Files
bitchat/bitchat/ViewModels/ChatMediaTransferCoordinator.swift
T

712 lines
28 KiB
Swift

import BitFoundation
import BitLogger
import Foundation
#if os(iOS)
import UIKit
#endif
struct LegacyPrivateMediaConsentRequest: Identifiable, Equatable {
let id: UUID
let peerID: PeerID
let peerName: String
let transferId: String
let messageID: String
}
struct PendingLegacyPrivateMediaConsent {
let request: LegacyPrivateMediaConsentRequest
let completion: @MainActor (Bool) -> Void
}
/// The narrow surface `ChatMediaTransferCoordinator` needs from its owner.
///
/// Follows the `ChatDeliveryContext` exemplar: the coordinator depends on the
/// minimal context it actually uses instead of holding an `unowned` back-ref
/// to the whole `ChatViewModel`. This keeps the coordinator independently
/// testable (see `ChatMediaTransferCoordinatorContextTests`) and makes its
/// true dependencies explicit.
@MainActor
protocol ChatMediaTransferContext: AnyObject {
// MARK: Composition state
var canSendMediaInCurrentContext: Bool { get }
var selectedPrivateChatPeer: PeerID? { get }
var nickname: String { get }
var myPeerID: PeerID { get }
var activeChannel: ChannelID { get }
func nicknameForPeer(_ peerID: PeerID) -> String
func currentPublicSender() -> (name: String, peerID: PeerID)
// MARK: Message state
/// Appends a private message via the single-writer store intent.
@discardableResult
func appendPrivateMessage(_ message: BitchatMessage, to peerID: PeerID) -> Bool
/// Appends a public message via the single-writer store intent
/// (immediate: outgoing media placeholders must render without batching).
@discardableResult
func appendPublicMessage(_ message: BitchatMessage, to conversationID: ConversationID) -> Bool
func removeMessage(withID messageID: String, cleanupFile: Bool)
func addSystemMessage(_ content: String)
/// Signals that message state changed so observers refresh (e.g. `objectWillChange.send()`).
func notifyUIChanged()
// MARK: Delivery status & dedup
func updateMessageDeliveryStatus(_ messageID: String, status: DeliveryStatus)
func normalizedContentKey(_ content: String) -> String
func recordContentKey(_ key: String, timestamp: Date)
// MARK: Mesh file transfer
func privateMediaSendPolicy(to peerID: PeerID) -> PrivateMediaSendPolicy
func resolvePrivateMediaSendPolicy(
to peerID: PeerID,
completion: @escaping @MainActor (PrivateMediaSendPolicy) -> Void
)
func requestLegacyPrivateMediaConsent(
for peerID: PeerID,
transferId: String,
messageID: String,
completion: @escaping @MainActor (Bool) -> Void
)
func cancelLegacyPrivateMediaConsent(transferId: String, messageID: String)
func sendFilePrivate(
_ packet: BitchatFilePacket,
to peerID: PeerID,
transferId: String,
allowLegacyFallback: Bool
)
func sendFileBroadcast(_ packet: BitchatFilePacket, transferId: String)
func cancelTransfer(_ transferId: String)
}
extension ChatViewModel: ChatMediaTransferContext {
// `canSendMediaInCurrentContext`, `selectedPrivateChatPeer`, `nickname`,
// `myPeerID`, `activeChannel`, `nicknameForPeer(_:)`,
// `currentPublicSender()`,
// `appendPublicMessage(_:to:)`, `removeMessage(withID:cleanupFile:)`,
// `addSystemMessage(_:)`, `notifyUIChanged()`,
// `updateMessageDeliveryStatus(_:status:)`, `normalizedContentKey(_:)`,
// and `recordContentKey(_:timestamp:)` are shared requirements with the
// other contexts or satisfied by existing `ChatViewModel` members. The
// members below flatten mesh service accesses.
