//
//  RulesHelpView.swift
//  Blackjack
//
//  Game rules and how to play guide.
//

import SwiftUI
import CasinoKit

struct RulesHelpView: View {
    @Environment(\.dismiss) private var dismiss
    @State private var currentPage = 0
    
    private let pages: [RulePage] = [
        RulePage(
            title: String(localized: "Objective"),
            icon: "target",
            content: [
                String(localized: "Beat the dealer by getting a hand value closer to 21 without going over."),
                String(localized: "If you go over 21, you 'bust' and lose immediately."),
                String(localized: "If the dealer busts and you haven't, you win.")
            ]
        ),
        RulePage(
            title: String(localized: "Card Values"),
            icon: "suit.spade.fill",
            content: [
                String(localized: "2-10: Face value"),
                String(localized: "Jack, Queen, King: 10"),
                String(localized: "Ace: 1 or 11 (whichever helps your hand)"),
                String(localized: "A 'soft' hand has an Ace counting as 11.")
            ]
        ),
        RulePage(
            title: String(localized: "Blackjack"),
            icon: "star.fill",
            content: [
                String(localized: "An Ace + 10-value card dealt initially is 'Blackjack'."),
                String(localized: "Blackjack pays 3:2 (1.5x your bet)."),
                String(localized: "If both you and dealer have Blackjack, it's a push (tie).")
            ]
        ),
        RulePage(
            title: String(localized: "Actions"),
            icon: "hand.tap.fill",
            content: [
                String(localized: "Hit: Take another card"),
                String(localized: "Stand: Keep your current hand"),
                String(localized: "Double Down: Double your bet, take one card, then stand"),
                String(localized: "Split: If you have two cards of the same value, split into two hands"),
                String(localized: "Surrender: Give up half your bet and end the hand")
            ]
        ),
        RulePage(
            title: String(localized: "Insurance"),
            icon: "shield.fill",
            content: [
                String(localized: "Offered when dealer shows an Ace."),
                String(localized: "Costs half your original bet."),
                String(localized: "Pays 2:1 if dealer has Blackjack."),
                String(localized: "Generally not recommended by basic strategy.")
            ]
        ),
        RulePage(
            title: String(localized: "Dealer Rules"),
            icon: "person.fill",
            content: [
                String(localized: "Dealer must hit on 16 or less."),
                String(localized: "Dealer must stand on 17 or more (varies by rules)."),
                String(localized: "Some games: Dealer hits on 'soft 17' (Ace + 6).")
            ]
        ),
        RulePage(
            title: String(localized: "Payouts"),
            icon: "dollarsign.circle.fill",
            content: [
                String(localized: "Win: 1:1 (even money)"),
                String(localized: "Blackjack: 3:2"),
                String(localized: "Insurance: 2:1"),
                String(localized: "Push: Bet returned"),
                String(localized: "Surrender: Half bet returned")
            ]
        ),
        RulePage(
            title: String(localized: "Vegas Strip"),
            icon: "sparkles",
            content: [
                String(localized: "Most popular style on the Las Vegas Strip."),
                String(localized: "6 decks shuffled together."),
                String(localized: "Dealer stands on all 17s (including soft 17)."),
                String(localized: "Double down allowed on any two cards."),
                String(localized: "Double after split (DAS) allowed."),
                String(localized: "Split up to 4 hands, but not aces."),
                String(localized: "No surrender option."),
                String(localized: "Blackjack pays 3:2.")
            ]
        ),
        RulePage(
            title: String(localized: "Atlantic City"),
            icon: "building.2.fill",
            content: [
                String(localized: "Standard rules on the East Coast."),
                String(localized: "8 decks shuffled together."),
                String(localized: "Dealer stands on all 17s."),
                String(localized: "Double down on any two cards."),
                String(localized: "Double after split allowed."),
                String(localized: "Re-split aces allowed."),
                String(localized: "Late surrender available."),
                String(localized: "Blackjack pays 3:2.")
            ]
        ),
        RulePage(
            title: String(localized: "European"),
            icon: "globe.europe.africa.fill",
            content: [
                String(localized: "Traditional European casino style."),
                String(localized: "6 decks shuffled together."),
                String(localized: "No hole card: dealer takes second card after player acts."),
                String(localized: "Dealer stands on all 17s."),
                String(localized: "Double on 9, 10, or 11 only (some venues)."),
                String(localized: "Double after split allowed."),
                String(localized: "No surrender option."),
                String(localized: "Higher house edge due to no hole card.")
            ]
        ),
        RulePage(
            title: String(localized: "Deck Count"),
            icon: "rectangle.stack.fill",
            content: [
                String(localized: "1 Deck: Lowest house edge (~0.17%), rare to find."),
                String(localized: "2 Decks: Low house edge (~0.35%), common online."),
                String(localized: "4 Decks: Moderate house edge (~0.45%)."),
                String(localized: "6 Decks: Standard in Vegas (~0.50%)."),
                String(localized: "8 Decks: Standard in Atlantic City (~0.55%)."),
                String(localized: "More decks = harder to count cards."),
                String(localized: "Fewer decks favor the player slightly.")
            ]
        ),
        RulePage(
            title: String(localized: "Rule Variations"),
            icon: "slider.horizontal.3",
            content: [
                String(localized: "Dealer Hits Soft 17: Increases house edge by ~0.2%."),
                String(localized: "Double After Split (DAS): Reduces house edge by ~0.15%."),
                String(localized: "Re-split Aces: Reduces house edge by ~0.05%."),
                String(localized: "Late Surrender: Reduces house edge by ~0.07%."),
                String(localized: "6:5 Blackjack (avoid!): Increases house edge by ~1.4%.")
            ]
        ),
        RulePage(
            title: String(localized: "Basic Strategy"),
            icon: "lightbulb.fill",
            content: [
                String(localized: "Always split Aces and 8s."),
                String(localized: "Never split 10s or 5s."),
                String(localized: "Double on 11 vs dealer 2-10."),
                String(localized: "Double on 10 vs dealer 2-9."),
                String(localized: "Stand on 17+ always."),
                String(localized: "Hit on soft 17 or less."),
                String(localized: "Surrender 16 vs dealer 9, 10, Ace.")
            ]
        ),
        RulePage(
            title: String(localized: "Card Counting"),
            icon: "number.circle.fill",
            content: [
                String(localized: "Hi-Lo is the most popular counting system."),
                String(localized: "2-6: +1 (low cards favor house)"),
                String(localized: "7-9: 0 (neutral cards)"),
                String(localized: "10-A: -1 (high cards favor player)"),
                String(localized: "Running Count: Sum of all card values seen."),
                String(localized: "True Count: Running count ÷ decks remaining."),
                String(localized: "Positive count = more high cards remain = player advantage.")
            ]
        ),
        RulePage(
            title: String(localized: "Using the Count"),
            icon: "chart.line.uptrend.xyaxis",
            content: [
                String(localized: "True count of +2 or higher favors the player."),
                String(localized: "Increase bets when the count is positive."),
                String(localized: "Decrease bets when the count is negative."),
                String(localized: "Fewer decks = easier to count accurately."),
                String(localized: "Count resets to 0 when the shoe is shuffled."),
                String(localized: "Enable 'Card Count' in Settings to practice.")
            ]
        )
    ]
    
