#include "SleepActivity.h"

#include <Epub.h>
#include <GfxRenderer.h>
#include <SDCardManager.h>
#include <Txt.h>
#include <Xtc.h>

#include "CrossPointSettings.h"
#include "CrossPointState.h"
#include "fontIds.h"
#include "images/CrossLarge.h"
#include "util/StringUtils.h"

namespace {
// Perimeter cache file format:
// - 4 bytes: uint32_t file size (for cache invalidation)
// - 1 byte: result (0 = white perimeter, 1 = black perimeter)
constexpr size_t PERIM_CACHE_SIZE = 5;
}  // namespace

void SleepActivity::onEnter() {
  Activity::onEnter();
  renderPopup("Entering Sleep...");

  if (SETTINGS.sleepScreen == CrossPointSettings::SLEEP_SCREEN_MODE::BLANK) {
    return renderBlankSleepScreen();
  }

  if (SETTINGS.sleepScreen == CrossPointSettings::SLEEP_SCREEN_MODE::CUSTOM) {
    return renderCustomSleepScreen();
  }

  if (SETTINGS.sleepScreen == CrossPointSettings::SLEEP_SCREEN_MODE::COVER) {
    return renderCoverSleepScreen();
  }

  renderDefaultSleepScreen();
}

void SleepActivity::renderPopup(const char* message) const {
  const int textWidth = renderer.getTextWidth(UI_12_FONT_ID, message, EpdFontFamily::BOLD);
  constexpr int margin = 20;
  const int x = (renderer.getScreenWidth() - textWidth - margin * 2) / 2;
  constexpr int y = 117;
  const int w = textWidth + margin * 2;
  const int h = renderer.getLineHeight(UI_12_FONT_ID) + margin * 2;
  // renderer.clearScreen();
  renderer.fillRect(x - 5, y - 5, w + 10, h + 10, true);
  renderer.fillRect(x + 5, y + 5, w - 10, h - 10, false);
  renderer.drawText(UI_12_FONT_ID, x + margin, y + margin, message, true, EpdFontFamily::BOLD);
  renderer.displayBuffer();
}

void SleepActivity::renderCustomSleepScreen() const {
  // Check if we have a /sleep directory
  auto dir = SdMan.open("/sleep");
  if (dir && dir.isDirectory()) {
    std::vector<std::string> files;
    char name[500];
    // collect all valid BMP files
    for (auto file = dir.openNextFile(); file; file = dir.openNextFile()) {
      if (file.isDirectory()) {
        file.close();
        continue;
      }
      file.getName(name, sizeof(name));
      auto filename = std::string(name);
      if (filename[0] == '.') {
        file.close();
        continue;
      }

      if (filename.substr(filename.length() - 4) != ".bmp") {
        Serial.printf("[%lu] [SLP] Skipping non-.bmp file name: %s\n", millis(), name);
        file.close();
        continue;
      }
      Bitmap bitmap(file);
      if (bitmap.parseHeaders() != BmpReaderError::Ok) {
        Serial.printf("[%lu] [SLP] Skipping invalid BMP file: %s\n", millis(), name);
        file.close();
        continue;
      }
      files.emplace_back(filename);
      file.close();
    }
    const auto numFiles = files.size();
    if (numFiles > 0) {
      // Generate a random number between 1 and numFiles
      auto randomFileIndex = random(numFiles);
      // If we picked the same image as last time, reroll
      while (numFiles > 1 && randomFileIndex == APP_STATE.lastSleepImage) {
        randomFileIndex = random(numFiles);
      }
      APP_STATE.lastSleepImage = randomFileIndex;
      APP_STATE.saveToFile();
      const auto bmpPath = "/sleep/" + files[randomFileIndex];
      FsFile file;
      if (SdMan.openFileForRead("SLP", bmpPath, file)) {
        Serial.printf("[%lu] [SLP] Randomly loading: /sleep/%s\n", millis(), files[randomFileIndex].c_str());
        delay(100);
        Bitmap bitmap(file, true);
        if (bitmap.parseHeaders() == BmpReaderError::Ok) {
          renderBitmapSleepScreen(bitmap, bmpPath);
          dir.close();
          return;
        }
      }
    }
  }
  if (dir) dir.close();

