//
//  StatisticsSheetView.swift
//  Baccarat
//
//  Detailed statistics and scoreboard view.
//

import SwiftUI
import CasinoKit

/// A sheet that displays detailed game statistics and Big Road scoreboard.
struct StatisticsSheetView: View {
    let results: [RoundResult]
    
    @Environment(\.dismiss) private var dismiss
    
    // MARK: - Computed Statistics
    
    private var totalRounds: Int { results.count }
    
    private var playerWins: Int {
        results.filter { $0.result == .playerWins }.count
    }
    
    private var bankerWins: Int {
        results.filter { $0.result == .bankerWins }.count
    }
    
    private var tieCount: Int {
        results.filter { $0.result == .tie }.count
    }
    
    private var playerPairs: Int {
        results.filter { $0.playerPair }.count
    }
    
    private var bankerPairs: Int {
        results.filter { $0.bankerPair }.count
    }
    
    private var naturals: Int {
        results.filter { $0.isNatural }.count
    }
    
    private func percentage(_ count: Int) -> String {
        guard totalRounds > 0 else { return "0%" }
        let pct = Double(count) / Double(totalRounds) * 100
        return String(format: "%.0f%%", pct)
    }
    
    var body: some View {
        SheetContainerView(
            title: String(localized: "Statistics"),
            content: {
                // Summary stats
                summarySection
                
                // Win distribution
                winDistributionSection
                
                // Side bet frequency
                sideBetSection
                
                // Big Road display
                bigRoadSection
            },
            onDone: {
                dismiss()
            },
            doneButtonText: String(localized: "Done")
        )
    }
    
    // MARK: - Summary Section
    
    private var summarySection: some View {
        SheetSection(title: "SESSION SUMMARY", icon: "chart.pie.fill") {
            HStack(spacing: Design.Spacing.xLarge) {
                StatBox(
                    value: "\(totalRounds)",
                    label: String(localized: "Rounds"),
                    color: .white
                )
                
                StatBox(
                    value: "\(naturals)",
                    label: String(localized: "Naturals"),
                    color: .yellow
                )
            }
            .frame(maxWidth: .infinity)
        }
    }
    
    // MARK: - Win Distribution Section
    
    private var winDistributionSection: some View {
        SheetSection(title: "WIN DISTRIBUTION", icon: "trophy.fill") {
            VStack(spacing: Design.Spacing.medium) {
                HStack(spacing: Design.Spacing.medium) {
                    WinStatView(
                        title: String(localized: "Player"),
                        count: playerWins,
                        percentage: percentage(playerWins),
                        color: .blue
                    )
                    
                    WinStatView(
                        title: String(localized: "Tie"),
                        count: tieCount,
                        percentage: percentage(tieCount),
                        color: .green
                    )
                    
                    WinStatView(
                        title: String(localized: "Banker"),
                        count: bankerWins,
                        percentage: percentage(bankerWins),
                        color: .red
                    )
                }
                
                // Win bar visualization
                if totalRounds > 0 {
                    WinDistributionBar(
                        playerWins: playerWins,
                        tieCount: tieCount,
                        bankerWins: bankerWins
                    )
                    .frame(height: Design.Spacing.large)
                    .clipShape(.rect(cornerRadius: Design.CornerRadius.small))
                }
            }
        }
    }
    
    // MARK: - Side Bet Section
    
    private var sideBetSection: some View {
        SheetSection(title: "SIDE BET FREQUENCY", icon: "sparkles") {
            HStack(spacing: Design.Spacing.xLarge) {
                PairStatView(
                    title: String(localized: "P Pair"),
                    count: playerPairs,
                    percentage: percentage(playerPairs),
                    color: .blue
                )
                
                PairStatView(
                    title: String(localized: "B Pair"),
                    count: bankerPairs,
                    percentage: percentage(bankerPairs),
                    color: .red
                )
            }
            .frame(maxWidth: .infinity)
        }
    }
    