    var body: some View {
        NavigationStack {
            ZStack {
                Color.Settings.background
                    .ignoresSafeArea()
                
                VStack(spacing: 0) {
                    // Page content
                    TabView(selection: $currentPage) {
                        ForEach(pages.indices, id: \.self) { index in
                            RulePageView(page: pages[index])
                                .tag(index)
                        }
                    }
                    .tabViewStyle(.page(indexDisplayMode: .never))
                    
                    // Page indicator
                    HStack(spacing: Design.Spacing.small) {
                        ForEach(pages.indices, id: \.self) { index in
                            Circle()
                                .fill(index == currentPage ? Color.Settings.accent : Color.white.opacity(Design.Opacity.light))
                                .frame(width: 8, height: 8)
                        }
                    }
                    .padding(.vertical, Design.Spacing.medium)
                }
            }
            .navigationTitle(String(localized: "How to Play"))
            .navigationBarTitleDisplayMode(.inline)
            .toolbar {
                ToolbarItem(placement: .topBarTrailing) {
                    Button(String(localized: "Done")) {
                        dismiss()
                    }
                    .foregroundStyle(Color.Settings.accent)
                }
            }
            .toolbarBackground(Color.Settings.background, for: .navigationBar)
            .toolbarColorScheme(.dark, for: .navigationBar)
        }
    }
}

// MARK: - Rule Page Model

struct RulePage: Identifiable {
    let id = UUID()
    let title: String
    let icon: String
    let content: [String]
}

// MARK: - Rule Page View

struct RulePageView: View {
    let page: RulePage
    
    @ScaledMetric(relativeTo: .title) private var iconSize: CGFloat = Design.BaseFontSize.display
    @ScaledMetric(relativeTo: .title) private var titleSize: CGFloat = Design.BaseFontSize.title
    @ScaledMetric(relativeTo: .body) private var bodySize: CGFloat = Design.BaseFontSize.body
    
    var body: some View {
        ScrollView {
            VStack(spacing: Design.Spacing.xLarge) {
                // Icon
                Image(systemName: page.icon)
                    .font(.system(size: iconSize))
                    .foregroundStyle(Color.Settings.accent)
                    .padding(.top, Design.Spacing.xxLarge)
                
                // Title
                Text(page.title)
                    .font(.system(size: titleSize, weight: .bold))
                    .foregroundStyle(.white)
                
                // Content
                VStack(alignment: .leading, spacing: Design.Spacing.medium) {
                    ForEach(page.content.indices, id: \.self) { index in
                        HStack(alignment: .top, spacing: Design.Spacing.medium) {
                            Text("•")
                                .foregroundStyle(Color.Settings.accent)
                            
                            Text(page.content[index])
                                .font(.system(size: bodySize))
                                .foregroundStyle(.white.opacity(Design.Opacity.heavy))
                        }
                    }
                }
                .padding(.horizontal, Design.Spacing.xxLarge)
                
                Spacer()
            }
        }
    }
}

#Preview {
    RulesHelpView()
}