Server returns all dates with data and data in particular day

src/main/scala/db/DBService.scala

@@ -1,6 +1,5 @@
 package db
 
-import cats.effect.unsafe.implicits.global
 import cats.effect.{IO, Resource}
 import cats.implicits.toTraverseOps
 
@@ -58,42 +57,21 @@ object DBService {
       )
   }
 
-  def getDates(): IO[Set[LocalDate]] = {
+  // dates in which we have saved data
+  def getDates(): IO[List[LocalDate]] = {
     val formatter = DateTimeFormatter.ofPattern("yyyyMMdd")
     for {
       fileNames <- readFileNames(dataPath)
-      datesStr <- IO.pure(fileNames.map(_.take(8)).toSet)
+      datesStr <- IO.pure(fileNames.map(_.take(8)).distinct) // take yyyyMMdd
       dates <- IO.pure(datesStr.flatMap(str => {
         Try(LocalDate.parse(str, formatter)).toOption
       }))
-    } yield dates
+    } yield dates.sorted
   }
 
-  def fetchDates(date: LocalDate): IO[List[String]] = {
-    ???
-  }
-
-  // TODO remove this. Just testing
-  private def testGetInRange: IO[Unit] = {
-    val from = LocalDateTime.parse("20230414_2200", dateFormatter)
-    val to = LocalDateTime.parse("20230501_1230", dateFormatter)
-
-    for {
-      lines <- getInRange(from, to)
-      _ <- lines.traverse(IO.println)
-    } yield ()
-  }
-
-  private def testGetDates: IO[Unit] = {
-    for {
-      dates <- getDates()
-      _ <- IO.println(dates)
-    } yield ()
-  }
-
-  def main(args: Array[String]): Unit = {
-    println("----------------> db main")
-//    testGetInRange.unsafeRunSync()
-    testGetDates.unsafeRunSync()
+  def getDateFileNames(date: LocalDate): IO[List[String]] = {
+    val formatter: DateTimeFormatter = DateTimeFormatter.ofPattern("yyyyMMdd")
+    val dateStr: String = date.format(formatter)
+    readFileNames(dataPath).map(_.filter(_.startsWith(dateStr)).sorted)
   }
 }

src/main/scala/db/Main.scala

@@ -0,0 +1,44 @@
+package db
+
+import cats.effect.IO
+import cats.effect.unsafe.implicits.global
+import cats.implicits.toTraverseOps
+import db.DBService
+
+import java.time.{LocalDate, LocalDateTime}
+import java.time.format.DateTimeFormatter
+
+object Main {
+  private val dateFormatter = DateTimeFormatter.ofPattern("yyyyMMdd_HHmm")
+
+  private def testGetInRange: IO[Unit] = {
+    val from = LocalDateTime.parse("20230414_2200", dateFormatter)
+    val to = LocalDateTime.parse("20230501_1230", dateFormatter)
+
+    for {
+      lines <- DBService.getInRange(from, to)
+      _ <- lines.traverse(IO.println)
+    } yield ()
+  }
+
+  private def testGetDates: IO[Unit] = {
+    for {
+      dates <- DBService.getDates()
+      _ <- IO.println(dates)
+    } yield ()
+  }
+
+  private def testGetDate: IO[Unit] = {
+    for {
+      dates <- DBService.getDateFileNames(LocalDate.of(2023, 4, 23))
+      _ <- IO.println(dates)
+    } yield ()
+  }
+
+  def main(args: Array[String]): Unit = {
+    println("----------------> db main")
+    //    testGetInRange.unsafeRunSync()
+    //    testGetDates.unsafeRunSync()
+    testGetDate.unsafeRunSync()
+  }
+}

src/main/scala/server/Server.scala

@@ -52,8 +52,8 @@ object Server extends IOApp {
         case _ => BadRequest(s"Invalid request format")
       }
 
-    // http://localhost:3000/fetchDate/20230423
-    case GET -> Root / "fetchDate" / dateStr => {
+    // http://localhost:3000/fetch/date/20230423
+    case GET -> Root / "fetch" / "date" / dateStr => {
       val dateFormatter = DateTimeFormatter.ofPattern("yyyyMMdd")
       val maybeDate = Try(LocalDate.parse(dateStr, dateFormatter)).toEither
       maybeDate match {
@@ -81,8 +81,28 @@ object Server extends IOApp {
       }
     }
 
-    case GET -> Root / "show" / "fetched_dates" =>
-      ???
+    // http://localhost:3000/show/all_dates
+    case GET -> Root / "show" / "all_dates" =>
+      DBService.getDates().flatMap(dates => {
+        val printer = Printer.spaces2.copy(dropNullValues = true)
+        val prettyJson = printer.print(dates.asJson)
+        Ok(prettyJson)
+      })
+
+    // http://localhost:3000/show/date/20230423
+    case GET -> Root / "show" / "date" / dateStr =>
+      val dateFormatter = DateTimeFormatter.ofPattern("yyyyMMdd")
+      val maybeDate = Try(LocalDate.parse(dateStr, dateFormatter)).toEither
+      maybeDate match {
+        case Right(date) => {
+          DBService.getDateFileNames(date).flatMap(fileNames => {
+            val printer = Printer.spaces2.copy(dropNullValues = true)
+            val prettyJson = printer.print(fileNames.asJson)
+            Ok(prettyJson)
+          })
+        }
+        case Left(_) => BadRequest("Invalid request format")
+      }
 
     case GET -> Root / "show" / dateRange =>
       ???