func privateMediaSendPolicy(to peerID: PeerID) -> PrivateMediaSendPolicy {
meshService.privateMediaSendPolicy(to: peerID)
}
func resolvePrivateMediaSendPolicy(
to peerID: PeerID,
completion: @escaping @MainActor (PrivateMediaSendPolicy) -> Void
) {
meshService.resolvePrivateMediaSendPolicy(to: peerID, completion: completion)
}
func requestLegacyPrivateMediaConsent(
for peerID: PeerID,
transferId: String,
messageID: String,
completion: @escaping @MainActor (Bool) -> Void
) {
enqueueLegacyPrivateMediaConsent(
for: peerID,
transferId: transferId,
messageID: messageID,
completion: completion
)
}
func cancelLegacyPrivateMediaConsent(transferId: String, messageID: String) {
invalidateLegacyPrivateMediaConsent(
transferId: transferId,
messageID: messageID
)
}
func sendFilePrivate(
_ packet: BitchatFilePacket,
to peerID: PeerID,
transferId: String,
allowLegacyFallback: Bool
) {
meshService.sendFilePrivate(
packet,
to: peerID,
transferId: transferId,
allowLegacyFallback: allowLegacyFallback
)
}
func sendFileBroadcast(_ packet: BitchatFilePacket, transferId: String) {
meshService.sendFileBroadcast(packet, transferId: transferId)
}
func cancelTransfer(_ transferId: String) {
meshService.cancelTransfer(transferId)
}
}
/// Synchronous boundary between detached image writers and panic deletion.
///
/// Invalidation closes admission before waiting for writers that already
/// entered. Those writers never need the main actor while inside the boundary,
/// so a synchronous panic transaction can safely join them and then delete
/// every output before reporting completion.
private final class ImagePreparationBarrier: @unchecked Sendable {
private let condition = NSCondition()
private var generation: UInt64 = 0
private var activeOperations = 0
var currentGeneration: UInt64 {
condition.lock()
defer { condition.unlock() }
return generation
}
func isCurrent(_ candidate: UInt64) -> Bool {
condition.lock()
defer { condition.unlock() }
return generation == candidate
}
func performIfCurrent<T>(
generation candidate: UInt64,
operation: () throws -> T
) rethrows -> T? {
condition.lock()
guard generation == candidate else {
condition.unlock()
return nil
}
activeOperations += 1
condition.unlock()
defer {
condition.lock()
activeOperations -= 1
if activeOperations == 0 {
condition.broadcast()
}
condition.unlock()
}
return try operation()
}
func invalidateAndWait() {
condition.lock()
generation &+= 1
while activeOperations > 0 {
condition.wait()
}
condition.unlock()
}
}
@MainActor
final class ChatMediaTransferCoordinator {
private unowned let context: any ChatMediaTransferContext
private let prepareImagePacket: @Sendable (URL) throws -> ChatPreparedImage
private let imagePreparationBarrier = ImagePreparationBarrier()
private let prepareVoiceNotePacket: @Sendable (URL) throws -> BitchatFilePacket
private(set) var transferIdToMessageIDs: [String: [String]] = [:]
private(set) var messageIDToTransferId: [String: String] = [:]
init(
context: any ChatMediaTransferContext,
prepareImagePacket: @escaping @Sendable (URL) throws -> ChatPreparedImage = {
try ChatMediaPreparation.prepareImagePacket(from: $0)
},
prepareVoiceNotePacket: @escaping @Sendable (URL) throws -> BitchatFilePacket = {
try ChatMediaPreparation.prepareVoiceNotePacket(at: $0)
}
) {
self.context = context
self.prepareImagePacket = prepareImagePacket
self.prepareVoiceNotePacket = prepareVoiceNotePacket
}
func sendVoiceNote(at url: URL) {
guard context.canSendMediaInCurrentContext else {
SecureLogger.info("Voice note blocked outside mesh/private context", category: .session)
try? FileManager.default.removeItem(at: url)
context.addSystemMessage("Voice notes are only available in mesh chats.")
return
}
let targetPeer = context.selectedPrivateChatPeer
let message = enqueueMediaMessage(
content: "\(MimeType.Category.audio.messagePrefix)\(url.lastPathComponent)",
targetPeer: targetPeer
)
let messageID = message.id
let transferId = makeTransferID(messageID: messageID)
// Own the transfer before detached preparation begins. Cancel/delete
// must be able to invalidate this exact invocation even while file I/O
// is still running off the main actor.
