#include "BookInfoActivity.h"

#include <algorithm>

#include <Bitmap.h>
#include <Epub.h>
#include <FsHelpers.h>
#include <GfxRenderer.h>
#include <HalStorage.h>
#include <I18n.h>
#include <Logging.h>
#include <PlaceholderCoverGenerator.h>
#include <Xtc.h>

#include "components/UITheme.h"
#include "fontIds.h"

namespace {
constexpr int MARGIN = 20;
constexpr int LABEL_VALUE_GAP = 4;
constexpr int SECTION_GAP = 14;
constexpr int MAX_WRAPPED_LINES = 60;
constexpr int COVER_GAP = 16;

std::string normalizeWhitespace(const std::string& s) {
  std::string out;
  out.reserve(s.size());
  bool prevSpace = false;
  for (const char c : s) {
    if (c == '\n' || c == '\r' || c == '\t') {
      if (!prevSpace) {
        out += ' ';
        prevSpace = true;
      }
    } else {
      out += c;
      prevSpace = (c == ' ');
    }
  }
  return out;
}
}  // namespace

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

  std::string fileName = filePath;
  const size_t lastSlash = filePath.rfind('/');
  if (lastSlash != std::string::npos) {
    fileName = filePath.substr(lastSlash + 1);
  }

  size_t fileSize = 0;
  {
    FsFile file;
    if (Storage.openFileForRead("BIF", filePath, file)) {
      fileSize = file.fileSize();
      file.close();
    }
  }

  std::string title, author, series, seriesIndex, description, language;

  if (FsHelpers::hasEpubExtension(fileName)) {
    Epub epub(filePath, "/.crosspoint");
    bool needsBuild = !epub.load(false, true);
    Rect popupRect{};
    if (needsBuild) {
      popupRect = GUI.drawPopup(renderer, tr(STR_LOADING));
      GUI.fillPopupProgress(renderer, popupRect, 10);
      epub.load(true, true);
      GUI.fillPopupProgress(renderer, popupRect, 50);
    }

    title = epub.getTitle();
    author = epub.getAuthor();
    series = epub.getSeries();
    seriesIndex = epub.getSeriesIndex();
    description = normalizeWhitespace(epub.getDescription());
    language = epub.getLanguage();

    const int coverH = renderer.getScreenHeight() * 2 / 5;
    if (epub.generateThumbBmp(coverH)) {
      coverBmpPath = epub.getThumbBmpPath(coverH);
    } else {
      const int thumbW = static_cast<int>(coverH * 0.6);
      const std::string placeholderPath = epub.getCachePath() + "/placeholder_" + std::to_string(coverH) + ".bmp";
      if (PlaceholderCoverGenerator::generate(placeholderPath, title.empty() ? fileName : title, author, thumbW,
                                              coverH)) {
        coverBmpPath = placeholderPath;
      }
    }
    if (needsBuild) {
      GUI.fillPopupProgress(renderer, popupRect, 100);
    }
  } else if (FsHelpers::hasXtcExtension(fileName)) {
    Xtc xtc(filePath, "/.crosspoint");
    bool needsBuild = !Storage.exists(xtc.getCachePath().c_str());
    Rect popupRect{};
    if (needsBuild) {
      popupRect = GUI.drawPopup(renderer, tr(STR_LOADING));
      GUI.fillPopupProgress(renderer, popupRect, 10);
    }
    if (xtc.load()) {
      if (needsBuild) {
        GUI.fillPopupProgress(renderer, popupRect, 50);
      }
      title = xtc.getTitle();
      author = xtc.getAuthor();

      const int coverH = renderer.getScreenHeight() * 2 / 5;
      if (xtc.generateThumbBmp(coverH)) {
        coverBmpPath = xtc.getThumbBmpPath(coverH);
      } else {
        const int thumbW = static_cast<int>(coverH * 0.6);
        const std::string placeholderPath = xtc.getCachePath() + "/placeholder_" + std::to_string(coverH) + ".bmp";
        if (PlaceholderCoverGenerator::generate(placeholderPath, title.empty() ? fileName : title, author, thumbW,
                                                coverH)) {
          coverBmpPath = placeholderPath;
        }
      }
    }
    if (needsBuild) {
      GUI.fillPopupProgress(renderer, popupRect, 100);
    }
  }

  if (title.empty()) {
    title = fileName;
  }

  buildLayout(title, author, series, seriesIndex, description, language, fileSize);
  requestUpdate();
}

void BookInfoActivity::onExit() { Activity::onExit(); }

void BookInfoActivity::buildLayout(const std::string& title, const std::string& author, const std::string& series,
                                   const std::string& seriesIndex, const std::string& description,
                                   const std::string& language, size_t fileSize) {
  const int contentW = renderer.getScreenWidth() - MARGIN * 2;
  fields.reserve(6);

  auto addField = [&](const char* label, const std::string& text, bool bold, EpdFontFamily::Style style) {
    if (text.empty()) return;
    InfoField field;
    field.label = label;
    field.bold = bold;
    field.lines = renderer.wrappedText(UI_12_FONT_ID, text.c_str(), contentW, MAX_WRAPPED_LINES, style);
    fields.push_back(std::move(field));
  };

  addField(nullptr, title, true, EpdFontFamily::BOLD);
  addField(tr(STR_AUTHOR), author, false, EpdFontFamily::REGULAR);

  if (!series.empty()) {
    std::string seriesStr = series;
    if (!seriesIndex.empty()) {
      seriesStr += " #" + seriesIndex;
    }
    addField(tr(STR_SERIES), seriesStr, false, EpdFontFamily::REGULAR);
  }

