import SwiftUI

// Gamepad-style visualization of a controller input snapshot: D-pad and face
// buttons on top, stick pads and triggers below, mirroring the physical
// layout of an Xbox controller.

struct DPadView: View {
    let controller: ControllerInput

    var body: some View {
        VStack(spacing: 3) {
            cell(.dPadUp)
            HStack(spacing: 3) {
                cell(.dPadLeft)
                RoundedRectangle(cornerRadius: 5)
                    .fill(Color.secondary.opacity(0.28))
                    .frame(width: 30, height: 26)
                cell(.dPadRight)
            }
            cell(.dPadDown)
        }
    }

    private func cell(_ button: XboxButton) -> some View {
        let pressed = controller.isPressed(button)
        return RoundedRectangle(cornerRadius: 5)
            .fill(pressed ? Color.green : Color.secondary.opacity(0.18))
            .frame(width: 30, height: 26)
            .overlay(
                Image(systemName: button.dPadSymbol ?? "")
                    .font(.system(size: 9))
                    .foregroundStyle(pressed ? .white : .secondary)
            )
    }
}

struct FaceButtonsView: View {
    let controller: ControllerInput

    var body: some View {
        VStack(spacing: 4) {
            faceButton(.y)
            HStack(spacing: 10) {
                faceButton(.x)
                faceButton(.b)
            }
            faceButton(.a)
        }
    }

    private func faceButton(_ button: XboxButton) -> some View {
        let pressed = controller.isPressed(button)
        return Text(button.label)
            .font(.callout.weight(.semibold))
            .frame(width: 32, height: 32)
            .background(Circle().fill(pressed ? Color.green : Color.secondary.opacity(0.18)))
            .foregroundStyle(pressed ? .white : .primary)
    }
}

struct StickPadView: View {
    let label: String
    let x: Int16
    let y: Int16
    // True while the stick is clicked in (LS/RS).
    var pressed = false

    private let diameter: CGFloat = 64

    var body: some View {
        VStack(spacing: 4) {
            ZStack {
                Circle()
                    .fill(Color.secondary.opacity(0.15))
                Circle()
                    .stroke(pressed ? Color.green : Color.secondary.opacity(0.35),
                            lineWidth: pressed ? 2.5 : 1)
                    .padding(4)
                Circle()
                    .fill(Color.accentColor)
                    .frame(width: 12, height: 12)
                    .offset(x: offset.width, y: offset.height)
            }
            .frame(width: diameter, height: diameter)
            Text(label)
                .font(.caption2)
                .foregroundStyle(.secondary)
        }
    }

    // Map the signed 16-bit stick values onto the pad, keeping the dot inside
    // the ring.
    private var offset: CGSize {
        let travel = diameter / 2 - 10
        return CGSize(
            width: CGFloat(Double(x) / 32768.0 * travel),
            height: CGFloat(Double(y) / 32768.0 * travel)
        )
    }
}

struct TriggerBarView: View {
    let label: String
    let value: UInt16

    private let barWidth: CGFloat = 56

    var body: some View {
        VStack(spacing: 4) {
            ZStack(alignment: .leading) {
                Color.secondary.opacity(0.18)
                Color.accentColor
                    .frame(width: barWidth * fraction, alignment: .leading)
            }
            .frame(width: barWidth, height: 6)
            .clipShape(RoundedRectangle(cornerRadius: 3))
            Text(label)
                .font(.caption2)
                .foregroundStyle(.secondary)
        }
    }

    private var fraction: CGFloat {
        min(max(CGFloat(Double(value) / 1023.0), 0), 1)
    }
}

// The large Guide button, centered between the D-pad and face buttons.
struct GuideButtonView: View {
    let pressed: Bool

    var body: some View {
        VStack(spacing: 4) {
            ZStack {
                Circle()
                    .fill(pressed ? Color.green : Color.secondary.opacity(0.25))
                Image(systemName: "gamecontroller.fill")
                    .font(.system(size: 14))
                    .foregroundStyle(pressed ? .white : .secondary)
            }
            .frame(width: 36, height: 36)
            Text("Guide")
                .font(.caption2)
                .foregroundStyle(.secondary)
        }
    }
}

struct ButtonChip: View {
    let button: XboxButton
    let pressed: Bool

    var body: some View {
        Text(button.label)
            .font(.caption2.weight(.medium))
            .frame(minWidth: 30, minHeight: 20)
            .background(pressed ? Color.green : Color.secondary.opacity(0.15))
            .foregroundStyle(pressed ? .white : .primary)
            .clipShape(RoundedRectangle(cornerRadius: 4))
    }
}