// Chrome shared by the gamepad-driven screens (GamepadHomeView, GamepadSettingsView,
// GamepadAddHostView, LibraryCoverflowView): the full-bleed console backdrop, the
// controller-glyph hint bar, and the connected-controller status chip. One look across every
// screen is what makes the gamepad UI read as a coherent mode rather than a set of themed pages.
// iOS/iPadOS and macOS (the couch Mac-mini case); tvOS keeps its native focus engine instead.

import PunktfunkKit
import SwiftUI
#if os(iOS) || os(macOS)
import GameController

/// The active controller's real glyph for a button (Xbox "A", DualSense ✕, …) via
/// `sfSymbolsName`; a generic fallback before a controller profile resolves.
/// @MainActor: GamepadManager is main-actor-bound (inside a View body this was implicit).
@MainActor
func buttonGlyph(
    _ button: KeyPath<GCExtendedGamepad, GCControllerButtonInput>, fallback: String
) -> String {
    GamepadManager.shared.active?.controller.extendedGamepad?[keyPath: button].sfSymbolsName
        ?? fallback
}

/// Top padding for a gamepad screen's pinned title. macOS gets extra clearance — the launcher
/// title sits right under the window titlebar and the settings/add-host sheets have no titlebar
/// at all, so the iOS value hugs the top edge there.
func gamepadTitleTopPadding(compact: Bool) -> CGFloat {
    #if os(macOS)
    26
    #else
    compact ? 4 : 10
    #endif
}

/// One glyph + label cell in a hint bar.
struct GamepadHint: Identifiable {
    let glyph: String
    let text: String
    var id: String { glyph + text }
}

/// The pinned controls legend every gamepad screen shows bottom-leading (via `.safeAreaInset`).
/// Same font/spacing everywhere so the legend reads as system chrome, not per-screen decoration —
/// worn as a self-contained Liquid Glass pill (like the top-bar controller chip) so it floats over
/// the backdrop instead of dissolving into it.
struct GamepadHintBar: View {
    let hints: [GamepadHint]

    var body: some View {
        HStack(spacing: 18) {
            ForEach(hints) { hint in
                HStack(spacing: 7) {
                    Image(systemName: hint.glyph)
                        .font(.system(size: 19))
                        .foregroundStyle(.white)
                    Text(hint.text)
                }
                .fixedSize() // keep glyph + label together; never truncate a hint mid-word
            }
        }
        .font(.geist(14, .semibold, relativeTo: .subheadline))
        .foregroundStyle(.white.opacity(0.85))
        .padding(13)
        .consoleGlass(Capsule())
        .overlay(Capsule().strokeBorder(.white.opacity(0.12), lineWidth: 1))
    }
}

/// The console backdrop: a living aurora in the brand's violet family, drifting slowly over black
/// so it reads as ambience behind the cards, never as content. On iOS 18 / macOS 15+ it's an
/// animated `MeshGradient` — a continuous silk of colour whose control points wander on slow,
/// out-of-phase sinusoids — finished with an elliptical vignette (pools light in the centre, sinks
/// the corners) and a top/bottom legibility scrim. Older OSes fall back to the original drifting
/// radial-blob field, unchanged, so nothing regresses.
///
/// Deliberately pure SwiftUI, no `.metal`: these sources build under both SwiftPM (`swift run`/
/// tests) and the Xcode project's synchronized folders, and a compiled metallib is only reliably
/// bundled in one of the two. MeshGradient + TimelineView give the silky look with none of that
/// risk. Applied via `.background { }` — NOT a ZStack sibling — so the `.ignoresSafeArea()` here
/// can't inflate the caller's layout past the safe area (see the layout note in GamepadHomeView's
/// header). Honors Reduce Motion by freezing the field at a fixed phase.
struct GamepadScreenBackground: View {
    @Environment(\.accessibilityReduceMotion) private var reduceMotion

    var body: some View {
        Group {
            if reduceMotion {
                composite(at: 0)
            } else {
                // 30 Hz is plenty for a field that drifts centimetres per minute, and halves the
                // redraw cost of a battery-fed couch device vs. the display's native rate.
                TimelineView(.animation(minimumInterval: 1.0 / 30.0)) { context in
                    composite(at: context.date.timeIntervalSinceReferenceDate)
                }
            }
        }
        .ignoresSafeArea()
    }

