#include "MyLibraryActivity.h"

#include <GfxRenderer.h>
#include <SDCardManager.h>

#include <algorithm>

#include "BookManager.h"
#include "MappedInputManager.h"
#include "RecentBooksStore.h"
#include "ScreenComponents.h"
#include "fontIds.h"
#include "util/StringUtils.h"

namespace {
// Layout constants
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

// Timing thresholds
constexpr int SKIP_PAGE_MS = 700;
constexpr unsigned long GO_HOME_MS = 1000;
constexpr unsigned long ACTION_MENU_MS = 700;  // Long press to open action menu

void sortFileList(std::vector<std::string>& strs) {
  std::sort(begin(strs), end(strs), [](const std::string& str1, const std::string& str2) {
    if (str1.back() == '/' && str2.back() != '/') return true;
    if (str1.back() != '/' && str2.back() == '/') return false;
    return lexicographical_compare(
        begin(str1), end(str1), begin(str2), end(str2),
        [](const char& char1, const char& char2) { return tolower(char1) < tolower(char2); });
  });
}
}  // namespace

int MyLibraryActivity::getPageItems() const {
  const int screenHeight = renderer.getScreenHeight();
  const int bottomBarHeight = 60;  // Space for button hints
  const int availableHeight = screenHeight - CONTENT_START_Y - bottomBarHeight;
  const int lineHeight = (currentTab == Tab::Recent) ? RECENTS_LINE_HEIGHT : LINE_HEIGHT;
  int items = availableHeight / lineHeight;
  if (items < 1) {
    items = 1;
  }
  return items;
}

int MyLibraryActivity::getCurrentItemCount() const {
  if (currentTab == Tab::Recent) {
    return static_cast<int>(recentBooks.size());
  }
  return static_cast<int>(files.size());
}

int MyLibraryActivity::getTotalPages() const {
  const int itemCount = getCurrentItemCount();
  const int pageItems = getPageItems();
  if (itemCount == 0) return 1;
  return (itemCount + pageItems - 1) / pageItems;
}

int MyLibraryActivity::getCurrentPage() const {
  const int pageItems = getPageItems();
  return selectorIndex / pageItems + 1;
}

void MyLibraryActivity::loadRecentBooks() {
  recentBooks.clear();
  const auto& books = RECENT_BOOKS.getBooks();
  recentBooks.reserve(books.size());

  for (const auto& book : books) {
    // Skip if file no longer exists
    if (!SdMan.exists(book.path.c_str())) {
      continue;
    }
    recentBooks.push_back(book);
  }
}

void MyLibraryActivity::loadFiles() {
  files.clear();

  auto root = SdMan.open(basepath.c_str());
  if (!root || !root.isDirectory()) {
    if (root) root.close();
    return;
  }

  root.rewindDirectory();

  char name[500];
  for (auto file = root.openNextFile(); file; file = root.openNextFile()) {
    file.getName(name, sizeof(name));
    if (name[0] == '.' || strcmp(name, "System Volume Information") == 0) {
      file.close();
      continue;
    }

    if (file.isDirectory()) {
      files.emplace_back(std::string(name) + "/");
    } else {
      auto filename = std::string(name);
      if (StringUtils::checkFileExtension(filename, ".epub") || StringUtils::checkFileExtension(filename, ".xtch") ||
          StringUtils::checkFileExtension(filename, ".xtc") || StringUtils::checkFileExtension(filename, ".txt")) {
        files.emplace_back(filename);
      }
    }
    file.close();
  }
  root.close();
  sortFileList(files);
}

size_t MyLibraryActivity::findEntry(const std::string& name) const {
  for (size_t i = 0; i < files.size(); i++) {
    if (files[i] == name) return i;
  }
  return 0;
}

void MyLibraryActivity::taskTrampoline(void* param) {
  auto* self = static_cast<MyLibraryActivity*>(param);
  self->displayTaskLoop();
}

void MyLibraryActivity::onEnter() {
  Activity::onEnter();

  renderingMutex = xSemaphoreCreateMutex();

  // Load data for both tabs
  loadRecentBooks();
  loadFiles();

  selectorIndex = 0;
  updateRequired = true;

  xTaskCreate(&MyLibraryActivity::taskTrampoline, "MyLibraryActivityTask",
              4096,               // Stack size (increased for epub metadata loading)
              this,               // Parameters
              1,                  // Priority
              &displayTaskHandle  // Task handle
  );
}

void MyLibraryActivity::onExit() {
  Activity::onExit();

