stats view

Gas Man/MainTabView.swift

@@ -22,6 +22,10 @@ struct MainTabView: View {
                 .tabItem {
                     Label("Maintenance", systemImage: "wrench.fill")
                 }
+            StatsView()
+                .tabItem {
+                    Label("Stats", systemImage: "chart.bar.fill")
+                }
         }
     }
 }

Gas Man/Stats/StatsView.swift

@@ -0,0 +1,234 @@
+//
+//  StatsView.swift
+//  Gas Man
+//
+//  Created by Kameron Kenny on 3/19/25.
+//
+
+
+import SwiftUI
+import CoreData
+
+struct StatsView: View {
+    @Environment(\.managedObjectContext) private var viewContext
+    
+    // Fetch all fuel logs sorted by date (descending)
+    @FetchRequest(
+        sortDescriptors: [NSSortDescriptor(keyPath: \FuelLog.date, ascending: false)],
+        animation: .default)
+    private var fuelLogs: FetchedResults<FuelLog>
+    
+    // Fetch all vehicles sorted by make (or any preferred order)
+    @FetchRequest(
+        sortDescriptors: [NSSortDescriptor(keyPath: \Vehicle.make, ascending: true)],
+        animation: .default)
+    private var vehicles: FetchedResults<Vehicle>
+    
+    @State private var selectedVehicleID: UUID? = nil
+    
+    // Filter fuel logs by the selected vehicle.
+    private var filteredFuelLogs: [FuelLog] {
+        if let vehicleID = selectedVehicleID {
+            return fuelLogs.filter { log in
+                log.vehicle?.id == vehicleID
+            }
+        } else {
+            return Array(fuelLogs)
+        }
+    }
+    
+    // Total number of fill-ups.
+    private var fillUpCount: Int {
+        filteredFuelLogs.count
+    }
+    
+    // Average MPG computed only for full-tank logs.
+    private var averageMPG: Double? {
+        let logs = filteredFuelLogs
+        guard logs.count > 1 else { return nil }
+        var mpgValues: [Double] = []
+        for i in 0..<logs.count - 1 {
+            let current = logs[i]
+            let next = logs[i + 1]
+            if current.fullTank, current.fuelVolume > 0, current.odometer > next.odometer {
+                let mpg = (current.odometer - next.odometer) / current.fuelVolume
+                mpgValues.append(mpg)
+            }
+        }
+        guard !mpgValues.isEmpty else { return nil }
+        let sum = mpgValues.reduce(0, +)
+        return sum / Double(mpgValues.count)
+    }
+    
+    // Price per gallon stats: lowest, highest, average.
+    private var pricePerGallonStats: (min: Double?, max: Double?, avg: Double?) {
+        let prices = filteredFuelLogs.map { $0.pricePerGalon }
+        guard !prices.isEmpty else { return (nil, nil, nil) }
+        let minPrice = prices.min()
+        let maxPrice = prices.max()
+        let avgPrice = prices.reduce(0, +) / Double(prices.count)
+        return (minPrice, maxPrice, avgPrice)
+    }
+    
+    // Distance between fill-ups stats: lowest, highest, average.
+    private var distanceStats: (min: Double?, max: Double?, avg: Double?) {
+        let logs = filteredFuelLogs
+        guard logs.count > 1 else { return (nil, nil, nil) }
+        var distances: [Double] = []
+        for i in 0..<logs.count - 1 {
+            let current = logs[i]
+            let next = logs[i + 1]
+            let dist = current.odometer - next.odometer
+            if dist > 0 {
+                distances.append(dist)
+            }
+        }
+        guard !distances.isEmpty else { return (nil, nil, nil) }
+        let minDistance = distances.min()!
+        let maxDistance = distances.max()!
+        let avgDistance = distances.reduce(0, +) / Double(distances.count)
+        return (minDistance, maxDistance, avgDistance)
+    }
+    
+    // Gallons per fill-up stats.
+    private var gallonsStats: (min: Double?, max: Double?, avg: Double?) {
+        let gallons = filteredFuelLogs.map { $0.fuelVolume }
+        guard !gallons.isEmpty else { return (nil, nil, nil) }
+        let minGallons = gallons.min()
+        let maxGallons = gallons.max()
+        let avgGallons = gallons.reduce(0, +) / Double(gallons.count)
+        return (minGallons, maxGallons, avgGallons)
+    }
+    
+    var body: some View {
+        NavigationView {
+            Form {
+                // Vehicle Selector
+                Section(header: Text("Select Vehicle")) {
+                    Picker("Vehicle", selection: $selectedVehicleID) {
+                        ForEach(vehicles, id: \.id) { vehicle in
+                            Text("\(vehicle.year ?? "") \(vehicle.make ?? "") \(vehicle.model ?? "")")
+                                .tag(vehicle.id)
+                        }
