import SwiftUI
import SwiftData

struct HistoryView: View {
    
    @Environment(\.modelContext)
    private var context

    @Query(sort: \HistoryItem.startDate, order: .reverse)
    private var items: [HistoryItem] = []

    private var unlockCount: Int {
        items.count { $0.response == .unlocked }
    }

    private var percentage: Double {
        guard items.count > 0 else {
            return 0
        }
        return Double(unlockCount * 100) / Double(items.count)
    }
    
    private var requestNumberText: String {
        guard items.count != 1 else {
            return "1 Request"
        }
        return "\(items.count) Requests"
    }

    var body: some View {
        NavigationView {
            List {
                HStack {
                    Text(requestNumberText)
                        .foregroundColor(.primary)
                        .font(.body)
                    Spacer()
                    Text(String(format: "%d successful (%.1f %%)", unlockCount, percentage))
                        .foregroundColor(.secondary)
                        .font(.footnote)
                }
                ForEach(items) {entry in
                    HistoryListItem(entry: entry)
                }.onDelete(perform: { indexSet in
                    let objects = indexSet.map { items[$0] }
                    for object in objects {
                        context.delete(object)
                    }
                    do {
                        try context.save()
                    } catch {
                        print("Failed to save after deleting \(objects.count) object(s): \(error)")
                    }
                })
            }
            .navigationTitle("History")
        }
    }
}

#Preview {
    do {
        let config = ModelConfiguration(isStoredInMemoryOnly: true)
        let container = try ModelContainer(for: HistoryItem.self, configurations: config)
        
        let item = HistoryItem.mock
        container.mainContext.insert(item)
        try container.mainContext.save()
        return HistoryView()
            .modelContainer(container)
    } catch {
        fatalError("Failed to create model container.")
    }
}