  // Wait until not rendering to delete task to avoid killing mid-instruction to
  // EPD
  xSemaphoreTake(renderingMutex, portMAX_DELAY);
  if (displayTaskHandle) {
    vTaskDelete(displayTaskHandle);
    displayTaskHandle = nullptr;
  }
  vSemaphoreDelete(renderingMutex);
  renderingMutex = nullptr;

  recentBooks.clear();
  files.clear();
}

bool MyLibraryActivity::isSelectedItemAFile() const {
  if (currentTab == Tab::Recent) {
    return !recentBooks.empty() && selectorIndex < static_cast<int>(recentBooks.size());
  } else {
    // Files tab - check if it's a file (not a directory)
    if (files.empty() || selectorIndex >= static_cast<int>(files.size())) {
      return false;
    }
    return files[selectorIndex].back() != '/';
  }
}

void MyLibraryActivity::openActionMenu() {
  if (!isSelectedItemAFile()) {
    return;
  }

  if (currentTab == Tab::Recent) {
    const auto& book = recentBooks[selectorIndex];
    actionTargetPath = book.path;
    // Use title if available, otherwise extract from path
    if (!book.title.empty()) {
      actionTargetName = book.title;
    } else {
      actionTargetName = book.path;
      const size_t lastSlash = actionTargetName.find_last_of('/');
      if (lastSlash != std::string::npos) {
        actionTargetName = actionTargetName.substr(lastSlash + 1);
      }
    }
  } else {
    if (basepath.back() != '/') {
      actionTargetPath = basepath + "/" + files[selectorIndex];
    } else {
      actionTargetPath = basepath + files[selectorIndex];
    }
    actionTargetName = files[selectorIndex];
  }

  uiState = UIState::ActionMenu;
  menuSelection = 0;  // Default to Archive
  ignoreNextConfirmRelease = true;  // Ignore the release from the long-press that opened this menu
  updateRequired = true;
}

void MyLibraryActivity::executeAction() {
  bool success = false;

  if (selectedAction == ActionType::Archive) {
    success = BookManager::archiveBook(actionTargetPath);
  } else {
    success = BookManager::deleteBook(actionTargetPath);
  }

  if (success) {
    // Reload data
    loadRecentBooks();
    loadFiles();

    // Adjust selector if needed
    const int itemCount = getCurrentItemCount();
    if (selectorIndex >= itemCount && itemCount > 0) {
      selectorIndex = itemCount - 1;
    } else if (itemCount == 0) {
      selectorIndex = 0;
    }
  }

  uiState = UIState::Normal;
  updateRequired = true;
}

void MyLibraryActivity::loop() {
  // Handle action menu state
  if (uiState == UIState::ActionMenu) {
    if (mappedInput.wasReleased(MappedInputManager::Button::Back)) {
      uiState = UIState::Normal;
      ignoreNextConfirmRelease = false;
      updateRequired = true;
      return;
    }

    if (mappedInput.wasReleased(MappedInputManager::Button::Up)) {
      menuSelection = 0;  // Archive
      updateRequired = true;
      return;
    }

    if (mappedInput.wasReleased(MappedInputManager::Button::Down)) {
      menuSelection = 1;  // Delete
      updateRequired = true;
      return;
    }

    if (mappedInput.wasReleased(MappedInputManager::Button::Confirm)) {
      // Ignore the release from the long-press that opened this menu
      if (ignoreNextConfirmRelease) {
        ignoreNextConfirmRelease = false;
        return;
      }
      selectedAction = (menuSelection == 0) ? ActionType::Archive : ActionType::Delete;
      uiState = UIState::Confirming;
      updateRequired = true;
      return;
    }

    return;
  }

  // Handle confirmation state
  if (uiState == UIState::Confirming) {
    if (mappedInput.wasReleased(MappedInputManager::Button::Back)) {
      uiState = UIState::ActionMenu;
      updateRequired = true;
      return;
    }

    if (mappedInput.wasReleased(MappedInputManager::Button::Confirm)) {
      executeAction();
      return;
    }

    return;
  }

  // Normal state handling
  const int itemCount = getCurrentItemCount();
  const int pageItems = getPageItems();

  // Long press BACK (1s+) in Files tab goes to root folder
  if (currentTab == Tab::Files && mappedInput.isPressed(MappedInputManager::Button::Back) &&
      mappedInput.getHeldTime() >= GO_HOME_MS) {
    if (basepath != "/") {
      basepath = "/";
      loadFiles();
      selectorIndex = 0;
      updateRequired = true;
    }
    return;
  }

  // Long press Confirm to open action menu (only for files, not directories)
  if (mappedInput.isPressed(MappedInputManager::Button::Confirm) &&
      mappedInput.getHeldTime() >= ACTION_MENU_MS && isSelectedItemAFile()) {
    openActionMenu();
    return;
  }

  const bool upReleased = mappedInput.wasReleased(MappedInputManager::Button::Up);
  const bool downReleased = mappedInput.wasReleased(MappedInputManager::Button::Down);
  const bool leftReleased = mappedInput.wasReleased(MappedInputManager::Button::Left);
  const bool rightReleased = mappedInput.wasReleased(MappedInputManager::Button::Right);

  const bool skipPage = mappedInput.getHeldTime() > SKIP_PAGE_MS;