  // Look for sleep.bmp on the root of the sd card to determine if we should
  // render a custom sleep screen instead of the default.
  FsFile file;
  const std::string rootSleepPath = "/sleep.bmp";
  if (SdMan.openFileForRead("SLP", rootSleepPath, file)) {
    Bitmap bitmap(file, true);
    if (bitmap.parseHeaders() == BmpReaderError::Ok) {
      Serial.printf("[%lu] [SLP] Loading: /sleep.bmp\n", millis());
      renderBitmapSleepScreen(bitmap, rootSleepPath);
      return;
    }
  }

  renderDefaultSleepScreen();
}

void SleepActivity::renderDefaultSleepScreen() const {
  const auto pageWidth = renderer.getScreenWidth();
  const auto pageHeight = renderer.getScreenHeight();

  renderer.clearScreen();
  renderer.drawImage(CrossLarge, (pageWidth + 128) / 2, (pageHeight - 128) / 2, 128, 128);
  renderer.drawCenteredText(UI_10_FONT_ID, pageHeight / 2 + 70, "CrossPoint", true, EpdFontFamily::BOLD);
  renderer.drawCenteredText(SMALL_FONT_ID, pageHeight / 2 + 95, "SLEEPING");

  // Make sleep screen dark unless light is selected in settings
  if (SETTINGS.sleepScreen != CrossPointSettings::SLEEP_SCREEN_MODE::LIGHT) {
    renderer.invertScreen();
  }

  renderer.displayBuffer(EInkDisplay::HALF_REFRESH);
}

void SleepActivity::renderBitmapSleepScreen(const Bitmap& bitmap, const std::string& bmpPath) const {
  int x, y;
  const auto pageWidth = renderer.getScreenWidth();
  const auto pageHeight = renderer.getScreenHeight();
  float cropX = 0, cropY = 0;
  int drawWidth = pageWidth;
  int drawHeight = pageHeight;
  int fillWidth = pageWidth;   // Actual area the image will occupy
  int fillHeight = pageHeight;

  Serial.printf("[%lu] [SLP] bitmap %d x %d, screen %d x %d\n", millis(), bitmap.getWidth(), bitmap.getHeight(),
                pageWidth, pageHeight);

  const float bitmapRatio = static_cast<float>(bitmap.getWidth()) / static_cast<float>(bitmap.getHeight());
  const float screenRatio = static_cast<float>(pageWidth) / static_cast<float>(pageHeight);
  Serial.printf("[%lu] [SLP] bitmap ratio: %f, screen ratio: %f\n", millis(), bitmapRatio, screenRatio);

  const auto coverMode = SETTINGS.sleepScreenCoverMode;

  if (coverMode == CrossPointSettings::SLEEP_SCREEN_COVER_MODE::ACTUAL) {
    // ACTUAL mode: Show image at actual size, centered (no scaling)
    x = (pageWidth - bitmap.getWidth()) / 2;
    y = (pageHeight - bitmap.getHeight()) / 2;
    // Don't constrain to screen dimensions - drawBitmap will clip
    drawWidth = 0;
    drawHeight = 0;
    fillWidth = bitmap.getWidth();
    fillHeight = bitmap.getHeight();
    Serial.printf("[%lu] [SLP] ACTUAL mode: centering at %d, %d\n", millis(), x, y);
  } else if (coverMode == CrossPointSettings::SLEEP_SCREEN_COVER_MODE::CROP) {
    // CROP mode: Scale to fill screen completely (may crop edges)
    // Calculate crop values to fill the screen while maintaining aspect ratio
    if (bitmapRatio > screenRatio) {
      // Image is wider than screen ratio - crop horizontally
      cropX = 1.0f - (screenRatio / bitmapRatio);
      Serial.printf("[%lu] [SLP] CROP mode: cropping x by %f\n", millis(), cropX);
    } else if (bitmapRatio < screenRatio) {
      // Image is taller than screen ratio - crop vertically
      cropY = 1.0f - (bitmapRatio / screenRatio);
      Serial.printf("[%lu] [SLP] CROP mode: cropping y by %f\n", millis(), cropY);
    }
    // After cropping, the image should fill the screen exactly
    x = 0;
    y = 0;
    fillWidth = pageWidth;
    fillHeight = pageHeight;
    Serial.printf("[%lu] [SLP] CROP mode: drawing at 0, 0 with crop %f, %f\n", millis(), cropX, cropY);
  } else {
    // FIT mode (default): Scale to fit entire image within screen (may have letterboxing)
    // Calculate the scaled dimensions
    float scale;
    if (bitmapRatio > screenRatio) {
      // Image is wider than screen ratio - fit to width
      scale = static_cast<float>(pageWidth) / static_cast<float>(bitmap.getWidth());
    } else {
      // Image is taller than screen ratio - fit to height
      scale = static_cast<float>(pageHeight) / static_cast<float>(bitmap.getHeight());
    }
    fillWidth = static_cast<int>(bitmap.getWidth() * scale);
    fillHeight = static_cast<int>(bitmap.getHeight() * scale);