    /// The colour field under a very slow warm/cool hue sway, an elliptical vignette, and the
    /// title/hints legibility scrim.
    private func composite(at t: TimeInterval) -> some View {
        ZStack {
            Color.black
            colorField(at: t)
                // ±8° over ~5 min — the whole field very slowly warms and cools.
                .hueRotation(.degrees(sin(t * 0.021) * 8))
            // Cinematic vignette: darker toward the edges so the cards sit in the pooled light.
            // Soft (extends past the frame) so the corners deepen rather than crush to black.
            EllipticalGradient(
                colors: [.clear, .black.opacity(0.42)],
                center: .center, startRadiusFraction: 0.25, endRadiusFraction: 1.15)
            // Legibility grounding for the pinned title (top) and hint pill (bottom). This one
            // darkens the aurora itself (it's the backdrop's bottom layer — nothing behind it to
            // blur), so it stays a gradient, just a light one now.
            LinearGradient(
                stops: [
                    .init(color: .black.opacity(0.38), location: 0),
                    .init(color: .black.opacity(0.06), location: 0.32),
                    .init(color: .black.opacity(0.08), location: 0.68),
                    .init(color: .black.opacity(0.40), location: 1),
                ],
                startPoint: .top, endPoint: .bottom)
        }
    }

    @ViewBuilder private func colorField(at t: TimeInterval) -> some View {
        if #available(iOS 18, macOS 15, tvOS 18, *) {
            MeshGradient(
                width: 4, height: 4,
                points: Self.meshPoints(at: t),
                colors: Self.meshColors,
                smoothsColors: true)
        } else {
            LegacyBlobField(t: t)
        }
    }

    // MARK: - MeshGradient aurora (iOS 18 / macOS 15+)

    /// Sixteen mesh colours (row-major, 4×4): dark-violet corners sink the frame, the edges carry
    /// mid-tone violets, and the four interior points hold the bright brand family — a violet and a
    /// blue-violet up top, a magenta-violet and a violet below — so warm pools on the left, cool on
    /// the right, and the silk shifts temperature as those interior points drift.
    private static let meshColors: [Color] = {
        let corner = Color(red: 0.075, green: 0.060, blue: 0.160)
        return [
            corner, Color(red: 0.34, green: 0.27, blue: 0.72), Color(red: 0.30, green: 0.26, blue: 0.74), corner,
            Color(red: 0.42, green: 0.20, blue: 0.54), Color(red: 0.49, green: 0.39, blue: 0.95), Color(red: 0.28, green: 0.31, blue: 0.84), Color(red: 0.16, green: 0.26, blue: 0.64),
            Color(red: 0.45, green: 0.23, blue: 0.60), Color(red: 0.53, green: 0.31, blue: 0.75), Color(red: 0.35, green: 0.35, blue: 0.91), Color(red: 0.19, green: 0.28, blue: 0.70),
            corner, Color(red: 0.22, green: 0.18, blue: 0.54), Color(red: 0.24, green: 0.20, blue: 0.58), corner,
        ]
    }()

    /// The 4×4 control points at time `t`: every boundary point is PINNED to the frame (so the mesh
    /// always fills edge-to-edge — a drifting edge point would shrink the mesh and expose the black
    /// behind it), while only the four interior points wander on slow, out-of-phase sinusoids
    /// (periods ~90–130 s) so the bright colour pools breathe without ever looking like they loop.
    private static func meshPoints(at t: TimeInterval) -> [SIMD2<Float>] {
        func wob(_ bx: Float, _ by: Float, _ a: Float,
                 _ sx: Double, _ sy: Double, _ ph: Double) -> SIMD2<Float> {
            SIMD2(bx + a * Float(sin(t * sx + ph)), by + a * Float(cos(t * sy + ph * 1.3)))
        }
        return [
            SIMD2(0, 0), SIMD2(0.333, 0), SIMD2(0.667, 0), SIMD2(1, 0),
            SIMD2(0, 0.333),
                wob(0.333, 0.333, 0.11, 0.049, 0.063, 0.4),
                wob(0.667, 0.333, 0.10, 0.055, 0.052, 2.1),
            SIMD2(1, 0.333),
            SIMD2(0, 0.667),
                wob(0.333, 0.667, 0.10, 0.058, 0.049, 3.6),
                wob(0.667, 0.667, 0.12, 0.047, 0.061, 5.0),
            SIMD2(1, 0.667),
            SIMD2(0, 1), SIMD2(0.333, 1), SIMD2(0.667, 1), SIMD2(1, 1),
        ]
    }
}

