session-ios/Session/Database/Migrations/_001_ThemePreferences.swift

// Copyright © 2022 Rangeproof Pty Ltd. All rights reserved.

import Foundation
import GRDB
import SessionUIKit
import SessionUtilitiesKit

/// This migration extracts an old theme preference from UserDefaults and saves it to the database as well as set the default for the other
/// theme preferences
///
/// **Note:** This migration used to live within `SessionUIKit` but we wanted to isolate it and remove dependencies from it so we
/// needed to extract this migration into the `Session` and `SessionShareExtension` targets (since both need theming they both
/// need to provide this migration as an option during setup)
enum _001_ThemePreferences: Migration {
    static let target: TargetMigrations.Identifier = ._deprecatedUIKit
    static let identifier: String = "ThemePreferences" // stringlint:disable
    static let needsConfigSync: Bool = false
    static let minExpectedRunDuration: TimeInterval = 0.1
    static let fetchedTables: [(TableRecord & FetchableRecord).Type] = [Identity.self]
    static let createdOrAlteredTables: [(TableRecord & FetchableRecord).Type] = []
    static let droppedTables: [(TableRecord & FetchableRecord).Type] = []
    
    static func migrate(_ db: Database, using dependencies: Dependencies) throws {
        // Determine if the user was matching the system setting (previously the absence of this value
        // indicated that the app should match the system setting)
        let isExistingUser: Bool = Identity.userExists(db, using: dependencies)
        let hadCustomLegacyThemeSetting: Bool = UserDefaults.standard.dictionaryRepresentation()
            .keys
            .contains("appMode") // stringlint:disable
        let matchSystemNightModeSetting: Bool = (isExistingUser && !hadCustomLegacyThemeSetting)
        let targetTheme: Theme = (!hadCustomLegacyThemeSetting ?
            Theme.classicDark :
            (UserDefaults.standard.integer(forKey: "appMode") == 0 ? // stringlint:disable
                Theme.classicLight :
                Theme.classicDark
            )
        )
        let targetPrimaryColor: Theme.PrimaryColor = .green
        
        // Save the settings
        db[.themeMatchSystemDayNightCycle] = matchSystemNightModeSetting
        db[.theme] = targetTheme
        db[.themePrimaryColor] = targetPrimaryColor
        
        Storage.update(progress: 1, for: self, in: target, using: dependencies)
    }
}

extension Theme: EnumStringSetting {}
extension Theme.PrimaryColor: EnumStringSetting {}

enum DeprecatedUIKitMigrationTarget: MigratableTarget {
    public static func migrations() -> TargetMigrations {
        return TargetMigrations(
            identifier: ._deprecatedUIKit,
            migrations: [
                // Want to ensure the initial DB stuff has been completed before doing any
                // SNUIKit migrations
                [], // Initial DB Creation
                [], // YDB to GRDB Migration
                [], // Legacy DB removal
                [
                    _001_ThemePreferences.self
                ]
            ]
        )
    }
}