Fix filename issue, add method for getDownloadModelById

Author: khushpanchal

ketch/src/main/java/com/ketch/Ketch.kt

@@ -180,6 +180,7 @@ class Ketch private constructor(
      * @param headers Optional headers sent when making api call for file download
      * @return Unique Download ID associated with current download
      */
+    @Synchronized
     fun download(
         url: String,
         path: String,
@@ -193,10 +194,15 @@ class Ketch private constructor(
             "Missing ${if (url.isEmpty()) "url" else if (path.isEmpty()) "path" else "fileName"}"
         }
 
+        // This will create a temp file which will be renamed after successful download.
+        // This will also make sure each file name is unique.
+        val newFileName = FileUtil.resolveNamingConflicts(fileName, path)
+        FileUtil.createTempFileIfNotExists(path, newFileName)
+
         val downloadRequest = DownloadRequest(
             url = url,
             path = path,
-            fileName = fileName,
+            fileName = newFileName,
             tag = tag,
             headers = headers,
             metaData = metaData
@@ -418,4 +424,12 @@ class Ketch private constructor(
      */
     suspend fun getAllDownloads() = downloadManager.getAllDownloads()
 
+    /**
+     * Suspend function to get download model by id
+     *
+     * @param id
+     * @return [DownloadModel] if present else null
+     */
+    suspend fun getDownloadModelById(id: Int) = downloadManager.getDownloadModelById(id)
+
 }

ketch/src/main/java/com/ketch/internal/download/DownloadManager.kt

@@ -492,4 +492,8 @@ internal class DownloadManager(
         }
     }
 
+    suspend fun getDownloadModelById(id: Int): DownloadModel? {
+        return downloadDao.find(id)?.toDownloadModel()
+    }
+
 }

ketch/src/main/java/com/ketch/internal/utils/FileUtil.kt

@@ -9,8 +9,8 @@ import kotlin.experimental.and
 
 internal object FileUtil {
 
-    fun getTempFileForFile(file: File): File{
-        return File(file.absolutePath+".temp")
+    fun getTempFileForFile(file: File): File {
+        return File(file.absolutePath + ".temp")
     }
 
     fun getFileNameFromUrl(url: String): String {
@@ -51,4 +51,31 @@ internal object FileUtil {
             if (it.exists()) it.delete()
         }
     }
+
+    // If file name already exist at given path, generate new file name with (1), (2) etc. suffix
+    fun resolveNamingConflicts(fileName: String, path: String): String {
+        var newFileName = fileName
+        var file = File(path, newFileName)
+        var tempFile = getTempFileForFile(file)
+        var counter = 1
+
+        while (file.exists() || tempFile.exists()) {
+            val name = fileName.substringBeforeLast(".")
+            val extension = fileName.substringAfterLast(".")
+            newFileName = "$name ($counter).$extension"
+            file = File(path, newFileName)
+            tempFile = getTempFileForFile(file)
+            counter++
+        }
+
+        return newFileName
+    }
+
+    fun createTempFileIfNotExists(path: String, fileName: String) {
+        val file = File(path, fileName)
+        val tempFile = getTempFileForFile(file)
+        if (!tempFile.exists()) {
+            tempFile.createNewFile()
+        }
+    }
 }