#include "sequence.h"
  #include "sequence_store.h"
  #include "cache_context.h"
  #include <poincare/layout_engine.h>
  #include "../../poincare/src/layout/char_layout.h"
  #include "../../poincare/src/layout/horizontal_layout.h"
  #include "../../poincare/src/layout/vertical_offset_layout.h"
  #include "../shared/poincare_helpers.h"
  #include <string.h>
  #include <cmath>
  
  using namespace Shared;
  using namespace Poincare;
  
  namespace Sequence {
  
  Sequence::Sequence(const char * text, KDColor color) :
    Function(text, color),
    m_type(Type::Explicit),
    m_firstInitialConditionText(),
    m_secondInitialConditionText(),
    m_firstInitialConditionExpression(nullptr),
    m_secondInitialConditionExpression(nullptr),
    m_firstInitialConditionLayout(nullptr),
    m_secondInitialConditionLayout(nullptr),
    m_nameLayout(nullptr),
    m_definitionName(nullptr),
    m_firstInitialConditionName(nullptr),
    m_secondInitialConditionName(nullptr),
    m_initialRank(0)
  {
  }
  
  Sequence::~Sequence() {
    if (m_firstInitialConditionLayout != nullptr) {
      delete m_firstInitialConditionLayout;
      m_firstInitialConditionLayout = nullptr;
    }
    if (m_secondInitialConditionLayout != nullptr) {
      delete m_secondInitialConditionLayout;
      m_secondInitialConditionLayout = nullptr;
    }
    if (m_firstInitialConditionExpression != nullptr) {
      delete m_firstInitialConditionExpression;
      m_firstInitialConditionExpression = nullptr;
    }
    if (m_secondInitialConditionExpression != nullptr) {
      delete m_secondInitialConditionExpression;
      m_secondInitialConditionExpression = nullptr;
    }
    if (m_nameLayout != nullptr) {
      delete m_nameLayout;
      m_nameLayout = nullptr;
    }
    if (m_definitionName != nullptr) {
      delete m_definitionName;
      m_definitionName = nullptr;
    }
    if (m_firstInitialConditionName != nullptr) {
      delete m_firstInitialConditionName;
      m_firstInitialConditionName = nullptr;
    }
    if (m_secondInitialConditionName != nullptr) {
      delete m_secondInitialConditionName;
      m_secondInitialConditionName = nullptr;
    }
  }
  
  Sequence& Sequence::operator=(const Sequence& other) {
    /* We temporarely store other's required features to be able to access them
     * after setType (which erase all contents and index buffer) even in case of
     * self assignement */
    const char * contentText = other.text();
    const char * firstInitialText = other.m_firstInitialConditionText;
    const char * secondInitialText = other.m_secondInitialConditionText;
    Function::operator=(other);
    setType(other.m_type);
    setInitialRank(other.m_initialRank);
    setContent(contentText);
    setFirstInitialConditionContent(firstInitialText);
    setSecondInitialConditionContent(secondInitialText);
    return *this;
  }
  
  uint32_t Sequence::checksum() {
    char data[k_dataLengthInBytes/sizeof(char)] = {};
    strlcpy(data, text(), TextField::maxBufferSize());
    strlcpy(data+TextField::maxBufferSize(), firstInitialConditionText(), TextField::maxBufferSize());
    strlcpy(data+2*TextField::maxBufferSize(), secondInitialConditionText(), TextField::maxBufferSize());
    int * intAdress = (int *)(&data[3*TextField::maxBufferSize()]);
    *intAdress = m_initialRank;
    data[k_dataLengthInBytes-3] = (char)m_type;
    data[k_dataLengthInBytes-2] = name()!= nullptr ? name()[0] : 0;
    data[k_dataLengthInBytes-1] = (char)(isActive() ? 1 : 0);
    return Ion::crc32((uint32_t *)data, k_dataLengthInBytes/sizeof(uint32_t));
  }
  
  const char * Sequence::firstInitialConditionText() {
    return m_firstInitialConditionText;
  }
  
  const char * Sequence::secondInitialConditionText() {
    return m_secondInitialConditionText;
  }
  
