#include "wled.h"
#ifdef ARDUINO_ARCH_ESP32
#include "esp_ota_ops.h"
#endif

/*
 * Adalight and TPM2 handler
 */

#define SERIAL_MAXTIME_MILLIS 100 // to avoid blocking other activities, do not spend more than 100ms with continuous reading
// at 115200 baud, 100ms is enough to send/receive 1280 chars

enum class AdaState {
  Header_A,
  Header_d,
  Header_a,
  Header_CountHi,
  Header_CountLo,
  Header_CountCheck,
  Data_Red,
  Data_Green,
  Data_Blue,
  TPM2_Header_Type,
  TPM2_Header_CountHi,
  TPM2_Header_CountLo,
};

uint16_t currentBaud = 1152; //default baudrate 115200 (divided by 100)
bool continuousSendLED = false;
uint32_t lastUpdate = 0;

void updateBaudRate(uint32_t rate){
  uint16_t rate100 = rate/100;
  if (rate100 == currentBaud || rate100 < 96) return;
  currentBaud = rate100;

  if (!pinManager.isPinAllocated(hardwareTX) || pinManager.getPinOwner(hardwareTX) == PinOwner::DebugOut){
    if (Serial) { Serial.print(F("Baud is now ")); Serial.println(rate); }
  }

  if (Serial) Serial.flush();
  Serial.begin(rate);
}

// RGB LED data return as JSON array. Slow, but easy to use on the other end.
void sendJSON(){
  if (!pinManager.isPinAllocated(hardwareTX) || pinManager.getPinOwner(hardwareTX) == PinOwner::DebugOut) {
    if (!Serial) return; // WLEDMM avoid writing to unconnected USB-CDC
    uint16_t used = strip.getLengthTotal();
    Serial.write('[');
    for (uint16_t i=0; i<used; i++) {
      Serial.print(strip.getPixelColor(i));
      if (i != used-1) Serial.write(',');
    }
    Serial.println("]");
  }
}

// RGB LED data returned as bytes in TPM2 format. Faster, and slightly less easy to use on the other end.
void sendBytes(){
  if (!pinManager.isPinAllocated(hardwareTX) || pinManager.getPinOwner(hardwareTX) == PinOwner::DebugOut) {
    if (!Serial) return; // WLEDMM avoid writing to unconnected USB-CDC
    Serial.write(0xC9); Serial.write(0xDA);
    uint16_t used = strip.getLengthTotal();
    uint16_t len = used*3;
    Serial.write(highByte(len));
    Serial.write(lowByte(len));
    for (uint16_t i=0; i < used; i++) {
      uint32_t c = strip.getPixelColor(i);
      Serial.write(qadd8(W(c), R(c))); //R, add white channel to RGB channels as a simple RGBW -> RGB map
      Serial.write(qadd8(W(c), G(c))); //G
      Serial.write(qadd8(W(c), B(c))); //B
    }
    Serial.write(0x36); Serial.write('\n');
  }
}

bool canUseSerial(void) {   // WLEDMM returns true if Serial can be used for debug output (i.e. not configured for other purpose)
  #if ARDUINO_USB_CDC_ON_BOOT && (defined(CONFIG_IDF_TARGET_ESP32S3) || defined(CONFIG_IDF_TARGET_ESP32C3) || defined(CONFIG_IDF_TARGET_ESP32C6) || defined(CONFIG_IDF_TARGET_ESP32P4)) && !defined(WLED_DEBUG_HOST)
  //  on S3/C3/C6/P4, USB CDC blocks if disconnected! so check if Serial is active before printing to it.
  if (!Serial) return false;
  #endif
  if (pinManager.isPinAllocated(hardwareTX) && (pinManager.getPinOwner(hardwareTX) != PinOwner::DebugOut)) 
    return false;  // TX allocated to LEDs or other functions
  if ((realtimeMode == REALTIME_MODE_GENERIC) ||  (realtimeMode == REALTIME_MODE_ADALIGHT) || (realtimeMode == REALTIME_MODE_TPM2NET)) 
    return false;  // Serial in use for adaLight or other serial communication
  //if ((improvActive == 1) || (improvActive == 2)) return false; // don't interfere when IMPROV communication is ongoing
  if (improvActive > 0) return false;              // don't interfere when IMPROV communication is ongoing
  if (continuousSendLED == true) return false;     // Continuous Serial Streaming

  return true;
} // WLEDMM end

#if defined(WLED_ENABLE_INFINITY_CONTROLLER) && defined(WLED_INFINITY_MASTER)
namespace {