registerTransfer(transferId: transferId, messageID: messageID)
let prepareVoiceNotePacket = self.prepareVoiceNotePacket
let barrier = imagePreparationBarrier
let generation = barrier.currentGeneration
Task.detached(priority: .userInitiated) { [weak self, barrier] in
do {
let packet = try prepareVoiceNotePacket(url)
await MainActor.run { [weak self, barrier] in
guard let self,
barrier.isCurrent(generation),
self.isRegisteredTransfer(transferId, messageID: messageID) else {
return
}
if let peerID = targetPeer {
self.beginPrivateMediaSend(
packet,
to: peerID,
transferId: transferId,
messageID: messageID
)
} else {
self.context.sendFileBroadcast(packet, transferId: transferId)
}
}
} catch ChatMediaPreparationError.voiceNoteTooLarge(let size) {
SecureLogger.warning("Voice note exceeds size limit (\(size) bytes)", category: .session)
try? FileManager.default.removeItem(at: url)
await MainActor.run { [weak self, barrier] in
guard let self,
barrier.isCurrent(generation),
self.isRegisteredTransfer(transferId, messageID: messageID) else {
return
}
self.handleMediaSendFailure(messageID: messageID, reason: String(localized: "content.delivery.reason.voice_too_large", comment: "Failure reason shown when a voice note exceeds the size limit"))
}
} catch {
SecureLogger.error("Voice note send failed: \(error)", category: .session)
await MainActor.run { [weak self, barrier] in
guard let self,
barrier.isCurrent(generation),
self.isRegisteredTransfer(transferId, messageID: messageID) else {
return
}
self.handleMediaSendFailure(messageID: messageID, reason: String(localized: "content.delivery.reason.voice_send_failed", comment: "Failure reason shown when a voice note could not be sent"))
}
}
}
}
#if os(iOS)
func processThenSendImage(_ image: UIImage?) {
guard let image else { return }
let generation = imagePreparationBarrier.currentGeneration
let barrier = imagePreparationBarrier
Task.detached(priority: .userInitiated) { [weak self, barrier] in
do {
guard let processedURL = try barrier.performIfCurrent(
generation: generation,
operation: {
try ImageUtils.processImage(image)
}
) else {
return
}
await MainActor.run { [weak self, barrier] in
guard let self,
barrier.isCurrent(generation) else {
try? FileManager.default.removeItem(at: processedURL)
return
}
self.sendImage(from: processedURL)
}
} catch {
SecureLogger.error("Image processing failed: \(error)", category: .session)
}
}
}
#elseif os(macOS)
func processThenSendImage(from url: URL?) {
guard let url else { return }
let generation = imagePreparationBarrier.currentGeneration
let barrier = imagePreparationBarrier
Task.detached(priority: .userInitiated) { [weak self, barrier] in
do {
guard let processedURL = try barrier.performIfCurrent(
generation: generation,
operation: {
try ImageUtils.processImage(at: url)
}
) else {
return
}
await MainActor.run { [weak self, barrier] in
guard let self,
barrier.isCurrent(generation) else {
try? FileManager.default.removeItem(at: processedURL)
return
}
self.sendImage(from: processedURL)
}
} catch {
SecureLogger.error("Image processing failed: \(error)", category: .session)
}
}
}
#endif
func sendImage(from sourceURL: URL, cleanup: (() -> Void)? = nil) {
guard context.canSendMediaInCurrentContext else {
SecureLogger.info("Image send blocked outside mesh/private context", category: .session)
cleanup?()
context.addSystemMessage("Images are only available in mesh chats.")
return
}
let targetPeer = context.selectedPrivateChatPeer
let generation = imagePreparationBarrier.currentGeneration
do {
try ImageUtils.validateImageSource(at: sourceURL)
} catch {
SecureLogger.error("Image send preparation failed: \(error)", category: .session)
context.addSystemMessage("Failed to prepare image for sending.")
return
}
let prepareImagePacket = self.prepareImagePacket
let barrier = imagePreparationBarrier
Task.detached(priority: .userInitiated) { [weak self, barrier] in
do {
guard let prepared = try barrier.performIfCurrent(
generation: generation,
operation: {
try prepareImagePacket(sourceURL)
}
) else {
return
}
await MainActor.run { [weak self, barrier] in
guard let self,
barrier.isCurrent(generation) else {
try? FileManager.default.removeItem(at: prepared.outputURL)
return
}
let message = self.enqueueMediaMessage(
content: "\(MimeType.Category.image.messagePrefix)\(prepared.outputURL.lastPathComponent)",
targetPeer: targetPeer
)
let messageID = message.id
let transferId = self.makeTransferID(messageID: messageID)
self.registerTransfer(transferId: transferId, messageID: messageID)
if let peerID = targetPeer {
self.beginPrivateMediaSend(
prepared.packet,
to: peerID,
transferId: transferId,
messageID: messageID
)
} else {
self.context.sendFileBroadcast(prepared.packet, transferId: transferId)
}
}
} catch ChatMediaPreparationError.imageTooLarge(let size) {
SecureLogger.warning("Processed image exceeds size limit (\(size) bytes)", category: .session)
await MainActor.run { [weak self, barrier] in
guard let self,
barrier.isCurrent(generation) else {
return
}
self.context.addSystemMessage("Image is too large to send.")
}
} catch {
SecureLogger.error("Image send preparation failed: \(error)", category: .session)
await MainActor.run { [weak self, barrier] in
guard let self,
barrier.isCurrent(generation) else {
return
}
self.context.addSystemMessage("Failed to prepare image for sending.")
