Server fetches and saves files. Also proper error handling

src/main/scala/fetch/FetchService.scala

@@ -0,0 +1,52 @@
+package fetch
+
+import cats.effect._
+import cats.implicits._
+import org.http4s._
+import org.http4s.blaze.client.BlazeClientBuilder
+import org.http4s.client.Client
+import org.http4s.headers.Authorization
+import com.typesafe.config.ConfigFactory
+
+import java.time.{LocalDate, LocalDateTime}
+import scala.concurrent.ExecutionContext.global
+
+object FetchService {
+  // TODO wrap config in IO
+  private val config = ConfigFactory.load()
+  private val basicCredentials = BasicCredentials(config.getString("username"), config.getString("password"))
+  private val baseUrl = Uri.unsafeFromString(config.getString("url")) // 20220831_1330.csv
+
+  private def makeRequest(client: Client[IO], url: Uri): IO[Either[Throwable, (String, String)]] = {
+    val fileName = url.path.toString()
+    for {
+      request <- Request[IO](Method.GET, url)
+        .withHeaders(Authorization(basicCredentials))
+        .pure[IO]
+      result <- client.expect[String](request).redeemWith(
+        error => IO(Left(error))
+//          .flatTap(_ => IO.println(s"Request failed to url: $url with error: ${error.getMessage}"))
+        ,
+        fileContent => IO(Right((fileName, fileContent)))
+//          .flatTap(_ => IO.println(s"Fetched: $fileName"))
+      )
+    } yield result
+  }
+
+  private def fetchFiles(fileNames: List[String]): IO[List[Either[Throwable, (String, String)]]] = {
+    val urls = fileNames.map(baseUrl / _)
+    BlazeClientBuilder[IO](global).resource.use { client =>
+      urls.traverse(url => makeRequest(client, url))
+    }
+  }
+
+  def fetchInRange(from: LocalDateTime, to: LocalDateTime): IO[List[Either[Throwable, (String, String)]]] = {
+    val fileNames = FileNameService.generate(from, to)
+    fetchFiles(fileNames)
+  }
+
+  def fetchFromDate(date: LocalDate): IO[List[Either[Throwable, (String, String)]]] = {
+    val fileNames = FileNameService.generateFromDate(date)
+    fetchFiles(fileNames)
+  }
+}