import SwiftUI

// 瞬时通知横幅（#2）：覆盖在标签内容顶部，醒目、状态分明（成功绿 / 失败红 / 信息中性）、自动消失
// （EngineController.notify 安排 4s 后移除）、可点叉手动清除。取代原先散落在设备页 / 设置页、串页显示
// 且永不清除的灰色小字（deviceActionStatus / clipboardStatus）。由 EngineController.notices 驱动。
struct NoticeOverlay: View
{
    @Environment(EngineController.self) private var engine

    var body: some View
    {
        VStack(spacing: 8)
        {
            ForEach(engine.notices)
            { notice in
                NoticeBanner(notice: notice) { engine.dismissNotice(notice.id) }
                    .transition(.move(edge: .top).combined(with: .opacity))
            }
        }
        .padding(.horizontal, 16)
        .padding(.top, 8)
        .animation(.spring(duration: 0.3), value: engine.notices)
        // 无通知时不拦截下方内容的点击；有通知时仅横幅自身（含叉按钮）可点。
        .allowsHitTesting(!engine.notices.isEmpty)
    }
}

private struct NoticeBanner: View
{
    let notice: Notice
    let onDismiss: () -> Void

    var body: some View
    {
        HStack(spacing: 10)
        {
            Image(systemName: symbol)
                .font(.headline)
                .foregroundStyle(tint)
            Text(notice.text)
                .font(.subheadline)
                .foregroundStyle(.primary)
                .lineLimit(2)
            Spacer(minLength: 8)
            Button { onDismiss() }
            label:
            {
                Image(systemName: "xmark")
                    .font(.caption.weight(.bold))
                    .foregroundStyle(.secondary)
            }
            .buttonStyle(.plain)
        }
        .padding(.vertical, 12)
        .padding(.horizontal, 14)
        .background(.regularMaterial, in: RoundedRectangle(cornerRadius: 14))
        .overlay(RoundedRectangle(cornerRadius: 14).strokeBorder(tint.opacity(0.35), lineWidth: 1))
        .shadow(color: .black.opacity(0.12), radius: 8, y: 2)
    }

    private var symbol: String
    {
        switch notice.kind
        {
        case .success: return "checkmark.circle.fill"
        case .error: return "exclamationmark.triangle.fill"
        case .info: return "info.circle.fill"
        }
    }

    private var tint: Color
    {
        switch notice.kind
        {
        case .success: return .green
        case .error: return .red
        case .info: return .cdropAccent
        }
    }
}