Support getting artist bios from Wikipedia (experimental)

lib/wikipedia/api.ex

@@ -0,0 +1,124 @@
+defmodule Wikipedia.API do
+  @moduledoc """
+  Interface to the Wikidata and Wikipedia APIs.
+  """
+
+  require Logger
+
+  def get_wikipedia_title(wikidata_id, config) do
+    request =
+      Req.new(
+        base_url: "https://www.wikidata.org",
+        max_retries: 1,
+        user_agent: config.user_agent
+      )
+      |> Req.Request.merge_options(config.req_options)
+      |> Req.Request.append_request_steps(log_attempt: &log_attempt/1)
+      |> Req.Request.append_response_steps(log_error: &log_error/1)
+      |> Req.merge(
+        url: "/w/api.php",
+        params: [
+          action: "wbgetentities",
+          ids: wikidata_id,
+          props: "sitelinks",
+          sitefilter: "enwiki",
+          format: "json"
+        ]
+      )
+
+    case Req.get(request) do
+      {:ok, response} when response.status == 200 ->
+        title =
+          get_in(response.body, ["entities", wikidata_id, "sitelinks", "enwiki", "title"])
+
+        {:ok, title}
+
+      {:ok, response} ->
+        {:error, response.body}
+
+      error ->
+        error
+    end
+  end
+
+  def get_article_summary(title, config) do
+    request =
+      Req.new(
+        base_url: "https://en.wikipedia.org",
+        max_retries: 1,
+        user_agent: config.user_agent
+      )
+      |> Req.Request.merge_options(config.req_options)
+      |> Req.Request.append_request_steps(log_attempt: &log_attempt/1)
+      |> Req.Request.append_response_steps(log_error: &log_error/1)
+      |> Req.merge(url: "/api/rest_v1/page/summary/#{URI.encode(title)}")
+
+    case Req.get(request) do
+      {:ok, response} when response.status == 200 ->
+        {:ok, response.body}
+
+      {:ok, response} ->
+        {:error, response.body}
+
+      error ->
+        error
+    end
+  end
+
+  def get_article_extract(title, config) do
+    request =
+      Req.new(
+        base_url: "https://en.wikipedia.org",
+        max_retries: 1,
+        user_agent: config.user_agent
+      )
+      |> Req.Request.merge_options(config.req_options)
+      |> Req.Request.append_request_steps(log_attempt: &log_attempt/1)
+      |> Req.Request.append_response_steps(log_error: &log_error/1)
+      |> Req.merge(
+        url: "/w/api.php",
+        params: [
+          action: "query",
+          titles: title,
+          prop: "extracts",
+          exintro: "1",
+          format: "json"
+        ]
+      )
+
+    case Req.get(request) do
+      {:ok, response} when response.status == 200 ->
+        extract =
+          response.body
+          |> get_in(["query", "pages"])
+          |> Map.values()
+          |> List.first()
+          |> Map.get("extract")
+
+        {:ok, extract}
+
+      {:ok, response} ->
+        {:error, response.body}
+
+      error ->
+        error
+    end
+  end
+
+  defp log_attempt(request) do
+    url = URI.to_string(request.url)
+    Logger.debug("Fetching data from #{url}")
+    request
+  end
+
+  defp log_error({request, response}) do
+    if response.status in 400..499 or response.status in 500..599 do
+      Logger.error(fn ->
+        url = URI.to_string(request.url)
+        "Failed to fetch data from #{url}, reason: #{inspect(response.body)}"
+      end)
+    end
+
+    {request, response}
+  end
+end

lib/wikipedia/config.ex

@@ -0,0 +1,32 @@
+defmodule Wikipedia.Config do
+  @type t :: %__MODULE__{
+          user_agent: String.t(),
+          req_options: Keyword.t()
+        }
+
+  defstruct user_agent: "change me",
+            req_options: []
+
+  @schema NimbleOptions.new!(
+            user_agent: [
+              type: :string,
+              required: false,
+              default: "change me"
+            ],
+            req_options: [
+              type: :keyword_list,
+              required: false,
+              default: []
+            ]
+          )
+
+  @doc NimbleOptions.docs(@schema)
+  @spec resolve(Application.app()) :: t | no_return
+  def resolve(otp_app) do
+    app_config =
+      Application.get_env(otp_app, Wikipedia)
+      |> NimbleOptions.validate!(@schema)
+
+    struct(__MODULE__, app_config)
+  end
+end