import Foundation
import Libbox
import Library
import SwiftUI

public struct ActiveDashboardView: View {
    public static let NotificationUpdateSelectedProfile = Notification.Name("update-selected-profile")

    @Environment(\.scenePhase) var scenePhase
    @Environment(\.selection) private var selection

    @EnvironmentObject private var profile: ExtensionProfile

    @State private var isLoading = true
    @State private var profileList: [Profile] = []
    @State private var selectedProfileID: Int64!
    @State private var reasserting = false
    @State private var observer: Any?

    @State private var errorPresented = false
    @State private var errorMessage = ""

    public init() {}

    public var body: some View {
        viewBuilder {
            if isLoading {
                ProgressView().onAppear {
                    Task.detached {
                        await doReload()
                    }
                }
            } else {
                if profileList.isEmpty {
                    Text("Empty profiles")
                } else {
                    #if os(iOS)
                        StartStopButton()
                    #endif
                    if profile.status.isConnected {
                        Section("Status") {
                            ExtensionStatusView()
                        }
                    }
                    Section("Profile") {
                        #if os(iOS)
                            Picker(selection: $selectedProfileID) {
                                ForEach(profileList, id: \.id) { profile in
                                    Text(profile.name).tag(profile.id)
                                }
                            } label: {}
                                .pickerStyle(.inline)

                        #elseif os(macOS)
                            ForEach(profileList, id: \.id) { profile in
                                Picker(profile.name, selection: $selectedProfileID) {
                                    Text("").tag(profile.id)
                                }
                            }
                            .pickerStyle(.radioGroup)
                        #endif
                    }
                    .onChange(of: selectedProfileID) { _ in
                        reasserting = true
                        Task.detached {
                            await switchProfile(selectedProfileID!)
                        }
                    }
                    .disabled(!profile.status.isSwitchable || reasserting)
                }
            }
        }
        #if os(iOS)
        .onChange(of: scenePhase, perform: { newValue in
            if newValue == .active {
                Task.detached {
                    await doReload()
                }
            }
        })
        .onChange(of: selection.wrappedValue, perform: { newValue in
            if newValue == .dashboard {
                Task.detached {
                    await doReload()
                }
            }
        })
        #elseif os(macOS)
        .onAppear {
            if observer == nil {
                observer = NotificationCenter.default.addObserver(forName: ActiveDashboardView.NotificationUpdateSelectedProfile, object: nil, queue: nil, using: { _ in
                    Task.detached {
                        await doReload()
                    }
                })
            }
        }
        .onDisappear {
            if let observer {
                NotificationCenter.default.removeObserver(observer)
            }
        }
        #endif
    }

    private func doReload() {
        defer {
            isLoading = false
        }
        do {
            profileList = try ProfileManager.list()
        } catch {
            errorMessage = error.localizedDescription
            errorPresented = true
            return
        }
        if profileList.isEmpty {
            return
        }

        selectedProfileID = SharedPreferences.selectedProfileID
        if profileList.filter({ profile in
            profile.id == selectedProfileID
        })
        .isEmpty {
            selectedProfileID = profileList[0].id!
            SharedPreferences.selectedProfileID = selectedProfileID
        }
    }

    private func switchProfile(_ newProfileID: Int64) {
        SharedPreferences.selectedProfileID = newProfileID
        NotificationCenter.default.post(name: ActiveDashboardView.NotificationUpdateSelectedProfile, object: nil)
        if profile.status.isConnected {
            do {
                try LibboxNewStandaloneCommandClient(FilePath.sharedDirectory.relativePath)?.serviceReload()
            } catch {
                errorMessage = error.localizedDescription
                errorPresented = true
            }
        }
        reasserting = false
    }
}