From 0bab855df7b8d03999f486ea0557df401a3808c0 Mon Sep 17 00:00:00 2001
From: Laila Becker <laila.becker@dreipol.ch>
Date: Thu, 19 Sep 2024 09:36:29 +0200
Subject: [PATCH] [file-writing] Add helpers for writing files

---
 .../dreipol/dreimultiplatform/FileManager.kt  | 58 ++++++++++++++++++-
 .../dreipol/dreimultiplatform/FileManager.kt  |  4 ++
 .../dreipol/dreimultiplatform/FileManager.kt  | 15 +++++
 3 files changed, 76 insertions(+), 1 deletion(-)

diff --git a/src/androidMain/kotlin/ch/dreipol/dreimultiplatform/FileManager.kt b/src/androidMain/kotlin/ch/dreipol/dreimultiplatform/FileManager.kt
index e306257..5002b28 100644
--- a/src/androidMain/kotlin/ch/dreipol/dreimultiplatform/FileManager.kt
+++ b/src/androidMain/kotlin/ch/dreipol/dreimultiplatform/FileManager.kt
@@ -2,10 +2,14 @@ package ch.dreipol.dreimultiplatform
 
 import android.os.Build
 import androidx.annotation.RequiresApi
+import androidx.core.util.AtomicFile
+import java.io.DataOutputStream
 import java.io.File
+import java.io.FileOutputStream
 import java.io.IOException
+import java.io.OutputStreamWriter
 import java.nio.file.Files
-import kotlin.streams.toList
+
 
 actual typealias FileIdentifier = File
 
@@ -45,4 +49,56 @@ actual object FileManager {
     actual fun byteArrayFrom(file: FileIdentifier): ByteArray? = file.readBytes()
 
     actual fun fileIdentifierFromPath(path: String): FileIdentifier? = File(path)
+
+    actual fun write(data: ByteArray, toFile: FileIdentifier, atomically: Boolean): Boolean =
+        if (atomically) {
+            AtomicFile(toFile).write(data)
+        } else {
+            runCatching {
+                toFile.writeBytes(data)
+            }.isSuccess
+        }
+
+    actual fun write(string: String, toFile: FileIdentifier, atomically: Boolean): Boolean =
+        if (atomically) {
+            AtomicFile(toFile).write(string)
+        } else {
+            runCatching {
+                toFile.writeText(string)
+            }.isSuccess
+        }
+
+    private fun AtomicFile.write(data: ByteArray): Boolean {
+        var dataOutput: DataOutputStream? = null
+        var outputStream: FileOutputStream? = null
+        try {
+            outputStream = startWrite()
+            dataOutput = DataOutputStream(outputStream) // Wrapper stream
+            dataOutput.write(data)
+            finishWrite(outputStream) // Pass wrapper stream
+            return true
+        } catch (_: Throwable) {
+            outputStream?.let { failWrite(it) }
+            return false
+        } finally {
+            dataOutput?.close()
+        }
+    }
+
+    private fun AtomicFile.write(string: String): Boolean {
+        var dataOutput: OutputStreamWriter? = null
+        var outputStream: FileOutputStream? = null
+        try {
+            outputStream = startWrite()
+            dataOutput = OutputStreamWriter(outputStream) // Wrapper stream
+            dataOutput.write(string)
+            finishWrite(outputStream) // Pass wrapper stream
+            return true
+        } catch (_: Throwable) {
+            outputStream?.let { failWrite(it) }
+            return false
+        } finally {
+            dataOutput?.close()
+        }
+    }
 }
\ No newline at end of file
diff --git a/src/commonMain/kotlin/ch/dreipol/dreimultiplatform/FileManager.kt b/src/commonMain/kotlin/ch/dreipol/dreimultiplatform/FileManager.kt
index 4e2dedc..4ba5e9b 100644
--- a/src/commonMain/kotlin/ch/dreipol/dreimultiplatform/FileManager.kt
+++ b/src/commonMain/kotlin/ch/dreipol/dreimultiplatform/FileManager.kt
@@ -23,4 +23,8 @@ expect object FileManager {
     fun byteArrayFrom(file: FileIdentifier): ByteArray?
 
     fun fileIdentifierFromPath(path: String): FileIdentifier?
+
+    fun write(data: ByteArray, toFile: FileIdentifier, atomically: Boolean): Boolean
+
+    fun write(string: String, toFile: FileIdentifier, atomically: Boolean): Boolean
 }
\ No newline at end of file
diff --git a/src/iosMain/kotlin/ch/dreipol/dreimultiplatform/FileManager.kt b/src/iosMain/kotlin/ch/dreipol/dreimultiplatform/FileManager.kt
index a8d4b66..0fb2d52 100644
--- a/src/iosMain/kotlin/ch/dreipol/dreimultiplatform/FileManager.kt
+++ b/src/iosMain/kotlin/ch/dreipol/dreimultiplatform/FileManager.kt
@@ -6,16 +6,22 @@ import kotlinx.cinterop.alloc
 import kotlinx.cinterop.memScoped
 import kotlinx.cinterop.ptr
 import kotlinx.cinterop.value
+import platform.Foundation.NSCachesDirectory
 import platform.Foundation.NSData
 import platform.Foundation.NSError
 import platform.Foundation.NSFileManager
+import platform.Foundation.NSSearchPathDirectory
+import platform.Foundation.NSSearchPathForDirectoriesInDomains
 import platform.Foundation.NSString
 import platform.Foundation.NSURL
 import platform.Foundation.NSUTF8StringEncoding
+import platform.Foundation.NSUserDomainMask
 import platform.Foundation.URLByAppendingPathComponent
 import platform.Foundation.dataWithContentsOfURL
 import platform.Foundation.lastPathComponent
 import platform.Foundation.stringWithContentsOfURL
+import platform.Foundation.stringWithString
+import platform.Foundation.writeToFile
 
 @kotlinx.cinterop.ExperimentalForeignApi
 typealias ErrorPointer = CPointer<ObjCObjectVar<NSError?>>
@@ -70,6 +76,15 @@ actual object FileManager {
     actual fun byteArrayFrom(file: FileIdentifier): ByteArray? = NSData.dataWithContentsOfURL(file.url)?.toByteArray()
 
     actual fun fileIdentifierFromPath(path: String): FileIdentifier? = NSURL.fileURLWithPath(path).toFileIdentifier()
+
+    actual fun write(data: ByteArray, toFile: FileIdentifier, atomically: Boolean): Boolean {
+        val path = toFile.filePath ?: return false
+        return data.toNSData().writeToFile(path, atomically)
+    }
+
+    @OptIn(ExperimentalStdlibApi::class)
+    actual fun write(string: String, toFile: FileIdentifier, atomically: Boolean): Boolean =
+        write(string.hexToByteArray(), toFile, atomically)
 }
 
 @OptIn(kotlinx.cinterop.ExperimentalForeignApi::class)