}
}
}
}
func enqueueMediaMessage(content: String, targetPeer: PeerID?) -> BitchatMessage {
let timestamp = Date()
let message: BitchatMessage
if let peerID = targetPeer {
message = BitchatMessage(
sender: context.nickname,
content: content,
timestamp: timestamp,
isRelay: false,
originalSender: nil,
isPrivate: true,
recipientNickname: context.nicknameForPeer(peerID),
senderPeerID: context.myPeerID,
deliveryStatus: .sending
)
context.appendPrivateMessage(message, to: peerID)
} else {
let (displayName, senderPeerID) = context.currentPublicSender()
message = BitchatMessage(
sender: displayName,
content: content,
timestamp: timestamp,
isRelay: false,
originalSender: nil,
isPrivate: false,
recipientNickname: nil,
senderPeerID: senderPeerID,
deliveryStatus: .sending
)
context.appendPublicMessage(message, to: ConversationID(channelID: context.activeChannel))
}
let key = context.normalizedContentKey(message.content)
context.recordContentKey(key, timestamp: timestamp)
context.notifyUIChanged()
return message
}
private func beginPrivateMediaSend(
_ packet: BitchatFilePacket,
to peerID: PeerID,
transferId: String,
messageID: String
) {
continuePrivateMediaSend(
packet,
to: peerID,
transferId: transferId,
messageID: messageID,
policy: context.privateMediaSendPolicy(to: peerID)
)
}
private func continuePrivateMediaSend(
_ packet: BitchatFilePacket,
to peerID: PeerID,
transferId: String,
messageID: String,
policy: PrivateMediaSendPolicy
) {
switch policy {
case .encrypted:
context.sendFilePrivate(
packet,
to: peerID,
transferId: transferId,
allowLegacyFallback: false
)
case .awaitingCapabilityProof:
context.resolvePrivateMediaSendPolicy(to: peerID) { [weak self] resolvedPolicy in
guard let self,
self.isRegisteredTransfer(transferId, messageID: messageID) else {
return
}
guard resolvedPolicy != .awaitingCapabilityProof else {
self.handleMediaSendFailure(
messageID: messageID,
reason: String(
localized: "content.delivery.reason.private_media_capability_unresolved",
defaultValue: "Could not confirm encrypted media support",
comment: "Failure reason when private-media capability negotiation did not resolve"
)
)
return
}
self.continuePrivateMediaSend(
packet,
to: peerID,
transferId: transferId,
messageID: messageID,
policy: resolvedPolicy
)
}
case .legacyRequiresConsent:
context.requestLegacyPrivateMediaConsent(
for: peerID,
transferId: transferId,
messageID: messageID
) { [weak self] approved in
guard let self else { return }
// Consent belongs to this exact placeholder/transfer. A late
// dialog callback after cancel/delete must never resurrect it.
guard self.messageIDToTransferId[messageID] == transferId,
self.transferIdToMessageIDs[transferId]?.contains(messageID) == true else {
return
}
guard approved else {
self.handleMediaSendFailure(
messageID: messageID,
reason: String(
localized: "content.delivery.reason.legacy_media_declined",
defaultValue: "Not sent without end-to-end encryption",
comment: "Failure reason after declining the warning for a legacy clear private-media send"
)
)
return
}
self.context.sendFilePrivate(
packet,
to: peerID,
transferId: transferId,
allowLegacyFallback: true
)
}
case .blockedDowngrade:
handleMediaSendFailure(
messageID: messageID,
reason: String(
localized: "content.delivery.reason.private_media_downgrade_blocked",
defaultValue: "Encrypted media required; ask this contact to upgrade",
comment: "Failure reason when a peer that previously supported encrypted media appears to downgrade"
)
)
}
}
func registerTransfer(transferId: String, messageID: String) {
transferIdToMessageIDs[transferId, default: []].append(messageID)
messageIDToTransferId[messageID] = transferId
}
private func isRegisteredTransfer(_ transferId: String, messageID: String) -> Bool {
messageIDToTransferId[messageID] == transferId
&& transferIdToMessageIDs[transferId]?.contains(messageID) == true
}
func makeTransferID(messageID: String) -> String {
"\(messageID)-\(UUID().uuidString)"
}
func clearTransferMapping(for messageID: String) {
guard let transferId = messageIDToTransferId.removeValue(forKey: messageID) else { return }
context.cancelLegacyPrivateMediaConsent(
transferId: transferId,
messageID: messageID
)
guard var queue = transferIdToMessageIDs[transferId] else { return }
if !queue.isEmpty {
if queue.first == messageID {
