// signal_manager.cpp - Signal Manager Implementation

#include "signal_manager.h"

SignalDefinition signalDefs[MAX_MANUAL_SIGNALS];
uint16_t signalDefCount = 0;
SignalValue signalValues[MAX_MANUAL_SIGNALS];

void initSignalManager() {
  signalDefCount = 0;
  for (int i = 0; i < MAX_MANUAL_SIGNALS; i++) {
    signalDefs[i].enabled = false;
    signalValues[i].valid = false;
  }
  
  // Try to load saved signals
  loadSignalsFromSD();
}

bool addManualSignal(const char* name, uint32_t canId, uint32_t startBit, 
                     uint32_t length, bool isLittleEndian, bool isSigned,
                     float factor, float offset) {
  if (signalDefCount >= MAX_MANUAL_SIGNALS) {
    return false;
  }
  
  // Check if signal already exists
  for (uint16_t i = 0; i < signalDefCount; i++) {
    if (strcmp(signalDefs[i].name, name) == 0) {
      // Update existing
      signalDefs[i].canId = canId;
      signalDefs[i].startBit = startBit;
      signalDefs[i].length = length;
      signalDefs[i].isLittleEndian = isLittleEndian;
      signalDefs[i].isSigned = isSigned;
      signalDefs[i].factor = factor;
      signalDefs[i].offset = offset;
      return true;
    }
  }
  
  // Add new signal
  SignalDefinition* sig = &signalDefs[signalDefCount++];
  strncpy(sig->name, name, 31);
  sig->canId = canId;
  sig->startBit = startBit;
  sig->length = length;
  sig->isLittleEndian = isLittleEndian;
  sig->isSigned = isSigned;
  sig->factor = factor;
  sig->offset = offset;
  sig->source = SIGNAL_SOURCE_MANUAL;
  sig->enabled = true;
  
  // Initialize value slot
  strncpy(signalValues[signalDefCount - 1].name, name, 31);
  signalValues[signalDefCount - 1].value = 0;
  signalValues[signalDefCount - 1].valid = false;
  
  return true;
}

bool removeSignal(const char* name) {
  for (uint16_t i = 0; i < signalDefCount; i++) {
    if (strcmp(signalDefs[i].name, name) == 0) {
      // Shift remaining signals
      for (uint16_t j = i; j < signalDefCount - 1; j++) {
        signalDefs[j] = signalDefs[j + 1];
        signalValues[j] = signalValues[j + 1];
      }
      signalDefCount--;
      return true;
    }
  }
  return false;
}

bool enableSignal(const char* name, bool enable) {
  SignalDefinition* sig = getSignalDef(name);
  if (sig) {
    sig->enabled = enable;
    return true;
  }
  return false;
}

SignalDefinition* getSignalDef(const char* name) {
  for (uint16_t i = 0; i < signalDefCount; i++) {
    if (strcmp(signalDefs[i].name, name) == 0) {
      return &signalDefs[i];
    }
  }
  return nullptr;
}

SignalValue* getSignalValue(const char* name) {
  for (uint16_t i = 0; i < signalDefCount; i++) {
    if (strcmp(signalValues[i].name, name) == 0) {
      return &signalValues[i];
    }
  }
  return nullptr;
}

void updateSignalFromCAN(const CanFrame* frame) {
  if (!frame) return;
  
  // Check DBC signals first
  if (dbcDB.loaded) {
    DbcMessage* msg = getMessageById(frame->id);
    if (msg) {
      DbcSignal* signals;
      uint16_t count = getSignalsForMessage(frame->id, &signals);
      for (uint16_t i = 0; i < count; i++) {
        float value = extractSignalValue(frame->data, &signals[i]);
        
        // Update signal value if we have a matching manual signal
        SignalValue* sv = getSignalValue(signals[i].name);
        if (sv) {
          sv->value = value;
          sv->timestamp = frame->timestamp / 1000; // Convert to ms
          sv->valid = true;
        }
      }
    }
  }
  
  // Check manual signals
  for (uint16_t i = 0; i < signalDefCount; i++) {
    if (signalDefs[i].canId == frame->id && signalDefs[i].enabled) {
      // Create a temporary DbcSignal for extraction
      DbcSignal tempSig;
      strncpy(tempSig.name, signalDefs[i].name, 32);
      tempSig.startBit = signalDefs[i].startBit;
      tempSig.length = signalDefs[i].length;
      tempSig.isLittleEndian = signalDefs[i].isLittleEndian;
      tempSig.isSigned = signalDefs[i].isSigned;
      tempSig.factor = signalDefs[i].factor;
      tempSig.offset = signalDefs[i].offset;
      
      float value = extractSignalValue(frame->data, &tempSig);
      signalValues[i].value = value;
      signalValues[i].timestamp = frame->timestamp / 1000;
      signalValues[i].valid = true;
    }
  }
}

void updateAllSignals(const CanFrame* frame) {
  updateSignalFromCAN(frame);
}

uint16_t getEnabledSignals(SignalValue* values, uint16_t maxCount) {
  uint16_t count = 0;
  for (uint16_t i = 0; i < signalDefCount && count < maxCount; i++) {
    if (signalDefs[i].enabled && signalValues[i].valid) {
      values[count++] = signalValues[i];
    }
  }
  return count;
}

bool loadSignalsFromSD() {
  // TODO: Implement loading from SD card
  return false;
}

bool saveSignalsToSD() {
  // TODO: Implement saving to SD card
  return false;
}

void getSignalsJSON(char* buffer, size_t bufferSize) {
  int pos = snprintf(buffer, bufferSize, "{\"count\":%d,\"signals\":[", signalDefCount);
  
  for (uint16_t i = 0; i < signalDefCount && pos < (int)bufferSize - 100; i++) {
    if (i > 0) {
      pos += snprintf(buffer + pos, bufferSize - pos, ",");
    }
    SignalDefinition* sig = &signalDefs[i];
    pos += snprintf(buffer + pos, bufferSize - pos,
                    "{\"name\":\"%s\",\"canId\":\"0x%X\",\"startBit\":%d,\"length\":%d,\"enabled\":%s,\"value\":%.2f}",
                    sig->name, sig->canId, sig->startBit, sig->length,
                    sig->enabled ? "true" : "false",
                    signalValues[i].value);
  }
  
  strncat(buffer, "]}", bufferSize - pos - 1);
}