//
//  PlanSettingsView.swift
//  Bible-Week
//
//  Configurações do Plano de 180 Dias: lembrete diário (horário, som),
//  pausar/continuar e reiniciar.
//

import SwiftUI
import UserNotifications

struct PlanSettingsView: View {
    @Bindable var plan: ReadingPlanState
    @Environment(\.dismiss) private var dismiss

    @State private var authorizationStatus: UNAuthorizationStatus = .notDetermined
    @State private var showRestartConfirmation = false

    var body: some View {
        NavigationStack {
            Form {
                remindersSection
                planSection
            }
            .navigationTitle("Plano de Leitura")
            .navigationBarTitleDisplayMode(.inline)
            .toolbar {
                ToolbarItem(placement: .confirmationAction) {
                    Button("OK") { dismiss() }
                }
            }
            .task {
                authorizationStatus = await ReadingReminderService.authorizationStatus()
            }
            .confirmationDialog(
                "Reiniciar o plano do dia 1? Seu progresso atual será apagado, mas a preferência de lembrete será mantida.",
                isPresented: $showRestartConfirmation,
                titleVisibility: .visible
            ) {
                Button("Reiniciar plano", role: .destructive) {
                    plan.restart()
                    Task { await ReadingReminderService.refresh(for: plan) }
                }
            }
        }
    }

    // MARK: - Lembretes

    @ViewBuilder
    private var remindersSection: some View {
        Section("Lembretes") {
            if authorizationStatus == .denied {
                VStack(alignment: .leading, spacing: 8) {
                    Text("Notificações desativadas")
                        .font(.headline)
                    Text("Para receber lembretes de leitura, habilite as notificações nos Ajustes do iPhone.")
                        .font(.caption)
                        .foregroundStyle(.secondary)
                    Button("Abrir Ajustes") {
                        openNotificationSettings()
                    }
                }
                .padding(.vertical, 4)
            } else {
                Toggle("Lembrete diário", isOn: reminderEnabledBinding)
                if plan.reminderEnabled {
                    DatePicker(
                        "Horário",
                        selection: reminderTimeBinding,
                        displayedComponents: .hourAndMinute
                    )
                    Toggle("Som", isOn: soundEnabledBinding)
                }
            }
        }
        .accessibilityElement(children: .contain)
    }

    /// Ligar pede autorização se necessário; desligar cancela o agendamento.
    private var reminderEnabledBinding: Binding<Bool> {
        Binding {
            plan.reminderEnabled
        } set: { newValue in
            if newValue {
                Task {
                    let status = await ReadingReminderService.authorizationStatus()
                    var granted = status == .authorized || status == .provisional
                    if status == .notDetermined {
                        granted = (try? await ReadingReminderService.requestAuthorization()) ?? false
                    }
                    if granted {
                        plan.reminderEnabled = true
                        await ReadingReminderService.refresh(for: plan)
                    } else {
                        plan.reminderEnabled = false
                        authorizationStatus = .denied
                    }
                }
            } else {
                plan.reminderEnabled = false
                ReadingReminderService.cancelDailyReminder()
            }
        }
    }

    /// Alterar o horário substitui o agendamento anterior (mesmo identificador,
    /// nunca duplica) e persiste o novo valor.
    private var reminderTimeBinding: Binding<Date> {
        Binding {
            Calendar.current.date(
                bySettingHour: plan.reminderHour,
                minute: plan.reminderMinute,
                second: 0,
                of: .now
            ) ?? .now
        } set: { newValue in
            let components = Calendar.current.dateComponents([.hour, .minute], from: newValue)
            plan.reminderHour = components.hour ?? 20
            plan.reminderMinute = components.minute ?? 0
            Task { await ReadingReminderService.refresh(for: plan) }
        }
    }

    private var soundEnabledBinding: Binding<Bool> {
        Binding {
            plan.reminderSoundEnabled
        } set: { newValue in
            plan.reminderSoundEnabled = newValue
            Task { await ReadingReminderService.refresh(for: plan) }
        }
    }

    // MARK: - Plano

    private var planSection: some View {
        Section("Plano") {
            LabeledContent("Progresso", value: "\(plan.completedDaysCount) de \(PlanSchedule.totalDays) dias")
            Button(plan.isPaused ? "Continuar plano" : "Pausar plano") {
                plan.isPaused.toggle()
                // Pausar remove o agendamento sem apagar a preferência;
                // continuar restaura automaticamente o horário salvo.
                Task { await ReadingReminderService.refresh(for: plan) }
            }
            Button("Reiniciar plano", role: .destructive) {
                showRestartConfirmation = true
            }
        }
    }
}