String rfpJsonValue(const String& json, const char* key) {
  StaticJsonDocument<384> command;
  DeserializationError error = deserializeJson(command, json);
  if (error) return String();
  return command[key] | "";
}

uint32_t rfpJsonU32(const String& json, const char* key) {
  StaticJsonDocument<384> command;
  DeserializationError error = deserializeJson(command, json);
  if (error) return 0;
  return command[key] | 0;
}

uint32_t rfpParseChunkLength(const String& line, String& encoded) {
  if (!line.startsWith("RFPCHUNK1 ")) return 0;
  const int separator = line.indexOf(' ', 10);
  if (separator < 0) return 0;
  const int32_t length = line.substring(10, separator).toInt();
  encoded = line.substring(separator + 1);
  return length > 0 ? static_cast<uint32_t>(length) : 0;
}

void rfpSerialPrintError(const __FlashStringHelper* message) {
  Serial.print(F("RFPERR1 {\"error\":\""));
  Serial.print(message);
  Serial.println(F("\"}"));
}

void rfpSerialPrintErrorDetail(const __FlashStringHelper* message, uint32_t a, uint32_t b) {
  Serial.print(F("RFPERR1 {\"error\":\""));
  Serial.print(message);
  Serial.print(F("\",\"a\":"));
  Serial.print(a);
  Serial.print(F(",\"b\":"));
  Serial.print(b);
  Serial.println(F("}"));
}

int8_t rfpBase64Value(char c) {
  if (c >= 'A' && c <= 'Z') return c - 'A';
  if (c >= 'a' && c <= 'z') return c - 'a' + 26;
  if (c >= '0' && c <= '9') return c - '0' + 52;
  if (c == '+') return 62;
  if (c == '/') return 63;
  return -1;
}

int rfpDecodeBase64Chunk(const String& encoded, uint8_t* output, size_t outputSize) {
  uint32_t accumulator = 0;
  uint8_t bits = 0;
  size_t written = 0;

  for (uint16_t i = 0; i < encoded.length(); i++) {
    const char c = encoded[i];
    if (c == '=') break;
    const int8_t value = rfpBase64Value(c);
    if (value < 0) return -1;

    accumulator = (accumulator << 6) | static_cast<uint8_t>(value);
    bits += 6;
    if (bits >= 8) {
      bits -= 8;
      if (written >= outputSize) return -1;
      output[written++] = static_cast<uint8_t>((accumulator >> bits) & 0xFF);
    }
  }

  return static_cast<int>(written);
}

bool rfpReadHttpBody(WiFiClient& client, String& body, uint32_t timeoutMs) {
  const uint32_t start = millis();
  bool inBody = false;
  String headerTail;
  body.reserve(512);
  while ((millis() - start) < timeoutMs) {
    while (client.available()) {
      const char c = static_cast<char>(client.read());
      if (!inBody) {
        headerTail += c;
        if (headerTail.length() > 4) headerTail.remove(0, headerTail.length() - 4);
        if (headerTail == "\r\n\r\n") inBody = true;
      } else if (body.length() < 2048) {
        body += c;
      }
    }
    if (!client.connected() && !client.available()) return inBody;
    delay(1);
  }
  return inBody;
}

void rfpHandleInfoCommand(const String& json) {
  const String target = rfpJsonValue(json, "target");
  if (target.length() == 0) {
    rfpSerialPrintError(F("missing target"));
    return;
  }

  WiFiClient client;
  if (!client.connect(target.c_str(), 80)) {
    rfpSerialPrintError(F("node connect failed"));
    return;
  }
  client.print(F("GET /json/info HTTP/1.1\r\nHost: "));
  client.print(target);
  client.print(F("\r\nConnection: close\r\n\r\n"));

