import SwiftUI

struct BlockedUsersView: View {
    @State private var blockedUsers: [BlockedUser] = []

    var body: some View {
        List {
            if blockedUsers.isEmpty {
                emptyState
            } else {
                Section(header: Text(NSLocalizedString("Заблокированные", comment: ""))) {
                    ForEach(blockedUsers) { user in
                        HStack(spacing: 12) {
                            Circle()
                                .fill(Color.accentColor.opacity(0.15))
                                .frame(width: 44, height: 44)
                                .overlay(
                                    Text(user.initials)
                                        .font(.headline)
                                        .foregroundColor(.accentColor)
                                )
                            VStack(alignment: .leading, spacing: 4) {
                                Text(user.displayName)
                                    .font(.body)
                                if let handle = user.handle {
                                    Text(handle)
                                        .font(.caption)
                                        .foregroundColor(.secondary)
                                }
                            }
                            Spacer()
                            Button(role: .destructive) {
                                unblock(user)
                            } label: {
                                Text(NSLocalizedString("Разблокировать", comment: ""))
                            }
                            .buttonStyle(.borderless)
                        }
                        .padding(.vertical, 4)
                    }
                }
            }
        }
        .navigationTitle(NSLocalizedString("Заблокированные", comment: ""))
        .navigationBarTitleDisplayMode(.inline)
        .task {
            await loadBlockedUsers()
        }
    }

    private var emptyState: some View {
        VStack(spacing: 12) {
            Image(systemName: "hand.raised")
                .font(.system(size: 48))
                .foregroundColor(.secondary)
            Text(NSLocalizedString("У вас нет заблокированных пользователей", comment: ""))
                .font(.headline)
                .multilineTextAlignment(.center)
//            Text(NSLocalizedString("Заблокируйте аккаунт, чтобы скрыть его сообщения и взаимодействия", comment: ""))
//                .font(.subheadline)
//                .foregroundColor(.secondary)
//                .multilineTextAlignment(.center)
        }
        .frame(maxWidth: .infinity, alignment: .center)
        .padding(.vertical, 32)
        .listRowInsets(EdgeInsets(top: 16, leading: 16, bottom: 16, trailing: 16))
        .listRowSeparator(.hidden)
    }

    private func loadBlockedUsers() async {
        // TODO: integrate with real data source once available
    }

    private func unblock(_ user: BlockedUser) {
        // TODO: implement unblock logic when backend is ready
        blockedUsers.removeAll { $0.id == user.id }
    }
}

private struct BlockedUser: Identifiable, Equatable {
    let id: UUID
    let displayName: String
    let handle: String?

    var initials: String {
        let components = displayName.split(separator: " ")
        let nameInitials = components.prefix(2).compactMap { $0.first }
        if !nameInitials.isEmpty {
            return nameInitials
                .map { String($0).uppercased() }
                .joined()
        }

        if let handle {
            let filtered = handle.filter { $0.isLetter }.prefix(2)
            if !filtered.isEmpty {
                return filtered.uppercased()
            }
        }

        return "??"
    }
}