//
//  Theme.swift
//  SportsTime
//
//  Central design system for colors, typography, spacing, and animations.
//

import SwiftUI

// MARK: - App Theme Selection

enum AppTheme: String, CaseIterable, Identifiable {
    case teal = "Teal"
    case orbit = "Orbit"
    case retro = "Retro"
    case clutch = "Clutch"
    case monochrome = "Monochrome"
    case sunset = "Sunset"
    case midnight = "Midnight"

    var id: String { rawValue }

    var displayName: String { rawValue }

    var description: String {
        switch self {
        case .teal: return "Cool cyan and teal tones"
        case .orbit: return "Bold navy and orange"
        case .retro: return "Classic columbia blue"
        case .clutch: return "Championship red and gold"
        case .monochrome: return "Clean grayscale aesthetic"
        case .sunset: return "Warm oranges and purples"
        case .midnight: return "Deep blues and gold"
        }
    }

    /// The alternate icon name in the asset catalog, or nil for the default (teal).
    var alternateIconName: String? {
        switch self {
        case .teal: return nil
        case .orbit: return "AppIcon-orbit"
        case .retro: return "AppIcon-retro"
        case .clutch: return "AppIcon-clutch"
        case .monochrome: return "AppIcon-monochrome"
        case .sunset: return "AppIcon-sunset"
        case .midnight: return "AppIcon-midnight"
        }
    }

    var previewColors: [Color] {
        switch self {
        case .teal: return [Color(hex: "4ECDC4"), Color(hex: "1A535C"), Color(hex: "FFE66D")]
        case .orbit: return [Color(hex: "EB6E1F"), Color(hex: "002D62"), Color(hex: "FFFFFF")]
        case .retro: return [Color(hex: "418FDE"), Color(hex: "C41E3A"), Color(hex: "FFFFFF")]
        case .clutch: return [Color(hex: "CE1141"), Color(hex: "FDB927"), Color(hex: "041E42")]
        case .monochrome: return [Color(hex: "808080"), Color(hex: "1A1A1A"), Color(hex: "FAFAFA")]
        case .sunset: return [Color(hex: "F97316"), Color(hex: "7C3AED"), Color(hex: "EC4899")]
        case .midnight: return [Color(hex: "3B82F6"), Color(hex: "1E3A5F"), Color(hex: "F59E0B")]
        }
    }
}

// MARK: - Theme Manager

@Observable
final class ThemeManager {
    static let shared = ThemeManager()

    var currentTheme: AppTheme {
        didSet {
            UserDefaults.standard.set(currentTheme.rawValue, forKey: "selectedTheme")
            updateAppIcon(for: currentTheme)
        }
    }

    private func updateAppIcon(for theme: AppTheme) {
        let iconName = theme.alternateIconName
        guard UIApplication.shared.alternateIconName != iconName else { return }
        UIApplication.shared.setAlternateIconName(iconName)
    }

    private init() {
        if let saved = UserDefaults.standard.string(forKey: "selectedTheme"),
           let theme = AppTheme(rawValue: saved) {
            self.currentTheme = theme
        } else {
            self.currentTheme = .teal
        }
    }
}

// MARK: - Appearance Mode

enum AppearanceMode: String, CaseIterable, Identifiable {
    case system = "System"
    case light = "Light"
    case dark = "Dark"

    var id: String { rawValue }

    var displayName: String { rawValue }

    var iconName: String {
        switch self {
        case .system: return "circle.lefthalf.filled"
        case .light: return "sun.max.fill"
        case .dark: return "moon.fill"
        }
    }

    var description: String {
        switch self {
        case .system: return "Match device settings"
        case .light: return "Always use light mode"
        case .dark: return "Always use dark mode"
        }
    }

    /// Returns the ColorScheme to apply, or nil for system default
    var colorScheme: ColorScheme? {
        switch self {
        case .system: return nil
        case .light: return .light
        case .dark: return .dark
        }
    }
}

