Public Search View (#2585)

Co-authored-by: Doug <6060466+pixlwave@users.noreply.github.com>

ElementX/Sources/Services/RoomDirectorySearch/RoomDirectorySearchProxy.swift

@@ -0,0 +1,172 @@
+//
+// Copyright 2024 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 Combine
+import Foundation
+
+import MatrixRustSDK
+
+final class RoomDirectorySearchProxy: RoomDirectorySearchProxyProtocol {
+    private let roomDirectorySearch: RoomDirectorySearchProtocol
+    private let serialDispatchQueue = DispatchQueue(label: "io.element.elementx.roomdirectorysearch", qos: .default)
+    
+    private let resultsSubject = CurrentValueSubject<[RoomDirectorySearchResult], Never>([])
+    
+    var resultsPublisher: CurrentValuePublisher<[RoomDirectorySearchResult], Never> {
+        resultsSubject.asCurrentValuePublisher()
+    }
+    
+    private var results: [RoomDirectorySearchResult] {
+        get { resultsSubject.value }
+        set { resultsSubject.send(newValue) }
+    }
+    
+    private let diffsPublisher = PassthroughSubject<[RoomDirectorySearchEntryUpdate], Never>()
+    
+    private var searchEntriesSubscription: TaskHandle?
+    
+    private var cancellables = Set<AnyCancellable>()
+    
+    init(roomDirectorySearch: RoomDirectorySearchProtocol) {
+        self.roomDirectorySearch = roomDirectorySearch
+        diffsPublisher
+            .receive(on: serialDispatchQueue)
+            .sink { [weak self] in self?.updateResultsWithDiffs($0) }
+            .store(in: &cancellables)
+        
+        Task {
+            searchEntriesSubscription = await roomDirectorySearch.results(listener: RoomDirectorySearchEntriesListenerProxy { [weak self] updates in
+                self?.diffsPublisher.send(updates)
+            })
+        }
+    }
+    
+    func search(query: String?) async -> Result<Void, RoomDirectorySearchError> {
+        do {
+            try await roomDirectorySearch.search(filter: query, batchSize: 50)
+            return .success(())
+        } catch {
+            return .failure(.searchFailed)
+        }
+    }
+    
+    func nextPage() async -> Result<Void, RoomDirectorySearchError> {
+        do {
+            try await roomDirectorySearch.nextPage()
+            return .success(())
+        } catch {
+            return .failure(.nextPageQueryFailed)
+        }
+    }
+    
+    private func updateResultsWithDiffs(_ updates: [RoomDirectorySearchEntryUpdate]) {
+        results = updates.reduce(results) { currentItems, diff in
+            processDiff(diff, on: currentItems)
+        }
+    }
+    
+    private func processDiff(_ diff: RoomDirectorySearchEntryUpdate, on currentItems: [RoomDirectorySearchResult]) -> [RoomDirectorySearchResult] {
+        guard let collectionDiff = buildDiff(from: diff, on: currentItems) else {
+            return currentItems
+        }
+        
+        guard let updatedItems = currentItems.applying(collectionDiff) else {
+            return currentItems
+        }
+        
+        return updatedItems
+    }
+    
+    private func buildDiff(from diff: RoomDirectorySearchEntryUpdate, on currentItems: [RoomDirectorySearchResult]) -> CollectionDifference<RoomDirectorySearchResult>? {
+        var changes = [CollectionDifference<RoomDirectorySearchResult>.Change]()
+        
+        switch diff {
+        case .append(let values):
+            for (index, value) in values.enumerated() {
+                let result = buildResultForRoomDescription(value)
+                changes.append(.insert(offset: results.count + index, element: result, associatedWith: nil))
+            }
+        case .clear:
+            for (index, value) in results.enumerated() {
+                changes.append(.remove(offset: index, element: value, associatedWith: nil))
+            }
+        case .insert(let index, let value):
+            let result = buildResultForRoomDescription(value)
+            changes.append(.insert(offset: Int(index), element: result, associatedWith: nil))
+        case .popBack:
+            guard let value = results.last else {
+                fatalError()
+            }
+            
+            changes.append(.remove(offset: results.count - 1, element: value, associatedWith: nil))
+        case .popFront:
+            let result = results[0]
+            changes.append(.remove(offset: 0, element: result, associatedWith: nil))
+        case .pushBack(let value):
+            let result = buildResultForRoomDescription(value)
+            changes.append(.insert(offset: results.count, element: result, associatedWith: nil))
+        case .pushFront(let value):
+            let result = buildResultForRoomDescription(value)
+            changes.append(.insert(offset: 0, element: result, associatedWith: nil))
+        case .remove(let index):
+            let result = results[Int(index)]
+            changes.append(.remove(offset: Int(index), element: result, associatedWith: nil))
+        case .reset(let values):
+            for (index, result) in results.enumerated() {
+                changes.append(.remove(offset: index, element: result, associatedWith: nil))
+            }
+            
+            for (index, value) in values.enumerated() {
+                changes.append(.insert(offset: index, element: buildResultForRoomDescription(value), associatedWith: nil))
+            }
+        case .set(let index, let value):
+            let result = buildResultForRoomDescription(value)
+            changes.append(.remove(offset: Int(index), element: result, associatedWith: nil))
+            changes.append(.insert(offset: Int(index), element: result, associatedWith: nil))
+        case .truncate(let length):
+            for (index, value) in results.enumerated() {
+                if index < length {
+                    continue
+                }
+                
+                changes.append(.remove(offset: index, element: value, associatedWith: nil))
+            }
+        }
+        
+        return CollectionDifference(changes)
+    }
+    
+    private func buildResultForRoomDescription(_ value: RoomDescription) -> RoomDirectorySearchResult {
+        RoomDirectorySearchResult(id: value.roomId,
+                                  alias: value.alias,
+                                  name: value.name,
+                                  topic: value.topic,
+                                  avatarURL: value.avatarUrl.flatMap(URL.init(string:)),
+                                  canBeJoined: value.joinRule == .public)
+    }
+}
+
+private final class RoomDirectorySearchEntriesListenerProxy: RoomDirectorySearchEntriesListener {
+    private let onUpdateClosure: ([RoomDirectorySearchEntryUpdate]) -> Void
+    
+    func onUpdate(roomEntriesUpdate: [RoomDirectorySearchEntryUpdate]) {
+        onUpdateClosure(roomEntriesUpdate)
+    }
+        
+    init(_ onUpdateClosure: @escaping (([RoomDirectorySearchEntryUpdate]) -> Void)) {
+        self.onUpdateClosure = onUpdateClosure
+    }
+}

ElementX/Sources/Services/RoomDirectorySearch/RoomDirectorySearchProxyProtocol.swift

@@ -0,0 +1,39 @@
+//
+// Copyright 2024 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
+
+// sourcery: AutoMockable
+protocol RoomDirectorySearchProxyProtocol {
+    var resultsPublisher: CurrentValuePublisher<[RoomDirectorySearchResult], Never> { get }
+    
+    func search(query: String?) async -> Result<Void, RoomDirectorySearchError>
+    func nextPage() async -> Result<Void, RoomDirectorySearchError>
+}
+
+enum RoomDirectorySearchError: Error {
+    case searchFailed
+    case nextPageQueryFailed
+}
+
+struct RoomDirectorySearchResult: Identifiable {
+    let id: String
+    let alias: String?
+    let name: String?
+    let topic: String?
+    let avatarURL: URL?
+    let canBeJoined: Bool
+}