From 0ba93d0e60807396849721a00f83d4ad3efa43fa Mon Sep 17 00:00:00 2001
From: InsanusMokrassar <ovsyannikov.alexey95@gmail.com>
Date: Wed, 14 Oct 2020 14:22:58 +0600
Subject: [PATCH] add in memory map based crud implementation

---
 .../pagination/utils/IterableExtensions.kt    | 35 ++++++++
 repos/inmemory/build.gradle                   | 17 ++++
 .../inmo/micro_utils/repos/HashMapCRUDRepo.kt | 89 +++++++++++++++++++
 settings.gradle                               |  1 +
 4 files changed, 142 insertions(+)
 create mode 100644 pagination/common/src/commonMain/kotlin/dev/inmo/micro_utils/pagination/utils/IterableExtensions.kt
 create mode 100644 repos/inmemory/build.gradle
 create mode 100644 repos/inmemory/src/commonMain/kotlin/dev/inmo/micro_utils/repos/HashMapCRUDRepo.kt

diff --git a/pagination/common/src/commonMain/kotlin/dev/inmo/micro_utils/pagination/utils/IterableExtensions.kt b/pagination/common/src/commonMain/kotlin/dev/inmo/micro_utils/pagination/utils/IterableExtensions.kt
new file mode 100644
index 00000000000..4b6a5d97240
--- /dev/null
+++ b/pagination/common/src/commonMain/kotlin/dev/inmo/micro_utils/pagination/utils/IterableExtensions.kt
@@ -0,0 +1,35 @@
+package dev.inmo.micro_utils.pagination.utils
+
+import dev.inmo.micro_utils.pagination.*
+
+fun <T> Iterable<T>.paginate(with: Pagination): PaginationResult<T> {
+    var i = 0
+    val result = mutableListOf<T>()
+    val lowerIndex = with.firstIndex
+    val greatestIndex = with.lastIndex
+    for (item in this) {
+        when {
+            i < lowerIndex || i > greatestIndex -> i++
+            else -> {
+                result.add(item)
+                i++
+            }
+        }
+    }
+
+    return result.createPaginationResult(with, i.toLong())
+}
+
+fun <T> List<T>.paginate(with: Pagination): PaginationResult<T> {
+    return subList(with.firstIndex, with.lastIndex + 1).createPaginationResult(
+        with,
+        size.toLong()
+    )
+}
+
+fun <T> Set<T>.paginate(with: Pagination): PaginationResult<T> {
+    return this.drop(with.firstIndex).take(with.size).createPaginationResult(
+        with,
+        size.toLong()
+    )
+}
diff --git a/repos/inmemory/build.gradle b/repos/inmemory/build.gradle
new file mode 100644
index 00000000000..162e4af700e
--- /dev/null
+++ b/repos/inmemory/build.gradle
@@ -0,0 +1,17 @@
+plugins {
+    id "org.jetbrains.kotlin.multiplatform"
+    id "org.jetbrains.kotlin.plugin.serialization"
+}
+
+apply from: "$mppProjectWithSerializationPresetPath"
+
+kotlin {
+    sourceSets {
+        commonMain {
+            dependencies {
+                api internalProject("micro_utils.repos.common")
+                api internalProject("micro_utils.coroutines")
+            }
+        }
+    }
+}
\ No newline at end of file
diff --git a/repos/inmemory/src/commonMain/kotlin/dev/inmo/micro_utils/repos/HashMapCRUDRepo.kt b/repos/inmemory/src/commonMain/kotlin/dev/inmo/micro_utils/repos/HashMapCRUDRepo.kt
new file mode 100644
index 00000000000..9815088d9ca
--- /dev/null
+++ b/repos/inmemory/src/commonMain/kotlin/dev/inmo/micro_utils/repos/HashMapCRUDRepo.kt
@@ -0,0 +1,89 @@
+package dev.inmo.micro_utils.repos
+
+import dev.inmo.micro_utils.coroutines.BroadcastFlow
+import dev.inmo.micro_utils.pagination.*
+import kotlinx.coroutines.flow.Flow
+
+class MapCRUDRepo<ObjectType, IdType>(
+    private val map: Map<IdType, ObjectType> = emptyMap()
+) : ReadStandardCRUDRepo<ObjectType, IdType> {
+    override suspend fun getByPagination(pagination: Pagination): PaginationResult<ObjectType> {
