import SwiftUI

/// Centralized theme system for MixBoard.
/// Supports retro and modern skins inspired by classic players.
final class AppTheme: ObservableObject {

    // MARK: - Available Skins

    enum Skin: String, CaseIterable, Identifiable, Codable {
        // Modern
        case dark       = "Dark"
        case midnight   = "Midnight"
        case forest     = "Forest"
        case ocean      = "Ocean"
        case warm       = "Warm"
        case light      = "Light"
        // Retro
        case winampClassic = "Winamp Classic"
        case winampModern  = "Winamp Modern"
        case foobarDark    = "foobar2000 Dark"
        case foobarLight   = "foobar2000 Light"
        case win95        = "Windows 95"
        case win98        = "Windows 98"
        case xpLuna       = "XP Luna"
        case macOSClassic = "Mac OS 9"

        var id: String { rawValue }

        /// Whether this skin requires dark or light appearance.
        var colorScheme: ColorScheme {
            switch self {
            case .dark, .midnight, .forest, .ocean, .warm,
                 .winampClassic, .winampModern, .foobarDark:
                return .dark
            case .light, .foobarLight, .win95, .win98, .xpLuna, .macOSClassic:
                return .light
            }
        }
    }

    // MARK: - Published

    @Published var currentSkin: Skin {
        didSet {
            applySkin(currentSkin)
            UserDefaults.standard.set(currentSkin.rawValue, forKey: "appThemeSkin")
        }
    }

    /// The color scheme the current skin requires (dark or light).
    var preferredScheme: ColorScheme {
        currentSkin.colorScheme
    }

    // MARK: - Colors

    @Published var accent: Color = .green
    @Published var seekbarBackground: Color = Color.gray.opacity(0.3)
    @Published var seekbarForeground: Color = .green
    @Published var waveformBackground: Color = Color.gray.opacity(0.25)
    @Published var waveformForeground: Color = Color(red: 0.2, green: 0.7, blue: 0.3)
    @Published var waveformSeparator: Color = Color.black.opacity(0.6)
    @Published var playerBarBackground: Color = Color(nsColor: .controlBackgroundColor)
    @Published var toolbarBackground: Color = Color(nsColor: .controlBackgroundColor)
    @Published var columnHeaderBackground: Color = Color(nsColor: .controlBackgroundColor)
    @Published var primaryText: Color = .primary
    @Published var secondaryText: Color = .secondary
    @Published var tertiaryText: Color = Color.gray.opacity(0.5)
    @Published var playingHighlight: Color = .green
    @Published var groupHeaderText: Color = .primary

    // MARK: - Sizes

    @Published var seekbarHeight: CGFloat = 8
    @Published var playerBarHeight: CGFloat = 32
    @Published var rowHeight: CGFloat = 22
    @Published var dataFontSize: CGFloat = 11
    @Published var smallFontSize: CGFloat = 9

    // MARK: - Init

    init() {
        let saved = UserDefaults.standard.string(forKey: "appThemeSkin")
        // Migrate legacy "foobar2000" → "foobar2000 Dark"
        let skinName = (saved == "foobar2000") ? "foobar2000 Dark" : saved
        let skin = skinName.flatMap { Skin(rawValue: $0) } ?? .dark
        self.currentSkin = skin
        applySkin(skin)
    }

    // MARK: - Apply Skin

    private func applySkin(_ skin: Skin) {
        // Reset to defaults first
        // Base sizes — readable defaults
        seekbarHeight = 8
        playerBarHeight = 36
        rowHeight = 24
        dataFontSize = 13
        smallFontSize = 11
        playerBarBackground = Color(nsColor: .controlBackgroundColor)
        toolbarBackground = Color(nsColor: .controlBackgroundColor)
        columnHeaderBackground = Color(nsColor: .controlBackgroundColor)

        switch skin {

        // ── Modern Skins ──────────────────────────────────

        case .dark:
            accent = Color(red: 0.3, green: 0.85, blue: 0.4)
            seekbarBackground = Color(red: 0.15, green: 0.25, blue: 0.35)
            seekbarForeground = Color(red: 0.3, green: 0.85, blue: 0.4)
            waveformBackground = Color(red: 0.12, green: 0.15, blue: 0.22)
            waveformForeground = Color(red: 0.3, green: 0.7, blue: 1.0)
            waveformSeparator = Color.black.opacity(0.7)
            playingHighlight = Color(red: 0.3, green: 0.85, blue: 0.4)
            primaryText = Color.white
            secondaryText = Color.white.opacity(0.75)
            tertiaryText = Color.white.opacity(0.5)
            groupHeaderText = Color.white