// MARK: - Appearance Manager

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

    var currentMode: AppearanceMode {
        didSet {
            UserDefaults.standard.set(currentMode.rawValue, forKey: "appearanceMode")
        }
    }

    private init() {
        if let saved = UserDefaults.standard.string(forKey: "appearanceMode"),
           let mode = AppearanceMode(rawValue: saved) {
            self.currentMode = mode
        } else {
            self.currentMode = .system
        }
    }
}

// MARK: - Theme

enum Theme {

    private static var current: AppTheme { ThemeManager.shared.currentTheme }

    // MARK: - Primary Accent Color

    static var warmOrange: Color {
        switch current {
        case .teal: return Color(hex: "4ECDC4")
        case .orbit: return Color(hex: "EB6E1F")
        case .retro: return Color(hex: "418FDE")
        case .clutch: return Color(hex: "CE1141")
        case .monochrome: return Color(hex: "808080")
        case .sunset: return Color(hex: "F97316")
        case .midnight: return Color(hex: "3B82F6")
        }
    }

    static var warmOrangeGlow: Color {
        warmOrange.opacity(0.7)
    }

    // MARK: - Secondary Accent Colors

    static var routeGold: Color {
        switch current {
        case .teal: return Color(hex: "FFE66D")
        case .orbit: return Color(hex: "002D62")
        case .retro: return Color(hex: "C41E3A")
        case .clutch: return Color(hex: "FDB927")
        case .monochrome: return Color(hex: "A0A0A0")
        case .sunset: return Color(hex: "7C3AED")
        case .midnight: return Color(hex: "F59E0B")
        }
    }

    static var routeAmber: Color {
        switch current {
        case .teal: return Color(hex: "FF6B6B")
        case .orbit: return Color(hex: "EB6E1F")
        case .retro: return Color(hex: "418FDE")
        case .clutch: return Color(hex: "CE1141")
        case .monochrome: return Color(hex: "505050")
        case .sunset: return Color(hex: "EC4899")
        case .midnight: return Color(hex: "60A5FA")
        }
    }

    // MARK: - Sport Colors (constant across themes)

    static let mlbRed = Color(hex: "E31937")
    static let nbaOrange = Color(hex: "F58426")
    static let nhlBlue = Color(hex: "003087")
    static let nflBrown = Color(hex: "8B5A2B")
    static let mlsGreen = Color(hex: "00A651")
    static let wnbaPurple = Color(hex: "FF6F20")  // WNBA orange
    static let nwslTeal = Color(hex: "009688")    // NWSL teal

    // MARK: - Dark Mode Colors

    static var darkBackground1: Color {
        switch current {
        case .teal: return Color(hex: "1A535C")
        case .orbit: return Color(hex: "002D62")
        case .retro: return Color(hex: "1A3A5C")
        case .clutch: return Color(hex: "041E42")
        case .monochrome: return Color(hex: "121212")
        case .sunset: return Color(hex: "1F1033")
        case .midnight: return Color(hex: "0F172A")
        }
    }

    static var darkBackground2: Color {
        switch current {
        case .teal: return Color(hex: "143F46")
        case .orbit: return Color(hex: "001A3A")
        case .retro: return Color(hex: "0F2840")
        case .clutch: return Color(hex: "020E1F")
        case .monochrome: return Color(hex: "0A0A0A")
        case .sunset: return Color(hex: "150A24")
        case .midnight: return Color(hex: "020617")
        }
    }

    static var darkCardBackground: Color {
        switch current {
        case .teal: return Color(hex: "1E5A64")
        case .orbit: return Color(hex: "0A3A6E")
        case .retro: return Color(hex: "234B6E")
        case .clutch: return Color(hex: "0A2847")
        case .monochrome: return Color(hex: "1C1C1C")
        case .sunset: return Color(hex: "2D1B4E")
        case .midnight: return Color(hex: "1E3A5F")
        }
    }

    static var darkCardBackgroundLight: Color {
        switch current {
        case .teal: return Color(hex: "2A6B75")
        case .orbit: return Color(hex: "154A7E")
        case .retro: return Color(hex: "2E5A7E")
        case .clutch: return Color(hex: "153557")
        case .monochrome: return Color(hex: "2A2A2A")
        case .sunset: return Color(hex: "3D2B5E")
        case .midnight: return Color(hex: "2A4A6F")
        }
    }

