#include "console_store.h"
#include <string.h>
#include <algorithm>

namespace Code {

void ConsoleStore::startNewSession() {
  if (k_historySize < 1) {
    return;
  }

  m_history[0] = makePrevious(m_history[0]);

  for (size_t i = 0; i < k_historySize - 1; i++) {
    if (m_history[i] == 0) {
      if (m_history[i+1] == 0) {
        return ;
      }
      m_history[i+1] = makePrevious(m_history[i+1]);
    }
  }
}

ConsoleLine ConsoleStore::lineAtIndex(int i) const {
  assert(i >= 0 && i < numberOfLines());
  int currentLineIndex = 0;
  for (size_t j=0; j<k_historySize; j++) {
    if (m_history[j] == 0) {
      currentLineIndex++;
      j++;
    }
    if (currentLineIndex == i) {
      return ConsoleLine(lineTypeForMarker(m_history[j]), m_history+j+1);
    }
  }
  assert(false);
  return ConsoleLine();
}

int ConsoleStore::numberOfLines() const {
  if (m_history[0] == 0) {
    return 0;
  }
  int result = 0;
  for (size_t i = 0; i < k_historySize - 1; i++) {
    if (m_history[i] == 0) {
      result++;
      if (m_history[i+1] == 0) {
        return result;
      }
    }
  }
  assert(false);
  return 0;
}

const char * ConsoleStore::pushCommand(const char * text) {
  return push(CurrentSessionCommandMarker, text);
}

void ConsoleStore::pushResult(const char * text) {
  push(CurrentSessionResultMarker, text);
}

void ConsoleStore::deleteLastLineIfEmpty() {
  ConsoleLine lastLine = lineAtIndex(numberOfLines()-1);
  char lastLineFirstChar = lastLine.text()[0];
  if (lastLineFirstChar == 0 || lastLineFirstChar == '\n') {
    deleteLastLine();
  }
}

int ConsoleStore::deleteCommandAndResultsAtIndex(int index) {
  int numberOfLinesAtStart = numberOfLines();
  assert(index >= 0 && index < numberOfLinesAtStart);
  int indexOfLineToDelete = index;
  while (indexOfLineToDelete < numberOfLinesAtStart - 1) {
   if (lineAtIndex(indexOfLineToDelete + 1).isCommand()) {
     break;
   }
   indexOfLineToDelete++;
  }
  ConsoleLine lineToDelete = lineAtIndex(indexOfLineToDelete);
  while (indexOfLineToDelete > 0 && !lineAtIndex(indexOfLineToDelete).isCommand()) {
    deleteLineAtIndex(indexOfLineToDelete);
    indexOfLineToDelete--;
    lineToDelete = lineAtIndex(indexOfLineToDelete);
  }
  deleteLineAtIndex(indexOfLineToDelete);
  return indexOfLineToDelete;
}

const char * ConsoleStore::push(const char marker, const char * text) {
  size_t textLength = strlen(text);
  if (ConsoleLine::sizeOfConsoleLine(textLength) > k_historySize - 1) {
    textLength = k_historySize - 1 - 1 - 1; // Marker, null termination and null marker.
  }
  size_t i = indexOfNullMarker();
  // If needed, make room for the text we want to push.
  while (i + ConsoleLine::sizeOfConsoleLine(textLength) > k_historySize - 1) {
    deleteFirstLine();
    i = indexOfNullMarker();
  }
  m_history[i] = marker;
  strlcpy(&m_history[i+1], text, std::min(k_historySize-(i+1),textLength+1));
  m_history[i+1+textLength+1] = 0;
  return &m_history[i+1];
}

ConsoleLine::Type ConsoleStore::lineTypeForMarker(char marker) const {
  assert(marker == CurrentSessionCommandMarker || marker == CurrentSessionResultMarker || marker == PreviousSessionCommandMarker || marker == PreviousSessionResultMarker);
  return static_cast<ConsoleLine::Type>(marker-1);
}

size_t ConsoleStore::indexOfNullMarker() const {
  if (m_history[0] == 0) {
    return 0;
  }
  for (size_t i=0; i<k_historySize; i++) {
    if (m_history[i] == 0 && m_history[i+1] == 0) {
      return (i+1);
    }
  }
  assert(false);
  return 0;
}

void ConsoleStore::deleteLineAtIndex(int index) {
  assert(index >=0 && index < numberOfLines());
  int currentLineIndex = 0;
  for (size_t i = 0; i < k_historySize - 1; i++) {
    if (m_history[i] == 0) {
      currentLineIndex++;
      continue;
    }
    if (currentLineIndex == index) {
      size_t nextLineStart = i;
      while (m_history[nextLineStart] != 0 && nextLineStart < k_historySize - 2) {
        nextLineStart++;
      }
      nextLineStart++;
      if (nextLineStart > k_historySize - 1) {
        return;
      }
      memmove(&m_history[i], &m_history[nextLineStart], (k_historySize - 1) - nextLineStart + 1);
      return;
    }
  }
}

void ConsoleStore::deleteFirstLine() {
  if (m_history[0] == 0) {
    return;
  }
  int secondLineMarkerIndex = 1;
  while (m_history[secondLineMarkerIndex] != 0) {
    secondLineMarkerIndex++;
  }
  secondLineMarkerIndex++;
  for (size_t i=0; i<k_historySize - secondLineMarkerIndex; i++) {
    m_history[i] = m_history[secondLineMarkerIndex+i];
  }
}

void ConsoleStore::deleteLastLine() {
  int lineCount = numberOfLines();
  if (lineCount < 0) {
    return;
  }
  if (lineCount == 1) {
    deleteFirstLine();
    return;
  }
  int currentLineIndex = 1;
  int lastLineMarkerIndex = 0;
  for (size_t i=0; i<k_historySize; i++) {
    if (m_history[i] == 0) {
      currentLineIndex++;
      if (currentLineIndex == lineCount) {
        lastLineMarkerIndex = i+1;
        break;
      }
    }
  }
  m_history[lastLineMarkerIndex] = 0;
}

}