#include "ListViewActivity.h"

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

#include <algorithm>

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

namespace {
// Layout constants (matching MyLibraryActivity's Recent tab)
constexpr int HEADER_Y = 15;
constexpr int CONTENT_START_Y = 60;
constexpr int LINE_HEIGHT = 65;  // Two-line items (title + author)
constexpr int LEFT_MARGIN = 20;
constexpr int RIGHT_MARGIN = 40;
constexpr int MICRO_THUMB_WIDTH = 45;
constexpr int MICRO_THUMB_HEIGHT = 60;
constexpr int THUMB_RIGHT_MARGIN = 50;

// Timing thresholds
constexpr int SKIP_PAGE_MS = 700;

// Helper function to get the micro-thumb path for a book based on its file path
std::string getMicroThumbPathForBook(const std::string& bookPath) {
  const size_t hash = std::hash<std::string>{}(bookPath);

  if (StringUtils::checkFileExtension(bookPath, ".epub")) {
    return "/.crosspoint/epub_" + std::to_string(hash) + "/micro_thumb.bmp";
  } else if (StringUtils::checkFileExtension(bookPath, ".xtc") || StringUtils::checkFileExtension(bookPath, ".xtch")) {
    return "/.crosspoint/xtc_" + std::to_string(hash) + "/micro_thumb.bmp";
  } else if (StringUtils::checkFileExtension(bookPath, ".txt") || StringUtils::checkFileExtension(bookPath, ".TXT")) {
    return "/.crosspoint/txt_" + std::to_string(hash) + "/micro_thumb.bmp";
  }
  return "";
}
}  // namespace

int ListViewActivity::getPageItems() const {
  const int screenHeight = renderer.getScreenHeight();
  const int bottomBarHeight = 60;
  const int availableHeight = screenHeight - CONTENT_START_Y - bottomBarHeight;
  int items = availableHeight / LINE_HEIGHT;
  if (items < 1) {
    items = 1;
  }
  return items;
}

int ListViewActivity::getTotalPages() const {
  const int itemCount = static_cast<int>(bookList.books.size());
  const int pageItems = getPageItems();
  if (itemCount == 0) return 1;
  return (itemCount + pageItems - 1) / pageItems;
}

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

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

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

  renderingMutex = xSemaphoreCreateMutex();

  // Load the list
  if (!BookListStore::loadList(listName, bookList)) {
    Serial.printf("[%lu] [LVA] Failed to load list: %s\n", millis(), listName.c_str());
  }

  selectorIndex = 0;
  updateRequired = true;

  xTaskCreate(&ListViewActivity::taskTrampoline, "ListViewActivityTask",
              4096,               // Stack size
              this,               // Parameters
              1,                  // Priority
              &displayTaskHandle  // Task handle
  );
}

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

  xSemaphoreTake(renderingMutex, portMAX_DELAY);
  if (displayTaskHandle) {
    vTaskDelete(displayTaskHandle);
    displayTaskHandle = nullptr;
    vTaskDelay(10 / portTICK_PERIOD_MS);  // Let idle task free stack
  }
  vSemaphoreDelete(renderingMutex);
  renderingMutex = nullptr;

  bookList.books.clear();
}

void ListViewActivity::loop() {
  const int itemCount = static_cast<int>(bookList.books.size());
  const int pageItems = getPageItems();

  // Back button - return to My Library
  if (mappedInput.wasReleased(MappedInputManager::Button::Back)) {
    if (onBack) {
      onBack();
    }
    return;
  }

  // Confirm button - open selected book
  if (mappedInput.wasReleased(MappedInputManager::Button::Confirm)) {
    if (!bookList.books.empty() && selectorIndex < itemCount) {
      const auto& book = bookList.books[selectorIndex];
      // Check if file exists before opening
      if (SdMan.exists(book.path.c_str())) {
        if (onSelectBook) {
          onSelectBook(book.path);
        }
      } else {
        Serial.printf("[%lu] [LVA] Book file not found: %s\n", millis(), book.path.c_str());
        // Could show an error message here
      }
    }
    return;
  }

  const bool upReleased = mappedInput.wasReleased(MappedInputManager::Button::Up);
  const bool downReleased = mappedInput.wasReleased(MappedInputManager::Button::Down);
  const bool skipPage = mappedInput.getHeldTime() > SKIP_PAGE_MS;