    // Center the scaled image
    x = (pageWidth - fillWidth) / 2;
    y = (pageHeight - fillHeight) / 2;
    Serial.printf("[%lu] [SLP] FIT mode: scale %f, scaled size %d x %d, position %d, %d\n", millis(), scale,
                  fillWidth, fillHeight, x, y);
  }

  // Detect perimeter color and clear to matching background
  const bool isBlackPerimeter = getPerimeterIsBlack(bitmap, bmpPath);
  const uint8_t clearColor = isBlackPerimeter ? 0x00 : 0xFF;

  Serial.printf("[%lu] [SLP] drawing to %d x %d\n", millis(), x, y);
  renderer.clearScreen(clearColor);

  // If background is black, fill the image area with white first so white pixels render correctly
  if (isBlackPerimeter) {
    renderer.fillRect(x, y, fillWidth, fillHeight, false);  // false = white
  }

  renderer.drawBitmap(bitmap, x, y, drawWidth, drawHeight, cropX, cropY);
  renderer.displayBuffer(EInkDisplay::HALF_REFRESH);

  if (bitmap.hasGreyscale()) {
    bitmap.rewindToData();
    renderer.clearScreen(0x00);
    renderer.setRenderMode(GfxRenderer::GRAYSCALE_LSB);
    renderer.drawBitmap(bitmap, x, y, drawWidth, drawHeight, cropX, cropY);
    renderer.copyGrayscaleLsbBuffers();

    bitmap.rewindToData();
    renderer.clearScreen(0x00);
    renderer.setRenderMode(GfxRenderer::GRAYSCALE_MSB);
    renderer.drawBitmap(bitmap, x, y, drawWidth, drawHeight, cropX, cropY);
    renderer.copyGrayscaleMsbBuffers();

    renderer.displayGrayBuffer();
    renderer.setRenderMode(GfxRenderer::BW);
  }
}

void SleepActivity::renderCoverSleepScreen() const {
  if (APP_STATE.openEpubPath.empty()) {
    return renderDefaultSleepScreen();
  }

  std::string coverBmpPath;
  bool cropped = SETTINGS.sleepScreenCoverMode == CrossPointSettings::SLEEP_SCREEN_COVER_MODE::CROP;

  // Check if the current book is XTC, TXT, or EPUB
  if (StringUtils::checkFileExtension(APP_STATE.openEpubPath, ".xtc") ||
      StringUtils::checkFileExtension(APP_STATE.openEpubPath, ".xtch")) {
    // Handle XTC file
    Xtc lastXtc(APP_STATE.openEpubPath, "/.crosspoint");
    if (!lastXtc.load()) {
      Serial.println("[SLP] Failed to load last XTC");
      return renderDefaultSleepScreen();
    }

    if (!lastXtc.generateCoverBmp()) {
      Serial.println("[SLP] Failed to generate XTC cover bmp");
      return renderDefaultSleepScreen();
    }

    coverBmpPath = lastXtc.getCoverBmpPath();
  } else if (StringUtils::checkFileExtension(APP_STATE.openEpubPath, ".txt")) {
    // Handle TXT file - looks for cover image in the same folder
    Txt lastTxt(APP_STATE.openEpubPath, "/.crosspoint");
    if (!lastTxt.load()) {
      Serial.println("[SLP] Failed to load last TXT");
      return renderDefaultSleepScreen();
    }

    if (!lastTxt.generateCoverBmp()) {
      Serial.println("[SLP] No cover image found for TXT file");
      return renderDefaultSleepScreen();
    }

    coverBmpPath = lastTxt.getCoverBmpPath();
  } else if (StringUtils::checkFileExtension(APP_STATE.openEpubPath, ".epub")) {
    // Handle EPUB file
    Epub lastEpub(APP_STATE.openEpubPath, "/.crosspoint");
    if (!lastEpub.load()) {
      Serial.println("[SLP] Failed to load last epub");
      return renderDefaultSleepScreen();
    }

    if (!lastEpub.generateCoverBmp(cropped)) {
      Serial.println("[SLP] Failed to generate cover bmp");
      return renderDefaultSleepScreen();
    }

    coverBmpPath = lastEpub.getCoverBmpPath(cropped);
  } else {
    return renderDefaultSleepScreen();
  }

