import ComposableArchitecture
import Dependencies
import Foundation
import LaunchAgentManager
import SwiftUI
import Toast
import UpdateChecker

#if canImport(ProHostApp)
import ProHostApp
#endif

@MainActor
let hostAppStore: StoreOf<HostApp> = .init(initialState: .init(), reducer: HostApp())

public struct TabContainer: View {
    let store: StoreOf<HostApp>
    @ObservedObject var toastController: ToastController
    @State private var tabBarItems = [TabBarItem]()
    @State var tag: Int = 0

    public init() {
        toastController = ToastControllerDependencyKey.liveValue
        store = hostAppStore
    }

    init(store: StoreOf<HostApp>, toastController: ToastController) {
        self.store = store
        self.toastController = toastController
    }

    public var body: some View {
        VStack(spacing: 0) {
            TabBar(tag: $tag, tabBarItems: tabBarItems)
                .padding(.bottom, 8)

            Divider()

            ZStack(alignment: .center) {
                GeneralView(store: store.scope(state: \.general, action: HostApp.Action.general))
                    .tabBarItem(
                        tag: 0,
                        title: "General",
                        image: "app.gift"
                    )
                ServiceView(store: store).tabBarItem(
                    tag: 1,
                    title: "Service",
                    image: "globe"
                )
                FeatureSettingsView().tabBarItem(
                    tag: 2,
                    title: "Feature",
                    image: "star.square"
                )
                CustomCommandView(store: customCommandStore).tabBarItem(
                    tag: 3,
                    title: "Custom Command",
                    image: "command.square"
                )
                #if canImport(ProHostApp)
                PlusView(onLicenseKeyChanged: {
                    store.send(.informExtensionServiceAboutLicenseKeyChange)
                }).tabBarItem(
                    tag: 5,
                    title: "Plus",
                    image: "plus.diamond"
                )
                #endif
                DebugSettingsView().tabBarItem(
                    tag: 4,
                    title: "Advanced",
                    image: "gearshape.2"
                )
            }
            .environment(\.tabBarTabTag, tag)
            .frame(minHeight: 400)
            .overlay(alignment: .bottom) {
                VStack(spacing: 4) {
                    ForEach(toastController.messages) { message in
                        message.content
                            .foregroundColor(.white)
                            .padding(8)
                            .background({
                                switch message.type {
                                case .info: return Color(nsColor: .systemIndigo)
                                case .error: return Color(nsColor: .systemRed)
                                case .warning: return Color(nsColor: .systemOrange)
                                }
                            }() as Color, in: RoundedRectangle(cornerRadius: 8))
                            .shadow(color: Color.black.opacity(0.2), radius: 4)
                    }
                }
                .padding()
                .allowsHitTesting(false)
            }
        }
        .focusable(false)
        .padding(.top, 8)
        .background(.ultraThinMaterial.opacity(0.01))
        .background(Color(nsColor: .controlBackgroundColor).opacity(0.4))
        .environment(\.toast) { [toastController] content, type in
            toastController.toast(content: content, type: type)
        }
        .onPreferenceChange(TabBarItemPreferenceKey.self) { items in
            tabBarItems = items
        }
        .onAppear {
            store.send(.appear)
        }
    }
}

struct TabBar: View {
    @Binding var tag: Int
    fileprivate var tabBarItems: [TabBarItem]

    var body: some View {
        HStack {
            ForEach(tabBarItems) { tab in
                TabBarButton(
                    currentTag: $tag,
                    tag: tab.tag,
                    title: tab.title,
                    image: tab.image
                )
            }
        }
    }
}

struct TabBarButton: View {
    @Binding var currentTag: Int
    @State var isHovered = false
    var tag: Int
    var title: String
    var image: String

    var body: some View {
        Button(action: {
            self.currentTag = tag
        }) {
            VStack(spacing: 2) {
                Image(systemName: image)
                    .resizable()
                    .scaledToFit()
                    .frame(height: 18)
                Text(title)
            }
            .font(.body)
            .padding(.horizontal, 12)
            .padding(.vertical, 4)
            .padding(.top, 4)
            .background(
                tag == currentTag
                    ? Color(nsColor: .textColor).opacity(0.1)
                    : Color.clear,
                in: RoundedRectangle(cornerRadius: 8)
            )
            .background(
                isHovered
                    ? Color(nsColor: .textColor).opacity(0.05)
                    : Color.clear,
                in: RoundedRectangle(cornerRadius: 8)
            )
        }
        .onHover(perform: { yes in
            isHovered = yes
        })
        .buttonStyle(.borderless)
    }
}

private struct TabBarTabViewWrapper<Content: View>: View {
    @Environment(\.tabBarTabTag) var tabBarTabTag
    var tag: Int
    var title: String
    var image: String
    var content: () -> Content

    var body: some View {
        Group {
            if tag == tabBarTabTag {
                content()
            } else {
                Color.clear
            }
        }
        .preference(
            key: TabBarItemPreferenceKey.self,
            value: [.init(tag: tag, title: title, image: image)]
        )
    }
}

private extension View {
    func tabBarItem(
        tag: Int,
        title: String,
        image: String
    ) -> some View {
        TabBarTabViewWrapper(
            tag: tag,
            title: title,
            image: image,
            content: { self }
        )
    }
}

private struct TabBarItem: Identifiable, Equatable {
    var id: Int { tag }
    var tag: Int
    var title: String
    var image: String
}

private struct TabBarItemPreferenceKey: PreferenceKey {
    static var defaultValue: [TabBarItem] = []
    static func reduce(value: inout [TabBarItem], nextValue: () -> [TabBarItem]) {
        value.append(contentsOf: nextValue())
    }
}

private struct TabBarTabTagKey: EnvironmentKey {
    static var defaultValue: Int = 0
}

private extension EnvironmentValues {
    var tabBarTabTag: Int {
        get { self[TabBarTabTagKey.self] }
        set { self[TabBarTabTagKey.self] = newValue }
    }
}

struct UpdateCheckerKey: EnvironmentKey {
    static var defaultValue: UpdateChecker = .init(hostBundle: nil)
}

public extension EnvironmentValues {
    var updateChecker: UpdateChecker {
        get { self[UpdateCheckerKey.self] }
        set { self[UpdateCheckerKey.self] = newValue }
    }
}

// MARK: - Previews

struct TabContainer_Previews: PreviewProvider {
    static var previews: some View {
        TabContainer()
            .frame(width: 800)
    }
}

struct TabContainer_Toasts_Previews: PreviewProvider {
    static var previews: some View {
        TabContainer(
            store: .init(initialState: .init(), reducer: HostApp()),
            toastController: .init(messages: [
                .init(id: UUID(), type: .info, content: Text("info")),
                .init(id: UUID(), type: .error, content: Text("error")),
                .init(id: UUID(), type: .warning, content: Text("warning")),
            ])
        )
        .frame(width: 800)
    }
}