import SwiftUI

struct AccountEditorView: View {
    @Environment(\.dismiss) private var dismiss
    @EnvironmentObject private var accountStore: AccountStore
    let account: Account?

    @State private var name = ""
    @State private var currencyCode = AppSettings.getOrCreate(in: CoreDataStack.shared.viewContext).currency
    @State private var inputMode: InputMode = .simple
    @State private var notificationFrequency: NotificationFrequency = .monthly
    @State private var customFrequencyMonths = 1

    private let accountRepository = AccountRepository()

    var body: some View {
        NavigationStack {
            Form {
                Section {
                    TextField("Account name", text: $name)
                    Picker("Currency", selection: $currencyCode) {
                        ForEach(CurrencyPicker.commonCodes, id: \.self) { code in
                            Text(code).tag(code)
                        }
                    }
                } header: {
                    Text("Account")
                }

                Section {
                    Picker("Input Mode", selection: $inputMode) {
                        ForEach(InputMode.allCases) { mode in
                            Text(mode.title).tag(mode)
                        }
                    }
                } header: {
                    Text("Input")
                } footer: {
                    Text(inputMode.description)
                }

                Section {
                    Picker("Reminder Frequency", selection: $notificationFrequency) {
                        ForEach(NotificationFrequency.allCases) { frequency in
                            Text(frequency.displayName).tag(frequency)
                        }
                    }

                    if notificationFrequency == .custom {
                        Stepper(
                            "Every \(customFrequencyMonths) month\(customFrequencyMonths > 1 ? "s" : "")",
                            value: $customFrequencyMonths,
                            in: 1...24
                        )
                    }
                } header: {
                    Text("Account Reminders")
                } footer: {
                    Text("Reminders apply to the whole account.")
                }
            }
            .navigationTitle(account == nil ? "New Account" : "Edit Account")
            .navigationBarTitleDisplayMode(.inline)
            .toolbar {
                ToolbarItem(placement: .navigationBarLeading) {
                    Button("Cancel") { dismiss() }
                }
                ToolbarItem(placement: .navigationBarTrailing) {
                    Button("Save") { saveAccount() }
                        .disabled(!isValid)
                }
            }
            .onAppear {
                loadAccount()
            }
        }
        .presentationDetents([.large])
    }

    private var isValid: Bool {
        !name.trimmingCharacters(in: .whitespaces).isEmpty
    }

    private func loadAccount() {
        guard let account else { return }
        name = account.name
        currencyCode = account.currencyCode ?? currencyCode
        inputMode = InputMode(rawValue: account.inputMode) ?? .simple
        notificationFrequency = account.frequency
        customFrequencyMonths = Int(account.customFrequencyMonths)
    }

    private func saveAccount() {
        if let account {
            accountRepository.updateAccount(
                account,
                name: name.trimmingCharacters(in: .whitespaces),
                currency: currencyCode,
                inputMode: inputMode,
                notificationFrequency: notificationFrequency,
                customFrequencyMonths: customFrequencyMonths
            )
        } else {
            _ = accountRepository.createAccount(
                name: name.trimmingCharacters(in: .whitespaces),
                currency: currencyCode,
                inputMode: inputMode,
                notificationFrequency: notificationFrequency,
                customFrequencyMonths: customFrequencyMonths
            )
        }

        accountStore.persistSelection()
        dismiss()
    }
}

#Preview {
    AccountEditorView(account: nil)
        .environmentObject(AccountStore(iapService: IAPService()))
}