    // MARK: - Big Road Section
    
    private var bigRoadSection: some View {
        SheetSection(title: "BIG ROAD", icon: "chart.bar.xaxis") {
            if results.isEmpty {
                Text(String(localized: "No rounds played yet"))
                    .font(.system(size: Design.BaseFontSize.body))
                    .foregroundStyle(.white.opacity(Design.Opacity.secondary))
                    .frame(maxWidth: .infinity)
                    .padding(.vertical, Design.Spacing.xLarge)
            } else {
                BigRoadView(results: results)
                    .frame(height: Design.Size.bigRoadHeight)
            }
        }
    }
}

// MARK: - Supporting Views

/// A box displaying a single statistic.
private struct StatBox: View {
    let value: String
    let label: String
    let color: Color
    
    var body: some View {
        VStack(spacing: Design.Spacing.xSmall) {
            Text(value)
                .font(.system(size: Design.BaseFontSize.xxLarge, weight: .bold, design: .rounded))
                .foregroundStyle(color)
            
            Text(label)
                .font(.system(size: Design.BaseFontSize.small))
                .foregroundStyle(.white.opacity(Design.Opacity.secondary))
        }
        .frame(minWidth: Design.Size.statBoxMinWidth)
        .padding(Design.Spacing.medium)
        .background(
            RoundedRectangle(cornerRadius: Design.CornerRadius.medium)
                .fill(Color.black.opacity(Design.Opacity.overlay))
        )
    }
}

/// A win stat display with count and percentage.
private struct WinStatView: View {
    let title: String
    let count: Int
    let percentage: String
    let color: Color
    
    var body: some View {
        VStack(spacing: Design.Spacing.xSmall) {
            Circle()
                .fill(color)
                .frame(width: Design.Size.winIndicatorSize, height: Design.Size.winIndicatorSize)
            
            Text("\(count)")
                .font(.system(size: Design.BaseFontSize.title, weight: .bold))
                .foregroundStyle(.white)
            
            Text(percentage)
                .font(.system(size: Design.BaseFontSize.small))
                .foregroundStyle(.white.opacity(Design.Opacity.secondary))
            
            Text(title)
                .font(.system(size: Design.BaseFontSize.small))
                .foregroundStyle(color)
        }
        .frame(maxWidth: .infinity)
    }
}

/// A pair stat display.
private struct PairStatView: View {
    let title: String
    let count: Int
    let percentage: String
    let color: Color
    
    var body: some View {
        VStack(spacing: Design.Spacing.xSmall) {
            Text("\(count)")
                .font(.system(size: Design.BaseFontSize.title, weight: .bold))
                .foregroundStyle(color)
            
            Text(percentage)
                .font(.system(size: Design.BaseFontSize.small))
                .foregroundStyle(.white.opacity(Design.Opacity.secondary))
            
            Text(title)
                .font(.system(size: Design.BaseFontSize.small))
                .foregroundStyle(.white.opacity(Design.Opacity.accent))
        }
    }
}

/// A horizontal bar showing win distribution.
private struct WinDistributionBar: View {
    let playerWins: Int
    let tieCount: Int
    let bankerWins: Int
    
    private var total: Int { playerWins + tieCount + bankerWins }
    
    var body: some View {
        GeometryReader { geometry in
            HStack(spacing: 0) {
                if playerWins > 0 {
                    Rectangle()
                        .fill(Color.blue)
                        .frame(width: geometry.size.width * CGFloat(playerWins) / CGFloat(total))
                }
                
                if tieCount > 0 {
                    Rectangle()
                        .fill(Color.green)
                        .frame(width: geometry.size.width * CGFloat(tieCount) / CGFloat(total))
                }
                
                if bankerWins > 0 {
                    Rectangle()
                        .fill(Color.red)
                        .frame(width: geometry.size.width * CGFloat(bankerWins) / CGFloat(total))
                }
            }
        }
    }
}

/// The Big Road scoreboard - a grid showing result patterns.
/// Results are arranged in columns, with each column representing a streak of same results.
private struct BigRoadView: View {
    let results: [RoundResult]
    
    private let maxRows = 6
    private let cellSize: CGFloat = Design.Size.bigRoadCellSize
    
    /// Convert results into columns for Big Road display.
    private var columns: [[RoundResult]] {
        var cols: [[RoundResult]] = []
        var currentCol: [RoundResult] = []
        var lastResult: GameResult?
        
