feat: Display epub metadata on Recents (#511)

* **What is the goal of this PR?** Implement a metadata viewer for the
Recents screen
* **What changes are included?**

| Recents | Files |
| --- | --- |
| <img alt="image"
src="https://github.com/user-attachments/assets/e0f2d816-ddce-4a2e-bd4a-cd431d0e6532"
/> | <img alt="image"
src="https://github.com/user-attachments/assets/3225cdce-d501-4175-bc92-73cb8bfe7a41"
/> |

For the Files screen, I have not made any changes on purpose. For the
Recents screen, we now display the Book title and author. If it is a
file with no epub metadata like txt or md, we display the file name
without the file extension.

---

Did you use AI tools to help write this code? _**< YES  >**_

Although I went trough all the code manually and made changes as well,
please be aware the majority of the code is AI generated.

---------

Co-authored-by: Eliz Kilic <elizk@google.com>

src/RecentBooksStore.cpp

@@ -7,22 +7,23 @@
 #include <algorithm>
 
 namespace {
-constexpr uint8_t RECENT_BOOKS_FILE_VERSION = 1;
+constexpr uint8_t RECENT_BOOKS_FILE_VERSION = 2;
 constexpr char RECENT_BOOKS_FILE[] = "/.crosspoint/recent.bin";
 constexpr int MAX_RECENT_BOOKS = 10;
 }  // namespace
 
 RecentBooksStore RecentBooksStore::instance;
 
-void RecentBooksStore::addBook(const std::string& path) {
+void RecentBooksStore::addBook(const std::string& path, const std::string& title, const std::string& author) {
   // Remove existing entry if present
-  auto it = std::find(recentBooks.begin(), recentBooks.end(), path);
+  auto it =
+      std::find_if(recentBooks.begin(), recentBooks.end(), [&](const RecentBook& book) { return book.path == path; });
   if (it != recentBooks.end()) {
     recentBooks.erase(it);
   }
 
   // Add to front
-  recentBooks.insert(recentBooks.begin(), path);
+  recentBooks.insert(recentBooks.begin(), {path, title, author});
 
   // Trim to max size
   if (recentBooks.size() > MAX_RECENT_BOOKS) {
@@ -46,7 +47,9 @@ bool RecentBooksStore::saveToFile() const {
   serialization::writePod(outputFile, count);
 
   for (const auto& book : recentBooks) {
-    serialization::writeString(outputFile, book);
+    serialization::writeString(outputFile, book.path);
+    serialization::writeString(outputFile, book.title);
+    serialization::writeString(outputFile, book.author);
   }
 
   outputFile.close();
@@ -63,24 +66,41 @@ bool RecentBooksStore::loadFromFile() {
   uint8_t version;
   serialization::readPod(inputFile, version);
   if (version != RECENT_BOOKS_FILE_VERSION) {
-    Serial.printf("[%lu] [RBS] Deserialization failed: Unknown version %u\n", millis(), version);
-    inputFile.close();
-    return false;
-  }
+    if (version == 1) {
+      // Old version, just read paths
+      uint8_t count;
+      serialization::readPod(inputFile, count);
+      recentBooks.clear();
+      recentBooks.reserve(count);
+      for (uint8_t i = 0; i < count; i++) {
+        std::string path;
+        serialization::readString(inputFile, path);
+        // Title and author will be empty, they will be filled when the book is
+        // opened again
+        recentBooks.push_back({path, "", ""});
+      }
+    } else {
+      Serial.printf("[%lu] [RBS] Deserialization failed: Unknown version %u\n", millis(), version);
+      inputFile.close();
+      return false;
+    }
+  } else {
+    uint8_t count;
+    serialization::readPod(inputFile, count);
 
-  uint8_t count;
-  serialization::readPod(inputFile, count);
+    recentBooks.clear();
+    recentBooks.reserve(count);
 
-  recentBooks.clear();
-  recentBooks.reserve(count);
-
-  for (uint8_t i = 0; i < count; i++) {
-    std::string path;
-    serialization::readString(inputFile, path);
-    recentBooks.push_back(path);
+    for (uint8_t i = 0; i < count; i++) {
+      std::string path, title, author;
+      serialization::readString(inputFile, path);
+      serialization::readString(inputFile, title);
+      serialization::readString(inputFile, author);
+      recentBooks.push_back({path, title, author});
+    }
   }
 
   inputFile.close();
-  Serial.printf("[%lu] [RBS] Recent books loaded from file (%d entries)\n", millis(), count);
+  Serial.printf("[%lu] [RBS] Recent books loaded from file (%d entries)\n", millis(), recentBooks.size());
   return true;
 }

src/RecentBooksStore.h

@@ -2,11 +2,19 @@
 #include <string>
 #include <vector>
 
+struct RecentBook {
+  std::string path;
+  std::string title;
+  std::string author;
+
+  bool operator==(const RecentBook& other) const { return path == other.path; }
+};
+
 class RecentBooksStore {
   // Static instance
   static RecentBooksStore instance;
 
