#include <Arduino.h>
#include <EInkDisplay.h>
#include <Epub.h>
#include <GfxRenderer.h>
#include <InputManager.h>
#include <SDCardManager.h>
#include <SPI.h>
#include <builtinFonts/all.h>

#include <cstring>

#include "Battery.h"
#include "CrossPointSettings.h"
#include "CrossPointState.h"
#include "KOReaderCredentialStore.h"
#include "MappedInputManager.h"
#include "RecentBooksStore.h"
#include "activities/boot_sleep/BootActivity.h"
#include "activities/boot_sleep/SleepActivity.h"
#include "activities/browser/OpdsBookBrowserActivity.h"
#include "activities/home/HomeActivity.h"
#include "activities/home/MyLibraryActivity.h"
#include "activities/network/CrossPointWebServerActivity.h"
#include "activities/reader/ReaderActivity.h"
#include "activities/settings/SettingsActivity.h"
#include "activities/util/FullScreenMessageActivity.h"
#include "fontIds.h"

#define SPI_FQ 40000000
// Display SPI pins (custom pins for XteinkX4, not hardware SPI defaults)
#define EPD_SCLK 8   // SPI Clock
#define EPD_MOSI 10  // SPI MOSI (Master Out Slave In)
#define EPD_CS 21    // Chip Select
#define EPD_DC 4     // Data/Command
#define EPD_RST 5    // Reset
#define EPD_BUSY 6   // Busy

#define UART0_RXD 20  // Used for USB connection detection

#define SD_SPI_MISO 7

EInkDisplay einkDisplay(EPD_SCLK, EPD_MOSI, EPD_CS, EPD_DC, EPD_RST, EPD_BUSY);
InputManager inputManager;
MappedInputManager mappedInputManager(inputManager);
GfxRenderer renderer(einkDisplay);
Activity* currentActivity;

// Fonts
EpdFont bookerly14RegularFont(&bookerly_14_regular);
EpdFont bookerly14BoldFont(&bookerly_14_bold);
EpdFont bookerly14ItalicFont(&bookerly_14_italic);
EpdFont bookerly14BoldItalicFont(&bookerly_14_bolditalic);
EpdFontFamily bookerly14FontFamily(&bookerly14RegularFont, &bookerly14BoldFont, &bookerly14ItalicFont,
                                   &bookerly14BoldItalicFont);
#ifndef OMIT_FONTS
EpdFont bookerly12RegularFont(&bookerly_12_regular);
EpdFont bookerly12BoldFont(&bookerly_12_bold);
EpdFont bookerly12ItalicFont(&bookerly_12_italic);
EpdFont bookerly12BoldItalicFont(&bookerly_12_bolditalic);
EpdFontFamily bookerly12FontFamily(&bookerly12RegularFont, &bookerly12BoldFont, &bookerly12ItalicFont,
                                   &bookerly12BoldItalicFont);
EpdFont bookerly16RegularFont(&bookerly_16_regular);
EpdFont bookerly16BoldFont(&bookerly_16_bold);
EpdFont bookerly16ItalicFont(&bookerly_16_italic);
EpdFont bookerly16BoldItalicFont(&bookerly_16_bolditalic);
EpdFontFamily bookerly16FontFamily(&bookerly16RegularFont, &bookerly16BoldFont, &bookerly16ItalicFont,
                                   &bookerly16BoldItalicFont);
EpdFont bookerly18RegularFont(&bookerly_18_regular);
EpdFont bookerly18BoldFont(&bookerly_18_bold);
EpdFont bookerly18ItalicFont(&bookerly_18_italic);
EpdFont bookerly18BoldItalicFont(&bookerly_18_bolditalic);
EpdFontFamily bookerly18FontFamily(&bookerly18RegularFont, &bookerly18BoldFont, &bookerly18ItalicFont,
                                   &bookerly18BoldItalicFont);