+        return map.keys.drop(pagination.firstIndex).take(pagination.size).mapNotNull {
+            map[it]
+        }.createPaginationResult(
+            pagination,
+            map.size.toLong()
+        )
+    }
+
+    override suspend fun getById(id: IdType): ObjectType? = map[id]
+
+    override suspend fun contains(id: IdType): Boolean = map.containsKey(id)
+}
+
+abstract class MutableMapCRUDRepo<ObjectType, IdType, InputValueType>(
+    private val map: MutableMap<IdType, ObjectType> = mutableMapOf()
+) : WriteStandardCRUDRepo<ObjectType, IdType, InputValueType> {
+    private val _newObjectsFlow: BroadcastFlow<ObjectType> = BroadcastFlow()
+    override val newObjectsFlow: Flow<ObjectType>
+        get() = _newObjectsFlow
+    private val _updatedObjectsFlow: BroadcastFlow<ObjectType> = BroadcastFlow()
+    override val updatedObjectsFlow: Flow<ObjectType>
+        get() = _updatedObjectsFlow
+    private val _deletedObjectsIdsFlow: BroadcastFlow<IdType> = BroadcastFlow()
+    override val deletedObjectsIdsFlow: Flow<IdType>
+        get() = _deletedObjectsIdsFlow
+
+    protected abstract suspend fun updateObject(newValue: InputValueType, id: IdType, old: ObjectType): ObjectType
+    protected abstract suspend fun createObject(newValue: InputValueType): Pair<IdType, ObjectType>
+
+    override suspend fun create(values: List<InputValueType>): List<ObjectType> {
+        return values.map {
+            val (id, newObject) = createObject(it)
+            map[id] = newObject
+            newObject.also { _ ->
+                _newObjectsFlow.send(newObject)
+            }
+        }
+    }
+
+    override suspend fun update(id: IdType, value: InputValueType): ObjectType? {
+        val newValue = updateObject(value, id, map[id] ?: return null)
+
+        return newValue.also {
+            map[id] = it
+            _updatedObjectsFlow.send(it)
+        }
+    }
+
+    override suspend fun update(values: List<UpdatedValuePair<IdType, InputValueType>>): List<ObjectType> {
+        return values.mapNotNull { update(it.first, it.second) }
+    }
+
+    override suspend fun deleteById(ids: List<IdType>) {
+        ids.forEach {
+            map.remove(it) ?.also { _ -> _deletedObjectsIdsFlow.send(it) }
+        }
+    }
+
+}
+
+abstract class HashMapCRUDRepo<ObjectType, IdType, InputValueType>(
+    map: MutableMap<IdType, ObjectType>
+) : StandardCRUDRepo<ObjectType, IdType, InputValueType>,
+    ReadStandardCRUDRepo<ObjectType, IdType> by MapCRUDRepo(map),
+    MutableMapCRUDRepo<ObjectType, IdType, InputValueType>(map)
+
+fun <ObjectType, IdType, InputValueType> HashMapCRUDRepo(
+    map: MutableMap<IdType, ObjectType>,
+    updateCallback: suspend (newValue: InputValueType, id: IdType, old: ObjectType) -> ObjectType,
+    createCallback: suspend (newValue: InputValueType) -> Pair<IdType, ObjectType>
+) = object : HashMapCRUDRepo<ObjectType, IdType, InputValueType>(map) {
+    override suspend fun updateObject(
+        newValue: InputValueType,
+        id: IdType,
+        old: ObjectType
+    ): ObjectType = updateCallback(newValue, id, old)
+
+    override suspend fun createObject(newValue: InputValueType): Pair<IdType, ObjectType> = createCallback(newValue)
+}
diff --git a/settings.gradle b/settings.gradle
index 333d1080497..54fb4ed3371 100644
--- a/settings.gradle
+++ b/settings.gradle
@@ -9,6 +9,7 @@ String[] includes = [
     ":mime_types",
     ":repos:common",
     ":repos:exposed",
+    ":repos:inmemory",
     ":repos:ktor:client",
     ":repos:ktor:common",
     ":repos:ktor:server",