-  std::vector<std::string> recentBooks;
+  std::vector<RecentBook> recentBooks;
 
  public:
   ~RecentBooksStore() = default;
@@ -14,11 +22,11 @@ class RecentBooksStore {
   // Get singleton instance
   static RecentBooksStore& getInstance() { return instance; }
 
-  // Add a book path to the recent list (moves to front if already exists)
-  void addBook(const std::string& path);
+  // Add a book to the recent list (moves to front if already exists)
+  void addBook(const std::string& path, const std::string& title, const std::string& author);
 
-  // Get the list of recent book paths (most recent first)
-  const std::vector<std::string>& getBooks() const { return recentBooks; }
+  // Get the list of recent books (most recent first)
+  const std::vector<RecentBook>& getBooks() const { return recentBooks; }
 
   // Get the count of recent books
   int getCount() const { return static_cast<int>(recentBooks.size()); }

src/activities/home/MyLibraryActivity.cpp

@@ -16,6 +16,7 @@ namespace {
 constexpr int TAB_BAR_Y = 15;
 constexpr int CONTENT_START_Y = 60;
 constexpr int LINE_HEIGHT = 30;
+constexpr int RECENTS_LINE_HEIGHT = 65;  // Increased for two-line items
 constexpr int LEFT_MARGIN = 20;
 constexpr int RIGHT_MARGIN = 40;  // Extra space for scroll indicator
 
@@ -47,7 +48,7 @@ int MyLibraryActivity::getPageItems() const {
 
 int MyLibraryActivity::getCurrentItemCount() const {
   if (currentTab == Tab::Recent) {
-    return static_cast<int>(bookTitles.size());
+    return static_cast<int>(recentBooks.size());
   }
   return static_cast<int>(files.size());
 }
@@ -65,34 +66,16 @@ int MyLibraryActivity::getCurrentPage() const {
 }
 
 void MyLibraryActivity::loadRecentBooks() {
-  constexpr size_t MAX_RECENT_BOOKS = 20;
-
-  bookTitles.clear();
-  bookPaths.clear();
+  recentBooks.clear();
   const auto& books = RECENT_BOOKS.getBooks();
-  bookTitles.reserve(std::min(books.size(), MAX_RECENT_BOOKS));
-  bookPaths.reserve(std::min(books.size(), MAX_RECENT_BOOKS));
-
-  for (const auto& path : books) {
-    // Limit to maximum number of recent books
-    if (bookTitles.size() >= MAX_RECENT_BOOKS) {
-      break;
-    }
+  recentBooks.reserve(books.size());
 
+  for (const auto& book : books) {
     // Skip if file no longer exists
-    if (!SdMan.exists(path.c_str())) {
+    if (!SdMan.exists(book.path.c_str())) {
       continue;
     }
-
-    // Extract filename from path for display
-    std::string title = path;
-    const size_t lastSlash = title.find_last_of('/');
-    if (lastSlash != std::string::npos) {
-      title = title.substr(lastSlash + 1);
-    }
-
-    bookTitles.push_back(title);
-    bookPaths.push_back(path);
+    recentBooks.push_back(book);
   }
 }
 
@@ -176,8 +159,6 @@ void MyLibraryActivity::onExit() {
   vSemaphoreDelete(renderingMutex);
   renderingMutex = nullptr;
 
-  bookTitles.clear();
-  bookPaths.clear();
   files.clear();
 }
 
@@ -207,8 +188,8 @@ void MyLibraryActivity::loop() {
   // Confirm button - open selected item
   if (mappedInput.wasReleased(MappedInputManager::Button::Confirm)) {
     if (currentTab == Tab::Recent) {
-      if (!bookPaths.empty() && selectorIndex < static_cast<int>(bookPaths.size())) {
-        onSelectBook(bookPaths[selectorIndex], currentTab);
+      if (!recentBooks.empty() && selectorIndex < static_cast<int>(recentBooks.size())) {
+        onSelectBook(recentBooks[selectorIndex].path, currentTab);
       }
     } else {
       // Files tab
@@ -333,7 +314,7 @@ void MyLibraryActivity::render() const {
 void MyLibraryActivity::renderRecentTab() const {
   const auto pageWidth = renderer.getScreenWidth();
   const int pageItems = getPageItems();
-  const int bookCount = static_cast<int>(bookTitles.size());
+  const int bookCount = static_cast<int>(recentBooks.size());
 
   if (bookCount == 0) {
     renderer.drawText(UI_10_FONT_ID, LEFT_MARGIN, CONTENT_START_Y, "No recent books");
@@ -343,14 +324,37 @@ void MyLibraryActivity::renderRecentTab() const {
   const auto pageStartIndex = selectorIndex / pageItems * pageItems;
 
