InvestmentTrackerApp/PortfolioJournal/Views/Charts/PerformanceBarChart.swift

import SwiftUI
import Charts

struct PerformanceBarChart: View {
    let data: [(category: String, cagr: Double, color: String)]
    var title: String = "Performance by Category"
    /// Drill-down: tapping a row jumps to Evolution filtered to it.
    var onDrillDown: ((String) -> Void)? = nil
    @Environment(\.horizontalSizeClass) private var horizontalSizeClass

    /// On iPhone, vertical bars collide once there are more than a handful of
    /// categories (labels + annotations fight for width). Horizontal bars give
    /// every name a full line.
    private var useHorizontalBars: Bool {
        horizontalSizeClass != .regular && data.count > 6
    }

    var body: some View {
        VStack(alignment: .leading, spacing: 16) {
            Text(title)
                .font(.headline)

            Text("Compound Annual Growth Rate (CAGR)")
                .font(.caption)
                .foregroundStyle(.secondary)

            if !data.isEmpty {
                ChartStatsRow(stats: perfStats)
            }

            if !data.isEmpty {
                if useHorizontalBars {
                    horizontalChart
                } else {
                    verticalChart
                }

                // Legend / Details — rows drill down when the owner wires it up.
                VStack(spacing: 8) {
                    ForEach(data.sorted(by: { $0.cagr > $1.cagr }), id: \.category) { item in
                        legendRow(item)
                    }
                }
                .padding(.top, 8)
            } else {
                Text("No performance data available")
                    .foregroundStyle(.secondary)
                    .chartFrame(height: 250)
                    .frame(maxWidth: .infinity)
            }
        }
        .padding()
        .background(Color(.systemBackground))
        .clipShape(RoundedRectangle(cornerRadius: AppConstants.UI.cornerRadius))
        .shadow(color: .black.opacity(0.05), radius: 8, y: 2)
    }

    private var verticalChart: some View {
        Chart(data, id: \.category) { item in
            BarMark(
                x: .value("Category", item.category),
                y: .value("CAGR", item.cagr)
            )
            .foregroundStyle(Color(hex: item.color) ?? .gray)
            .clipShape(RoundedRectangle(cornerRadius: 4))
            .annotation(position: item.cagr >= 0 ? .top : .bottom) {
                Text(String(format: "%.1f%%", item.cagr))
                    .font(.caption2)
                    .foregroundStyle(item.cagr >= 0 ? Color.positiveGreen : Color.negativeRed)
            }
        }
        .chartXAxis {
            AxisMarks { value in
                AxisValueLabel {
                    if let category = value.as(String.self) {
                        Text(category)
                            .font(.caption)
                            .lineLimit(1)
                    }
                }
            }
        }
        .chartYAxis {
            AxisMarks { value in
                AxisGridLine()
                AxisValueLabel {
                    if let doubleValue = value.as(Double.self) {
                        Text(String(format: "%.0f%%", doubleValue))
                            .font(.caption)
                    }
                }
            }
        }
        .chartFrame(height: 250)
    }

    private var horizontalChart: some View {
        Chart(data.sorted(by: { $0.cagr > $1.cagr }), id: \.category) { item in
            BarMark(
                x: .value("CAGR", item.cagr),
                y: .value("Category", item.category)
            )
            .foregroundStyle(Color(hex: item.color) ?? .gray)
            .clipShape(RoundedRectangle(cornerRadius: 4))
            .annotation(position: item.cagr >= 0 ? .trailing : .leading) {
                Text(String(format: "%.1f%%", item.cagr))
                    .font(.caption2)
                    .foregroundStyle(item.cagr >= 0 ? Color.positiveGreen : Color.negativeRed)
            }
        }
        .chartXAxis {
            AxisMarks { value in
                AxisGridLine()
                AxisValueLabel {
                    if let doubleValue = value.as(Double.self) {
                        Text(String(format: "%.0f%%", doubleValue))
                            .font(.caption)
                    }
                }
            }
        }
        .chartYAxis {
            AxisMarks { value in
                AxisValueLabel {
                    if let category = value.as(String.self) {
                        Text(category)
                            .font(.caption)
                            .lineLimit(1)
                    }
                }
            }
        }
        .frame(height: CGFloat(data.count) * 34 + 40)
    }

