feat: add SwiftData persistence for lists and todos

MindDump/ViewModels/ListStore.swift

@@ -1,26 +1,35 @@
 import Foundation
 import Observation
+import SwiftData
 
 @Observable
 class ListStore {
-    var lists: [TodoList]
+    var lists: [TodoList] = []
+
+    private let modelContext: ModelContext
 
     var inboxID: UUID {
         lists.first { $0.isInbox }!.id
     }
 
-    init() {
-        self.lists = [TodoList(name: "Inbox", isInbox: true)]
+    init(modelContext: ModelContext) {
+        self.modelContext = modelContext
+        ensureInbox()
+        fetchLists()
     }
 
     func addList(name: String) {
         let list = TodoList(name: name)
-        lists.append(list)
+        modelContext.insert(list)
+        save()
+        fetchLists()
     }
 
     func deleteList(_ list: TodoList) {
         guard !list.isInbox else { return }
-        lists.removeAll { $0.id == list.id }
+        modelContext.delete(list)
+        save()
+        fetchLists()
     }
 
     func addItem(
@@ -30,14 +39,19 @@ class ListStore {
         deadline: Date? = nil,
         priority: Priority? = nil
     ) {
-        guard let index = lists.firstIndex(where: { $0.id == listID }) else { return }
+        guard let list = lists.first(where: { $0.id == listID }) else { return }
         let item = TodoItem(title: title, notes: notes, deadline: deadline, priority: priority)
-        lists[index].items.append(item)
+        list.items.append(item)
+        save()
+        fetchLists()
     }
 
     func deleteItem(_ itemID: UUID, from listID: UUID) {
-        guard let listIndex = lists.firstIndex(where: { $0.id == listID }) else { return }
-        lists[listIndex].items.removeAll { $0.id == itemID }
+        guard let list = lists.first(where: { $0.id == listID }),
+              let item = list.items.first(where: { $0.id == itemID }) else { return }
+        modelContext.delete(item)
+        save()
+        fetchLists()
     }
 
     func updateItem(
@@ -49,22 +63,51 @@ class ListStore {
         priority: Priority? = nil,
         isCompleted: Bool? = nil
     ) {
-        guard let listIndex = lists.firstIndex(where: { $0.id == listID }),
-              let itemIndex = lists[listIndex].items.firstIndex(where: { $0.id == itemID }) else { return }
-        lists[listIndex].items[itemIndex].title = title
-        lists[listIndex].items[itemIndex].notes = notes
-        lists[listIndex].items[itemIndex].deadline = deadline
-        lists[listIndex].items[itemIndex].priority = priority
+        guard let list = lists.first(where: { $0.id == listID }),
+              let item = list.items.first(where: { $0.id == itemID }) else { return }
+        item.title = title
+        item.notes = notes
+        item.deadline = deadline
+        item.priority = priority
         if let isCompleted {
-            lists[listIndex].items[itemIndex].isCompleted = isCompleted
+            item.isCompleted = isCompleted
         }
-        lists[listIndex].items[itemIndex].modifiedAt = Date()
+        item.modifiedAt = Date()
+        save()
+        fetchLists()
     }
 
     func toggleItemCompleted(_ itemID: UUID, in listID: UUID) {
-        guard let listIndex = lists.firstIndex(where: { $0.id == listID }),
-              let itemIndex = lists[listIndex].items.firstIndex(where: { $0.id == itemID }) else { return }
-        lists[listIndex].items[itemIndex].isCompleted.toggle()
-        lists[listIndex].items[itemIndex].modifiedAt = Date()
+        guard let list = lists.first(where: { $0.id == listID }),
+              let item = list.items.first(where: { $0.id == itemID }) else { return }
+        item.isCompleted.toggle()
+        item.modifiedAt = Date()
+        save()
+        fetchLists()
+    }
+
+    // MARK: - Private
+
+    private func ensureInbox() {
+        let descriptor = FetchDescriptor<TodoList>(predicate: #Predicate { $0.isInbox })
+        let count = (try? modelContext.fetchCount(descriptor)) ?? 0
+        if count == 0 {
+            let inbox = TodoList(name: "Inbox", isInbox: true)
+            modelContext.insert(inbox)
+            save()
+        }
+    }
+
+    private func fetchLists() {
+        let descriptor = FetchDescriptor<TodoList>(sortBy: [SortDescriptor(\.name)])
+        let fetched = (try? modelContext.fetch(descriptor)) ?? []
+        // Inbox always first
+        let inbox = fetched.filter { $0.isInbox }
+        let rest = fetched.filter { !$0.isInbox }
+        lists = inbox + rest
+    }
+
+    private func save() {
+        try? modelContext.save()
     }
 }