Begin work splitting source IDs to different hydration services (#476)

* Begin work splitting source IDs to different hydration services

* Fix test inaccuracies

* Fix more oopsies

lib/src/main/java/graphql/nadel/engine/transform/artificial/NadelAliasHelper.kt

@@ -58,6 +58,7 @@ class NadelAliasHelper private constructor(private val alias: String) {
     fun getQueryPath(
         path: NadelQueryPath,
     ): NadelQueryPath {
+        // todo: why not just clone and set first index here?
         return path.mapIndexed { index, segment ->
             when (index) {
                 0 -> getResultKey(segment)

lib/src/main/java/graphql/nadel/engine/transform/hydration/NadelHydrationFieldsBuilder.kt

@@ -61,6 +61,22 @@ internal object NadelHydrationFieldsBuilder {
             userContext = userContext,
         )
 
+        return makeBatchActorQueries(
+            executionBlueprint = executionBlueprint,
+            instruction = instruction,
+            aliasHelper = aliasHelper,
+            hydratedField = hydratedField,
+            argBatches = argBatches,
+        )
+    }
+
+    fun makeBatchActorQueries(
+        executionBlueprint: NadelOverallExecutionBlueprint,
+        instruction: NadelBatchHydrationFieldInstruction,
+        aliasHelper: NadelAliasHelper,
+        hydratedField: ExecutableNormalizedField,
+        argBatches: List<Map<NadelHydrationActorInputDef, NormalizedInputValue>>,
+    ): List<ExecutableNormalizedField> {
         val actorFieldOverallObjectTypeNames = getActorFieldOverallObjectTypenames(instruction, executionBlueprint)
         val fieldChildren = deepClone(fields = hydratedField.children)
             .mapNotNull { childField ->

lib/src/main/java/graphql/nadel/engine/transform/hydration/NadelHydrationInputBuilder.kt

@@ -9,7 +9,6 @@ import graphql.nadel.engine.blueprint.hydration.NadelHydrationStrategy
 import graphql.nadel.engine.transform.artificial.NadelAliasHelper
 import graphql.nadel.engine.transform.result.json.JsonNode
 import graphql.nadel.engine.transform.result.json.JsonNodeExtractor
-import graphql.nadel.engine.util.AnyAstValue
 import graphql.nadel.engine.util.emptyOrSingle
 import graphql.nadel.engine.util.flatten
 import graphql.nadel.engine.util.javaValueToAstValue

lib/src/main/java/graphql/nadel/engine/transform/hydration/batch/NadelBatchHydrationInputBuilder.kt

@@ -37,7 +37,7 @@ internal object NadelBatchHydrationInputBuilder {
         return batchArgs.map { nonBatchArgs + it }
     }
 
-    private fun getNonBatchInputValues(
+    internal fun getNonBatchInputValues(
         instruction: NadelBatchHydrationFieldInstruction,
         hydrationField: ExecutableNormalizedField,
     ): Map<NadelHydrationActorInputDef, NormalizedInputValue> {

lib/src/main/java/graphql/nadel/engine/transform/hydration/batch/NadelNewBatchHydrationInputBuilder.kt

@@ -0,0 +1,65 @@
+package graphql.nadel.engine.transform.hydration.batch
+
+import graphql.nadel.engine.blueprint.NadelBatchHydrationFieldInstruction
+import graphql.nadel.engine.blueprint.hydration.NadelBatchHydrationMatchStrategy
+import graphql.nadel.engine.blueprint.hydration.NadelHydrationActorInputDef
+import graphql.nadel.engine.transform.hydration.batch.NadelBatchHydrationInputBuilder.getBatchInputDef
+import graphql.nadel.engine.transform.hydration.batch.NadelBatchHydrationInputBuilder.getNonBatchInputValues
+import graphql.nadel.engine.transform.result.json.JsonNode
+import graphql.nadel.engine.util.javaValueToAstValue
+import graphql.nadel.hooks.NadelExecutionHooks
+import graphql.normalized.ExecutableNormalizedField
+import graphql.normalized.NormalizedInputValue
+import graphql.schema.GraphQLTypeUtil
+
+/**
+ * todo: did I follow this README when forking?
+ *
+ * README
+ *
+ * Please ensure that the batch arguments are ordered according to the input.
+ * This is required for [NadelBatchHydrationMatchStrategy.MatchIndex].
+ */
+internal object NadelNewBatchHydrationInputBuilder {
+    fun getInputValueBatches(
+        hooks: NadelExecutionHooks,
+        userContext: Any?,
+        instruction: NadelBatchHydrationFieldInstruction,
+        hydrationField: ExecutableNormalizedField,
+        sourceIds: List<JsonNode>,
+    ): List<Map<NadelHydrationActorInputDef, NormalizedInputValue>> {
+        val nonBatchArgs = getNonBatchInputValues(instruction, hydrationField)
+        val batchArgs = getBatchInputValues(instruction, sourceIds, hooks, userContext)
+
+        return batchArgs.map { nonBatchArgs + it }
+    }
+
+    private fun getBatchInputValues(
+        instruction: NadelBatchHydrationFieldInstruction,
+        sourceIds: List<JsonNode>,
+        hooks: NadelExecutionHooks,
+        userContext: Any?,
+    ): List<Pair<NadelHydrationActorInputDef, NormalizedInputValue>> {
+        val batchSize = instruction.batchSize
+
+        val (batchInputDef, batchInputValueSource) = getBatchInputDef(instruction) ?: return emptyList()
+        val actorBatchArgDef = instruction.actorFieldDef.getArgument(batchInputDef.name)
+
+        val partitionArgumentList = hooks.partitionBatchHydrationArgumentList(
+            argumentValues = sourceIds.map { it.value },
+            instruction = instruction,
+            userContext = userContext,
+        )
+
+        return partitionArgumentList
+            .flatMap {
+                it.chunked(size = batchSize)
+            }
+            .map { chunk ->
+                batchInputDef to NormalizedInputValue(
+                    GraphQLTypeUtil.simplePrint(actorBatchArgDef.type),
+                    javaValueToAstValue(chunk),
+                )
+            }
+    }
+}