  Sequence::Type Sequence::type() {
    return m_type;
  }
  
  void Sequence::setType(Type type) {
    if (m_type == Type::Explicit) {
      setInitialRank(0);
    }
    m_type = type;
    tidy();
    /* Reset all contents */
    switch (m_type) {
      case Type::Explicit:
        setContent("");
        break;
      case Type::SingleRecurrence:
      {
        char ex[5] = "u(n)";
        ex[0] = name()[0];
        setContent(ex);
        break;
      }
      case Type::DoubleRecurrence:
      {
        char ex[12] = "u(n+1)+u(n)";
        ex[0] = name()[0];
        ex[7] = name()[0];
        setContent(ex);
        break;
      }
    }
    setFirstInitialConditionContent("");
    setSecondInitialConditionContent("");
  }
  
  void Sequence::setInitialRank(int rank) {
    m_initialRank = rank;
    if (m_firstInitialConditionName != nullptr) {
      delete m_firstInitialConditionName;
      m_firstInitialConditionName = nullptr;
    }
    if (m_secondInitialConditionName != nullptr) {
      delete m_secondInitialConditionName;
      m_secondInitialConditionName = nullptr;
    }
  }
  
  Poincare::Expression * Sequence::firstInitialConditionExpression(Context * context) const {
    if (m_firstInitialConditionExpression == nullptr) {
      m_firstInitialConditionExpression = PoincareHelpers::ParseAndSimplify(m_firstInitialConditionText, *context);
    }
    return m_firstInitialConditionExpression;
  }
  
  Poincare::Expression * Sequence::secondInitialConditionExpression(Context * context) const {
    if (m_secondInitialConditionExpression == nullptr) {
      m_secondInitialConditionExpression = PoincareHelpers::ParseAndSimplify(m_secondInitialConditionText, *context);
    }
    return m_secondInitialConditionExpression;
  }
  
  Poincare::ExpressionLayout * Sequence::firstInitialConditionLayout() {
    if (m_firstInitialConditionLayout == nullptr) {
      Expression * nonSimplifedExpression = Expression::parse(m_firstInitialConditionText);
      if (nonSimplifedExpression) {
        m_firstInitialConditionLayout = PoincareHelpers::CreateLayout(nonSimplifedExpression);
        delete nonSimplifedExpression;
      }
    }
    return m_firstInitialConditionLayout;
  }
  
  Poincare::ExpressionLayout * Sequence::secondInitialConditionLayout() {
    if (m_secondInitialConditionLayout == nullptr) {
      Expression * nonSimplifedExpression = Expression::parse(m_secondInitialConditionText);
      if (nonSimplifedExpression) {
        m_secondInitialConditionLayout = PoincareHelpers::CreateLayout(nonSimplifedExpression);
        delete nonSimplifedExpression;
      }
    }
    return m_secondInitialConditionLayout;
  }
  
  void Sequence::setFirstInitialConditionContent(const char * c) {
    strlcpy(m_firstInitialConditionText, c, sizeof(m_firstInitialConditionText));
    if (m_firstInitialConditionExpression != nullptr) {
      delete m_firstInitialConditionExpression;
      m_firstInitialConditionExpression = nullptr;
    }
    if (m_firstInitialConditionLayout != nullptr) {
      delete m_firstInitialConditionLayout;
      m_firstInitialConditionLayout = nullptr;
    }
  }
  
  void Sequence::setSecondInitialConditionContent(const char * c) {
    strlcpy(m_secondInitialConditionText, c, sizeof(m_secondInitialConditionText));
    if (m_secondInitialConditionExpression != nullptr) {
      delete m_secondInitialConditionExpression;
      m_secondInitialConditionExpression = nullptr;
    }
    if (m_secondInitialConditionLayout != nullptr) {
      delete m_secondInitialConditionLayout;
      m_secondInitialConditionLayout = nullptr;
    }
  }
  
  char Sequence::symbol() const {
    return 'n';
  }
  
  int Sequence::numberOfElements() {
    return (int)m_type + 1;
  }
  
  Poincare::ExpressionLayout * Sequence::nameLayout() {
    if (m_nameLayout == nullptr) {
      m_nameLayout = new HorizontalLayout(
          new CharLayout(name()[0], KDText::FontSize::Small),
          new VerticalOffsetLayout(new CharLayout('n', KDText::FontSize::Small), VerticalOffsetLayout::Type::Subscript, false),
          false);
    }
    return m_nameLayout;
  }
  