  String body;
  if (!rfpReadHttpBody(client, body, 5000) || body.length() == 0) {
    rfpSerialPrintError(F("node info failed"));
    client.stop();
    return;
  }
  client.stop();
  body.replace("\r", "");
  body.replace("\n", "");
  Serial.print(F("RFPINFO1 "));
  Serial.println(body);
}

void rfpHandleOtaCommand(const String& json) {
  const String target = rfpJsonValue(json, "target");
  const uint32_t firmwareSize = rfpJsonU32(json, "size");
  const uint32_t ackBytes = rfpJsonU32(json, "ackBytes");
  if (target.length() == 0 || firmwareSize == 0) {
    rfpSerialPrintError(F("missing target or size"));
    return;
  }

  constexpr char boundary[] = "----RFPInfinityOtaBoundary";
  const String head =
    String("--") + boundary + "\r\n"
    "Content-Disposition: form-data; name=\"update\"; filename=\"firmware.bin\"\r\n"
    "Content-Type: application/octet-stream\r\n\r\n";
  const String tail =
    String("\r\n--") + boundary + "\r\n"
    "Content-Disposition: form-data; name=\"skipValidation\"\r\n\r\n"
    "1\r\n"
    "--" + boundary + "--\r\n";
  const uint32_t contentLength = head.length() + firmwareSize + tail.length();

  WiFiClient client;
  if (!client.connect(target.c_str(), 80)) {
    rfpSerialPrintError(F("node connect failed"));
    return;
  }

  client.print(F("POST /update?skipValidation=1 HTTP/1.1\r\nHost: "));
  client.print(target);
  client.print(F("\r\nConnection: close\r\nContent-Type: multipart/form-data; boundary="));
  client.print(boundary);
  client.print(F("\r\nContent-Length: "));
  client.print(contentLength);
  client.print(F("\r\n\r\n"));
  client.print(head);

  Serial.print(F("RFPREADY1 {\"target\":\""));
  Serial.print(target);
  Serial.print(F("\",\"size\":"));
  Serial.print(firmwareSize);
  Serial.print(F(",\"ackBytes\":"));
  Serial.print(ackBytes);
  Serial.print(F(",\"proto\":4"));
  Serial.println(F("}"));
  Serial.flush();

  Serial.setTimeout(20000);
  String dataStart = Serial.readStringUntil('\n');
  dataStart.trim();
  if (dataStart != "RFPDATA1") {
    client.stop();
    rfpSerialPrintError(F("serial data start timeout"));
    return;
  }

  uint8_t buffer[768];
  uint32_t remaining = firmwareSize;
  uint32_t nextAck = ackBytes;
  uint32_t lastDataMs = millis();
  while (remaining > 0) {
    String chunkHeader = Serial.readStringUntil('\n');
    chunkHeader.trim();
    String encoded;
    const uint32_t chunkLength = rfpParseChunkLength(chunkHeader, encoded);
    if (chunkLength == 0 || chunkLength > remaining) {
      client.stop();
      rfpSerialPrintError(F("serial chunk header invalid"));
      return;
    }
    if (chunkLength > sizeof(buffer) || encoded.length() == 0) {
      client.stop();
      rfpSerialPrintError(F("serial chunk too large"));
      return;
    }

    const int decoded = rfpDecodeBase64Chunk(encoded, buffer, sizeof(buffer));
    if (decoded != static_cast<int>(chunkLength)) {
      client.stop();
      rfpSerialPrintErrorDetail(F("serial chunk decode failed"), encoded.length(), decoded < 0 ? 0 : decoded);
      return;
    }
    lastDataMs = millis();
    if (client.write(buffer, decoded) != static_cast<size_t>(decoded)) {
      client.stop();
      rfpSerialPrintError(F("node write failed"));
      return;
    }
    remaining -= decoded;
    yield();

    const uint32_t received = firmwareSize - remaining;
    if (ackBytes > 0 && (received >= nextAck || remaining == 0)) {
      Serial.print(F("RFPACK1 {\"bytes\":"));
      Serial.print(received);
      Serial.println(F("}"));
      nextAck += ackBytes;
    }
  }

  client.print(tail);
  String body;
  rfpReadHttpBody(client, body, 30000);
  client.stop();
  body.replace("\r", " ");
  body.replace("\n", " ");
  if (body.length() > 360) body = body.substring(0, 360);
  Serial.print(F("RFPDONE1 {\"target\":\""));
  Serial.print(target);
  Serial.print(F("\",\"bytes\":"));
  Serial.print(firmwareSize);
  Serial.print(F(",\"response\":\""));
  for (uint16_t i = 0; i < body.length(); i++) {
    const char c = body[i];
    Serial.print(c == '"' || c == '\\' ? '_' : c);
  }
  Serial.println(F("\"}"));
}

bool rfpHandleSerialCommandLine() {
  Serial.setTimeout(2000);
  String line = Serial.readStringUntil('\n');
  line.trim();
  if (line.startsWith("RFPINFO1 ")) {
    rfpHandleInfoCommand(line.substring(9));
    return true;
  }
  if (line.startsWith("RFPOTA1 ")) {
    rfpHandleOtaCommand(line.substring(8));
    return true;
  }
  rfpSerialPrintError(F("unknown rfp command"));
  return true;
}