/// Pre-18/15 fallback for `GamepadScreenBackground`: the original drifting radial-blob field — four
/// soft colour blobs on slow Lissajous paths, additively blended. Kept verbatim so older OSes see
/// exactly the aurora they shipped with (the mesh path is the upgrade for OS 18/15+).
private struct LegacyBlobField: View {
    let t: TimeInterval

    /// One drifting color blob: a base position + drift ellipse (unit coordinates), angular speeds
    /// (rad/s — periods of 30–90 s), and a radius that slowly breathes.
    private struct Blob {
        let color: Color
        let center: CGPoint
        let drift: CGSize
        let speed: (x: Double, y: Double)
        let phase: (x: Double, y: Double)
        let radius: CGFloat
        let breathe: (amount: CGFloat, speed: Double)
        let opacity: Double
    }

    private static let blobs: [Blob] = [
        Blob(color: Color(red: 0.53, green: 0.47, blue: 0.96), // brand violet
             center: CGPoint(x: 0.30, y: 0.24), drift: CGSize(width: 0.16, height: 0.10),
             speed: (0.111, 0.083), phase: (0.0, 1.9),
             radius: 0.52, breathe: (0.07, 0.061), opacity: 0.52),
        Blob(color: Color(red: 0.24, green: 0.20, blue: 0.72), // deep indigo
             center: CGPoint(x: 0.78, y: 0.66), drift: CGSize(width: 0.13, height: 0.14),
             speed: (0.071, 0.096), phase: (2.4, 0.7),
             radius: 0.58, breathe: (0.08, 0.049), opacity: 0.55),
        Blob(color: Color(red: 0.62, green: 0.30, blue: 0.80), // plum
             center: CGPoint(x: 0.16, y: 0.82), drift: CGSize(width: 0.12, height: 0.09),
             speed: (0.089, 0.067), phase: (4.1, 3.2),
             radius: 0.44, breathe: (0.09, 0.078), opacity: 0.42),
        Blob(color: Color(red: 0.22, green: 0.38, blue: 0.86), // cool blue
             center: CGPoint(x: 0.70, y: 0.12), drift: CGSize(width: 0.10, height: 0.08),
             speed: (0.059, 0.104), phase: (1.2, 5.0),
             radius: 0.40, breathe: (0.06, 0.055), opacity: 0.38),
    ]

    var body: some View {
        GeometryReader { geo in
            let side = max(geo.size.width, geo.size.height)
            ZStack {
                ForEach(Self.blobs.indices, id: \.self) { i in
                    blobView(Self.blobs[i], in: geo.size, side: side)
                }
            }
            .drawingGroup()
        }
    }

    private func blobView(_ blob: Blob, in size: CGSize, side: CGFloat) -> some View {
        let x = blob.center.x + blob.drift.width * CGFloat(sin(t * blob.speed.x + blob.phase.x))
        let y = blob.center.y + blob.drift.height * CGFloat(cos(t * blob.speed.y + blob.phase.y))
        let r = side * blob.radius
            * (1 + blob.breathe.amount * CGFloat(sin(t * blob.breathe.speed + blob.phase.x)))
        return Circle()
            .fill(RadialGradient(
                colors: [blob.color, blob.color.opacity(0)],
                center: .center, startRadius: 0, endRadius: r / 2))
            .frame(width: r, height: r)
            .position(x: x * size.width, y: y * size.height)
            .opacity(blob.opacity)
            .blendMode(.plusLighter)
    }
}

