//
// Swiftfin is subject to the terms of the Mozilla Public
// License, v2.0. If a copy of the MPL was not distributed with this
// file, you can obtain one at https://mozilla.org/MPL/2.0/.
//
// Copyright (c) 2025 Jellyfin & Jellyfin Contributors
//

import Combine
import Defaults
import SwiftUI

struct ConnectToXtreamView: View {

    // MARK: - Defaults

    @Default(.accentColor)
    private var accentColor

    @Default(.xtreamServers)
    private var savedServers

    // MARK: - Focus Fields

    @FocusState
    private var focusedField: Field?

    enum Field {
        case name
        case url
        case username
        case password
    }

    // MARK: - State & Environment Objects

    @EnvironmentObject
    private var router: SelectUserCoordinator.Router

    @StateObject
    private var viewModel = ConnectToXtreamViewModel()

    // MARK: - Connect to Xtream Variables

    @State
    private var name: String = ""
    @State
    private var url: String = ""
    @State
    private var username: String = ""
    @State
    private var password: String = ""

    // MARK: - Error States

    @State
    private var error: Error? = nil

    // MARK: - Connect Section

    @ViewBuilder
    private var connectSection: some View {
        TextField(L10n.name, text: $name)
            .disableAutocorrection(true)
            .textInputAutocapitalization(.words)
            .focused($focusedField, equals: .name)

        TextField("Server URL", text: $url)
            .disableAutocorrection(true)
            .textInputAutocapitalization(.never)
            .keyboardType(.URL)
            .focused($focusedField, equals: .url)

        TextField("Username", text: $username)
            .disableAutocorrection(true)
            .textInputAutocapitalization(.never)
            .focused($focusedField, equals: .username)

        SecureField("Password", text: $password)
            .focused($focusedField, equals: .password)

        if viewModel.state == .connecting || viewModel.state == .testing {
            ListRowButton(L10n.cancel) {
                viewModel.send(.cancel)
            }
            .foregroundStyle(.red, accentColor)
            .padding(.vertical)
        } else {
            ListRowButton(L10n.connect) {
                focusedField = nil
                viewModel.send(.connect(name: name, url: url, username: username, password: password))
            }
            .disabled(url.isEmpty || username.isEmpty || password.isEmpty)
            .foregroundStyle(
                accentColor.overlayColor,
                (url.isEmpty || username.isEmpty || password.isEmpty) ? Color.white.opacity(0.5) : accentColor
            )
            .opacity((url.isEmpty || username.isEmpty || password.isEmpty) ? 0.5 : 1)
            .padding(.vertical)
        }
    }

    // MARK: - Saved Servers Section

    @ViewBuilder
    private var savedServersSection: some View {
        if savedServers.isEmpty {
            Text("No saved Xtream servers")
                .font(.callout)
                .foregroundColor(.secondary)
                .frame(maxWidth: .infinity)
        } else {
            LazyVGrid(
                columns: Array(repeating: GridItem(.flexible()), count: 1),
                spacing: 30
            ) {
                ForEach(savedServers) { server in
                    XtreamServerButton(server: server) {
                        // Select this server
                        Defaults[.currentXtreamServerID] = server.id
                        router.popLast()
                    }
                    .environment(
                        \.isEnabled,
                        viewModel.state != .connecting && viewModel.state != .testing
                    )
                }
            }
        }
    }

    // MARK: - Body

    var body: some View {
        SplitLoginWindowView(
            isLoading: viewModel.state == .connecting || viewModel.state == .testing,
            leadingTitle: "Connect to Xtream Server",
            trailingTitle: "Saved Servers"
        ) {
            connectSection
        } trailingContentView: {
            savedServersSection
        }
        .onFirstAppear {
            focusedField = .url
        }
        .onReceive(viewModel.events) { event in
            switch event {
            case let .connected(server):
                viewModel.saveServer(server)
                Defaults[.currentXtreamServerID] = server.id
                router.popLast()
            case let .error(eventError):
                error = eventError
                focusedField = .url
            }
        }
        .errorMessage($error)
    }
}

// MARK: - Xtream Server Button

struct XtreamServerButton: View {

    @Default(.accentColor)
    private var accentColor

    let server: XtreamServer
    let action: () -> Void

    @Environment(\.isEnabled)
    private var isEnabled

    var body: some View {
        Button {
            action()
        } label: {
            HStack {
                VStack(alignment: .leading, spacing: 8) {
                    Text(server.name)
                        .font(.headline)
                        .foregroundColor(.primary)

                    Text(server.url.absoluteString)
                        .font(.subheadline)
                        .foregroundColor(.secondary)
                        .lineLimit(1)

                    Text("User: \(server.username)")
                        .font(.caption)
                        .foregroundColor(.secondary)
                }

                Spacer()

                Image(systemName: "tv")
                    .font(.title)
                    .foregroundColor(accentColor)
            }
            .padding()
            .background(Color.gray.opacity(0.2))
            .cornerRadius(10)
        }
        .buttonStyle(.card)
        .disabled(!isEnabled)
        .opacity(isEnabled ? 1 : 0.5)
    }
}