        case .midnight:
            accent = Color(red: 0.5, green: 0.6, blue: 1.0)
            seekbarBackground = Color(red: 0.2, green: 0.1, blue: 0.15)
            seekbarForeground = Color(red: 0.5, green: 0.6, blue: 1.0)
            waveformBackground = Color(red: 0.15, green: 0.08, blue: 0.12)
            waveformForeground = Color(red: 0.9, green: 0.3, blue: 0.6)
            waveformSeparator = Color.black.opacity(0.7)
            playingHighlight = Color(red: 0.5, green: 0.6, blue: 1.0)
            primaryText = Color.white
            secondaryText = Color.white.opacity(0.75)
            tertiaryText = Color.white.opacity(0.45)
            groupHeaderText = Color.white

        case .forest:
            accent = Color(red: 0.35, green: 0.85, blue: 0.35)
            seekbarBackground = Color(red: 0.25, green: 0.2, blue: 0.1)
            seekbarForeground = Color(red: 0.35, green: 0.85, blue: 0.35)
            waveformBackground = Color(red: 0.18, green: 0.14, blue: 0.06)
            waveformForeground = Color(red: 0.95, green: 0.75, blue: 0.2)
            waveformSeparator = Color.black.opacity(0.7)
            playingHighlight = Color(red: 0.35, green: 0.85, blue: 0.35)
            primaryText = Color.white
            secondaryText = Color.white.opacity(0.7)
            tertiaryText = Color.white.opacity(0.45)
            groupHeaderText = Color.white

        case .ocean:
            accent = Color(red: 0.3, green: 0.8, blue: 0.95)
            seekbarBackground = Color(red: 0.2, green: 0.12, blue: 0.1)
            seekbarForeground = Color(red: 0.3, green: 0.8, blue: 0.95)
            waveformBackground = Color(red: 0.15, green: 0.08, blue: 0.06)
            waveformForeground = Color(red: 1.0, green: 0.45, blue: 0.3)
            waveformSeparator = Color.black.opacity(0.7)
            playingHighlight = Color(red: 0.3, green: 0.8, blue: 0.95)
            primaryText = Color.white
            secondaryText = Color.white.opacity(0.75)
            tertiaryText = Color.white.opacity(0.45)
            groupHeaderText = Color.white

        case .warm:
            accent = Color(red: 1.0, green: 0.65, blue: 0.25)
            seekbarBackground = Color(red: 0.1, green: 0.18, blue: 0.2)
            seekbarForeground = Color(red: 1.0, green: 0.65, blue: 0.25)
            waveformBackground = Color(red: 0.06, green: 0.12, blue: 0.15)
            waveformForeground = Color(red: 0.2, green: 0.8, blue: 0.75)
            waveformSeparator = Color.black.opacity(0.7)
            playingHighlight = Color(red: 1.0, green: 0.65, blue: 0.25)
            primaryText = Color.white
            secondaryText = Color.white.opacity(0.75)
            tertiaryText = Color.white.opacity(0.45)
            groupHeaderText = Color.white

        case .light:
            accent = Color(red: 0.15, green: 0.45, blue: 0.85)
            seekbarBackground = Color(red: 0.92, green: 0.88, blue: 0.85)
            seekbarForeground = Color(red: 0.15, green: 0.45, blue: 0.85)
            waveformBackground = Color(red: 0.94, green: 0.9, blue: 0.88)
            waveformForeground = Color(red: 0.85, green: 0.3, blue: 0.15)
            waveformSeparator = Color.black.opacity(0.15)
            playingHighlight = Color(red: 0.15, green: 0.45, blue: 0.85)
            playerBarBackground = Color(red: 0.95, green: 0.95, blue: 0.96)
            toolbarBackground = Color(red: 0.95, green: 0.95, blue: 0.96)
            columnHeaderBackground = Color(red: 0.92, green: 0.92, blue: 0.93)
            primaryText = Color.black
            secondaryText = Color(red: 0.25, green: 0.25, blue: 0.3)
            tertiaryText = Color(red: 0.5, green: 0.5, blue: 0.55)
            groupHeaderText = Color.black

        // ── Retro Skins ──────────────────────────────────

        case .winampClassic:
            // Classic Winamp: dark background, neon green text, dark chrome
            accent = Color(red: 0.0, green: 1.0, blue: 0.0)               // #00FF00
            seekbarBackground = Color(red: 0.15, green: 0.15, blue: 0.15)
            seekbarForeground = Color(red: 0.0, green: 1.0, blue: 0.0)
            waveformBackground = Color(red: 0.05, green: 0.05, blue: 0.05)
            waveformForeground = Color(red: 1.0, green: 0.9, blue: 0.0)
            waveformSeparator = Color(red: 0.0, green: 0.3, blue: 0.0)
            playingHighlight = Color(red: 0.0, green: 1.0, blue: 0.0)
            playerBarBackground = Color(red: 0.12, green: 0.12, blue: 0.14)
            toolbarBackground = Color(red: 0.12, green: 0.12, blue: 0.14)
            columnHeaderBackground = Color(red: 0.1, green: 0.1, blue: 0.12)
            primaryText = Color(red: 0.0, green: 0.9, blue: 0.0)          // green text
            secondaryText = Color(red: 0.0, green: 0.7, blue: 0.0)
            tertiaryText = Color(red: 0.0, green: 0.4, blue: 0.0)
            groupHeaderText = Color(red: 0.0, green: 1.0, blue: 0.0)
            seekbarHeight = 6
            dataFontSize = 11

