//
//  ProfileView.swift
//  Passepartout
//
//  Created by Davide De Rosa on 10/31/24.
//  Copyright (c) 2024 Davide De Rosa. All rights reserved.
//
//  https://github.com/passepartoutvpn
//
//  This file is part of Passepartout.
//
//  Passepartout is free software: you can redistribute it and/or modify
//  it under the terms of the GNU General Public License as published by
//  the Free Software Foundation, either version 3 of the License, or
//  (at your option) any later version.
//
//  Passepartout is distributed in the hope that it will be useful,
//  but WITHOUT ANY WARRANTY; without even the implied warranty of
//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//  GNU General Public License for more details.
//
//  You should have received a copy of the GNU General Public License
//  along with Passepartout.  If not, see <http://www.gnu.org/licenses/>.
//

import AppLibrary
import CommonUtils
import PassepartoutKit
import SwiftUI
import UILibrary

// FIXME: #788, UI for TV

struct ProfileView: View, TunnelInstallationProviding {
    enum Field: Hashable {
        case connect

        case switchProfile

        case profile(Profile.ID)
    }

    @EnvironmentObject
    private var theme: Theme

    @ObservedObject
    var profileManager: ProfileManager

    @ObservedObject
    var tunnel: ExtendedTunnel

    @State
    private var isSwitching = false

    @FocusState
    private var focusedField: Field?

    @StateObject
    private var interactiveManager = InteractiveManager()

    @StateObject
    private var errorHandler: ErrorHandler = .default()

    var body: some View {
        GeometryReader { geo in
            HStack(spacing: .zero) {
                VStack {
                    activeView
                        .padding(.horizontal)
                        .frame(width: geo.size.width * 0.5)
                        .focusSection()
                }
                .frame(maxWidth: .infinity)
                .disabled(interactiveManager.isPresented)

                if isSwitching {
                    ZStack {
                        listView
                            .padding(.horizontal)
                            .opacity(interactiveManager.isPresented ? 0.0 : 1.0)

                        if interactiveManager.isPresented {
                            interactiveView
                                .padding(.horizontal, 100)
                        }
                    }
//                    .frame(width: geo.size.width * 0.5) // seems redundant
                    .focusSection()
                }
            }
        }
        .ignoresSafeArea(edges: .horizontal)
        .background(theme.primaryColor.gradient)
        .animation(.default, value: isSwitching)
        .withErrorHandler(errorHandler)
        .defaultFocus($focusedField, .switchProfile)
        .onChange(of: tunnel.status) { _, new in
            if new == .activating {
                isSwitching = false
                focusedField = .connect
            }
        }
        .onChange(of: tunnel.currentProfile) { _, new in
            if focusedField == .connect && new == nil {
                focusedField = .switchProfile
            }
        }
        .onChange(of: focusedField) { _, new in
            switch new {
            case .connect:
                isSwitching = false

            case .switchProfile:
                isSwitching = true

            default:
                break
            }
        }
    }
}

private extension ProfileView {
    var currentProfile: Profile? {
        guard let id = tunnel.currentProfile?.id else {
            return nil
        }
        return profileManager.profile(withId: id)
    }

    var activeView: some View {
        ActiveProfileView(
            profile: currentProfile,
            tunnel: tunnel,
            isSwitching: $isSwitching,
            focusedField: $focusedField,
            interactiveManager: interactiveManager,
            errorHandler: errorHandler
        )
    }

    var interactiveView: some View {
        InteractiveCoordinator(style: .inline(withCancel: false), manager: interactiveManager) {
            errorHandler.handle(
                $0,
                title: Strings.Global.connection,
                message: Strings.Views.Profiles.Errors.tunnel
            )
        }
        .font(.body)
        .onExitCommand {
            let formerProfileId = interactiveManager.editor.profile.id
            focusedField = .profile(formerProfileId)
            interactiveManager.isPresented = false
        }
    }

    var listView: some View {
        ProfileListView(
            profileManager: profileManager,
            tunnel: tunnel,
            focusedField: $focusedField,
            interactiveManager: interactiveManager,
            errorHandler: errorHandler
        )
    }
}

#Preview {
    ProfileView(
        profileManager: .mock,
        tunnel: .mock
    )
}