        for result in results {
            // Skip ties for column tracking (ties go in the current column)
            let currentResult = result.result
            
            if currentResult == .tie {
                // Ties don't start new columns, they go with the current streak
                if !currentCol.isEmpty {
                    currentCol.append(result)
                } else if !cols.isEmpty {
                    cols[cols.count - 1].append(result)
                } else {
                    currentCol.append(result)
                }
            } else if lastResult == nil || currentResult == lastResult {
                // Same as last or first result - continue column
                currentCol.append(result)
                lastResult = currentResult
            } else {
                // Different result - start new column
                if !currentCol.isEmpty {
                    cols.append(currentCol)
                }
                currentCol = [result]
                lastResult = currentResult
            }
        }
        
        // Add remaining column
        if !currentCol.isEmpty {
            cols.append(currentCol)
        }
        
        return cols
    }
    
    var body: some View {
        ScrollView(.horizontal) {
            HStack(spacing: Design.Spacing.xxSmall) {
                ForEach(Array(columns.enumerated()), id: \.offset) { _, column in
                    VStack(spacing: Design.Spacing.xxSmall) {
                        ForEach(Array(column.prefix(maxRows).enumerated()), id: \.offset) { _, result in
                            BigRoadCell(result: result)
                        }
                        
                        // If column has more than maxRows, show overflow count
                        if column.count > maxRows {
                            Text("+\(column.count - maxRows)")
                                .font(.system(size: Design.BaseFontSize.xxSmall))
                                .foregroundStyle(.white.opacity(Design.Opacity.secondary))
                        }
                        
                        Spacer(minLength: 0)
                    }
                }
            }
            .padding(Design.Spacing.small)
        }
        .background(
            RoundedRectangle(cornerRadius: Design.CornerRadius.medium)
                .fill(Color.black.opacity(Design.Opacity.overlay))
        )
        .scrollIndicators(.hidden)
    }
}

/// A single cell in the Big Road display.
private struct BigRoadCell: View {
    let result: RoundResult
    
    private let cellSize: CGFloat = Design.Size.bigRoadCellSize
    
    private var color: Color {
        switch result.result {
        case .playerWins: return .blue
        case .bankerWins: return .red
        case .tie: return .green
        }
    }
    
    var body: some View {
        ZStack {
            // Main circle
            Circle()
                .stroke(color, lineWidth: Design.LineWidth.medium)
                .frame(width: cellSize, height: cellSize)
            
            // Pair indicator (small dot at bottom)
            if result.hasPair {
                Circle()
                    .fill(Color.yellow)
                    .frame(width: cellSize * 0.25, height: cellSize * 0.25)
                    .offset(y: cellSize * 0.3)
            }
            
            // Natural indicator (small dot at top)
            if result.isNatural {
                Circle()
                    .fill(Color.white)
                    .frame(width: cellSize * 0.25, height: cellSize * 0.25)
                    .offset(y: -cellSize * 0.3)
            }
            
            // Tie diagonal line if it's a tie
            if result.result == .tie {
                Rectangle()
                    .fill(color)
                    .frame(width: cellSize * 0.8, height: Design.LineWidth.medium)
                    .rotationEffect(.degrees(-45))
            }
        }
    }
}

// MARK: - Design Constants Extensions

extension Design.Size {
    static let bigRoadHeight: CGFloat = 200
    static let bigRoadCellSize: CGFloat = 24
    static let statBoxMinWidth: CGFloat = 80
    static let winIndicatorSize: CGFloat = 24
}

// MARK: - Preview

#Preview {
    StatisticsSheetView(results: [
        RoundResult(result: .playerWins, playerValue: 8, bankerValue: 6, playerPair: true),
        RoundResult(result: .playerWins, playerValue: 7, bankerValue: 5),
        RoundResult(result: .bankerWins, playerValue: 4, bankerValue: 7),
        RoundResult(result: .bankerWins, playerValue: 3, bankerValue: 8, bankerPair: true),
        RoundResult(result: .bankerWins, playerValue: 2, bankerValue: 6),
        RoundResult(result: .tie, playerValue: 5, bankerValue: 5),
        RoundResult(result: .playerWins, playerValue: 9, bankerValue: 3),
        RoundResult(result: .bankerWins, playerValue: 2, bankerValue: 8, playerPair: true, bankerPair: true)
    ])
}