session-ios/SessionMessagingKit/Database/Migrations/_016_ThemePreferences.swift

// Copyright © 2022 Rangeproof Pty Ltd. All rights reserved.
//
// stringlint:disable

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 _016_ThemePreferences: Migration {
    static let identifier: String = "uiKit.ThemePreferences"
    static let minExpectedRunDuration: TimeInterval = 0.1
    static let createdTables: [(TableRecord & FetchableRecord).Type] = []
    
    static func migrate(_ db: ObservingDatabase, 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 = MigrationHelper.userExists(db)
        let hadCustomLegacyThemeSetting: Bool = UserDefaults.standard.dictionaryRepresentation()
            .keys
            .contains("appMode")
        var matchSystemNightModeSetting: Bool = (isExistingUser && !hadCustomLegacyThemeSetting)
        let targetTheme: Theme = (!hadCustomLegacyThemeSetting ?
            Theme.classicDark :
            (UserDefaults.standard.integer(forKey: "appMode") == 0 ?
                Theme.classicLight :
                Theme.classicDark
            )
        )
        let targetPrimaryColor: Theme.PrimaryColor = .green
        
        // Save the settings
        try db.execute(sql: """
            DELETE FROM setting
            WHERE key IN ('themeMatchSystemDayNightCycle', 'selectedTheme', 'selectedThemePrimaryColor')
        """)
        
        let matchSystemNightModeSettingAsData: Data = withUnsafeBytes(of: &matchSystemNightModeSetting) { Data($0) }
        try db.execute(
            sql: """
                INSERT INTO setting (key, value)
                VALUES
                    ('themeMatchSystemDayNightCycle', ?),
                    ('selectedTheme', ?),
                    ('selectedThemePrimaryColor', ?)
            """,
            arguments: [
                matchSystemNightModeSettingAsData,
                targetTheme.legacyStringKey.data(using: .utf8),
                targetPrimaryColor.legacyStringKey.data(using: .utf8)
            ]
        )
        
        MigrationExecution.updateProgress(1)
    }
}

private extension Theme {
    var legacyStringKey: String {
        switch self {
            case .classicDark: return "classic_dark"
            case .classicLight: return "classic_light"
            case .oceanDark: return "ocean_dark"
            case .oceanLight: return "ocean_light"
        }
    }
}

private extension Theme.PrimaryColor {
    var legacyStringKey: String {
        switch self {
            case .green: return "green"
            case .blue: return "blue"
            case .yellow: return "yellow"
            case .pink: return "pink"
            case .purple: return "purple"
            case .orange: return "orange"
            case .red: return "red"
        }
    }
}