学习记录新增日历视图，支持按日期切换查看学习记录

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

LearnEnglish/LearnEnglish/Views/HistoryViewController.swift

@@ -1,12 +1,22 @@
 import UIKit
 
-final class HistoryViewController: UITableViewController {
-    private let sections: [(title: String, items: [LearnedRecord])]
+final class HistoryViewController: UIViewController {
+    private var selectedDate = Date()
+    private var selectedRecords: [LearnedRecord] = []
     private var speechObserver: NSObjectProtocol?
 
+    private let calendarView = UICalendarView()
+    private let tableView = UITableView(frame: .zero, style: .plain)
+    private let emptyLabel = UILabel()
+    private let formatter: DateFormatter = {
+        let f = DateFormatter()
+        f.locale = Locale(identifier: "zh_CN")
+        f.dateFormat = "yyyy-MM-dd"
+        return f
+    }()
+
     init() {
-        sections = LearnedStore.shared.sectioned
-        super.init(style: .plain)
+        super.init(nibName: nil, bundle: nil)
     }
 
     @available(*, unavailable)
@@ -22,11 +32,11 @@ final class HistoryViewController: UITableViewController {
         super.viewDidLoad()
         title = "学习记录"
         navigationItem.largeTitleDisplayMode = .never
-        tableView.register(WordCardCell.self, forCellReuseIdentifier: "cell")
-        tableView.separatorStyle = .none
-        tableView.backgroundColor = .systemBackground
-        tableView.contentInset.top = 8
-        updateEmptyState()
+        view.backgroundColor = .systemBackground
+
+        setupCalendar()
+        setupTable()
+        loadRecords(for: selectedDate)
 
         speechObserver = NotificationCenter.default.addObserver(
             forName: SpeechService.speakingDidChangeNotification, object: nil, queue: .main
@@ -35,22 +45,71 @@ final class HistoryViewController: UITableViewController {
         }
     }
 
-    private func updateEmptyState() {
-        if sections.isEmpty {
-            let label = UILabel()
-            label.text = "暂无学习记录"
-            label.textAlignment = .center
-            label.textColor = .secondaryLabel
-            label.font = .preferredFont(forTextStyle: .body)
-            let bg = UIView()
-            bg.addSubview(label)
-            label.translatesAutoresizingMaskIntoConstraints = false
-            NSLayoutConstraint.activate([
-                label.centerXAnchor.constraint(equalTo: bg.centerXAnchor),
-                label.centerYAnchor.constraint(equalTo: bg.centerYAnchor)
-            ])
-            tableView.backgroundView = bg
+    override func viewWillAppear(_ animated: Bool) {
+        super.viewWillAppear(animated)
+        calendarView.reloadDecorations(forDateComponents: recordDates(), animated: false)
+        loadRecords(for: selectedDate)
     }
+
+    private func setupCalendar() {
+        calendarView.delegate = self
+        calendarView.calendar = .current
+        calendarView.locale = Locale(identifier: "zh_CN")
+        let selection = UICalendarSelectionSingleDate(delegate: self)
+        calendarView.selectionBehavior = selection
+        selection.selectedDate = dateComponents(from: selectedDate)
+
+        view.addSubview(calendarView)
+        calendarView.translatesAutoresizingMaskIntoConstraints = false
+        NSLayoutConstraint.activate([
+            calendarView.topAnchor.constraint(equalTo: view.safeAreaLayoutGuide.topAnchor),
+            calendarView.leadingAnchor.constraint(equalTo: view.leadingAnchor),
+            calendarView.trailingAnchor.constraint(equalTo: view.trailingAnchor),
+            calendarView.heightAnchor.constraint(equalToConstant: 360)
+        ])
+    }
+
+    private func setupTable() {
+        tableView.dataSource = self
+        tableView.delegate = self
+        tableView.register(WordCardCell.self, forCellReuseIdentifier: "cell")
+        tableView.separatorStyle = .none
+        tableView.backgroundColor = .systemBackground
+
+        emptyLabel.text = "当天暂无学习记录"
+        emptyLabel.textAlignment = .center
+        emptyLabel.textColor = .secondaryLabel
+        emptyLabel.font = .preferredFont(forTextStyle: .body)
+        emptyLabel.isHidden = true
+        tableView.backgroundView = emptyLabel
+
+        view.addSubview(tableView)
+        tableView.translatesAutoresizingMaskIntoConstraints = false
+        NSLayoutConstraint.activate([
+            tableView.topAnchor.constraint(equalTo: calendarView.bottomAnchor),
+            tableView.leadingAnchor.constraint(equalTo: view.leadingAnchor),
+            tableView.trailingAnchor.constraint(equalTo: view.trailingAnchor),
+            tableView.bottomAnchor.constraint(equalTo: view.bottomAnchor)
+        ])
+    }
+
+    private func loadRecords(for date: Date) {
+        let dateStr = formatter.string(from: date)
+        let all = LearnedStore.shared.records
+        selectedRecords = all.filter { formatter.string(from: $0.learnedAt) == dateStr }
+            .sorted { $0.learnedAt > $1.learnedAt }
+        emptyLabel.isHidden = !selectedRecords.isEmpty
+        tableView.reloadData()
+    }
+
+    private func recordDates() -> [DateComponents] {
+        LearnedStore.shared.records.map {
+            dateComponents(from: $0.learnedAt)
+        }
+    }
+
+    private func dateComponents(from date: Date) -> DateComponents {
+        Calendar.current.dateComponents([.year, .month, .day], from: date)
     }
 
