PadelClub/PadelClub/Views/Subscription/PurchaseListView.swift

//
//  PurchaseListView.swift
//  PadelClub
//
//  Created by Laurent Morvillier on 22/04/2024.
//

import SwiftUI
import StoreKit
import LeStorage

class PurchaseManager: ObservableObject {
    
    static let main: PurchaseManager = PurchaseManager()
    
    fileprivate var _products: [Product] = []
    fileprivate var _purchases: [Purchase] = []
    
    @Published var purchaseRows: [PurchaseRow] = []
    
    init() {
        NotificationCenter.default.addObserver(self, selector: #selector(_purchasesChanged(notification:)), name: NSNotification.Name.CollectionDidChange, object: Guard.main.purchases)
        
        let identifiers: [String] = StoreItem.allCases.map { $0.rawValue }
        Task {
            do {
                self._products = try await Product.products(for: identifiers)
                self._buildRows()
            } catch {
                Logger.error(error)
            }
        }
    }

    @objc fileprivate func _purchasesChanged(notification: Notification) {
        guard let collection = notification.object as? StoredCollection<Purchase> else {
            return
        }
        self._purchases.removeAll()
        self._purchases.append(contentsOf: collection)
        self._buildRows()
    }
    
    fileprivate func _buildRows() {
        
        DispatchQueue.main.async {
            
            var rows: [PurchaseRow] = []
            let userPurchases: [StoreKit.Transaction] = Guard.main.userFilteredPurchases()
            for userPurchase in userPurchases {
                
                if let item = StoreItem(rawValue: userPurchase.productID),
                   let product = self._products.first(where: { $0.id == item.rawValue } ) {
                    switch item {
                    case .unit:
                        let remainingTournaments = Guard.main.remainingTournaments
                        if remainingTournaments > 0 {
                            rows.append(PurchaseRow(name: product.displayName, item: item, quantity: remainingTournaments))
                        }
                    default:
                        rows.append(PurchaseRow(name: product.displayName, item: item))
                    }
                }
            }
            self.purchaseRows = rows
        }
        
    }
    
}

struct PurchaseListView: View {
    
    @ObservedObject var manager = PurchaseManager()
    
    var body: some View {
        
        if self.manager.purchaseRows.count > 0 {
            
            Section {
                ForEach(self.manager.purchaseRows) { purchaseRow in
                    
                    Link(destination: URLs.subscriptions.url) {
                        PurchaseView(purchaseRow: purchaseRow)
                    }
                }
            } header: {
                Text("Vos achats")
            }
            
        }
    }
}

struct PurchaseView: View {
    
    var purchaseRow: PurchaseRow
    
    var body: some View {
        HStack {
            Image(systemName: self.purchaseRow.item.systemImage)
                .foregroundColor(.accentColor)
            Text(self.purchaseRow.name)
            Spacer()
            if let quantity = purchaseRow.quantity {
                let remaining = Guard.main.remainingTournaments
                Text("\(remaining) / \(quantity.formatted())")
            }
        }
    }
}

#Preview {
    PurchaseListView()
}