} // namespace
#endif

void handleSerial()
{
#if !ARDUINO_USB_CDC_ON_BOOT
  // some USB-CDC boards.json set RX and TX to the USB+ and USB- pins. These pins cannot be assigned to other purposes, so always availeable 
  if (pinManager.isPinAllocated(hardwareRX)) return;
#endif
  if (((pinManager.isPinAllocated(hardwareTX)) && (pinManager.getPinOwner(hardwareTX) != PinOwner::DebugOut))) return; // WLEDMM serial TX is necessary for adalight / TPM2
  if (!Serial) return;              // arduino docs: `if (Serial)` indicates whether or not the USB CDC serial connection is open. For all non-USB CDC ports, this will always return true

  #ifdef WLED_ENABLE_ADALIGHT
  static auto state = AdaState::Header_A;
  static uint16_t count = 0;
  static uint16_t pixel = 0;
  static byte check = 0x00;
  static byte red   = 0x00;
  static byte green = 0x00;

  unsigned long startTime = millis();
  while ((Serial.available() > 0) && (millis() - startTime < SERIAL_MAXTIME_MILLIS))
  {
    yield();
    byte next = Serial.peek();
    switch (state) {
      case AdaState::Header_A:
        if (next == 'A') state = AdaState::Header_d;
        else if (next == 0xC9) { //TPM2 start byte
          state = AdaState::TPM2_Header_Type;
        }
        else if (next == 'I') {
          handleImprovPacket();
          return;
        } else if (next == 'v') {
          Serial.print("WLED"); Serial.write(' '); Serial.println(VERSION);

        } else if (next == '^') {
          #ifdef ARDUINO_ARCH_ESP32
          esp_err_t err;
          const esp_partition_t *boot_partition = esp_ota_get_boot_partition();
          const esp_partition_t *running_partition = esp_ota_get_running_partition();
          USER_PRINTF("Running on %s and we should have booted from %s. This %s\n",running_partition->label,boot_partition->label,(String(running_partition->label) == String(boot_partition->label))?"is what we expect.":"means OTA messed up!");
          if (String(running_partition->label) == String(boot_partition->label)) {
            esp_partition_iterator_t new_boot_partition_iterator = NULL;
            if (boot_partition->subtype == ESP_PARTITION_SUBTYPE_APP_OTA_0) {
              new_boot_partition_iterator = esp_partition_find(ESP_PARTITION_TYPE_APP,ESP_PARTITION_SUBTYPE_APP_OTA_1,"app1");
            } else {
              new_boot_partition_iterator = esp_partition_find(ESP_PARTITION_TYPE_APP,ESP_PARTITION_SUBTYPE_APP_OTA_0,"app0");
            }
            const esp_partition_t* new_boot_partition = esp_partition_get(new_boot_partition_iterator);
            err = esp_ota_set_boot_partition(new_boot_partition);
            if (err == ESP_OK) {
              USER_PRINTF("Switching boot partitions from %s to %s in 3 seconds!\n",boot_partition->label,new_boot_partition->label);
              delay(3000);
              esp_restart();
            } else {
              USER_PRINTF("Looks like the other app partition (%s) is invalid. Ignoring.\n",new_boot_partition->label);
            }
          } else {
            USER_PRINTF("Looks like the other partion is invalid as we exepected %s but we booted failsafe to %s. Ignoring boot change.\n",boot_partition->label,running_partition->label);
          }
          #else
          USER_PRINTLN("Boot partition switching is only available for ESP32 and newer boards.");
          #endif
        } else if (next == 'X') {
          forceReconnect = true; // WLEDMM - force reconnect via Serial
        } else if (next == 'R') {
          #if defined(WLED_ENABLE_INFINITY_CONTROLLER) && defined(WLED_INFINITY_MASTER)
          rfpHandleSerialCommandLine();
          return;
          #endif
        } else if (next == 0xB0) {updateBaudRate( 115200);
        } else if (next == 0xB1) {updateBaudRate( 230400);
        } else if (next == 0xB2) {updateBaudRate( 460800);
        } else if (next == 0xB3) {updateBaudRate( 500000);
        } else if (next == 0xB4) {updateBaudRate( 576000);
        } else if (next == 0xB5) {updateBaudRate( 921600);
        } else if (next == 0xB6) {updateBaudRate(1000000);
        } else if (next == 0xB7) {updateBaudRate(1500000);