EpdFont notosans12RegularFont(&notosans_12_regular);
EpdFont notosans12BoldFont(&notosans_12_bold);
EpdFont notosans12ItalicFont(&notosans_12_italic);
EpdFont notosans12BoldItalicFont(&notosans_12_bolditalic);
EpdFontFamily notosans12FontFamily(&notosans12RegularFont, &notosans12BoldFont, &notosans12ItalicFont,
                                   &notosans12BoldItalicFont);
EpdFont notosans14RegularFont(&notosans_14_regular);
EpdFont notosans14BoldFont(&notosans_14_bold);
EpdFont notosans14ItalicFont(&notosans_14_italic);
EpdFont notosans14BoldItalicFont(&notosans_14_bolditalic);
EpdFontFamily notosans14FontFamily(&notosans14RegularFont, &notosans14BoldFont, &notosans14ItalicFont,
                                   &notosans14BoldItalicFont);
EpdFont notosans16RegularFont(&notosans_16_regular);
EpdFont notosans16BoldFont(&notosans_16_bold);
EpdFont notosans16ItalicFont(&notosans_16_italic);
EpdFont notosans16BoldItalicFont(&notosans_16_bolditalic);
EpdFontFamily notosans16FontFamily(&notosans16RegularFont, &notosans16BoldFont, &notosans16ItalicFont,
                                   &notosans16BoldItalicFont);
EpdFont notosans18RegularFont(&notosans_18_regular);
EpdFont notosans18BoldFont(&notosans_18_bold);
EpdFont notosans18ItalicFont(&notosans_18_italic);
EpdFont notosans18BoldItalicFont(&notosans_18_bolditalic);
EpdFontFamily notosans18FontFamily(&notosans18RegularFont, &notosans18BoldFont, &notosans18ItalicFont,
                                   &notosans18BoldItalicFont);

EpdFont opendyslexic8RegularFont(&opendyslexic_8_regular);
EpdFont opendyslexic8BoldFont(&opendyslexic_8_bold);
EpdFont opendyslexic8ItalicFont(&opendyslexic_8_italic);
EpdFont opendyslexic8BoldItalicFont(&opendyslexic_8_bolditalic);
EpdFontFamily opendyslexic8FontFamily(&opendyslexic8RegularFont, &opendyslexic8BoldFont, &opendyslexic8ItalicFont,
                                      &opendyslexic8BoldItalicFont);
EpdFont opendyslexic10RegularFont(&opendyslexic_10_regular);
EpdFont opendyslexic10BoldFont(&opendyslexic_10_bold);
EpdFont opendyslexic10ItalicFont(&opendyslexic_10_italic);
EpdFont opendyslexic10BoldItalicFont(&opendyslexic_10_bolditalic);
EpdFontFamily opendyslexic10FontFamily(&opendyslexic10RegularFont, &opendyslexic10BoldFont, &opendyslexic10ItalicFont,
                                       &opendyslexic10BoldItalicFont);
EpdFont opendyslexic12RegularFont(&opendyslexic_12_regular);
EpdFont opendyslexic12BoldFont(&opendyslexic_12_bold);
EpdFont opendyslexic12ItalicFont(&opendyslexic_12_italic);
EpdFont opendyslexic12BoldItalicFont(&opendyslexic_12_bolditalic);
EpdFontFamily opendyslexic12FontFamily(&opendyslexic12RegularFont, &opendyslexic12BoldFont, &opendyslexic12ItalicFont,
                                       &opendyslexic12BoldItalicFont);
EpdFont opendyslexic14RegularFont(&opendyslexic_14_regular);
EpdFont opendyslexic14BoldFont(&opendyslexic_14_bold);
EpdFont opendyslexic14ItalicFont(&opendyslexic_14_italic);
EpdFont opendyslexic14BoldItalicFont(&opendyslexic_14_bolditalic);
EpdFontFamily opendyslexic14FontFamily(&opendyslexic14RegularFont, &opendyslexic14BoldFont, &opendyslexic14ItalicFont,
                                       &opendyslexic14BoldItalicFont);
#endif  // OMIT_FONTS

EpdFont smallFont(&notosans_8_regular);
EpdFontFamily smallFontFamily(&smallFont);

