import SwiftUI

struct OnboardingView: View {
    @Binding var onboardingCompleted: Bool

    @State private var currentPage = 0

    private let pages: [OnboardingPage] = [
        OnboardingPage(
            icon: "chart.pie.fill",
            title: "Track Your Investments",
            description: "Monitor all your investment sources in one place. Stocks, bonds, real estate, crypto, and more.",
            color: .appPrimary
        ),
        OnboardingPage(
            icon: "chart.line.uptrend.xyaxis",
            title: "Visualize Your Growth",
            description: "Beautiful charts show your portfolio evolution, allocation, and performance over time.",
            color: .positiveGreen
        ),
        OnboardingPage(
            icon: "bell.badge.fill",
            title: "Never Miss an Update",
            description: "Set reminders to track your investments regularly. Monthly, quarterly, or custom schedules.",
            color: .appWarning
        ),
        OnboardingPage(
            icon: "icloud.fill",
            title: "Sync Everywhere",
            description: "Your data syncs automatically via iCloud across all your Apple devices.",
            color: .appSecondary
        )
    ]

    var body: some View {
        VStack {
            // Pages
            TabView(selection: $currentPage) {
                ForEach(0..<pages.count, id: \.self) { index in
                    OnboardingPageView(page: pages[index])
                        .tag(index)
                }
            }
            .tabViewStyle(.page(indexDisplayMode: .never))
            .animation(.easeInOut, value: currentPage)

            // Page indicators
            HStack(spacing: 8) {
                ForEach(0..<pages.count, id: \.self) { index in
                    Circle()
                        .fill(currentPage == index ? Color.appPrimary : Color.gray.opacity(0.3))
                        .frame(width: 8, height: 8)
                        .animation(.easeInOut, value: currentPage)
                }
            }
            .padding(.bottom, 20)

            // Buttons
            VStack(spacing: 12) {
                if currentPage < pages.count - 1 {
                    Button {
                        withAnimation {
                            currentPage += 1
                        }
                    } label: {
                        Text("Continue")
                            .font(.headline)
                            .foregroundColor(.white)
                            .frame(maxWidth: .infinity)
                            .padding()
                            .background(Color.appPrimary)
                            .cornerRadius(AppConstants.UI.cornerRadius)
                    }

                    Button {
                        completeOnboarding()
                    } label: {
                        Text("Skip")
                            .font(.subheadline)
                            .foregroundColor(.secondary)
                    }
                } else {
                    Button {
                        completeOnboarding()
                    } label: {
                        Text("Get Started")
                            .font(.headline)
                            .foregroundColor(.white)
                            .frame(maxWidth: .infinity)
                            .padding()
                            .background(Color.appPrimary)
                            .cornerRadius(AppConstants.UI.cornerRadius)
                    }
                }
            }
            .padding(.horizontal, 24)
            .padding(.bottom, 40)
        }
        .background(Color(.systemBackground))
    }

    private func completeOnboarding() {
        // Create default categories
        let categoryRepository = CategoryRepository()
        categoryRepository.createDefaultCategoriesIfNeeded()

        // Mark onboarding as complete
        let context = CoreDataStack.shared.viewContext
        AppSettings.markOnboardingComplete(in: context)

        // Log analytics
        FirebaseService.shared.logOnboardingCompleted(stepCount: pages.count)

        // Request notification permission
        Task {
            await NotificationService.shared.requestAuthorization()
        }

        withAnimation {
            onboardingCompleted = true
        }
    }
}

// MARK: - Onboarding Page Model

struct OnboardingPage {
    let icon: String
    let title: String
    let description: String
    let color: Color
}

// MARK: - Onboarding Page View

struct OnboardingPageView: View {
    let page: OnboardingPage

    var body: some View {
        VStack(spacing: 32) {
            Spacer()

            // Icon
            ZStack {
                Circle()
                    .fill(page.color.opacity(0.15))
                    .frame(width: 140, height: 140)

                Circle()
                    .fill(page.color.opacity(0.3))
                    .frame(width: 100, height: 100)

                Image(systemName: page.icon)
                    .font(.system(size: 50))
                    .foregroundColor(page.color)
            }

            // Content
            VStack(spacing: 16) {
                Text(page.title)
                    .font(.title.weight(.bold))
                    .multilineTextAlignment(.center)

                Text(page.description)
                    .font(.body)
                    .foregroundColor(.secondary)
                    .multilineTextAlignment(.center)
                    .padding(.horizontal, 40)
            }

            Spacer()
            Spacer()
        }
    }
}

// MARK: - First Launch Welcome

struct WelcomeView: View {
    @Binding var showWelcome: Bool
    let userName: String?

    var body: some View {
        VStack(spacing: 24) {
            Spacer()

            Image(systemName: "hand.wave.fill")
                .font(.system(size: 60))
                .foregroundColor(.appPrimary)

            VStack(spacing: 8) {
                if let name = userName {
                    Text("Welcome back, \(name)!")
                        .font(.title.weight(.bold))
                } else {
                    Text("Welcome!")
                        .font(.title.weight(.bold))
                }

                Text("Your investment data has been synced from iCloud.")
                    .font(.subheadline)
                    .foregroundColor(.secondary)
                    .multilineTextAlignment(.center)
            }

            Spacer()

            Button {
                withAnimation {
                    showWelcome = false
                }
            } label: {
                Text("Continue")
                    .font(.headline)
                    .foregroundColor(.white)
                    .frame(maxWidth: .infinity)
                    .padding()
                    .background(Color.appPrimary)
                    .cornerRadius(AppConstants.UI.cornerRadius)
            }
            .padding(.horizontal, 24)
            .padding(.bottom, 40)
        }
        .background(Color(.systemBackground))
    }
}

#Preview {
    OnboardingView(onboardingCompleted: .constant(false))
}