simplex-chat/apps/ios/SimpleXChat/FileUtils.swift

//
//  FileUtils.swift
//  SimpleX (iOS)
//
//  Created by JRoberts on 15.04.2022.
//  Copyright © 2022 SimpleX Chat. All rights reserved.
//
// Spec: spec/services/files.md

import Foundation
import OSLog
import UIKit

let logger = Logger()

// image file size for complession
// Spec: spec/services/files.md#MAX_IMAGE_SIZE
public let MAX_IMAGE_SIZE: Int64 = 261_120 // 255KB

// Spec: spec/services/files.md#MAX_IMAGE_SIZE_AUTO_RCV
public let MAX_IMAGE_SIZE_AUTO_RCV: Int64 = MAX_IMAGE_SIZE * 2

// Spec: spec/services/files.md#MAX_VOICE_SIZE_AUTO_RCV
public let MAX_VOICE_SIZE_AUTO_RCV: Int64 = MAX_IMAGE_SIZE * 2

// Spec: spec/services/files.md#MAX_VIDEO_SIZE_AUTO_RCV
public let MAX_VIDEO_SIZE_AUTO_RCV: Int64 = 1_047_552 // 1023KB

// Spec: spec/services/files.md#MAX_FILE_SIZE_XFTP
public let MAX_FILE_SIZE_XFTP: Int64 = 1_073_741_824 // 1GB

// raised XFTP limits for a user with a supporter badge (also investor) or a legend badge
public let MAX_FILE_SIZE_XFTP_SUPPORTER: Int64 = 2_147_483_648 // 2GB
public let MAX_FILE_SIZE_XFTP_LEGEND: Int64 = 5_368_709_120 // 5GB

// a badge raises the limit at send for this long after its expiry, shorter than the receiver's grace
public let BADGE_SND_GRACE_INTERVAL = TimeInterval(86400)

public let MAX_FILE_SIZE_LOCAL: Int64 = Int64.max

public let MAX_FILE_SIZE_SMP: Int64 = 8000000

public let MAX_VOICE_MESSAGE_LENGTH = TimeInterval(300)

let CHAT_DB: String = "_chat.db"

let AGENT_DB: String = "_agent.db"

private let CHAT_DB_BAK: String = "_chat.db.bak"

private let AGENT_DB_BAK: String = "_agent.db.bak"

// Spec: spec/database.md#getDocumentsDirectory
public func getDocumentsDirectory() -> URL {
    FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first!
}

// Spec: spec/database.md#getGroupContainerDirectory
public func getGroupContainerDirectory() -> URL {
    FileManager.default.containerURL(forSecurityApplicationGroupIdentifier: APP_GROUP_NAME)!
}

func getAppDirectory() -> URL {
    dbContainerGroupDefault.get() == .group
    ? getGroupContainerDirectory()
    : getDocumentsDirectory()
}

// Spec: spec/database.md#DB_FILE_PREFIX
let DB_FILE_PREFIX = "simplex_v1"

func getLegacyDatabasePath() -> URL {
    getDocumentsDirectory().appendingPathComponent("mobile_v1", isDirectory: false)
}

// Spec: spec/database.md#getAppDatabasePath
public func getAppDatabasePath() -> URL {
    dbContainerGroupDefault.get() == .group
    ? getGroupContainerDirectory().appendingPathComponent(DB_FILE_PREFIX, isDirectory: false)
    : getLegacyDatabasePath()
}

func fileModificationDate(_ path: String) -> Date? {
    do {
        let attr = try FileManager.default.attributesOfItem(atPath: path)
        return attr[FileAttributeKey.modificationDate] as? Date
    } catch {
        return nil
    }
}

// Spec: spec/services/files.md#deleteAppDatabaseAndFiles
public func deleteAppDatabaseAndFiles() {
    let fm = FileManager.default
    let dbPath = getAppDatabasePath().path
    do {
        try fm.removeItem(atPath: dbPath + CHAT_DB)
        try fm.removeItem(atPath: dbPath + AGENT_DB)
    } catch let error {
        logger.error("Failed to delete all databases: \(error)")
    }
    try? fm.removeItem(atPath: dbPath + CHAT_DB_BAK)
    try? fm.removeItem(atPath: dbPath + AGENT_DB_BAK)
    try? fm.removeItem(at: getTempFilesDirectory())
    try? fm.removeItem(at: getMigrationTempFilesDirectory())
    try? fm.createDirectory(at: getTempFilesDirectory(), withIntermediateDirectories: true)
    try? fm.removeItem(at: getWallpaperDirectory())
    try? fm.createDirectory(at: getWallpaperDirectory(), withIntermediateDirectories: true)
    deleteAppFiles()
    _ = kcDatabasePassword.remove()
    storeDBPassphraseGroupDefault.set(true)
}

