create contentview view model

add background to content view
make contentview list split by year / month
test data will add 120 days instead of 25

closed #35
closed #36

Shared/Persistence.swift

@@ -84,7 +84,7 @@ class PersistenceController {
     }
     
     func populateTestData() {
-        for idx in 1..<25 {
+        for idx in 1..<120 {
             let newItem = MoodEntry(context: viewContext)
             newItem.timestamp = Date()
             newItem.moodValue = Int16(Mood.allValues.randomElement()!.rawValue)
@@ -198,6 +198,49 @@ class PersistenceController {
             }
         })
     }
+    
+    
+    public func splitIntoYearMonth() ->  [Int: [Int: [MoodEntry]]] {
+        let data = PersistenceController.shared.getData(startDate: Date(timeIntervalSince1970: 0),
+                                                        endDate: Date(),
+                                                        includedDays: [1,2,3,4,5,6,7]).sorted(by: {
+            $0.forDate! < $1.forDate!
+        })
+        var returnData = [Int: [Int: [MoodEntry]]]()
+        
+        if let earliestEntry = data.first,
+           let lastEntry = data.last {
+            
+            let calendar = Calendar.current
+            let components = calendar.dateComponents([.year], from: earliestEntry.forDate!)
+            let earliestYear = components.year!
+            
+            let latestComponents = calendar.dateComponents([.year], from: lastEntry.forDate!)
+            let latestYear = latestComponents.year!
+            
+            for year in earliestYear...latestYear {
+                var allMonths = [Int: [MoodEntry]]()
+                
+                for month in (1...12) {
+                    var components = DateComponents()
+                    components.month = month
+                    components.year = year
+                    let startDateOfMonth = Calendar.current.date(from: components)!
+                    
+                    let items = data.filter({ entry in
+                        let components = calendar.dateComponents([.month, .year], from: startDateOfMonth)
+                        let entryComponents = calendar.dateComponents([.month, .year], from: entry.forDate!)
+                        return (components.month == entryComponents.month && components.year == entryComponents.year)
+                    })
+                    if !items.isEmpty {
+                        allMonths[month] = items
+                    }
+                }
+                returnData[year] = allMonths
+            }
+        }
+        return returnData
+    }
 }
 
 extension NSManagedObjectContext {