queue.removeFirst()
} else if let index = queue.firstIndex(of: messageID) {
queue.remove(at: index)
}
}
transferIdToMessageIDs[transferId] = queue.isEmpty ? nil : queue
}
func handleMediaSendFailure(messageID: String, reason: String) {
context.updateMessageDeliveryStatus(messageID, status: .failed(reason: reason))
clearTransferMapping(for: messageID)
}
func handleTransferEvent(_ event: TransferProgressManager.Event) {
switch event {
case .started(let id, let total):
guard let messageID = transferIdToMessageIDs[id]?.first else { return }
context.updateMessageDeliveryStatus(messageID, status: .partiallyDelivered(reached: 0, total: total))
case .updated(let id, let sent, let total):
guard let messageID = transferIdToMessageIDs[id]?.first else { return }
context.updateMessageDeliveryStatus(messageID, status: .partiallyDelivered(reached: sent, total: total))
case .completed(let id, _):
guard let messageID = transferIdToMessageIDs[id]?.first else { return }
context.updateMessageDeliveryStatus(messageID, status: .sent)
clearTransferMapping(for: messageID)
case .cancelled(let id, _, _):
guard let messageID = transferIdToMessageIDs[id]?.first else { return }
clearTransferMapping(for: messageID)
context.removeMessage(withID: messageID, cleanupFile: true)
case .rejected(let id, let reason):
guard let messageID = transferIdToMessageIDs[id]?.first else { return }
handleMediaSendFailure(messageID: messageID, reason: reason)
}
}
func cleanupLocalFile(forMessage message: BitchatMessage) {
let categories: [MimeType.Category] = [.audio, .image, .file]
guard let category = categories.first(where: { message.content.hasPrefix($0.messagePrefix) }),
let rawFilename = String(message.content.dropFirst(category.messagePrefix.count)).trimmedOrNilIfEmpty,
let base = try? applicationFilesDirectory(),
let safeFilename = (rawFilename as NSString).lastPathComponent.nilIfEmpty,
safeFilename != ".",
safeFilename != ".." else {
return
}
let subdirs = categories.flatMap { ["\($0.mediaDir)/outgoing", "\($0.mediaDir)/incoming"] }
for subdir in subdirs {
let target = base.appendingPathComponent(subdir, isDirectory: true).appendingPathComponent(safeFilename)
guard target.path.hasPrefix(base.path) else { continue }
do {
try FileManager.default.removeItem(at: target)
} catch CocoaError.fileNoSuchFile {
continue
} catch {
SecureLogger.error("Failed to cleanup \(safeFilename): \(error)", category: .session)
}
}
}
func cancelMediaSend(messageID: String) {
if let transferId = messageIDToTransferId[messageID],
let active = transferIdToMessageIDs[transferId]?.first,
active == messageID {
context.cancelTransfer(transferId)
}
clearTransferMapping(for: messageID)
context.removeMessage(withID: messageID, cleanupFile: true)
}
func deleteMediaMessage(messageID: String) {
// Delete is also a send cancellation. In particular, an approved
// legacy-clear send may still be waiting on BLEService.messageQueue;
// removing only the UI mapping would let that deferred work transmit.
if let transferId = messageIDToTransferId[messageID],
transferIdToMessageIDs[transferId]?.first == messageID {
context.cancelTransfer(transferId)
}
clearTransferMapping(for: messageID)
context.removeMessage(withID: messageID, cleanupFile: true)
}
/// Invalidates detached preparation work and cancels every transfer that
/// reached the transport. Closing image-preparation admission and joining
/// active synchronous writers ensures the following panic media deletion
/// is the last filesystem mutation before the transaction can complete.
func resetForPanic() {
imagePreparationBarrier.invalidateAndWait()
let transferIDs = Set(transferIdToMessageIDs.keys)
transferIdToMessageIDs.removeAll(keepingCapacity: false)
messageIDToTransferId.removeAll(keepingCapacity: false)
for transferID in transferIDs {
context.cancelTransfer(transferID)
}
}
}
private extension ChatMediaTransferCoordinator {
func applicationFilesDirectory() throws -> URL {
let base = try FileManager.default.url(
for: .applicationSupportDirectory,
in: .userDomainMask,
appropriateFor: nil,
create: true
)
let filesDirectory = base.appendingPathComponent("files", isDirectory: true)
try FileManager.default.createDirectory(
at: filesDirectory,
withIntermediateDirectories: true,
attributes: nil
)
return filesDirectory
}
}