// Spec: spec/services/files.md#deleteAppFiles
public func deleteAppFiles() {
    let fm = FileManager.default
    do {
        try fm.removeItem(at: getAppFilesDirectory())
        try fm.createDirectory(at: getAppFilesDirectory(), withIntermediateDirectories: true)
    } catch {
        logger.error("FileUtils deleteAppFiles error: \(error.localizedDescription)")
    }
}

public func fileSize(_ url: URL) -> Int? { // in bytes
    do {
        let val = try url.resourceValues(forKeys: [.totalFileAllocatedSizeKey, .fileAllocatedSizeKey])
        return val.totalFileAllocatedSize ?? val.fileAllocatedSize
    } catch {
        logger.error("FileUtils fileSize error: \(error.localizedDescription)")
        return nil
    }
}

public func directoryFileCountAndSize(_ dir: URL) -> (Int, Int)? { // size in bytes
    let fm = FileManager.default
    if let enumerator = fm.enumerator(at: dir, includingPropertiesForKeys: [.totalFileAllocatedSizeKey, .fileAllocatedSizeKey], options: [], errorHandler: { (_, error) -> Bool in
        logger.error("FileUtils directoryFileCountAndSize error: \(error.localizedDescription)")
        return false
    }) {
        var fileCount = 0
        var bytes = 0
        for case let url as URL in enumerator {
            fileCount += 1
            bytes += fileSize(url) ?? 0
        }
        return (fileCount, bytes)
    } else {
        return nil
    }
}

public func hasBackup(newerThan date: Date) -> Bool {
    let dbPath = getAppDatabasePath().path
    return hasBackupFile(dbPath + AGENT_DB_BAK, newerThan: date)
        && hasBackupFile(dbPath + CHAT_DB_BAK, newerThan: date)
}

private func hasBackupFile(_ path: String, newerThan date: Date) -> Bool {
    let fm = FileManager.default
    return fm.fileExists(atPath: path)
            && date <= (fileModificationDate(path) ?? Date.distantPast)
}

public func restoreBackup() throws {
    let dbPath = getAppDatabasePath().path
    try restoreBackupFile(fromPath: dbPath + AGENT_DB_BAK, toPath: dbPath + AGENT_DB)
    try restoreBackupFile(fromPath: dbPath + CHAT_DB_BAK, toPath: dbPath + CHAT_DB)
}

private func restoreBackupFile(fromPath: String, toPath: String) throws {
    let fm = FileManager.default
    if fm.fileExists(atPath: toPath) {
        try fm.removeItem(atPath: toPath)
    }
    try fm.copyItem(atPath: fromPath, toPath: toPath)
}

public func hasLegacyDatabase() -> Bool {
    hasDatabaseAtPath(getLegacyDatabasePath())
}

public func hasDatabase() -> Bool {
    hasDatabaseAtPath(getAppDatabasePath())
}

func hasDatabaseAtPath(_ dbPath: URL) -> Bool {
    let fm = FileManager.default
    return fm.isReadableFile(atPath: dbPath.path + AGENT_DB) &&
           fm.isReadableFile(atPath: dbPath.path + CHAT_DB)
}

public func removeLegacyDatabaseAndFiles() -> Bool {
    let dbPath = getLegacyDatabasePath()
    let appFiles = getDocumentsDirectory().appendingPathComponent("app_files", isDirectory: true)
    let fm = FileManager.default
    let r1 = nil != (try? fm.removeItem(atPath: dbPath.path + AGENT_DB))
    let r2 = nil != (try? fm.removeItem(atPath: dbPath.path + CHAT_DB))
    try? fm.removeItem(atPath: dbPath.path + AGENT_DB_BAK)
    try? fm.removeItem(atPath: dbPath.path + CHAT_DB_BAK)
    try? fm.removeItem(at: appFiles)
    return r1 && r2
}

// Spec: spec/services/files.md#getTempFilesDirectory
public func getTempFilesDirectory() -> URL {
    getAppDirectory().appendingPathComponent("temp_files", isDirectory: true)
}

public func getMigrationTempFilesDirectory() -> URL {
    getDocumentsDirectory().appendingPathComponent("migration_temp_files", isDirectory: true)
}

// Spec: spec/services/files.md#getAppFilesDirectory
public func getAppFilesDirectory() -> URL {
    getAppDirectory().appendingPathComponent("app_files", isDirectory: true)
}

public func getAppFilePath(_ fileName: String) -> URL {
    getAppFilesDirectory().appendingPathComponent(fileName)
}

// Spec: spec/services/files.md#getWallpaperDirectory
public func getWallpaperDirectory() -> URL {
    getAppDirectory().appendingPathComponent("assets", isDirectory: true).appendingPathComponent("wallpapers", isDirectory: true)
}

public func getWallpaperFilePath(_ filename: String) -> URL {
    getWallpaperDirectory().appendingPathComponent(filename)
}