    @ViewBuilder
    private func legendRow(_ item: (category: String, cagr: Double, color: String)) -> some View {
        let row = HStack {
            Circle()
                .fill(Color(hex: item.color) ?? .gray)
                .frame(width: 10, height: 10)

            Text(item.category)
                .font(.subheadline)

            Spacer()

            Text(String(format: "%.2f%%", item.cagr))
                .font(.subheadline.weight(.semibold))
                .foregroundStyle(item.cagr >= 0 ? Color.positiveGreen : Color.negativeRed)

            if onDrillDown != nil {
                Image(systemName: "chevron.right")
                    .font(.caption2.weight(.semibold))
                    .foregroundStyle(.secondary)
            }
        }
        if let onDrillDown {
            Button {
                onDrillDown(item.category)
            } label: {
                row.contentShape(Rectangle())
            }
            .buttonStyle(.plain)
        } else {
            row
        }
    }

    private var perfStats: [ChartStat] {
        guard !data.isEmpty else { return [] }
        let values = data.map { $0.cagr }
        let best = values.max() ?? 0
        let worst = values.min() ?? 0
        let avg = values.reduce(0, +) / Double(values.count)
        return [
            ChartStat(label: "Best", value: String(format: "%.1f%%", best), color: .positiveGreen),
            ChartStat(label: "Worst", value: String(format: "%.1f%%", worst), color: .negativeRed),
            ChartStat(label: "Average", value: String(format: "%.1f%%", avg), color: .secondary),
        ]
    }
}

// MARK: - Horizontal Bar Version

struct HorizontalPerformanceChart: View {
    let data: [(category: String, cagr: Double, color: String)]
    /// Hidden when the host (e.g. a dashboard card) already shows a title.
    var showsTitle: Bool = true

    var sortedData: [(category: String, cagr: Double, color: String)] {
        data.sorted { $0.cagr > $1.cagr }
    }

    var maxValue: Double {
        max(abs(data.map { $0.cagr }.max() ?? 0), abs(data.map { $0.cagr }.min() ?? 0))
    }

    var body: some View {
        VStack(alignment: .leading, spacing: 16) {
            if showsTitle {
                Text("Performance by Category")
                    .font(.headline)
            }

            ForEach(sortedData, id: \.category) { item in
                VStack(alignment: .leading, spacing: 4) {
                    HStack {
                        Text(item.category)
                            .font(.subheadline)

                        Spacer()

                        Text(String(format: "%.2f%%", item.cagr))
                            .font(.subheadline.weight(.semibold))
                            .foregroundStyle(item.cagr >= 0 ? Color.positiveGreen : Color.negativeRed)
                    }

                    GeometryReader { geometry in
                        let normalizedValue = maxValue > 0 ? abs(item.cagr) / maxValue : 0
                        let barWidth = geometry.size.width * normalizedValue

                        ZStack(alignment: item.cagr >= 0 ? .leading : .trailing) {
                            Rectangle()
                                .fill(Color.gray.opacity(0.1))
                                .frame(height: 8)
                                .clipShape(RoundedRectangle(cornerRadius: 4))

                            Rectangle()
                                .fill(item.cagr >= 0 ? Color.positiveGreen : Color.negativeRed)
                                .frame(width: barWidth, height: 8)
                                .clipShape(RoundedRectangle(cornerRadius: 4))
                        }
                    }
                    .frame(height: 8)
                }
            }
        }
        .padding()
        .background(Color(.systemBackground))
        .clipShape(RoundedRectangle(cornerRadius: AppConstants.UI.cornerRadius))
        .shadow(color: .black.opacity(0.05), radius: 8, y: 2)
    }
}

#Preview {
    let sampleData: [(category: String, cagr: Double, color: String)] = [
        ("Stocks", 12.5, "#10B981"),
        ("Bonds", 4.2, "#3B82F6"),
        ("Real Estate", 8.1, "#F59E0B"),
        ("Crypto", -5.3, "#8B5CF6")
    ]

    return VStack(spacing: 20) {
        PerformanceBarChart(data: sampleData)
        HorizontalPerformanceChart(data: sampleData)
    }
    .padding()
}