  FsFile file;
  if (SdMan.openFileForRead("SLP", coverBmpPath, file)) {
    Bitmap bitmap(file);
    if (bitmap.parseHeaders() == BmpReaderError::Ok) {
      renderBitmapSleepScreen(bitmap, coverBmpPath);
      return;
    }
  }

  renderDefaultSleepScreen();
}

void SleepActivity::renderBlankSleepScreen() const {
  renderer.clearScreen();
  renderer.displayBuffer(EInkDisplay::HALF_REFRESH);
}

std::string SleepActivity::getPerimeterCachePath(const std::string& bmpPath) {
  // Convert "/dir/file.bmp" to "/dir/.file.bmp.perim"
  const size_t lastSlash = bmpPath.find_last_of('/');
  if (lastSlash == std::string::npos) {
    // No directory, just prepend dot
    return "." + bmpPath + ".perim";
  }
  const std::string dir = bmpPath.substr(0, lastSlash + 1);
  const std::string filename = bmpPath.substr(lastSlash + 1);
  return dir + "." + filename + ".perim";
}

bool SleepActivity::getPerimeterIsBlack(const Bitmap& bitmap, const std::string& bmpPath) const {
  const std::string cachePath = getPerimeterCachePath(bmpPath);

  // Try to read from cache
  FsFile cacheFile;
  if (SdMan.openFileForRead("SLP", cachePath, cacheFile)) {
    uint8_t cacheData[PERIM_CACHE_SIZE];
    if (cacheFile.read(cacheData, PERIM_CACHE_SIZE) == PERIM_CACHE_SIZE) {
      // Extract cached file size
      const uint32_t cachedSize = static_cast<uint32_t>(cacheData[0]) |
                                  (static_cast<uint32_t>(cacheData[1]) << 8) |
                                  (static_cast<uint32_t>(cacheData[2]) << 16) |
                                  (static_cast<uint32_t>(cacheData[3]) << 24);

      // Get current BMP file size
      FsFile bmpFile;
      uint32_t currentSize = 0;
      if (SdMan.openFileForRead("SLP", bmpPath, bmpFile)) {
        currentSize = bmpFile.size();
        bmpFile.close();
      }

      // Validate cache
      if (cachedSize == currentSize && currentSize > 0) {
        const bool result = cacheData[4] != 0;
        Serial.printf("[%lu] [SLP] Perimeter cache hit for %s: %s\n", millis(), bmpPath.c_str(),
                      result ? "black" : "white");
        cacheFile.close();
        return result;
      }
      Serial.printf("[%lu] [SLP] Perimeter cache invalid (size mismatch: %lu vs %lu)\n", millis(),
                    static_cast<unsigned long>(cachedSize), static_cast<unsigned long>(currentSize));
    }
    cacheFile.close();
  }

  // Cache miss - calculate perimeter
  Serial.printf("[%lu] [SLP] Calculating perimeter for %s\n", millis(), bmpPath.c_str());
  const bool isBlack = bitmap.detectPerimeterIsBlack();
  Serial.printf("[%lu] [SLP] Perimeter detected: %s\n", millis(), isBlack ? "black" : "white");

  // Get BMP file size for cache
  FsFile bmpFile;
  uint32_t fileSize = 0;
  if (SdMan.openFileForRead("SLP", bmpPath, bmpFile)) {
    fileSize = bmpFile.size();
    bmpFile.close();
  }

  // Save to cache
  if (fileSize > 0 && SdMan.openFileForWrite("SLP", cachePath, cacheFile)) {
    uint8_t cacheData[PERIM_CACHE_SIZE];
    cacheData[0] = fileSize & 0xFF;
    cacheData[1] = (fileSize >> 8) & 0xFF;
    cacheData[2] = (fileSize >> 16) & 0xFF;
    cacheData[3] = (fileSize >> 24) & 0xFF;
    cacheData[4] = isBlack ? 1 : 0;
    cacheFile.write(cacheData, PERIM_CACHE_SIZE);
    cacheFile.close();
    Serial.printf("[%lu] [SLP] Saved perimeter cache to %s\n", millis(), cachePath.c_str());
  }

  return isBlack;
}