/// A blur gradient behind a pinned tray (a screen title, the hints/detail bar, the keyboard tray):
/// scrollable rows pass beneath those insets, so without this the tray text and the row underneath
/// render interleaved. Pure blur — a dark material faded out by a gradient mask, no dark tint — so
/// the tray's text sits on a softly blurred backdrop that dissolves into the rows.
struct GamepadTrayScrim: View {
    let edge: VerticalEdge

    var body: some View {
        let fromEdge: UnitPoint = edge == .top ? .top : .bottom
        let toContent: UnitPoint = edge == .top ? .bottom : .top
        Rectangle()
            .fill(.ultraThinMaterial)
            // These trays always sit on the dark console UI; force dark so the material frosts dark
            // (white text stays legible) regardless of the system appearance.
            .environment(\.colorScheme, .dark)
            // Fade the whole blur out toward the content so it dissolves rather than ending on a line.
            .mask {
                LinearGradient(
                    stops: [
                        .init(color: .black, location: 0),
                        .init(color: .black.opacity(0.9), location: 0.5),
                        .init(color: .clear, location: 1),
                    ],
                    startPoint: fromEdge, endPoint: toContent)
            }
            // Grow past the tray so the fade-to-clear happens OUTSIDE its bounds — the tray's own
            // text always sits on the strong part, rows blur out before they reach it.
            .padding(edge == .top ? .bottom : .top, -32)
            .ignoresSafeArea()
    }
}

/// The calm backdrop for the gamepad UI's form screens (settings, add-host) — NOT the launcher's
/// drifting aurora (this stays still and quiet), but deliberately NOT near-black either: Liquid
/// Glass refracts whatever sits behind it, so over black the rows turn invisible. A deep indigo
/// base plus two soft, static violet/indigo glows give the glass real colour and luminance to lens,
/// so the rows read as glass while the screen stays restful.
struct GamepadFormBackground: View {
    var body: some View {
        ZStack {
            Color(red: 0.075, green: 0.062, blue: 0.150)
            // Violet lift top-leading, cooler indigo bottom-trailing — resolution-independent
            // (fraction radii) so the glow scale tracks the window on any screen.
            EllipticalGradient(
                colors: [Color(red: 0.40, green: 0.31, blue: 0.68).opacity(0.9), .clear],
                center: UnitPoint(x: 0.26, y: 0.14),
                startRadiusFraction: 0, endRadiusFraction: 0.78)
            EllipticalGradient(
                colors: [Color(red: 0.20, green: 0.24, blue: 0.58).opacity(0.75), .clear],
                center: UnitPoint(x: 0.82, y: 0.9),
                startRadiusFraction: 0, endRadiusFraction: 0.78)
        }
        .ignoresSafeArea()
    }
}

/// "Which pad is driving this UI" — the active controller's name and battery, worn as a quiet
/// chip in the launcher's top bar. Callers observe GamepadManager already, so this re-renders
/// when the pad or its battery state changes.
struct ControllerStatusChip: View {
    let controller: GamepadManager.DiscoveredController

    var body: some View {
        HStack(spacing: 7) {
            Image(systemName: controller.hasTouchpadAndMotion
                ? "playstation.logo" : "gamecontroller.fill")
                .font(.system(size: 12))
            Text(controller.name)
                .lineLimit(1)
            if let level = controller.batteryLevel {
                Image(systemName: batterySymbol(level))
                    .font(.system(size: 12))
                    .foregroundStyle(level <= 0.2 && !controller.isCharging
                        ? AnyShapeStyle(.red) : AnyShapeStyle(.white.opacity(0.7)))
            }
        }
        .font(.geist(12, .medium, relativeTo: .caption))
        .foregroundStyle(.white.opacity(0.7))
        .padding(.horizontal, 12)
        .padding(.vertical, 7)
        .background(Capsule().fill(.white.opacity(0.08)))
        .overlay(Capsule().strokeBorder(.white.opacity(0.12), lineWidth: 1))
    }

    private func batterySymbol(_ level: Float) -> String {
        if controller.isCharging { return "battery.100.bolt" }
        switch level {
        case ..<0.125: return "battery.0"
        case ..<0.375: return "battery.25"
        case ..<0.625: return "battery.50"
        case ..<0.875: return "battery.75"
        default: return "battery.100"
        }
    }
}
#endif