+                    }
+                    .pickerStyle(MenuPickerStyle())
+                }
+                
+                // Stats for Fuel Logs
+                Section(header: Text("Fill-Up Count")) {
+                    Text("\(fillUpCount)")
+                }
+                
+                Section(header: Text("Average MPG")) {
+                    if let avgMPG = averageMPG {
+                        Text("\(avgMPG, specifier: "%.1f") MPG")
+                    } else {
+                        Text("N/A")
+                            .foregroundColor(.secondary)
+                    }
+                }
+                
+                Section(header: Text("Price per Gallon")) {
+                    let stats = pricePerGallonStats
+                    HStack {
+                        Text("Lowest:")
+                        Spacer()
+                        if let minPrice = stats.min {
+                            Text("$\(minPrice, specifier: "%.3f")")
+                        } else {
+                            Text("N/A")
+                        }
+                    }
+                    HStack {
+                        Text("Highest:")
+                        Spacer()
+                        if let maxPrice = stats.max {
+                            Text("$\(maxPrice, specifier: "%.3f")")
+                        } else {
+                            Text("N/A")
+                        }
+                    }
+                    HStack {
+                        Text("Average:")
+                        Spacer()
+                        if let avgPrice = stats.avg {
+                            Text("$\(avgPrice, specifier: "%.3f")")
+                        } else {
+                            Text("N/A")
+                        }
+                    }
+                }
+                
+                // Distance Between Fill-Ups Stats
+                Section(header: Text("Distance Between Fill-Ups")) {
+                    let dStats = distanceStats
+                    HStack {
+                        Text("Lowest:")
+                        Spacer()
+                        if let minDistance = dStats.min {
+                            Text("\(minDistance, specifier: "%.0f") miles")
+                        } else {
+                            Text("N/A")
+                        }
+                    }
+                    HStack {
+                        Text("Highest:")
+                        Spacer()
+                        if let maxDistance = dStats.max {
+                            Text("\(maxDistance, specifier: "%.0f") miles")
+                        } else {
+                            Text("N/A")
+                        }
+                    }
+                    HStack {
+                        Text("Average:")
+                        Spacer()
+                        if let avgDistance = dStats.avg {
+                            Text("\(avgDistance, specifier: "%.0f") miles")
+                        } else {
+                            Text("N/A")
+                        }
+                    }
+                }
+                
+                Section(header: Text("Gallons per Fill-Up")) {
+                    let gStats = gallonsStats
+                    HStack {
+                        Text("Lowest:")
+                        Spacer()
+                        if let minGallons = gStats.min {
+                            Text("\(minGallons, specifier: "%.3f") gallons")
+                        } else {
+                            Text("N/A")
+                        }
+                    }
+                    HStack {
+                        Text("Highest:")
+                        Spacer()
+                        if let maxGallons = gStats.max {
+                            Text("\(maxGallons, specifier: "%.3f") gallons")
+                        } else {
+                            Text("N/A")
+                        }
+                    }
+                    HStack {
+                        Text("Average:")
+                        Spacer()
+                        if let avgGallons = gStats.avg {
+                            Text("\(avgGallons, specifier: "%.3f") gallons")
+                        } else {
+                            Text("N/A")
+                        }
+                    }
+                }
+            }
+            .navigationTitle("Stats")
+        }
+        .onAppear {
+            if selectedVehicleID == nil {
+                selectedVehicleID = vehicles.first?.id
+            }
+        }
+    }
+}
+