#748 - Implement methods for processing various media types and prepa… (#772)

* #748 - Implement methods for processing various media types and preparing them for upload

* Various tweaks following code review:
- added blurhash generation
- changed thumbnails to jpeg
- throwing if file size cannot be retrieved
- move MediaProvider files to separate folder so they can cleanly be imported in the NSE
- added audio file processing
- switched all image resizing methods to ImageIO
- various renames

* Fix blurhash formatting issues, `swift-format-ignore-file` doesn't work

* Processing all media within unique folders to avoid conflicts

* Fix various warnings

* Rename `sizeForItemAt(_ url: URL)` to `sizeForItem(at url: URL)`

* Remove unnecessary resizeImage(UIImage) method, start by copying not moving the file to the unique location

* Add back warning for roomDetails.avatarURL

ElementX/Sources/Services/Media/Provider/MediaFileHandleProxy.swift

@@ -0,0 +1,68 @@
+//
+// Copyright 2023 New Vector Ltd
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+import Foundation
+import MatrixRustSDK
+
+/// A wrapper around Rust's `MediaFileHandle` type that provides us with a
+/// media file that is stored unencrypted in a temporary location for previewing.
+class MediaFileHandleProxy {
+    /// The underlying handle for the file.
+    private let handle: MediaFileHandleProtocol
+    
+    /// Creates a new instance from the Rust type.
+    init(handle: MediaFileHandleProtocol) {
+        self.handle = handle
+    }
+    
+    /// Creates an unmanaged instance (for mocking etc), using a raw `URL`
+    ///
+    /// A media file created from a URL won't have the automatic clean-up mechanism
+    /// that is provided by the SDK's `MediaFileHandle`.
+    static func unmanaged(url: URL) -> MediaFileHandleProxy {
+        MediaFileHandleProxy(handle: UnmanagedMediaFileHandle(url: url))
+    }
+    
+    /// The media file's location on disk.
+    var url: URL {
+        URL(filePath: handle.path())
+    }
+}
+
+// MARK: - Hashable
+
+extension MediaFileHandleProxy: Hashable {
+    static func == (lhs: MediaFileHandleProxy, rhs: MediaFileHandleProxy) -> Bool {
+        lhs.url == rhs.url
+    }
+    
+    func hash(into hasher: inout Hasher) {
+        hasher.combine(url)
+    }
+}
+
+// MARK: -
+
+/// An unmanaged file handle that can be created direct from a URL.
+///
+/// This type allows for mocking but doesn't provide the automatic clean-up mechanism provided by the SDK.
+private struct UnmanagedMediaFileHandle: MediaFileHandleProtocol {
+    let url: URL
+    
+    func path() -> String {
+        url.path()
+    }
+}