import SwiftUI

enum AppTheme {
    // MARK: — Surfaces
    static let background       = Color.white
    static let surfaceRaised    = Color.white
    static let surfaceSunken    = Color(hex: "#F5F5F5")

    // MARK: — Ink
    static let ink              = Color(hex: "#0F0F0F")
    static let inkSecondary     = Color(hex: "#6B6B6B")
    static let inkTertiary      = Color(hex: "#ABABAB")
    static let inkQuaternary    = Color(hex: "#D4D4D4")

    // MARK: — Semantic
    static let positive         = Color(hex: "#16A34A")
    static let destructive      = Color(hex: "#DC2626")
    static let interactive      = Color(hex: "#2563EB")

    // MARK: — Chrome
    static let separator        = Color.black.opacity(0.07)
    static let cardShadow       = Color.black.opacity(0.05)
    static let cardBorderColor  = Color.black.opacity(0.07)

    // MARK: — Metrics
    static let radius: CGFloat           = 14
    static let radiusLarge: CGFloat      = 18
    static let hPad: CGFloat             = 20
    static let cardPad: CGFloat          = 16
    static let sectionGap: CGFloat       = 28

    // MARK: — Typography
    static func display(_ size: CGFloat = 32) -> Font {
        .system(size: size, weight: .semibold, design: .default)
    }
    static func title(_ size: CGFloat = 20) -> Font {
        .system(size: size, weight: .semibold)
    }
    static func headline(_ size: CGFloat = 15) -> Font {
        .system(size: size, weight: .medium)
    }
    static func body(_ size: CGFloat = 15) -> Font {
        .system(size: size, weight: .regular)
    }
    static func caption(_ size: CGFloat = 13) -> Font {
        .system(size: size, weight: .regular)
    }
    static func micro(_ size: CGFloat = 11) -> Font {
        .system(size: size, weight: .medium)
    }

    // MARK: — Back-compat aliases used by existing call sites
    static let blue             = interactive
    static let green            = positive
    static let red              = destructive
    static let textPrimary      = ink
    static let textSecondary    = inkSecondary
    static let textTertiary     = inkTertiary
    static let cardBorder       = cardBorderColor
    static let connectedBorder  = positive
    static let lanBorder        = interactive
    static let cardCornerRadius = radius
    static let cardBackground   = surfaceRaised
    static let titleFont        = Font.system(size: 28, weight: .bold)
    static let headlineFont     = Font.system(size: 17, weight: .semibold)
    static let bodyFont         = Font.system(size: 15, weight: .regular)
    static let captionFont      = Font.system(size: 13, weight: .regular)
    static let smallFont        = Font.system(size: 11, weight: .medium)
    static let sectionSpacing: CGFloat = 28
}

// MARK: — Card modifier
struct CardStyle: ViewModifier {
    var padded: Bool = true
    func body(content: Content) -> some View {
        content
            .if(padded) { $0.padding(AppTheme.cardPad) }
            .background(AppTheme.surfaceRaised)
            .clipShape(RoundedRectangle(cornerRadius: AppTheme.radius, style: .continuous))
            .shadow(color: AppTheme.cardShadow, radius: 12, x: 0, y: 2)
    }
}

extension View {
    func card(padded: Bool = true) -> some View {
        modifier(CardStyle(padded: padded))
    }

    @ViewBuilder func `if`<T: View>(_ condition: Bool, transform: (Self) -> T) -> some View {
        if condition { transform(self) } else { self }
    }
}

extension Color {
    init(hex: String) {
        var h = hex.trimmingCharacters(in: .init(charactersIn: "#"))
        if h.count == 3 { h = h.map { "\($0)\($0)" }.joined() }
        let n = UInt64(h, radix: 16) ?? 0
        self.init(
            red:   Double((n >> 16) & 0xFF) / 255,
            green: Double((n >>  8) & 0xFF) / 255,
            blue:  Double( n        & 0xFF) / 255
        )
    }
}