     private func updateVisibleSpeakers() {
@@ -58,22 +117,35 @@ final class HistoryViewController: UITableViewController {
             cell.updateSpeakerState()
         }
     }
-
-    override func numberOfSections(in tableView: UITableView) -> Int {
-        sections.count
 }
 
-    override func tableView(_ tableView: UITableView, titleForHeaderInSection section: Int) -> String? {
-        sections[section].title
+extension HistoryViewController: UICalendarViewDelegate {
+    func calendarView(_ calendarView: UICalendarView, decorationFor dateComponents: DateComponents) -> UICalendarView.Decoration? {
+        let dates = recordDates()
+        if dates.contains(where: { $0.year == dateComponents.year && $0.month == dateComponents.month && $0.day == dateComponents.day }) {
+            return .default(color: Theme.Color.accent, size: .small)
+        }
+        return nil
+    }
 }
 
-    override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
-        sections[section].items.count
+extension HistoryViewController: UICalendarSelectionSingleDateDelegate {
+    func dateSelection(_ selection: UICalendarSelectionSingleDate, didSelectDate dateComponents: DateComponents?) {
+        guard let dateComponents,
+              let date = Calendar.current.date(from: dateComponents) else { return }
+        selectedDate = date
+        loadRecords(for: date)
+    }
 }
 
-    override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
+extension HistoryViewController: UITableViewDataSource, UITableViewDelegate {
+    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
+        selectedRecords.count
+    }
+
+    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
         let cell = tableView.dequeueReusableCell(withIdentifier: "cell", for: indexPath) as! WordCardCell
-        let record = sections[indexPath.section].items[indexPath.row]
+        let record = selectedRecords[indexPath.row]
         cell.configure(with: record.word)
         cell.onSpeak = { word in
             SpeechService.shared.speak(word.word)
@@ -86,9 +158,9 @@ final class HistoryViewController: UITableViewController {
         return cell
     }
 
-    override func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
+    func tableView(_ tableView: UITableView, didSelectRowAt indexPath: IndexPath) {
         Haptics.selection()
-        let record = sections[indexPath.section].items[indexPath.row]
+        let record = selectedRecords[indexPath.row]
         let detail = WordDetailViewController(word: record.word, categoryName: "")
         navigationController?.pushViewController(detail, animated: true)
     }