import SwiftUI

struct AddTransactionView: View {
    @Binding var isPresented: Bool
    @EnvironmentObject var authManager: AuthManager
    let categories: [FinanceCategory]
    let onAdded: () async -> Void
    
    @State private var amount = ""
    @State private var description = ""
    @State private var type = "expense"
    @State private var selectedCategoryId: Int? = nil
    @State private var isLoading = false
    
    var filteredCategories: [FinanceCategory] { categories.filter { $0.type == type } }
    var isExpense: Bool { type == "expense" }
    
    var body: some View {
        ZStack {
            Color(hex: "0a0a1a").ignoresSafeArea()
            
            VStack(spacing: 0) {
                // Handle
                RoundedRectangle(cornerRadius: 3)
                    .fill(Color.white.opacity(0.2))
                    .frame(width: 40, height: 4)
                    .padding(.top, 12)
                
                // Header
                HStack {
                    Button("Отмена") { isPresented = false }.foregroundColor(Color(hex: "8888aa"))
                    Spacer()
                    Text("Новая операция").font(.headline).foregroundColor(.white)
                    Spacer()
                    Button(action: save) {
                        if isLoading { ProgressView().tint(Color(hex: "00d4aa")).scaleEffect(0.8) }
                        else { Text("Добавить").foregroundColor(amount.isEmpty ? Color(hex: "8888aa") : Color(hex: "00d4aa")).fontWeight(.semibold) }
                    }.disabled(amount.isEmpty || isLoading)
                }
                .padding(.horizontal, 20).padding(.vertical, 16)
                
                Divider().background(Color.white.opacity(0.1))
                
                ScrollView {
                    VStack(spacing: 20) {
                        // Type toggle
                        HStack(spacing: 0) {
                            Button(action: { type = "expense" }) {
                                Text("Расход")
                                    .font(.callout.bold())
                                    .foregroundColor(isExpense ? .black : Color(hex: "ff4757"))
                                    .frame(maxWidth: .infinity).padding(.vertical, 12)
                                    .background(isExpense ? Color(hex: "ff4757") : Color.clear)
                            }
                            Button(action: { type = "income" }) {
                                Text("Доход")
                                    .font(.callout.bold())
                                    .foregroundColor(!isExpense ? .black : Color(hex: "00d4aa"))
                                    .frame(maxWidth: .infinity).padding(.vertical, 12)
                                    .background(!isExpense ? Color(hex: "00d4aa") : Color.clear)
                            }
                        }
                        .background(Color.white.opacity(0.07))
                        .cornerRadius(12)
                        
                        // Amount
                        VStack(spacing: 8) {
                            Text(isExpense ? "Сумма расхода" : "Сумма дохода")
                                .font(.caption).foregroundColor(Color(hex: "8888aa"))
                            HStack {
                                Text(isExpense ? "−" : "+")
                                    .font(.title.bold())
                                    .foregroundColor(isExpense ? Color(hex: "ff4757") : Color(hex: "00d4aa"))
                                TextField("0", text: $amount)
                                    .keyboardType(.decimalPad)
                                    .font(.system(size: 36, weight: .bold))
                                    .foregroundColor(.white)
                                    .multilineTextAlignment(.center)
                                Text("₽")
                                    .font(.title.bold())
                                    .foregroundColor(Color(hex: "8888aa"))
                            }
                            .padding(20)
                            .background(RoundedRectangle(cornerRadius: 16).fill(Color.white.opacity(0.07)))
                        }
                        
                        // Description
                        VStack(alignment: .leading, spacing: 8) {
                            Label("Описание", systemImage: "text.alignleft").font(.caption).foregroundColor(Color(hex: "8888aa"))
                            TextField("Комментарий...", text: $description)
                                .foregroundColor(.white).padding(14)
                                .background(RoundedRectangle(cornerRadius: 12).fill(Color.white.opacity(0.07)))
                        }
                        
                        // Categories
                        if !filteredCategories.isEmpty {
                            VStack(alignment: .leading, spacing: 8) {
                                Label("Категория", systemImage: "tag.fill").font(.caption).foregroundColor(Color(hex: "8888aa"))
                                LazyVGrid(columns: [GridItem(.adaptive(minimum: 100))], spacing: 8) {
                                    ForEach(filteredCategories) { cat in
                                        Button(action: { selectedCategoryId = selectedCategoryId == cat.id ? nil : cat.id }) {
                                            HStack(spacing: 6) {
                                                Text(cat.icon ?? "").font(.callout)
                                                Text(cat.name).font(.caption).lineLimit(1)
                                            }
                                            .foregroundColor(selectedCategoryId == cat.id ? .black : .white)
                                            .padding(.horizontal, 10).padding(.vertical, 8)
                                            .frame(maxWidth: .infinity)
                                            .background(
                                                RoundedRectangle(cornerRadius: 10)
                                                    .fill(selectedCategoryId == cat.id ? Color(hex: "00d4aa") : Color.white.opacity(0.07))
                                            )
                                        }
                                    }
                                }
                            }
                        }
                    }
                    .padding(20)
                }
            }
        }
    }
    
    func save() {
        guard let a = Double(amount.replacingOccurrences(of: ",", with: ".")) else { return }
        isLoading = true
        Task {
            let req = CreateTransactionRequest(amount: a, categoryId: selectedCategoryId, description: description.isEmpty ? nil : description, type: type)
            try? await APIService.shared.createTransaction(token: authManager.token, request: req)
            await onAdded()
            await MainActor.run { isPresented = false }
        }
    }
}