LeCountdown/LeCountdown/Views/Stats/ActivityStatsView.swift

//
//  ActivityView.swift
//  LeCountdown
//
//  Created by Laurent Morvillier on 20/02/2023.
//

import SwiftUI
import CoreData

struct ActivityStatsView: View {
    
    @Environment(\.managedObjectContext) private var viewContext

    let activity: Activity
    var filter: Filter? = nil
    
    @State var subFilters: [Filter] = []
    
    var body: some View {
        
        List {
            Section {
                StatisticsView(activity: self.activity, filter: self.filter) { statValues in
                    ForEach(statValues) { statValue in
                        StatView(statValue: statValue)
                    }
                }.environment(\.managedObjectContext, viewContext)
            }
            
            //                Picker("Time", selection: $selectedTimeFrame) {
            //                    ForEach(TimeFrame.allCases) { timeFrame in
            //                        Text(timeFrame.localizedString).tag(timeFrame)
            //                    }
            //                }
            //                .pickerStyle(.segmented)
            //                .padding(.horizontal)
            
            
            StatisticsSubView(activity: self.activity, subFilters: self.subFilters)
                .environment(\.managedObjectContext, viewContext)
            
        }
        .navigationTitle(self.filter?.localizedString ?? self.activity.name ?? "no name")
        .onAppear {
            self._load()
        }
        
    }
    
    fileprivate func _load() {
        
        do {
            switch self.filter {
            case nil:
                let years = try CoreDataRequests.years(context: self.viewContext, activity: self.activity)
                self.subFilters = years.map { Filter.year($0) }
            case .some(let filter):
                switch filter {
                case .year(let year):
                    let months = try CoreDataRequests.months(context: self.viewContext, activity: self.activity, year: year)
                    self.subFilters = months.map { Filter.month(Month(month: $0, year: year)) }
                default:
                    break
                }
            }
        } catch {
            Logger.error(error)
        }
    }
    
}

enum TimeFrame: Int, Identifiable, CaseIterable {
    
    var id: Int { return self.rawValue }
    
//    case all
    case year
    case month
    
    var localizedString: String {
        switch self {
//        case .all: return NSLocalizedString("All", comment: "")
        case .year: return NSLocalizedString("Year", comment: "")
        case .month: return NSLocalizedString("Month", comment: "")
        }
    }
    
    func filters(context: NSManagedObjectContext, activity: Activity) -> [Filter] {
        
        let predicate = NSPredicate(format: "activity = %@", activity)
        
        do {
            switch self {
//            case .all:
//                return [.none]
            case .year:
                let distinct = try context.distinct(entityName: "Record", attributes: ["year"], predicate: predicate)
                if let yearsMap = distinct as? [[String : Int]] {
                    let years = yearsMap.compactMap { $0.first?.value }
                    return years.map { Filter.year($0) }
                } else {
                    Logger.w("Could not cast \(distinct) as [Int]")
                }
            case .month:
                
                let monthes = try CoreDataRequests.months(context: context, activity: activity)
                return monthes.map { Filter.month($0) }
                
//                let distinct = try context.distinct(entityName: "Record", attributes: ["year", "month"], predicate: predicate)
//                if let distinctMonths = distinct as? [[String : Int]] {
//
//                    let months = distinctMonths.compactMap {
//                        if let month = $0["month"],
//                           let year = $0["year"] {
//                            return Month(month: month, year: year)
//                        } else {
//                            Logger.w("issue with dictionary \($0)")
//                            return nil
//                        }
//                    }
//                    return months.map { Filter.month($0) }
//                } else {
//                    Logger.w("Could not cast \(distinct) as [Int]")
//                }
            }
        } catch {
            Logger.error(error)
        }
        return []
    }
    
}

struct ActivityStatsView_Previews: PreviewProvider {
    static var previews: some View {
        ActivityStatsView(activity: Activity.fake(context: PersistenceController.preview.container.viewContext))
            .environment(\.managedObjectContext, PersistenceController.preview.container.viewContext)
    }
}