  // Confirm button - open selected item (short press)
  if (mappedInput.wasReleased(MappedInputManager::Button::Confirm)) {
    // Ignore if it was a long press that triggered the action menu
    if (mappedInput.getHeldTime() >= ACTION_MENU_MS) {
      return;
    }

    if (currentTab == Tab::Recent) {
      if (!recentBooks.empty() && selectorIndex < static_cast<int>(recentBooks.size())) {
        onSelectBook(recentBooks[selectorIndex].path, currentTab);
      }
    } else {
      // Files tab
      if (!files.empty() && selectorIndex < static_cast<int>(files.size())) {
        if (basepath.back() != '/') basepath += "/";
        if (files[selectorIndex].back() == '/') {
          // Enter directory
          basepath += files[selectorIndex].substr(0, files[selectorIndex].length() - 1);
          loadFiles();
          selectorIndex = 0;
          updateRequired = true;
        } else {
          // Open file
          onSelectBook(basepath + files[selectorIndex], currentTab);
        }
      }
    }
    return;
  }

  // Back button
  if (mappedInput.wasReleased(MappedInputManager::Button::Back)) {
    if (mappedInput.getHeldTime() < GO_HOME_MS) {
      if (currentTab == Tab::Files && basepath != "/") {
        // Go up one directory, remembering the directory we came from
        const std::string oldPath = basepath;
        basepath.replace(basepath.find_last_of('/'), std::string::npos, "");
        if (basepath.empty()) basepath = "/";
        loadFiles();

        // Select the directory we just came from
        const auto pos = oldPath.find_last_of('/');
        const std::string dirName = oldPath.substr(pos + 1) + "/";
        selectorIndex = static_cast<int>(findEntry(dirName));

        updateRequired = true;
      } else {
        // Go home
        onGoHome();
      }
    }
    return;
  }

  // Tab switching: Left/Right always control tabs
  if (leftReleased && currentTab == Tab::Files) {
    currentTab = Tab::Recent;
    selectorIndex = 0;
    updateRequired = true;
    return;
  }
  if (rightReleased && currentTab == Tab::Recent) {
    currentTab = Tab::Files;
    selectorIndex = 0;
    updateRequired = true;
    return;
  }

  // Navigation: Up/Down moves through items only
  const bool prevReleased = upReleased;
  const bool nextReleased = downReleased;

  if (prevReleased && itemCount > 0) {
    if (skipPage) {
      selectorIndex = ((selectorIndex / pageItems - 1) * pageItems + itemCount) % itemCount;
    } else {
      selectorIndex = (selectorIndex + itemCount - 1) % itemCount;
    }
    updateRequired = true;
  } else if (nextReleased && itemCount > 0) {
    if (skipPage) {
      selectorIndex = ((selectorIndex / pageItems + 1) * pageItems) % itemCount;
    } else {
      selectorIndex = (selectorIndex + 1) % itemCount;
    }
    updateRequired = true;
  }
}

void MyLibraryActivity::displayTaskLoop() {
  while (true) {
    if (updateRequired) {
      updateRequired = false;
      xSemaphoreTake(renderingMutex, portMAX_DELAY);
      render();
      xSemaphoreGive(renderingMutex);
    }
    vTaskDelay(10 / portTICK_PERIOD_MS);
  }
}

void MyLibraryActivity::render() const {
  renderer.clearScreen();

  // Handle different UI states
  if (uiState == UIState::ActionMenu) {
    renderActionMenu();
    renderer.displayBuffer();
    return;
  }

  if (uiState == UIState::Confirming) {
    renderConfirmation();
    renderer.displayBuffer();
    return;
  }

  // Normal state - draw library view
  // Draw tab bar
  std::vector<TabInfo> tabs = {{"Recent", currentTab == Tab::Recent}, {"Files", currentTab == Tab::Files}};
  ScreenComponents::drawTabBar(renderer, TAB_BAR_Y, tabs);

  // Draw content based on current tab
  if (currentTab == Tab::Recent) {
    renderRecentTab();
  } else {
    renderFilesTab();
  }

  // Draw scroll indicator
  const int screenHeight = renderer.getScreenHeight();
  const int contentHeight = screenHeight - CONTENT_START_Y - 60;  // 60 for bottom bar
  ScreenComponents::drawScrollIndicator(renderer, getCurrentPage(), getTotalPages(), CONTENT_START_Y, contentHeight);

  // Draw side button hints (up/down navigation on right side)
  // Note: text is rotated 90° CW, so ">" appears as "^" and "<" appears as "v"
  renderer.drawSideButtonHints(UI_10_FONT_ID, ">", "<");