  // Navigation: Up/Down moves through items
  if (upReleased && itemCount > 0) {
    if (skipPage) {
      selectorIndex = ((selectorIndex / pageItems - 1) * pageItems + itemCount) % itemCount;
    } else {
      selectorIndex = (selectorIndex + itemCount - 1) % itemCount;
    }
    updateRequired = true;
  } else if (downReleased && itemCount > 0) {
    if (skipPage) {
      selectorIndex = ((selectorIndex / pageItems + 1) * pageItems) % itemCount;
    } else {
      selectorIndex = (selectorIndex + 1) % itemCount;
    }
    updateRequired = true;
  }
}

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

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

  const auto pageWidth = renderer.getScreenWidth();
  const int pageItems = getPageItems();
  const int bookCount = static_cast<int>(bookList.books.size());

  // Draw header with list name
  auto truncatedTitle = renderer.truncatedText(UI_12_FONT_ID, listName.c_str(), pageWidth - LEFT_MARGIN - RIGHT_MARGIN);
  renderer.drawText(UI_12_FONT_ID, LEFT_MARGIN, HEADER_Y, truncatedTitle.c_str(), true, EpdFontFamily::BOLD);

  if (bookCount == 0) {
    renderer.drawText(UI_10_FONT_ID, LEFT_MARGIN, CONTENT_START_Y, "This list is empty");

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

    renderer.displayBuffer();
    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);

  // Calculate available text width
  const int textMaxWidth = pageWidth - LEFT_MARGIN - RIGHT_MARGIN - MICRO_THUMB_WIDTH - 10;
  const int thumbX = pageWidth - THUMB_RIGHT_MARGIN - MICRO_THUMB_WIDTH;

  // Draw items
  for (int i = pageStartIndex; i < bookCount && i < pageStartIndex + pageItems; i++) {
    const auto& book = bookList.books[i];
    const int y = CONTENT_START_Y + (i % pageItems) * LINE_HEIGHT;
    const bool isSelected = (i == selectorIndex);

    // Try to load and draw micro-thumbnail
    bool hasThumb = false;
    const std::string microThumbPath = getMicroThumbPathForBook(book.path);

    if (!microThumbPath.empty() && SdMan.exists(microThumbPath.c_str())) {
      FsFile thumbFile;
      if (SdMan.openFileForRead("LVA", microThumbPath, thumbFile)) {
        Bitmap bitmap(thumbFile);
        if (bitmap.parseHeaders() == BmpReaderError::Ok) {
          const int bmpW = bitmap.getWidth();
          const int bmpH = bitmap.getHeight();
          const float scaleX = static_cast<float>(MICRO_THUMB_WIDTH) / static_cast<float>(bmpW);
          const float scaleY = static_cast<float>(MICRO_THUMB_HEIGHT) / static_cast<float>(bmpH);
          const float scale = std::min(scaleX, scaleY);
          const int drawnW = static_cast<int>(bmpW * scale);
          const int drawnH = static_cast<int>(bmpH * scale);

          const int thumbY = y + (LINE_HEIGHT - drawnH) / 2;
          if (isSelected) {
            renderer.fillRect(thumbX, thumbY, drawnW, drawnH, false);
          }
          renderer.drawBitmap(bitmap, thumbX, thumbY, MICRO_THUMB_WIDTH, MICRO_THUMB_HEIGHT, 0, 0, isSelected);
          hasThumb = true;
        }
        thumbFile.close();
      }
    }

    // Use full width if no thumbnail
    const int availableWidth = hasThumb ? textMaxWidth : (pageWidth - LEFT_MARGIN - RIGHT_MARGIN);

    // Line 1: Title
    std::string title = book.title;
    if (title.empty()) {
      // Fallback: extract filename from path
      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 truncatedBookTitle = renderer.truncatedText(UI_12_FONT_ID, title.c_str(), availableWidth);
    renderer.drawText(UI_12_FONT_ID, LEFT_MARGIN, y + 2, truncatedBookTitle.c_str(), !isSelected);

    // Line 2: Author
    if (!book.author.empty()) {
      auto truncatedAuthor = renderer.truncatedText(UI_10_FONT_ID, book.author.c_str(), availableWidth);
      renderer.drawText(UI_10_FONT_ID, LEFT_MARGIN, y + 32, truncatedAuthor.c_str(), !isSelected);
    }
  }

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

  // Draw side button hints
  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();
}