    static var darkSurfaceGlow: Color {
        warmOrange.opacity(0.15)
    }

    static var darkTextPrimary: Color {
        switch current {
        case .teal: return Color(hex: "F7FFF7")
        case .orbit: return Color(hex: "FFFFFF")
        case .retro: return Color(hex: "FFFFFF")
        case .clutch: return Color(hex: "FFFFFF")
        case .monochrome: return Color(hex: "FAFAFA")
        case .sunset: return Color(hex: "FFF7ED")
        case .midnight: return Color(hex: "F8FAFC")
        }
    }

    static var darkTextSecondary: Color {
        switch current {
        case .teal: return Color(hex: "B8E8E4")
        case .orbit: return Color(hex: "FFB380")
        case .retro: return Color(hex: "A8C8E8")
        case .clutch: return Color(hex: "FFD080")
        case .monochrome: return Color(hex: "D0D0D0")
        case .sunset: return Color(hex: "FED7AA")
        case .midnight: return Color(hex: "93C5FD")
        }
    }

    static var darkTextMuted: Color {
        switch current {
        case .teal: return Color(hex: "7FADA8")
        case .orbit: return Color(hex: "8090A0")
        case .retro: return Color(hex: "7898B8")
        case .clutch: return Color(hex: "8898A8")
        case .monochrome: return Color(hex: "707070")
        case .sunset: return Color(hex: "9D8AA8")
        case .midnight: return Color(hex: "64748B")
        }
    }

    // MARK: - Light Mode Colors

    static var lightBackground1: Color {
        switch current {
        case .teal: return Color(hex: "F7FFF7")
        case .orbit: return Color(hex: "FFF8F5")
        case .retro: return Color(hex: "F5F9FF")
        case .clutch: return Color(hex: "FFFAF5")
        case .monochrome: return Color(hex: "FAFAFA")
        case .sunset: return Color(hex: "FFFBF5")
        case .midnight: return Color(hex: "F8FAFC")
        }
    }

    static var lightBackground2: Color {
        switch current {
        case .teal: return Color(hex: "E8F8F5")
        case .orbit: return Color(hex: "FFF0E8")
        case .retro: return Color(hex: "E8F0FF")
        case .clutch: return Color(hex: "FFF0E8")
        case .monochrome: return Color(hex: "F0F0F0")
        case .sunset: return Color(hex: "FFF3E8")
        case .midnight: return Color(hex: "EFF6FF")
        }
    }

    static var lightCardBackground: Color { .white }

    static var lightCardBackgroundElevated: Color { lightBackground1 }

    static var lightSurfaceBorder: Color {
        warmOrange.opacity(0.3)
    }

    static var lightTextPrimary: Color {
        switch current {
        case .teal: return Color(hex: "1A535C")
        case .orbit: return Color(hex: "002D62")
        case .retro: return Color(hex: "1A3A5C")
        case .clutch: return Color(hex: "041E42")
        case .monochrome: return Color(hex: "1A1A1A")
        case .sunset: return Color(hex: "431407")
        case .midnight: return Color(hex: "1E3A5F")
        }
    }

    static var lightTextSecondary: Color {
        switch current {
        case .teal: return Color(hex: "2A6B75")
        case .orbit: return Color(hex: "1A4A7A")
        case .retro: return Color(hex: "2A5A7C")
        case .clutch: return Color(hex: "1A3A5A")
        case .monochrome: return Color(hex: "404040")
        case .sunset: return Color(hex: "7C2D12")
        case .midnight: return Color(hex: "2A4A6F")
        }
    }

    static var lightTextMuted: Color {
        switch current {
        case .teal: return Color(hex: "5A9A94")
        case .orbit: return Color(hex: "5A7A9A")
        case .retro: return Color(hex: "5A8AAA")
        case .clutch: return Color(hex: "6A7A8A")
        case .monochrome: return Color(hex: "707070")
        case .sunset: return Color(hex: "9A6A5A")
        case .midnight: return Color(hex: "64748B")
        }
    }