  addField(tr(STR_LANGUAGE), language, false, EpdFontFamily::REGULAR);

  if (fileSize > 0) {
    addField(tr(STR_FILE_SIZE), formatFileSize(fileSize), false, EpdFontFamily::REGULAR);
  }

  addField(tr(STR_DESCRIPTION), description, false, EpdFontFamily::REGULAR);

  const int lineH10 = renderer.getLineHeight(UI_10_FONT_ID);
  const int lineH12 = renderer.getLineHeight(UI_12_FONT_ID);
  int h = MARGIN;

  if (!coverBmpPath.empty()) {
    FsFile file;
    if (Storage.openFileForRead("BIF", coverBmpPath, file)) {
      Bitmap bitmap(file);
      if (bitmap.parseHeaders() == BmpReaderError::Ok) {
        coverDisplayHeight = bitmap.getHeight();
        coverDisplayWidth = bitmap.getWidth();
      }
      file.close();
    }
    if (coverDisplayHeight > 0) {
      h += coverDisplayHeight + COVER_GAP;
    }
  }

  for (const auto& field : fields) {
    if (field.label) {
      h += lineH10 + LABEL_VALUE_GAP;
    }
    h += static_cast<int>(field.lines.size()) * lineH12;
    h += SECTION_GAP;
  }
  contentHeight = h;
}

void BookInfoActivity::loop() {
  if (mappedInput.wasReleased(MappedInputManager::Button::Back)) {
    ActivityResult r;
    r.isCancelled = true;
    setResult(std::move(r));
    finish();
    return;
  }

  const int pageH = renderer.getScreenHeight();
  const int scrollStep = pageH / 3;

  if (mappedInput.wasReleased(MappedInputManager::Button::Down) ||
      mappedInput.wasReleased(MappedInputManager::Button::PageForward) ||
      mappedInput.wasReleased(MappedInputManager::Button::Left)) {
    if (scrollOffset + pageH < contentHeight) {
      scrollOffset += scrollStep;
      requestUpdate();
    }
  }

  if (mappedInput.wasReleased(MappedInputManager::Button::Up) ||
      mappedInput.wasReleased(MappedInputManager::Button::PageBack) ||
      mappedInput.wasReleased(MappedInputManager::Button::Right)) {
    if (scrollOffset > 0) {
      scrollOffset -= scrollStep;
      if (scrollOffset < 0) scrollOffset = 0;
      requestUpdate();
    }
  }
}

void BookInfoActivity::render(RenderLock&&) {
  renderer.clearScreen();

  const int pageH = renderer.getScreenHeight();
  const int lineH10 = renderer.getLineHeight(UI_10_FONT_ID);
  const int lineH12 = renderer.getLineHeight(UI_12_FONT_ID);
  int y = MARGIN - scrollOffset;

  // Cover image — only draw if at least partially visible
  if (!coverBmpPath.empty() && coverDisplayHeight > 0) {
    if (y + coverDisplayHeight > 0 && y < pageH) {
      FsFile file;
      if (Storage.openFileForRead("BIF", coverBmpPath, file)) {
        Bitmap bitmap(file);
        if (bitmap.parseHeaders() == BmpReaderError::Ok) {
          const int coverX = (renderer.getScreenWidth() - coverDisplayWidth) / 2;
          renderer.drawBitmap1Bit(bitmap, coverX, y, coverDisplayWidth, std::min(coverDisplayHeight, pageH - y));
        }
        file.close();
      }
    }
    y += coverDisplayHeight + COVER_GAP;
  }

  for (const auto& field : fields) {
    if (y >= pageH) break;

    if (field.label) {
      if (y + lineH10 > 0 && y < pageH) {
        renderer.drawText(UI_10_FONT_ID, MARGIN, y, field.label, true, EpdFontFamily::BOLD);
      }
      y += lineH10 + LABEL_VALUE_GAP;
    }

    const auto style = field.bold ? EpdFontFamily::BOLD : EpdFontFamily::REGULAR;
    for (const auto& line : field.lines) {
      if (y >= pageH) break;
      if (y + lineH12 > 0) {
        renderer.drawText(UI_12_FONT_ID, MARGIN, y, line.c_str(), true, style);
      }
      y += lineH12;
    }
    y += SECTION_GAP;
  }

  const bool canScrollDown = scrollOffset + pageH < contentHeight;
  const bool canScrollUp = scrollOffset > 0;
  const char* downHint = canScrollDown ? tr(STR_DIR_DOWN) : "";
  const char* upHint = canScrollUp ? tr(STR_DIR_UP) : "";
  const auto labels = mappedInput.mapLabels(tr(STR_BACK), "", downHint, upHint);
  GUI.drawButtonHints(renderer, labels.btn1, labels.btn2, labels.btn3, labels.btn4);

  renderer.displayBuffer();
}

std::string BookInfoActivity::formatFileSize(size_t bytes) {
  char buf[32];
  if (bytes < 1024) {
    snprintf(buf, sizeof(buf), "%u B", static_cast<unsigned>(bytes));
  } else if (bytes < 1024 * 1024) {
    snprintf(buf, sizeof(buf), "%.1f KB", static_cast<float>(bytes) / 1024.0f);
  } else {
    snprintf(buf, sizeof(buf), "%.1f MB", static_cast<float>(bytes) / (1024.0f * 1024.0f));
  }
  return buf;
}