server: Allow to retrieve blocks by hash

server/app/com/xsn/explorer/data/BlockDataHandler.scala

@@ -1,6 +1,7 @@
 package com.xsn.explorer.data
 
 import com.alexitc.playsonify.core.ApplicationResult
+import com.xsn.explorer.models.Blockhash
 import com.xsn.explorer.models.rpc.Block
 
 import scala.language.higherKinds
@@ -8,7 +9,8 @@ import scala.language.higherKinds
 trait BlockDataHandler[F[_]] {
 
   def create(block: Block): F[Block]
+
+  def getBy(blockhash: Blockhash): F[Block]
 }
 
 trait BlockBlockingDataHandler extends BlockDataHandler[ApplicationResult]
-

server/app/com/xsn/explorer/data/anorm/BlockPostgresDataHandler.scala

@@ -5,7 +5,8 @@ import javax.inject.Inject
 import com.alexitc.playsonify.core.ApplicationResult
 import com.xsn.explorer.data.BlockBlockingDataHandler
 import com.xsn.explorer.data.anorm.dao.BlockPostgresDAO
-import com.xsn.explorer.errors.BlockUnknownError
+import com.xsn.explorer.errors.{BlockNotFoundError, BlockUnknownError}
+import com.xsn.explorer.models.Blockhash
 import com.xsn.explorer.models.rpc.Block
 import org.scalactic.{One, Or}
 import play.api.db.Database
@@ -20,4 +21,9 @@ class BlockPostgresDataHandler @Inject() (
     val maybe = blockPostgresDAO.create(block)
     Or.from(maybe, One(BlockUnknownError))
   }
+
+  override def getBy(blockhash: Blockhash): ApplicationResult[Block] = database.withConnection { implicit conn =>
+    val maybe = blockPostgresDAO.getBy(blockhash)
+    Or.from(maybe, One(BlockNotFoundError))
+  }
 }

server/app/com/xsn/explorer/data/anorm/dao/BlockPostgresDAO.scala

@@ -4,6 +4,7 @@ import java.sql.Connection
 
 import anorm._
 import com.xsn.explorer.data.anorm.parsers.BlockParsers._
+import com.xsn.explorer.models.Blockhash
 import com.xsn.explorer.models.rpc.Block
 
 class BlockPostgresDAO {
@@ -56,4 +57,17 @@ class BlockPostgresDAO {
       'difficulty -> block.difficulty
     ).as(parseBlock.singleOpt).flatten
   }
+
+  def getBy(blockhash: Blockhash)(implicit conn: Connection): Option[Block] = {
+    SQL(
+      """
+        |SELECT hash, previous_blockhash, next_blockhash, tpos_contract, merkle_root, size,
+        |       height, version, time, median_time, nonce, bits, chainwork, difficulty
+        |FROM blocks
+        |WHERE hash = {hash}
+      """.stripMargin
+    ).on(
+      "hash" -> blockhash.string
+    ).as(parseBlock.singleOpt).flatten
+  }
 }

server/test/com/xsn/explorer/data/BlockPostgresDataHandlerSpec.scala

@@ -3,8 +3,11 @@ package com.xsn.explorer.data
 import com.xsn.explorer.data.anorm.BlockPostgresDataHandler
 import com.xsn.explorer.data.anorm.dao.BlockPostgresDAO
 import com.xsn.explorer.data.common.PostgresDataHandlerSpec
+import com.xsn.explorer.errors.BlockNotFoundError
 import com.xsn.explorer.helpers.BlockLoader
+import com.xsn.explorer.models.Blockhash
 import com.xsn.explorer.models.rpc.Block
+import org.scalactic.Bad
 
 class BlockPostgresDataHandlerSpec extends PostgresDataHandlerSpec {
 
@@ -32,6 +35,25 @@ class BlockPostgresDataHandlerSpec extends PostgresDataHandlerSpec {
     }
   }
 
+  "getBy" should {
+    "return a block" in {
+      val block = BlockLoader.get("1ca318b7a26ed67ca7c8c9b5069d653ba224bf86989125d1dfbb0973b7d6a5e0")
+
+      dataHandler.create(block)
+
+      val result = dataHandler.getBy(block.hash)
+      result.isGood mustEqual true
+      matches(block, result.get)
+    }
+
+    "fail on block not found" in {
+      val blockhash = Blockhash.from("b858d38a3552c83aea58f66fe00ae220352a235e33fcf1f3af04507a61a9dc32").get
+
+      val result = dataHandler.getBy(blockhash)
+      result mustEqual Bad(BlockNotFoundError).accumulating
+    }
+  }
+
   private def matches(expected: Block, result: Block) = {
     // NOTE: transactions and confirmations are not matched intentionally
     result.hash mustEqual expected.hash