    // MARK: - Adaptive Gradients

    static func backgroundGradient(_ colorScheme: ColorScheme) -> LinearGradient {
        colorScheme == .dark
            ? LinearGradient(colors: [darkBackground1, darkBackground2], startPoint: .top, endPoint: .bottom)
            : LinearGradient(colors: [lightBackground1, lightBackground2], startPoint: .top, endPoint: .bottom)
    }

    // MARK: - Adaptive Colors

    static func cardBackground(_ colorScheme: ColorScheme) -> Color {
        colorScheme == .dark ? darkCardBackground : lightCardBackground
    }

    static func cardBackgroundElevated(_ colorScheme: ColorScheme) -> Color {
        colorScheme == .dark ? darkCardBackgroundLight : lightCardBackgroundElevated
    }

    static func textPrimary(_ colorScheme: ColorScheme) -> Color {
        colorScheme == .dark ? darkTextPrimary : lightTextPrimary
    }

    static func textSecondary(_ colorScheme: ColorScheme) -> Color {
        colorScheme == .dark ? darkTextSecondary : lightTextSecondary
    }

    static func textMuted(_ colorScheme: ColorScheme) -> Color {
        colorScheme == .dark ? darkTextMuted : lightTextMuted
    }

    static func surfaceGlow(_ colorScheme: ColorScheme) -> Color {
        colorScheme == .dark ? darkSurfaceGlow : lightSurfaceBorder
    }

    static func cardShadow(_ colorScheme: ColorScheme) -> Color {
        colorScheme == .dark ? Color.black.opacity(0.3) : Color.black.opacity(0.08)
    }

    // MARK: - Spacing

    enum Spacing {
        static let xxs: CGFloat = 4
        static let xs: CGFloat = 8
        static let sm: CGFloat = 12
        static let md: CGFloat = 16
        static let lg: CGFloat = 20
        static let xl: CGFloat = 24
        static let xxl: CGFloat = 32
    }

    // MARK: - Corner Radius

    enum CornerRadius {
        static let small: CGFloat = 8
        static let medium: CGFloat = 12
        static let large: CGFloat = 16
        static let xlarge: CGFloat = 20
    }

    // MARK: - Animation

    enum Animation {
        static let springResponse: Double = 0.3
        static let springDamping: Double = 0.7
        static let staggerDelay: Double = 0.1
        static let routeDrawDuration: Double = 2.0

        static var spring: SwiftUI.Animation {
            .spring(response: springResponse, dampingFraction: springDamping)
        }

        static var gentleSpring: SwiftUI.Animation {
            .spring(response: 0.5, dampingFraction: 0.8)
        }
    }
}

// MARK: - Color Hex Extension

extension Color {
    init(hex: String) {
        let hex = hex.trimmingCharacters(in: CharacterSet.alphanumerics.inverted)
        var int: UInt64 = 0
        Scanner(string: hex).scanHexInt64(&int)
        let a, r, g, b: UInt64
        switch hex.count {
        case 3: // RGB (12-bit)
            (a, r, g, b) = (255, (int >> 8) * 17, (int >> 4 & 0xF) * 17, (int & 0xF) * 17)
        case 6: // RGB (24-bit)
            (a, r, g, b) = (255, int >> 16, int >> 8 & 0xFF, int & 0xFF)
        case 8: // ARGB (32-bit)
            (a, r, g, b) = (int >> 24, int >> 16 & 0xFF, int >> 8 & 0xFF, int & 0xFF)
        default:
            (a, r, g, b) = (255, 0, 0, 0)
        }
        self.init(
            .sRGB,
            red: Double(r) / 255,
            green: Double(g) / 255,
            blue: Double(b) / 255,
            opacity: Double(a) / 255
        )
    }
}

// MARK: - Environment Key for Theme

private struct ColorSchemeKey: EnvironmentKey {
    static let defaultValue: ColorScheme = .light
}

extension EnvironmentValues {
    var themeColorScheme: ColorScheme {
        get { self[ColorSchemeKey.self] }
        set { self[ColorSchemeKey.self] = newValue }
    }
}