        case .winampModern:
            // Winamp Modern/Bento: dark blue-gray, orange accent
            accent = Color(red: 1.0, green: 0.55, blue: 0.0)              // orange
            seekbarBackground = Color(red: 0.15, green: 0.17, blue: 0.22)
            seekbarForeground = Color(red: 1.0, green: 0.55, blue: 0.0)
            waveformBackground = Color(red: 0.08, green: 0.09, blue: 0.12)
            waveformForeground = Color(red: 0.3, green: 0.85, blue: 0.9)
            waveformSeparator = Color(red: 0.25, green: 0.15, blue: 0.0)
            playingHighlight = Color(red: 1.0, green: 0.55, blue: 0.0)
            playerBarBackground = Color(red: 0.13, green: 0.14, blue: 0.18)
            toolbarBackground = Color(red: 0.13, green: 0.14, blue: 0.18)
            columnHeaderBackground = Color(red: 0.11, green: 0.12, blue: 0.16)
            primaryText = Color(red: 0.85, green: 0.85, blue: 0.9)
            secondaryText = Color(red: 0.6, green: 0.6, blue: 0.65)
            tertiaryText = Color(red: 0.4, green: 0.4, blue: 0.45)
            groupHeaderText = Color(red: 1.0, green: 0.55, blue: 0.0)

        case .foobarDark:
            // foobar2000 Dark: dark gray background, light text, minimal chrome
            accent = Color(red: 0.35, green: 0.55, blue: 0.85)            // muted blue
            seekbarBackground = Color(red: 0.25, green: 0.25, blue: 0.25)
            seekbarForeground = Color(red: 0.35, green: 0.55, blue: 0.85)
            waveformBackground = Color(red: 0.1, green: 0.1, blue: 0.12)
            waveformForeground = Color(red: 0.9, green: 0.65, blue: 0.2)
            waveformSeparator = Color(red: 0.18, green: 0.18, blue: 0.25)
            playingHighlight = Color(red: 0.35, green: 0.55, blue: 0.85)
            playerBarBackground = Color(red: 0.14, green: 0.14, blue: 0.14)
            toolbarBackground = Color(red: 0.14, green: 0.14, blue: 0.14)
            columnHeaderBackground = Color(red: 0.16, green: 0.16, blue: 0.16)
            primaryText = Color(red: 0.85, green: 0.85, blue: 0.85)
            secondaryText = Color(red: 0.6, green: 0.6, blue: 0.6)
            tertiaryText = Color(red: 0.4, green: 0.4, blue: 0.4)
            groupHeaderText = Color(red: 0.85, green: 0.85, blue: 0.85)
            rowHeight = 18
            dataFontSize = 11

        case .foobarLight:
            // foobar2000 Light: classic foobar — white/light gray, minimal, system colors
            accent = Color(red: 0.0, green: 0.0, blue: 0.5)               // navy selection
            seekbarBackground = Color(red: 0.85, green: 0.85, blue: 0.85)
            seekbarForeground = Color(red: 0.0, green: 0.0, blue: 0.6)
            waveformBackground = Color(red: 0.93, green: 0.93, blue: 0.95)
            waveformForeground = Color(red: 0.7, green: 0.15, blue: 0.1)
            waveformSeparator = Color(red: 0.75, green: 0.75, blue: 0.75)
            playingHighlight = Color(red: 0.0, green: 0.0, blue: 0.5)
            playerBarBackground = Color(red: 0.94, green: 0.94, blue: 0.94)
            toolbarBackground = Color(red: 0.94, green: 0.94, blue: 0.94)
            columnHeaderBackground = Color(red: 0.9, green: 0.9, blue: 0.9)
            primaryText = Color.black
            secondaryText = Color(red: 0.3, green: 0.3, blue: 0.3)
            tertiaryText = Color(red: 0.55, green: 0.55, blue: 0.55)
            groupHeaderText = Color.black
            rowHeight = 18
            dataFontSize = 11