  // Draw bottom button hints
  const auto labels = mappedInput.mapLabels("« Back", "Open", "<", ">");
  renderer.drawButtonHints(UI_10_FONT_ID, labels.btn1, labels.btn2, labels.btn3, labels.btn4);

  renderer.displayBuffer();
}

void MyLibraryActivity::renderRecentTab() const {
  const auto pageWidth = renderer.getScreenWidth();
  const int pageItems = getPageItems();
  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");
    return;
  }

  const auto pageStartIndex = selectorIndex / pageItems * pageItems;

  // Draw selection highlight
  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++) {
    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);
    }
  }
}

void MyLibraryActivity::renderFilesTab() const {
  const auto pageWidth = renderer.getScreenWidth();
  const int pageItems = getPageItems();
  const int fileCount = static_cast<int>(files.size());

  if (fileCount == 0) {
    renderer.drawText(UI_10_FONT_ID, LEFT_MARGIN, CONTENT_START_Y, "No books found");
    return;
  }

  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);

  // Draw items
  for (int i = pageStartIndex; i < fileCount && i < pageStartIndex + pageItems; i++) {
    auto item = renderer.truncatedText(UI_10_FONT_ID, files[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);
  }
}

void MyLibraryActivity::renderActionMenu() const {
  const auto pageWidth = renderer.getScreenWidth();
  const auto pageHeight = renderer.getScreenHeight();

  // Title
  renderer.drawCenteredText(UI_12_FONT_ID, 20, "Book Actions", true, EpdFontFamily::BOLD);

  // Show filename
  const int filenameY = 70;
  auto truncatedName = renderer.truncatedText(UI_10_FONT_ID, actionTargetName.c_str(), pageWidth - 40);
  renderer.drawCenteredText(UI_10_FONT_ID, filenameY, truncatedName.c_str());

  // Menu options
  const int menuStartY = pageHeight / 2 - 30;
  constexpr int menuLineHeight = 40;
  constexpr int menuItemWidth = 120;
  const int menuX = (pageWidth - menuItemWidth) / 2;

  // Archive option
  if (menuSelection == 0) {
    renderer.fillRect(menuX - 10, menuStartY - 5, menuItemWidth + 20, menuLineHeight);
  }
  renderer.drawCenteredText(UI_10_FONT_ID, menuStartY, "Archive", menuSelection != 0);

  // Delete option
  if (menuSelection == 1) {
    renderer.fillRect(menuX - 10, menuStartY + menuLineHeight - 5, menuItemWidth + 20, menuLineHeight);
  }
  renderer.drawCenteredText(UI_10_FONT_ID, menuStartY + menuLineHeight, "Delete", menuSelection != 1);

  // Draw side button hints (up/down navigation)
  renderer.drawSideButtonHints(UI_10_FONT_ID, ">", "<");

  // Draw bottom button hints
  const auto labels = mappedInput.mapLabels("« Cancel", "Select", "", "");
  renderer.drawButtonHints(UI_10_FONT_ID, labels.btn1, labels.btn2, labels.btn3, labels.btn4);
}

void MyLibraryActivity::renderConfirmation() const {
  const auto pageWidth = renderer.getScreenWidth();
  const auto pageHeight = renderer.getScreenHeight();

  // Title based on action
  const char* actionTitle = (selectedAction == ActionType::Archive) ? "Archive Book?" : "Delete Book?";
  renderer.drawCenteredText(UI_12_FONT_ID, 20, actionTitle, true, EpdFontFamily::BOLD);

  // Show filename
  const int filenameY = pageHeight / 2 - 40;
  auto truncatedName = renderer.truncatedText(UI_10_FONT_ID, actionTargetName.c_str(), pageWidth - 40);
  renderer.drawCenteredText(UI_10_FONT_ID, filenameY, truncatedName.c_str());

  // Warning text
  const int warningY = pageHeight / 2;
  if (selectedAction == ActionType::Archive) {
    renderer.drawCenteredText(UI_10_FONT_ID, warningY, "Book will be moved to archive.");
    renderer.drawCenteredText(UI_10_FONT_ID, warningY + 25, "Reading progress will be saved.");
  } else {
    renderer.drawCenteredText(UI_10_FONT_ID, warningY, "Book will be permanently deleted!", true, EpdFontFamily::BOLD);
    renderer.drawCenteredText(UI_10_FONT_ID, warningY + 25, "This cannot be undone.");
  }

  // Draw bottom button hints
  const auto labels = mappedInput.mapLabels("« Cancel", "Confirm", "", "");
  renderer.drawButtonHints(UI_10_FONT_ID, labels.btn1, labels.btn2, labels.btn3, labels.btn4);
}