  Poincare::ExpressionLayout * Sequence::definitionName() {
    if (m_definitionName == nullptr) {
      if (m_type == Type::Explicit) {
        m_definitionName = new HorizontalLayout(
          new CharLayout(name()[0], KDText::FontSize::Large),
          new VerticalOffsetLayout(LayoutEngine::createStringLayout("n", 1, KDText::FontSize::Large), VerticalOffsetLayout::Type::Subscript, false),
          false);
      }
      if (m_type == Type::SingleRecurrence) {
        m_definitionName = new HorizontalLayout(
          new CharLayout(name()[0], KDText::FontSize::Large),
          new VerticalOffsetLayout(LayoutEngine::createStringLayout("n+1", 3, KDText::FontSize::Large), VerticalOffsetLayout::Type::Subscript, false),
          false);
      }
      if (m_type == Type::DoubleRecurrence) {
        m_definitionName = new HorizontalLayout(
          new CharLayout(name()[0], KDText::FontSize::Large),
          new VerticalOffsetLayout(LayoutEngine::createStringLayout("n+2", 3, KDText::FontSize::Large), VerticalOffsetLayout::Type::Subscript, false),
          false);
      }
    }
    return m_definitionName;
  }
  
  Poincare::ExpressionLayout * Sequence::firstInitialConditionName() {
    char buffer[k_initialRankNumberOfDigits+1];
    Integer(m_initialRank).writeTextInBuffer(buffer, k_initialRankNumberOfDigits+1);
    if (m_firstInitialConditionName == nullptr
        && (m_type == Type::SingleRecurrence
         || m_type == Type::DoubleRecurrence))
    {
      ExpressionLayout * indexLayout = LayoutEngine::createStringLayout(buffer, strlen(buffer), KDText::FontSize::Large);
      m_firstInitialConditionName = new HorizontalLayout(
          new CharLayout(name()[0], KDText::FontSize::Large),
          new VerticalOffsetLayout(indexLayout, VerticalOffsetLayout::Type::Subscript, false),
          false);
    }
    return m_firstInitialConditionName;
  }
  
  Poincare::ExpressionLayout * Sequence::secondInitialConditionName() {
    char buffer[k_initialRankNumberOfDigits+1];
    Integer(m_initialRank+1).writeTextInBuffer(buffer, k_initialRankNumberOfDigits+1);
    if (m_secondInitialConditionName == nullptr) {
      if (m_type == Type::DoubleRecurrence) {
        ExpressionLayout * indexLayout = LayoutEngine::createStringLayout(buffer, strlen(buffer), KDText::FontSize::Large);
        m_secondInitialConditionName = new HorizontalLayout(
          new CharLayout(name()[0], KDText::FontSize::Large),
          new VerticalOffsetLayout(indexLayout, VerticalOffsetLayout::Type::Subscript, false),
          false);
      }
    }
    return m_secondInitialConditionName;
  }
  
  bool Sequence::isDefined() {
    switch (m_type) {
      case Type::Explicit:
        return strlen(text()) != 0;
      case Type::SingleRecurrence:
        return strlen(text()) != 0 && strlen(firstInitialConditionText()) != 0;
      default:
        return strlen(text()) != 0 && strlen(firstInitialConditionText()) != 0 && strlen(secondInitialConditionText()) != 0;
    }
  }
  
  bool Sequence::isEmpty() {
    switch (m_type) {
      case Type::Explicit:
        return Function::isEmpty();
      case Type::SingleRecurrence:
        return Function::isEmpty() && strlen(m_firstInitialConditionText) == 0;
      default:
        return Function::isEmpty() && strlen(m_firstInitialConditionText) == 0 && strlen(m_secondInitialConditionText) == 0;
    }
  }
  
  template<typename T>
  T Sequence::templatedApproximateAtAbscissa(T x, SequenceContext * sqctx) const {
    T n = std::round(x);
    int sequenceIndex = name()[0] == SequenceStore::k_sequenceNames[0][0] ? 0 : 1;
    if (sqctx->iterateUntilRank<T>(n)) {
      return sqctx->valueOfSequenceAtPreviousRank<T>(sequenceIndex, 0);
    }
    return NAN;
  }
  