        } else if (next == 'l') {sendJSON(); // Send LED data as JSON Array
        } else if (next == 'L') {sendBytes(); // Send LED data as TPM2 Data Packet

        } else if (next == 'o') {continuousSendLED = false; // Disable Continuous Serial Streaming
        } else if (next == 'O') {continuousSendLED = true; // Enable Continuous Serial Streaming

        } else if (next == '{') { //JSON API
          bool verboseResponse = false;
          if (!requestJSONBufferLock(16)) {
             if (Serial) Serial.println(F("{\"error\":3}")); // ERR_NOBUF
            return;
          }
          Serial.setTimeout(100);
          DeserializationError error = deserializeJson(doc, Serial);
          if (error) {
            releaseJSONBufferLock();
            return;
          }
          verboseResponse = deserializeState(doc.as<JsonObject>());
          //only send response if TX pin is unused for other purposes
          if (verboseResponse && (!pinManager.isPinAllocated(hardwareTX) || pinManager.getPinOwner(hardwareTX) == PinOwner::DebugOut)) {
            doc.clear();
            JsonObject state = doc.createNestedObject("state");
            serializeState(state);
            JsonObject info  = doc.createNestedObject("info");
            serializeInfo(info);

            serializeJson(doc, Serial);
            Serial.println();
          }
          releaseJSONBufferLock();
        }
        break;
      case AdaState::Header_d:
        if (next == 'd') state = AdaState::Header_a;
        else             state = AdaState::Header_A;
        break;
      case AdaState::Header_a:
        if (next == 'a') state = AdaState::Header_CountHi;
        else             state = AdaState::Header_A;
        break;
      case AdaState::Header_CountHi:
        pixel = 0;
        count = next * 0x100;
        check = next;
        state = AdaState::Header_CountLo;
        break;
      case AdaState::Header_CountLo:
        count += next + 1;
        check = check ^ next ^ 0x55;
        state = AdaState::Header_CountCheck;
        break;
      case AdaState::Header_CountCheck:
        if (check == next) state = AdaState::Data_Red;
        else               state = AdaState::Header_A;
        break;
      case AdaState::TPM2_Header_Type:
        state = AdaState::Header_A; //(unsupported) TPM2 command or invalid type
        if (next == 0xDA) state = AdaState::TPM2_Header_CountHi; //TPM2 data
        else if (next == 0xAA) Serial.write(0xAC); //TPM2 ping
        break;
      case AdaState::TPM2_Header_CountHi:
        pixel = 0;
        count = (next * 0x100) /3;
        state = AdaState::TPM2_Header_CountLo;
        break;
      case AdaState::TPM2_Header_CountLo:
        count += next /3;
        state = AdaState::Data_Red;
        break;
      case AdaState::Data_Red:
        red   = next;
        state = AdaState::Data_Green;
        break;
      case AdaState::Data_Green:
        green = next;
        state = AdaState::Data_Blue;
        break;
      case AdaState::Data_Blue:
        byte blue  = next;
        if (!realtimeOverride) setRealtimePixel(pixel++, red, green, blue, 0);
        if (--count > 0) state = AdaState::Data_Red;
        else {
          realtimeLock(realtimeTimeoutMs, REALTIME_MODE_ADALIGHT);

          if (!realtimeOverride) strip.show();
          state = AdaState::Header_A;
        }
        break;
    }

    // All other received bytes will disable Continuous Serial Streaming
    if (continuousSendLED && next != 'O'){
      continuousSendLED = false;
      }

    Serial.read(); //discard the byte
  }
  //#ifdef WLED_DEBUG
    if ((millis() - startTime) > SERIAL_MAXTIME_MILLIS) { USER_PRINTLN(F("handleSerial(): need a break after >100ms of activity.")); }
  //#endif
  #else
    #pragma message "Serial protocols (AdaLight, Serial JSON, Serial LED driver, improv) disabled"
  #endif

  // If Continuous Serial Streaming is enabled, send new LED data as bytes
  if (continuousSendLED && (lastUpdate != strip.getLastShow())){
    sendBytes();
    lastUpdate = strip.getLastShow();
  }
}