        case .win95:
            // Windows 95: classic silver/gray, teal highlights, 3D beveled look
            accent = Color(red: 0.0, green: 0.0, blue: 0.5)               // navy blue
            seekbarBackground = Color(red: 0.75, green: 0.75, blue: 0.75)
            seekbarForeground = Color(red: 0.0, green: 0.0, blue: 0.5)
            waveformBackground = Color(red: 0.65, green: 0.65, blue: 0.65)
            waveformForeground = Color(red: 0.0, green: 0.5, blue: 0.5)
            waveformSeparator = Color(red: 0.5, green: 0.5, blue: 0.5)
            playingHighlight = Color(red: 0.0, green: 0.0, blue: 0.5)
            playerBarBackground = Color(red: 0.75, green: 0.75, blue: 0.75)  // classic gray
            toolbarBackground = Color(red: 0.75, green: 0.75, blue: 0.75)
            columnHeaderBackground = Color(red: 0.8, green: 0.8, blue: 0.8)
            primaryText = Color.black
            secondaryText = Color(red: 0.25, green: 0.25, blue: 0.25)
            tertiaryText = Color(red: 0.5, green: 0.5, blue: 0.5)
            groupHeaderText = Color.black
            dataFontSize = 11
            seekbarHeight = 10

        case .win98:
            // Windows 98/2000: slightly softer than 95, classic blue title bars
            accent = Color(red: 0.0, green: 0.0, blue: 0.65)
            seekbarBackground = Color(red: 0.82, green: 0.82, blue: 0.82)
            seekbarForeground = Color(red: 0.0, green: 0.27, blue: 0.65)
            waveformBackground = Color(red: 0.72, green: 0.72, blue: 0.72)
            waveformForeground = Color(red: 0.0, green: 0.5, blue: 0.25)
            waveformSeparator = Color(red: 0.55, green: 0.55, blue: 0.55)
            playingHighlight = Color(red: 0.0, green: 0.0, blue: 0.65)
            playerBarBackground = Color(red: 0.83, green: 0.82, blue: 0.78)  // warm gray
            toolbarBackground = Color(red: 0.83, green: 0.82, blue: 0.78)
            columnHeaderBackground = Color(red: 0.87, green: 0.86, blue: 0.82)
            primaryText = Color.black
            secondaryText = Color(red: 0.2, green: 0.2, blue: 0.2)
            tertiaryText = Color(red: 0.45, green: 0.45, blue: 0.45)
            groupHeaderText = Color(red: 0.0, green: 0.0, blue: 0.4)
            seekbarHeight = 10

        case .xpLuna:
            // Windows XP Luna: blue toolbar, olive/silver accents, rounded
            accent = Color(red: 0.22, green: 0.44, blue: 0.87)            // XP blue
            seekbarBackground = Color(red: 0.88, green: 0.9, blue: 0.94)
            seekbarForeground = Color(red: 0.22, green: 0.44, blue: 0.87)
            waveformBackground = Color(red: 0.82, green: 0.85, blue: 0.92)
            waveformForeground = Color(red: 0.1, green: 0.6, blue: 0.3)
            waveformSeparator = Color(red: 0.7, green: 0.73, blue: 0.82)
            playingHighlight = Color(red: 0.22, green: 0.44, blue: 0.87)
            playerBarBackground = Color(red: 0.92, green: 0.93, blue: 0.96) // XP light blue
            toolbarBackground = Color(red: 0.85, green: 0.89, blue: 0.95)
            columnHeaderBackground = Color(red: 0.88, green: 0.91, blue: 0.96)
            primaryText = Color.black
            secondaryText = Color(red: 0.2, green: 0.2, blue: 0.3)
            tertiaryText = Color(red: 0.45, green: 0.45, blue: 0.55)
            groupHeaderText = Color(red: 0.1, green: 0.2, blue: 0.6)
            seekbarHeight = 10

        case .macOSClassic:
            // Classic Mac OS 9: platinum gray, black text, pinstripes
            accent = Color(red: 0.0, green: 0.0, blue: 0.6)
            seekbarBackground = Color(red: 0.8, green: 0.8, blue: 0.8)
            seekbarForeground = Color(red: 0.3, green: 0.3, blue: 0.85)
            waveformBackground = Color(red: 0.75, green: 0.75, blue: 0.75)
            waveformForeground = Color(red: 0.7, green: 0.3, blue: 0.1)
            waveformSeparator = Color(red: 0.6, green: 0.6, blue: 0.6)
            playingHighlight = Color(red: 0.3, green: 0.3, blue: 0.85)
            playerBarBackground = Color(red: 0.86, green: 0.86, blue: 0.86) // platinum
            toolbarBackground = Color(red: 0.86, green: 0.86, blue: 0.86)
            columnHeaderBackground = Color(red: 0.9, green: 0.9, blue: 0.9)
            primaryText = Color.black
            secondaryText = Color(red: 0.2, green: 0.2, blue: 0.2)
            tertiaryText = Color(red: 0.5, green: 0.5, blue: 0.5)
            groupHeaderText = Color.black
            dataFontSize = 12
            seekbarHeight = 8
        }
    }
}