app_for_reddit/Reddit App/Managers/AppearanceManager.swift

import AppKit
import Foundation
import SwiftUI

@MainActor
@Observable
final class AppearanceManager {
    static let shared = AppearanceManager()

    private static let storageKey = "isDarkMode"

    var isDarkMode: Bool {
        didSet {
            guard isDarkMode != oldValue else { return }
            UserDefaults.standard.set(isDarkMode, forKey: Self.storageKey)
        }
    }

    var palette: ThemePalette {
        isDarkMode ? .dark : .light
    }

    var webUnderPageBackgroundColor: NSColor {
        Self.webUnderPageBackgroundColor(isDarkMode: isDarkMode)
    }

    static func webUnderPageBackgroundColor(isDarkMode: Bool) -> NSColor {
        NSColor(hex: (isDarkMode ? ThemePalette.dark : ThemePalette.light).webUnderPageBackgroundHex)
    }

    init() {
        if UserDefaults.standard.object(forKey: Self.storageKey) != nil {
            isDarkMode = UserDefaults.standard.bool(forKey: Self.storageKey)
        } else {
            isDarkMode = true
        }
    }
}

struct ThemePalette {
    let webUnderPageBackgroundHex: UInt
    let background: Color
    let sidebarBackground: Color
    let panelBackground: Color
    let cardBackground: Color
    let quickAccessBackground: Color
    let border: Color
    let cardBorder: Color
    let textPrimary: Color
    let textSecondary: Color
    let textTertiary: Color
    let hoverFill: Color
    let hoverBorder: Color
    let selectedRowFill: Color
    let scrim: Color

    static let dark = ThemePalette(
        webUnderPageBackgroundHex: 0x0B0E14,
        background: Color(hex: 0x0B0E14),
        sidebarBackground: Color(hex: 0x0B0E14),
        panelBackground: Color(hex: 0x11141C),
        cardBackground: Color(hex: 0x151922),
        quickAccessBackground: Color(hex: 0x151922),
        border: Color.white.opacity(0.06),
        cardBorder: Color.white.opacity(0.08),
        textPrimary: Color.white,
        textSecondary: Color(hex: 0x8E9297),
        textTertiary: Color(hex: 0x6B7280),
        hoverFill: Color.white.opacity(0.06),
        hoverBorder: Color.white.opacity(0.14),
        selectedRowFill: Color.white.opacity(0.05),
        scrim: Color.black.opacity(0.35)
    )

    static let light = ThemePalette(
        webUnderPageBackgroundHex: 0xFFFFFF,
        background: Color(hex: 0xF5F6F8),
        sidebarBackground: Color(hex: 0xFFFFFF),
        panelBackground: Color(hex: 0xF9FAFB),
        cardBackground: Color(hex: 0xFFFFFF),
        quickAccessBackground: Color(hex: 0xF0F2F5),
        border: Color(hex: 0xE5E7EB),
        cardBorder: Color(hex: 0xD1D5DB),
        textPrimary: Color(hex: 0x111827),
        textSecondary: Color(hex: 0x6B7280),
        textTertiary: Color(hex: 0x9CA3AF),
        hoverFill: Color.black.opacity(0.05),
        hoverBorder: Color(hex: 0x9CA3AF),
        selectedRowFill: Color.black.opacity(0.06),
        scrim: Color.black.opacity(0.25)
    )
}

private extension NSColor {
    convenience init(hex: UInt, alpha: CGFloat = 1.0) {
        self.init(
            red: CGFloat((hex >> 16) & 0xFF) / 255,
            green: CGFloat((hex >> 8) & 0xFF) / 255,
            blue: CGFloat(hex & 0xFF) / 255,
            alpha: alpha
        )
    }
}