EpdFont ui10RegularFont(&ubuntu_10_regular);
EpdFont ui10BoldFont(&ubuntu_10_bold);
EpdFontFamily ui10FontFamily(&ui10RegularFont, &ui10BoldFont);

EpdFont ui12RegularFont(&ubuntu_12_regular);
EpdFont ui12BoldFont(&ubuntu_12_bold);
EpdFontFamily ui12FontFamily(&ui12RegularFont, &ui12BoldFont);

// measurement of power button press duration calibration value
unsigned long t1 = 0;
unsigned long t2 = 0;

void exitActivity() {
  if (currentActivity) {
    currentActivity->onExit();
    delete currentActivity;
    currentActivity = nullptr;
  }
}

void enterNewActivity(Activity* activity) {
  currentActivity = activity;
  currentActivity->onEnter();
}

// Verify long press on wake-up from deep sleep
void verifyWakeupLongPress() {
  // Give the user up to 1000ms to start holding the power button, and must hold for SETTINGS.getPowerButtonDuration()
  const auto start = millis();
  bool abort = false;
  // Subtract the current time, because inputManager only starts counting the HeldTime from the first update()
  // This way, we remove the time we already took to reach here from the duration,
  // assuming the button was held until now from millis()==0 (i.e. device start time).
  const uint16_t calibration = start;
  const uint16_t calibratedPressDuration =
      (calibration < SETTINGS.getPowerButtonDuration()) ? SETTINGS.getPowerButtonDuration() - calibration : 1;

  inputManager.update();
  // Verify the user has actually pressed
  while (!inputManager.isPressed(InputManager::BTN_POWER) && millis() - start < 1000) {
    delay(10);  // only wait 10ms each iteration to not delay too much in case of short configured duration.
    inputManager.update();
  }

  t2 = millis();
  if (inputManager.isPressed(InputManager::BTN_POWER)) {
    do {
      delay(10);
      inputManager.update();
    } while (inputManager.isPressed(InputManager::BTN_POWER) && inputManager.getHeldTime() < calibratedPressDuration);
    abort = inputManager.getHeldTime() < calibratedPressDuration;
  } else {
    abort = true;
  }

  if (abort) {
    // Button released too early. Returning to sleep.
    // IMPORTANT: Re-arm the wakeup trigger before sleeping again
    esp_deep_sleep_enable_gpio_wakeup(1ULL << InputManager::POWER_BUTTON_PIN, ESP_GPIO_WAKEUP_GPIO_LOW);
    esp_deep_sleep_start();
  }
}

void waitForPowerRelease() {
  inputManager.update();
  while (inputManager.isPressed(InputManager::BTN_POWER)) {
    delay(50);
    inputManager.update();
  }
}

// Enter deep sleep mode
void enterDeepSleep() {
  exitActivity();
  enterNewActivity(new SleepActivity(renderer, mappedInputManager));

  einkDisplay.deepSleep();
  Serial.printf("[%lu] [   ] Power button press calibration value: %lu ms\n", millis(), t2 - t1);
  Serial.printf("[%lu] [   ] Entering deep sleep.\n", millis());
  esp_deep_sleep_enable_gpio_wakeup(1ULL << InputManager::POWER_BUTTON_PIN, ESP_GPIO_WAKEUP_GPIO_LOW);
  // Ensure that the power button has been released to avoid immediately turning back on if you're holding it
  waitForPowerRelease();
  // Enter Deep Sleep
  esp_deep_sleep_start();
}

void onGoHome();
void onGoToMyLibraryWithTab(const std::string& path, MyLibraryActivity::Tab tab);
void onGoToReader(const std::string& initialEpubPath, MyLibraryActivity::Tab fromTab) {
  exitActivity();
  enterNewActivity(
      new ReaderActivity(renderer, mappedInputManager, initialEpubPath, fromTab, onGoHome, onGoToMyLibraryWithTab));
}
void onContinueReading() { onGoToReader(APP_STATE.openEpubPath, MyLibraryActivity::Tab::Recent); }