   // Draw selection highlight
-  renderer.fillRect(0, CONTENT_START_Y + (selectorIndex % pageItems) * LINE_HEIGHT - 2, pageWidth - RIGHT_MARGIN,
-                    LINE_HEIGHT);
+  renderer.fillRect(0, CONTENT_START_Y + (selectorIndex % pageItems) * RECENTS_LINE_HEIGHT - 2,
+                    pageWidth - RIGHT_MARGIN, RECENTS_LINE_HEIGHT);
 
   // Draw items
   for (int i = pageStartIndex; i < bookCount && i < pageStartIndex + pageItems; i++) {
-    auto item = renderer.truncatedText(UI_10_FONT_ID, bookTitles[i].c_str(), pageWidth - LEFT_MARGIN - RIGHT_MARGIN);
-    renderer.drawText(UI_10_FONT_ID, LEFT_MARGIN, CONTENT_START_Y + (i % pageItems) * LINE_HEIGHT, item.c_str(),
-                      i != selectorIndex);
+    const auto& book = recentBooks[i];
+    const int y = CONTENT_START_Y + (i % pageItems) * RECENTS_LINE_HEIGHT;
+
+    // Line 1: Title
+    std::string title = book.title;
+    if (title.empty()) {
+      // Fallback for older entries or files without metadata
+      title = book.path;
+      const size_t lastSlash = title.find_last_of('/');
+      if (lastSlash != std::string::npos) {
+        title = title.substr(lastSlash + 1);
+      }
+      const size_t dot = title.find_last_of('.');
+      if (dot != std::string::npos) {
+        title.resize(dot);
+      }
+    }
+    auto truncatedTitle = renderer.truncatedText(UI_12_FONT_ID, title.c_str(), pageWidth - LEFT_MARGIN - RIGHT_MARGIN);
+    renderer.drawText(UI_12_FONT_ID, LEFT_MARGIN, y + 2, truncatedTitle.c_str(), i != selectorIndex);
+
+    // Line 2: Author
+    if (!book.author.empty()) {
+      auto truncatedAuthor =
+          renderer.truncatedText(UI_10_FONT_ID, book.author.c_str(), pageWidth - LEFT_MARGIN - RIGHT_MARGIN);
+      renderer.drawText(UI_10_FONT_ID, LEFT_MARGIN, y + 32, truncatedAuthor.c_str(), i != selectorIndex);
+    }
   }
 }
 

src/activities/home/MyLibraryActivity.h

@@ -8,6 +8,7 @@
 #include <vector>
 
 #include "../Activity.h"
+#include "RecentBooksStore.h"
 
 class MyLibraryActivity final : public Activity {
  public:
@@ -22,8 +23,7 @@ class MyLibraryActivity final : public Activity {
   bool updateRequired = false;
 
   // Recent tab state
-  std::vector<std::string> bookTitles;  // Display titles for each book
-  std::vector<std::string> bookPaths;   // Paths for each visible book (excludes missing)
+  std::vector<RecentBook> recentBooks;
 
   // Files tab state (from FileSelectionActivity)
   std::string basepath = "/";

src/activities/reader/EpubReaderActivity.cpp

@@ -85,7 +85,7 @@ void EpubReaderActivity::onEnter() {
   // Save current epub as last opened epub and add to recent books
   APP_STATE.openEpubPath = epub->getPath();
   APP_STATE.saveToFile();
-  RECENT_BOOKS.addBook(epub->getPath());
+  RECENT_BOOKS.addBook(epub->getPath(), epub->getTitle(), epub->getAuthor());
 
   // Trigger first update
   updateRequired = true;

src/activities/reader/TxtReaderActivity.cpp

@@ -60,7 +60,7 @@ void TxtReaderActivity::onEnter() {
   // Save current txt as last opened file and add to recent books
   APP_STATE.openEpubPath = txt->getPath();
   APP_STATE.saveToFile();
-  RECENT_BOOKS.addBook(txt->getPath());
+  RECENT_BOOKS.addBook(txt->getPath(), "", "");
 
   // Trigger first update
   updateRequired = true;

src/activities/reader/XtcReaderActivity.cpp

@@ -45,7 +45,7 @@ void XtcReaderActivity::onEnter() {
   // Save current XTC as last opened book and add to recent books
   APP_STATE.openEpubPath = xtc->getPath();
   APP_STATE.saveToFile();
-  RECENT_BOOKS.addBook(xtc->getPath());
+  RECENT_BOOKS.addBook(xtc->getPath(), xtc->getTitle(), xtc->getAuthor());
 
   // Trigger first update
   updateRequired = true;