// Spec: spec/services/files.md#saveFile
public func saveFile(_ data: Data, _ fileName: String, encrypted: Bool) -> CryptoFile? {
    let filePath = getAppFilePath(fileName)
    do {
        if encrypted {
            let cfArgs = try writeCryptoFile(path: filePath.path, data: data)
            return CryptoFile(filePath: fileName, cryptoArgs: cfArgs)
        } else {
            try data.write(to: filePath)
            return CryptoFile.plain(fileName)
        }
    } catch {
        logger.error("FileUtils.saveFile error: \(error.localizedDescription)")
        return nil
    }
}

// Spec: spec/services/files.md#removeFile
public func removeFile(_ url: URL) {
    do {
        try FileManager.default.removeItem(atPath: url.path)
    } catch {
        logger.error("FileUtils.removeFile error: \(error.localizedDescription)")
    }
}

public func removeFile(_ fileName: String) {
    do {
        try FileManager.default.removeItem(atPath: getAppFilePath(fileName).path)
    } catch {
        logger.error("FileUtils.removeFile error: \(error.localizedDescription)")
    }
}

// Spec: spec/services/files.md#cleanupDirectFile
public func cleanupDirectFile(_ aChatItem: AChatItem) {
    if aChatItem.chatInfo.chatType == .direct {
        cleanupFile(aChatItem)
    }
}

// Spec: spec/services/files.md#cleanupFile
public func cleanupFile(_ aChatItem: AChatItem) {
    let cItem = aChatItem.chatItem
    let mc = cItem.content.msgContent
    if case .file = mc,
       let fileName = cItem.file?.fileSource?.filePath {
        removeFile(fileName)
    }
}

public func badgeMaxFileSize(_ badge: LocalBadge) -> Int64 {
    badge.badge.badgeType == .legend ? MAX_FILE_SIZE_XFTP_LEGEND : MAX_FILE_SIZE_XFTP_SUPPORTER
}

// a badge raises the limit at send until one day past its expiry, as the core applies it
public func badgeActiveForSend(_ badge: LocalBadge) -> Bool {
    badge.status == .active && badge.badge.badgeExpiry.addingTimeInterval(BADGE_SND_GRACE_INTERVAL) >= Date.now
}

// in incognito chats and above the largest badge's limit no badge applies, so badgeIssue is not used
public func largeFileMessage(_ fileSize: Int64, incognito: Bool = false, badgeIssue: String = "") -> String {
    if incognito {
        return String.localizedStringWithFormat(
            NSLocalizedString("Files larger than %@ cannot be sent in incognito chats.", comment: "file alert"),
            ByteCountFormatter.string(fromByteCount: MAX_FILE_SIZE_XFTP, countStyle: .binary)
        )
    }
    if fileSize > MAX_FILE_SIZE_XFTP_LEGEND {
        return String.localizedStringWithFormat(
            NSLocalizedString("Maximum supported file size is %1$@, with a %2$@.", comment: "file alert"),
            ByteCountFormatter.string(fromByteCount: MAX_FILE_SIZE_XFTP_LEGEND, countStyle: .binary),
            NSLocalizedString("legend badge", comment: "badge required to send a large file")
        )
    }
    let supporter = fileSize <= MAX_FILE_SIZE_XFTP_SUPPORTER
    let message = String.localizedStringWithFormat(
        NSLocalizedString("You need a %1$@ to send files larger than %2$@.", comment: "file alert"),
        supporter
        ? NSLocalizedString("supporter badge", comment: "badge required to send a large file")
        : NSLocalizedString("legend badge", comment: "badge required to send a large file"),
        ByteCountFormatter.string(fromByteCount: supporter ? MAX_FILE_SIZE_XFTP : MAX_FILE_SIZE_XFTP_SUPPORTER, countStyle: .binary)
    )
    return badgeIssue.isEmpty ? message : message + " " + badgeIssue
}

// the badge lapsed, and while active it would have allowed this file
public func expiredBadgeReason(_ fileSize: Int64, _ senderProfile: LocalProfile?) -> String {
    if let badge = senderProfile?.localBadge, !badgeActiveForSend(badge), badgeMaxFileSize(badge) >= fileSize {
        NSLocalizedString("Your badge expired.", comment: "file alert")
    } else {
        ""
    }
}

public func getMaxFileSize(_ fileProtocol: FileProtocol, _ senderProfile: LocalProfile? = nil) -> Int64 {
    switch fileProtocol {
    case .smp: MAX_FILE_SIZE_SMP
    case .local: MAX_FILE_SIZE_LOCAL
    case .xftp:
        if let badge = senderProfile?.localBadge, badgeActiveForSend(badge) {
            badgeMaxFileSize(badge)
        } else {
            MAX_FILE_SIZE_XFTP
        }
    }
}

public struct RuntimeError: Error {
    let message: String

    public init(_ message: String) {
        self.message = message
    }

    public var localizedDescription: String {
        return message
    }
}