import SwiftUI

struct RootCanvas: View {
    @EnvironmentObject private var appModel: NodeAppModel
    @EnvironmentObject private var voiceWake: VoiceWakeManager
    @AppStorage(VoiceWakePreferences.enabledKey) private var voiceWakeEnabled: Bool = false
    @State private var presentedSheet: PresentedSheet?
    @State private var voiceWakeToastText: String?
    @State private var toastDismissTask: Task<Void, Never>?

    private enum PresentedSheet: Identifiable {
        case settings
        case chat

        var id: Int {
            switch self {
            case .settings: 0
            case .chat: 1
            }
        }
    }

    var body: some View {
        ZStack(alignment: .topTrailing) {
            ScreenTab()

            VStack(spacing: 10) {
                OverlayButton(systemImage: "text.bubble.fill") {
                    self.presentedSheet = .chat
                }
                .accessibilityLabel("Chat")

                OverlayButton(systemImage: "gearshape.fill") {
                    self.presentedSheet = .settings
                }
                .accessibilityLabel("Settings")
            }
            .padding(.top, 10)
            .padding(.trailing, 10)
        }
        .overlay(alignment: .topLeading) {
            StatusPill(
                bridge: self.bridgeStatus,
                voiceWakeEnabled: self.voiceWakeEnabled,
                onTap: { self.presentedSheet = .settings })
                .padding(.leading, 10)
                .safeAreaPadding(.top, 10)
        }
        .overlay(alignment: .topLeading) {
            if let voiceWakeToastText, !voiceWakeToastText.isEmpty {
                VoiceWakeToast(command: voiceWakeToastText)
                    .padding(.leading, 10)
                    .safeAreaPadding(.top, 58)
                    .transition(.move(edge: .top).combined(with: .opacity))
            }
        }
        .sheet(item: self.$presentedSheet) { sheet in
            switch sheet {
            case .settings:
                SettingsTab()
            case .chat:
                ChatSheet(bridge: self.appModel.bridgeSession)
            }
        }
        .preferredColorScheme(.dark)
        .onChange(of: self.voiceWake.lastTriggeredCommand) { _, newValue in
            guard let newValue else { return }
            let trimmed = newValue.trimmingCharacters(in: .whitespacesAndNewlines)
            guard !trimmed.isEmpty else { return }

            self.toastDismissTask?.cancel()
            withAnimation(.spring(response: 0.25, dampingFraction: 0.85)) {
                self.voiceWakeToastText = trimmed
            }

            self.toastDismissTask = Task {
                try? await Task.sleep(nanoseconds: 2_300_000_000)
                await MainActor.run {
                    withAnimation(.easeOut(duration: 0.25)) {
                        self.voiceWakeToastText = nil
                    }
                }
            }
        }
        .onDisappear {
            self.toastDismissTask?.cancel()
            self.toastDismissTask = nil
        }
    }

    private var bridgeStatus: StatusPill.BridgeState {
        if self.appModel.bridgeServerName != nil { return .connected }

        let text = self.appModel.bridgeStatusText.trimmingCharacters(in: .whitespacesAndNewlines)
        if text.localizedCaseInsensitiveContains("connecting") ||
            text.localizedCaseInsensitiveContains("reconnecting")
        {
            return .connecting
        }

        if text.localizedCaseInsensitiveContains("error") {
            return .error
        }

        return .disconnected
    }
}

private struct OverlayButton: View {
    let systemImage: String
    let action: () -> Void

    var body: some View {
        Button(action: self.action) {
            Image(systemName: self.systemImage)
                .font(.system(size: 16, weight: .semibold))
                .foregroundStyle(.primary)
                .padding(10)
                .background {
                    RoundedRectangle(cornerRadius: 12, style: .continuous)
                        .fill(.ultraThinMaterial)
                        .overlay {
                            RoundedRectangle(cornerRadius: 12, style: .continuous)
                                .fill(
                                    LinearGradient(
                                        colors: [
                                            .white.opacity(0.18),
                                            .white.opacity(0.04),
                                            .clear,
                                        ],
                                        startPoint: .topLeading,
                                        endPoint: .bottomTrailing))
                                .blendMode(.overlay)
                        }
                        .overlay {
                            RoundedRectangle(cornerRadius: 12, style: .continuous)
                                .strokeBorder(.white.opacity(0.18), lineWidth: 0.5)
                        }
                        .shadow(color: .black.opacity(0.35), radius: 12, y: 6)
                }
        }
        .buttonStyle(.plain)
    }
}