void onGoToFileTransfer() {
  exitActivity();
  enterNewActivity(new CrossPointWebServerActivity(renderer, mappedInputManager, onGoHome));
}

void onGoToSettings() {
  exitActivity();
  enterNewActivity(new SettingsActivity(renderer, mappedInputManager, onGoHome));
}

void onGoToMyLibrary() {
  exitActivity();
  enterNewActivity(new MyLibraryActivity(renderer, mappedInputManager, onGoHome, onGoToReader));
}

void onGoToMyLibraryWithTab(const std::string& path, MyLibraryActivity::Tab tab) {
  exitActivity();
  enterNewActivity(new MyLibraryActivity(renderer, mappedInputManager, onGoHome, onGoToReader, tab, path));
}

void onGoToBrowser() {
  exitActivity();
  enterNewActivity(new OpdsBookBrowserActivity(renderer, mappedInputManager, onGoHome));
}

void onGoHome() {
  exitActivity();
  enterNewActivity(new HomeActivity(renderer, mappedInputManager, onContinueReading, onGoToMyLibrary, onGoToSettings,
                                    onGoToFileTransfer, onGoToBrowser));
}

void setupDisplayAndFonts() {
  einkDisplay.begin();
  Serial.printf("[%lu] [   ] Display initialized\n", millis());
  renderer.insertFont(BOOKERLY_14_FONT_ID, bookerly14FontFamily);
#ifndef OMIT_FONTS
  renderer.insertFont(BOOKERLY_12_FONT_ID, bookerly12FontFamily);
  renderer.insertFont(BOOKERLY_16_FONT_ID, bookerly16FontFamily);
  renderer.insertFont(BOOKERLY_18_FONT_ID, bookerly18FontFamily);

  renderer.insertFont(NOTOSANS_12_FONT_ID, notosans12FontFamily);
  renderer.insertFont(NOTOSANS_14_FONT_ID, notosans14FontFamily);
  renderer.insertFont(NOTOSANS_16_FONT_ID, notosans16FontFamily);
  renderer.insertFont(NOTOSANS_18_FONT_ID, notosans18FontFamily);
  renderer.insertFont(OPENDYSLEXIC_8_FONT_ID, opendyslexic8FontFamily);
  renderer.insertFont(OPENDYSLEXIC_10_FONT_ID, opendyslexic10FontFamily);
  renderer.insertFont(OPENDYSLEXIC_12_FONT_ID, opendyslexic12FontFamily);
  renderer.insertFont(OPENDYSLEXIC_14_FONT_ID, opendyslexic14FontFamily);
#endif  // OMIT_FONTS
  renderer.insertFont(UI_10_FONT_ID, ui10FontFamily);
  renderer.insertFont(UI_12_FONT_ID, ui12FontFamily);
  renderer.insertFont(SMALL_FONT_ID, smallFontFamily);
  Serial.printf("[%lu] [   ] Fonts setup\n", millis());
}

bool isUsbConnected() {
  // U0RXD/GPIO20 reads HIGH when USB is connected
  return digitalRead(UART0_RXD) == HIGH;
}

bool isWakeupAfterFlashing() {
  const auto wakeupCause = esp_sleep_get_wakeup_cause();
  const auto resetReason = esp_reset_reason();

  return isUsbConnected() && (wakeupCause == ESP_SLEEP_WAKEUP_UNDEFINED) && (resetReason == ESP_RST_UNKNOWN);
}

void setup() {
  t1 = millis();

  // Only start serial if USB connected
  pinMode(UART0_RXD, INPUT);
  if (isUsbConnected()) {
    Serial.begin(115200);
    // Wait up to 3 seconds for Serial to be ready to catch early logs
    unsigned long start = millis();
    while (!Serial && (millis() - start) < 3000) {
      delay(10);
    }
  }

  inputManager.begin();
  // Initialize pins
  pinMode(BAT_GPIO0, INPUT);

  // Initialize SPI with custom pins
  SPI.begin(EPD_SCLK, SD_SPI_MISO, EPD_MOSI, EPD_CS);

