import SwiftUI

// MARK: - Stat definition
struct ChartStat {
    let label: String
    let value: String
    let color: Color
}

// MARK: - Stats summary row (horizontal scroll of chips)
struct ChartStatsRow: View {
    let stats: [ChartStat]
    var body: some View {
        ScrollView(.horizontal, showsIndicators: false) {
            HStack(spacing: 10) {
                ForEach(stats.indices, id: \.self) { i in
                    VStack(alignment: .center, spacing: 3) {
                        Text(stats[i].label)
                            .font(.caption2)
                            .foregroundColor(.secondary)
                        Text(stats[i].value)
                            .font(.subheadline.weight(.semibold))
                            .foregroundColor(stats[i].color)
                    }
                    .frame(minWidth: 60)
                    .padding(.horizontal, 12)
                    .padding(.vertical, 8)
                    .background(Color(.systemGray6))
                    .cornerRadius(8)
                }
            }
        }
    }
}

// MARK: - Data table row model
struct ChartDataTableRow: Identifiable {
    let id = UUID()
    let label: String
    let value: String
    let deltaPrev: String?
    let deltaFirst: String?
    let isPrevPositive: Bool
    let isFirstPositive: Bool
}

// MARK: - Expandable data table
struct ChartDataTable: View {
    let rows: [ChartDataTableRow]
    let valueHeader: String
    let deltaPrevHeader: String?
    let deltaFirstHeader: String?

    @State private var isExpanded = false
    private let previewCount = 5

    var body: some View {
        VStack(spacing: 0) {
            tableHeader
            Divider()
            let displayed = isExpanded ? rows : Array(rows.suffix(previewCount))
            ForEach(displayed) { row in
                tableDataRow(row)
                if row.id != displayed.last?.id {
                    Divider().opacity(0.35)
                }
            }
            if rows.count > previewCount {
                Divider().opacity(0.35)
                Button {
                    withAnimation(.easeInOut(duration: 0.15)) { isExpanded.toggle() }
                } label: {
                    HStack(spacing: 4) {
                        Text(isExpanded ? "Show less" : "Show all \(rows.count)")
                            .font(.caption)
                        Image(systemName: isExpanded ? "chevron.up" : "chevron.down")
                            .font(.caption2)
                    }
                    .foregroundColor(.appPrimary)
                    .frame(maxWidth: .infinity)
                    .padding(.vertical, 8)
                }
            }
        }
        .background(Color(.systemGray6))
        .cornerRadius(8)
    }

    private var tableHeader: some View {
        HStack(spacing: 0) {
            Text("Date").font(.caption2.weight(.semibold)).foregroundColor(.secondary)
                .frame(maxWidth: .infinity, alignment: .leading)
            Text(valueHeader).font(.caption2.weight(.semibold)).foregroundColor(.secondary)
                .frame(width: 72, alignment: .trailing)
            if let h = deltaPrevHeader {
                Text(h).font(.caption2.weight(.semibold)).foregroundColor(.secondary)
                    .frame(width: 62, alignment: .trailing)
            }
            if let h = deltaFirstHeader {
                Text(h).font(.caption2.weight(.semibold)).foregroundColor(.secondary)
                    .frame(width: 62, alignment: .trailing)
            }
        }
        .padding(.horizontal, 12)
        .padding(.vertical, 6)
    }

    private func tableDataRow(_ row: ChartDataTableRow) -> some View {
        HStack(spacing: 0) {
            Text(row.label).font(.caption2).foregroundColor(.primary)
                .frame(maxWidth: .infinity, alignment: .leading)
            Text(row.value).font(.caption2.weight(.medium))
                .frame(width: 72, alignment: .trailing)
            if let dp = row.deltaPrev, deltaPrevHeader != nil {
                Text(dp).font(.caption2.weight(.medium))
                    .foregroundColor(row.isPrevPositive ? .positiveGreen : .negativeRed)
                    .frame(width: 62, alignment: .trailing)
            }
            if let df = row.deltaFirst, deltaFirstHeader != nil {
                Text(df).font(.caption2.weight(.medium))
                    .foregroundColor(row.isFirstPositive ? .positiveGreen : .negativeRed)
                    .frame(width: 62, alignment: .trailing)
            }
        }
        .padding(.horizontal, 12)
        .padding(.vertical, 5)
    }
}

// MARK: - Compact date formatter
private let tableMonthFormatter: DateFormatter = {
    let f = DateFormatter()
    f.setLocalizedDateFormatFromTemplate("MMMy")
    return f
}()

func chartTableDateLabel(_ date: Date) -> String {
    tableMonthFormatter.string(from: date)
}