = Enum.filter(pokemon, fn %{name: n} -> n != "" end)
@@ -71,20 +137,41 @@ defmodule CobblemonUi.TierListScraper do
     %{name: name, tier: tier}
   end
 
-  def write_json(data) do
-    json = Jason.encode!(data, pretty: true)
-    File.write(output_file(), json)
+  defp write_json(data) do
+    path = output_file()
+    Logger.debug("[TierListScraper] Writing cache to #{path}")
+    File.mkdir_p!(Path.dirname(path))
+    File.write(path, Jason.encode!(data, pretty: true))
   end
 
-  # Returns a map of %{lowercase_name => tier} for fast lookup, or an empty map if unavailable.
-  def load_tier_list do
-    with {:ok, contents} <- File.read(output_file()),
+  defp load_from_file do
+    path = output_file()
+
+    with {:ok, contents} <- File.read(path),
          {:ok, entries} <- Jason.decode(contents) do
-      Map.new(entries, fn %{"name" => name, "tier" => tier} ->
-        {String.downcase(name), tier}
-      end)
+      map = to_tier_map(entries)
+      Logger.info("[TierListScraper] Loaded #{map_size(map)} pokemon from #{path}")
+      map
     else
-      _ -> %{}
+      {:error, :enoent} ->
+        Logger.info("[TierListScraper] Cache file not found at #{path}")
+        %{}
+
+      {:error, reason} ->
+        Logger.warning("[TierListScraper] Failed to load cache file: #{inspect(reason)}")
+        %{}
     end
   end
+
+  defp to_tier_map(entries) do
+    Map.new(entries, fn
+      %{"name" => name, "tier" => tier} -> {String.downcase(name), tier}
+      %{name: name, tier: tier} -> {String.downcase(name), tier}
+    end)
+  end
+
+  defp output_file do
+    dir = System.get_env("CACHE_DIR", ".")
+    Path.join(dir, @filename)
+  end
 end