  // SD Card Initialization
  // We need 6 open files concurrently when parsing a new chapter
  if (!SdMan.begin()) {
    Serial.printf("[%lu] [   ] SD card initialization failed\n", millis());
    setupDisplayAndFonts();
    exitActivity();
    enterNewActivity(new FullScreenMessageActivity(renderer, mappedInputManager, "SD card error", EpdFontFamily::BOLD));
    return;
  }

  SETTINGS.loadFromFile();
  KOREADER_STORE.loadFromFile();

  if (!isWakeupAfterFlashing()) {
    // For normal wakeups (not immediately after flashing), verify long press
    verifyWakeupLongPress();
  }

  // First serial output only here to avoid timing inconsistencies for power button press duration verification
  Serial.printf("[%lu] [   ] Starting CrossPoint version " CROSSPOINT_VERSION "\n", millis());

  setupDisplayAndFonts();

  exitActivity();
  enterNewActivity(new BootActivity(renderer, mappedInputManager));

  APP_STATE.loadFromFile();
  RECENT_BOOKS.loadFromFile();

  if (APP_STATE.openEpubPath.empty()) {
    onGoHome();
  } else {
    // Clear app state to avoid getting into a boot loop if the epub doesn't load
    const auto path = APP_STATE.openEpubPath;
    APP_STATE.openEpubPath = "";
    APP_STATE.lastSleepImage = 0;
    APP_STATE.saveToFile();
    onGoToReader(path, MyLibraryActivity::Tab::Recent);
  }

  // Ensure we're not still holding the power button before leaving setup
  waitForPowerRelease();
}

void loop() {
  static unsigned long maxLoopDuration = 0;
  const unsigned long loopStartTime = millis();
  static unsigned long lastMemPrint = 0;

  inputManager.update();

  if (Serial && millis() - lastMemPrint >= 10000) {
    Serial.printf("[%lu] [MEM] Free: %d bytes, Total: %d bytes, Min Free: %d bytes\n", millis(), ESP.getFreeHeap(),
                  ESP.getHeapSize(), ESP.getMinFreeHeap());
    lastMemPrint = millis();
  }

  // Check for any user activity (button press or release) or active background work
  static unsigned long lastActivityTime = millis();
  if (inputManager.wasAnyPressed() || inputManager.wasAnyReleased() ||
      (currentActivity && currentActivity->preventAutoSleep())) {
    lastActivityTime = millis();  // Reset inactivity timer
  }

  const unsigned long sleepTimeoutMs = SETTINGS.getSleepTimeoutMs();
  if (millis() - lastActivityTime >= sleepTimeoutMs) {
    Serial.printf("[%lu] [SLP] Auto-sleep triggered after %lu ms of inactivity\n", millis(), sleepTimeoutMs);
    enterDeepSleep();
    // This should never be hit as `enterDeepSleep` calls esp_deep_sleep_start
    return;
  }

  if (inputManager.isPressed(InputManager::BTN_POWER) &&
      inputManager.getHeldTime() > SETTINGS.getPowerButtonDuration()) {
    enterDeepSleep();
    // This should never be hit as `enterDeepSleep` calls esp_deep_sleep_start
    return;
  }

  const unsigned long activityStartTime = millis();
  if (currentActivity) {
    currentActivity->loop();
  }
  const unsigned long activityDuration = millis() - activityStartTime;

  const unsigned long loopDuration = millis() - loopStartTime;
  if (loopDuration > maxLoopDuration) {
    maxLoopDuration = loopDuration;
    if (maxLoopDuration > 50) {
      Serial.printf("[%lu] [LOOP] New max loop duration: %lu ms (activity: %lu ms)\n", millis(), maxLoopDuration,
                    activityDuration);
    }
  }

  // Add delay at the end of the loop to prevent tight spinning
  // When an activity requests skip loop delay (e.g., webserver running), use yield() for faster response
  // Otherwise, use longer delay to save power
  if (currentActivity && currentActivity->skipLoopDelay()) {
    yield();  // Give FreeRTOS a chance to run tasks, but return immediately
  } else {
    delay(10);  // Normal delay when no activity requires fast response
  }
}