  template<typename T>
  T Sequence::approximateToNextRank(int n, SequenceContext * sqctx) const {
    if (n < m_initialRank || n < 0) {
      return NAN;
    }
    CacheContext<T> ctx = CacheContext<T>(sqctx);
    T un = sqctx->valueOfSequenceAtPreviousRank<T>(0, 0);
    T unm1 = sqctx->valueOfSequenceAtPreviousRank<T>(0, 1);
    T unm2 = sqctx->valueOfSequenceAtPreviousRank<T>(0, 2);
    T vn = sqctx->valueOfSequenceAtPreviousRank<T>(1, 0);
    T vnm1 = sqctx->valueOfSequenceAtPreviousRank<T>(1, 1);
    T vnm2 = sqctx->valueOfSequenceAtPreviousRank<T>(1, 2);
    Poincare::Symbol vnSymbol(Symbol::SpecialSymbols::vn);
    Poincare::Symbol vn1Symbol(Symbol::SpecialSymbols::vn1);
    Poincare::Symbol unSymbol(Symbol::SpecialSymbols::un);
    Poincare::Symbol un1Symbol(Symbol::SpecialSymbols::un1);
    switch (m_type) {
      case Type::Explicit:
      {
        ctx.setValueForSymbol(un, &unSymbol);
        ctx.setValueForSymbol(vn, &vnSymbol);
        return expression(sqctx)->approximateWithValueForSymbol(symbol(), (T)n, ctx, Poincare::Preferences::sharedPreferences()->angleUnit());
      }
      case Type::SingleRecurrence:
      {
        if (n == m_initialRank) {
          return PoincareHelpers::ApproximateToScalar<T>(firstInitialConditionExpression(sqctx), *sqctx);
        }
        ctx.setValueForSymbol(un, &un1Symbol);
        ctx.setValueForSymbol(unm1, &unSymbol);
        ctx.setValueForSymbol(vn, &vn1Symbol);
        ctx.setValueForSymbol(vnm1, &vnSymbol);
        return expression(sqctx)->approximateWithValueForSymbol(symbol(), (T)(n-1), ctx, Poincare::Preferences::sharedPreferences()->angleUnit());
      }
      default:
      {
        if (n == m_initialRank) {
          return PoincareHelpers::ApproximateToScalar<T>(firstInitialConditionExpression(sqctx), *sqctx);
        }
        if (n == m_initialRank+1) {
          return PoincareHelpers::ApproximateToScalar<T>(secondInitialConditionExpression(sqctx), *sqctx);
        }
        ctx.setValueForSymbol(unm1, &un1Symbol);
        ctx.setValueForSymbol(unm2, &unSymbol);
        ctx.setValueForSymbol(vnm1, &vn1Symbol);
        ctx.setValueForSymbol(vnm2, &vnSymbol);
        return expression(sqctx)->approximateWithValueForSymbol(symbol(), (T)(n-2), ctx, Poincare::Preferences::sharedPreferences()->angleUnit());
      }
    }
  }
  
  double Sequence::sumBetweenBounds(double start, double end, Context * context) const {
    double result = 0.0;
    if (end-start > k_maxNumberOfTermsInSum || start + 1.0 == start) {
      return NAN;
    }
    for (double i = std::round(start); i <= std::round(end); i = i + 1.0) {
      /* When |start| >> 1.0, start + 1.0 = start. In that case, quit the
       * infinite loop. */
      if (i == i-1.0 || i == i+1.0) {
        return NAN;
      }
      result += evaluateAtAbscissa(i, context);
    }
    return result;
  }
  
  void Sequence::tidy() {
    Function::tidy();
    if (m_firstInitialConditionLayout != nullptr) {
      delete m_firstInitialConditionLayout;
      m_firstInitialConditionLayout = nullptr;
    }
    if (m_secondInitialConditionLayout != nullptr) {
      delete m_secondInitialConditionLayout;
      m_secondInitialConditionLayout = nullptr;
    }
    if (m_firstInitialConditionExpression != nullptr) {
      delete m_firstInitialConditionExpression;
      m_firstInitialConditionExpression = nullptr;
    }
    if (m_secondInitialConditionExpression != nullptr) {
      delete m_secondInitialConditionExpression;
      m_secondInitialConditionExpression = nullptr;
    }
    if (m_nameLayout != nullptr) {
      delete m_nameLayout;
      m_nameLayout = nullptr;
    }
    if (m_definitionName != nullptr) {
      delete m_definitionName;
      m_definitionName = nullptr;
    }
    if (m_firstInitialConditionName != nullptr) {
      delete m_firstInitialConditionName;
      m_firstInitialConditionName = nullptr;
    }
    if (m_secondInitialConditionName != nullptr) {
      delete m_secondInitialConditionName;
      m_secondInitialConditionName = nullptr;
    }
  }
  
  template double Sequence::templatedApproximateAtAbscissa<double>(double, SequenceContext*) const;
  template float Sequence::templatedApproximateAtAbscissa<float>(float, SequenceContext*) const;
  template double Sequence::approximateToNextRank<double>(int, SequenceContext*) const;
  template float Sequence::approximateToNextRank<float>(int, SequenceContext*) const;
  }