From 3f132da62d520e46e6a9fa0b049b95fdebc37f9e Mon Sep 17 00:00:00 2001
From: InsanusMokrassar <ovsyannikov.alexey95@gmail.com>
Date: Sat, 2 Jan 2021 23:56:31 +0600
Subject: [PATCH] add KronSchedulerWork

---
 CHANGELOG.md                                  |  2 +-
 .../dev/inmo/krontab/KronSchedulerWork.kt     | 94 +++++++++++++++++++
 .../inmo/krontab/KronSchedulerWorkRequest.kt  | 18 ----
 3 files changed, 95 insertions(+), 19 deletions(-)
 create mode 100644 src/main/kotlin/dev/inmo/krontab/KronSchedulerWork.kt
 delete mode 100644 src/main/kotlin/dev/inmo/krontab/KronSchedulerWorkRequest.kt

diff --git a/CHANGELOG.md b/CHANGELOG.md
index f446586..9bda26c 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -17,7 +17,7 @@
 * `KrontabTemplateWrapper` has been added
 * New extension `KrontabTemplate#toKronScheduler` (works as `toSchedule`)
 * **Fixed issue related to the fact that `toNearDateTime` of `CronDateTime` incorrectly handled months
-
+* **Android target has been added**
 
 ## 0.4.2
 
diff --git a/src/main/kotlin/dev/inmo/krontab/KronSchedulerWork.kt b/src/main/kotlin/dev/inmo/krontab/KronSchedulerWork.kt
new file mode 100644
index 0000000..c770cc3
--- /dev/null
+++ b/src/main/kotlin/dev/inmo/krontab/KronSchedulerWork.kt
@@ -0,0 +1,94 @@
+package dev.inmo.krontab
+
+import android.content.Context
+import androidx.work.*
+import com.soywiz.klock.DateTime
+import java.util.concurrent.TimeUnit
+
+suspend fun <T : KronSchedulerWork> Context.enqueueKronSchedulerWork(
+    workName: String,
+    delayMillis: Long,
+    workClass: Class<T>,
+    setUpRequest: suspend OneTimeWorkRequest.Builder.() -> Unit
+) = WorkManager.getInstance(applicationContext).enqueueUniqueWork(
+    workName,
+    ExistingWorkPolicy.REPLACE,
+    OneTimeWorkRequest.Builder(workClass).apply {
+        setInitialDelay(delayMillis, TimeUnit.MILLISECONDS)
+        setUpRequest()
+    }.build()
+)
+suspend inline fun <reified T : KronSchedulerWork> Context.enqueueKronSchedulerWork(
+    workName: String,
+    delayMillis: Long,
+    noinline setUpRequest: suspend OneTimeWorkRequest.Builder.() -> Unit
+) = enqueueKronSchedulerWork(workName, delayMillis, T::class.java, setUpRequest)
+
+suspend fun <T : KronSchedulerWork> Context.enqueueKronSchedulerWork(
+    workName: String,
+    initialScheduler: KronScheduler,
+    workClass: Class<T>,
+    setUpRequest: suspend OneTimeWorkRequest.Builder.() -> Unit
+): Operation? {
+    val now = DateTime.now()
+    val nextTriggerTime = initialScheduler.next(now)
+    val delayMillis = nextTriggerTime ?.minus(now) ?.millisecondsLong ?: return null
+
+    return enqueueKronSchedulerWork(workName, delayMillis, workClass, setUpRequest)
+}
+suspend inline fun <reified T : KronSchedulerWork> Context.enqueueKronSchedulerWork(
+    workName: String,
+    initialScheduler: KronScheduler,
+    noinline setUpRequest: suspend OneTimeWorkRequest.Builder.() -> Unit
+) = enqueueKronSchedulerWork(workName, initialScheduler, T::class.java, setUpRequest)
+
+/**
+ * Use this class as an super class in case you wish to implement krontab-based enqueuing of works
+ */
+abstract class KronSchedulerWork(
+    context: Context,
+    workerParams: WorkerParameters
+) : CoroutineWorker(
+    context,
+    workerParams
+) {
+    protected abstract val workName: String
+    protected open val prolongWork: Boolean = true
+    protected open val prolongOnFailure
+        get() = prolongWork
+    protected open val prolongOnException = false
+    protected open val prolongOnNextAbsent = false
+
+    protected abstract suspend fun kronScheduler(): KronScheduler?
+    protected abstract suspend fun onWork(): Result
+    protected open suspend fun OneTimeWorkRequest.Builder.setUpRequest() {}
+
+    protected suspend fun prolong() {
+        val now = DateTime.now()
+        val nextTriggerTime = kronScheduler() ?.let {
+            if (prolongOnNextAbsent) {
+                it.nextOrRelative(now)
+            } else {
+                it.next(now)
+            }
+        }
+        val delayMillis = nextTriggerTime ?.minus(now) ?.millisecondsLong ?: return
+
+        applicationContext.enqueueKronSchedulerWork(workName, delayMillis, this::class.java) { setUpRequest() }
+    }
+
+    override suspend fun doWork(): Result {
+        val result = try {
+            onWork()
+        } catch (e: Throwable) {
+            if (prolongOnException) {
+                prolong()
+            }
+            throw e
+        }
+        if (result !is Result.Failure || prolongOnFailure) {
+            prolong()
+        }
+        return result
+    }
+}
diff --git a/src/main/kotlin/dev/inmo/krontab/KronSchedulerWorkRequest.kt b/src/main/kotlin/dev/inmo/krontab/KronSchedulerWorkRequest.kt
deleted file mode 100644
index 534f820..0000000
--- a/src/main/kotlin/dev/inmo/krontab/KronSchedulerWorkRequest.kt
+++ /dev/null
@@ -1,18 +0,0 @@
-package dev.inmo.krontab
-
-import android.content.Context
-import androidx.work.*
-
-//fun KronScheduler.workRequest(context: Context) = OneTimeWorkRequestBuilder<>()
-//
-//abstract class KronSchedulerWorkRequest(
-//    context: Context,
-//    workerParams: WorkerParameters
-//) : CoroutineWorker(
-//    context,
-//    workerParams
-//) {
-//    override suspend fun doWork(): Result {
-//
-//    }
-//}