From bc7ca057a084bcd8f9fa8d93d9769fb2ecb24c2d Mon Sep 17 00:00:00 2001
From: Gabriel Ozouf <gabriel.ozouf@numworks.com>
Date: Fri, 25 Sep 2020 12:37:05 +0200
Subject: [PATCH] [apps/calculation] Add Joules to results on energy

Change-Id: Ib775b1bd2bac1fd3bf755a9a4d3d5b3739a67cfa
---
 poincare/include/poincare/unit.h        |  2 ++
 poincare/src/unit.cpp                   | 17 ++++++++++++-----
 poincare/test/expression_properties.cpp |  4 ++--
 3 files changed, 16 insertions(+), 7 deletions(-)

diff --git a/poincare/include/poincare/unit.h b/poincare/include/poincare/unit.h
index d6c22f381..c44138a41 100644
--- a/poincare/include/poincare/unit.h
+++ b/poincare/include/poincare/unit.h
@@ -653,6 +653,8 @@ public:
   static_assert(strings_equal(k_temperatureRepresentatives[k_celsiusRepresentativeIndex].m_rootSymbol, "°C"), "Index for the Celsius Representative is incorrect.");
   static constexpr int k_fahrenheitRepresentativeIndex = 2;
   static_assert(strings_equal(k_temperatureRepresentatives[k_fahrenheitRepresentativeIndex].m_rootSymbol, "°F"), "Index for the Fahrenheit Representative is incorrect.");
+  static constexpr int k_jouleRepresentativeIndex = 0;
+  static_assert(strings_equal(k_energyRepresentatives[k_jouleRepresentativeIndex].m_rootSymbol, "J"), "Index for the Joule Representative is incorrect.");
   static constexpr int k_electronVoltRepresentativeIndex = 1;
   static_assert(strings_equal(k_energyRepresentatives[k_electronVoltRepresentativeIndex].m_rootSymbol, "eV"), "Index for the Electron Volt Representative is incorrect.");
   static constexpr int k_wattRepresentativeIndex = 0;
diff --git a/poincare/src/unit.cpp b/poincare/src/unit.cpp
index 52ba22f4d..237f45200 100644
--- a/poincare/src/unit.cpp
+++ b/poincare/src/unit.cpp
@@ -58,6 +58,7 @@ constexpr const int
   Unit::k_kelvinRepresentativeIndex,
   Unit::k_celsiusRepresentativeIndex,
   Unit::k_fahrenheitRepresentativeIndex,
+  Unit::k_jouleRepresentativeIndex,
   Unit::k_electronVoltRepresentativeIndex,
   Unit::k_wattRepresentativeIndex,
   Unit::k_hectareRepresentativeIndex,
@@ -526,26 +527,32 @@ int UnitNode::TemperatureRepresentative::setAdditionalExpressions(double value,
 
 int UnitNode::EnergyRepresentative::setAdditionalExpressions(double value, Expression * dest, int availableLength, ExpressionNode::ReductionContext reductionContext) const {
   assert(availableLength >= 2);
-  /* 1. Convert into Wh
+  int index = 0;
+  /* 1. Convert into Joules
+   * As J is just a shorthand for _kg_m^2_s^-2, the value is used as is. */
+  const Representative * joule = representativesOfSameDimension() + Unit::k_jouleRepresentativeIndex;
+  const Prefix * joulePrefix = joule->findBestPrefix(value, 1.);
+  dest[index++] = Multiplication::Builder(Float<double>::Builder(value * std::pow(10., -joulePrefix->exponent())), Unit::Builder(joule, joulePrefix));
+  /* 2. Convert into Wh
    * As value is expressed in SI units (ie _kg_m^2_s^-2), the ratio is that of
    * hours to seconds. */
   const Representative * hour = TimeRepresentative::Default().representativesOfSameDimension() + Unit::k_hourRepresentativeIndex;
   const Representative * watt = PowerRepresentative::Default().representativesOfSameDimension() + Unit::k_wattRepresentativeIndex;
   double adjustedValue = value / hour->ratio() / watt->ratio();
   const Prefix * wattPrefix = watt->findBestPrefix(adjustedValue, 1.);
-  dest[0] = Multiplication::Builder(
+  dest[index++] = Multiplication::Builder(
       Float<double>::Builder(adjustedValue * std::pow(10., -wattPrefix->exponent())),
       Multiplication::Builder(
         Unit::Builder(watt, wattPrefix),
         Unit::Builder(hour, Prefix::EmptyPrefix())));
-  /* 2. Convert into eV */
+  /* 3. Convert into eV */
   const Representative * eV = representativesOfSameDimension() + Unit::k_electronVoltRepresentativeIndex;
   adjustedValue = value / eV->ratio();
   const Prefix * eVPrefix = eV->findBestPrefix(adjustedValue, 1.);
-  dest[1] = Multiplication::Builder(
+  dest[index++] = Multiplication::Builder(
       Float<double>::Builder(adjustedValue * std::pow(10., -eVPrefix->exponent())),
       Unit::Builder(eV, eVPrefix));
-  return 2;
+  return index;
 }
 
 const UnitNode::Representative * UnitNode::SurfaceRepresentative::standardRepresentative(double value, double exponent, ExpressionNode::ReductionContext reductionContext, const Prefix * * prefix) const {
diff --git a/poincare/test/expression_properties.cpp b/poincare/test/expression_properties.cpp
index b3d6aa5b5..d6a80ce21 100644
--- a/poincare/test/expression_properties.cpp
+++ b/poincare/test/expression_properties.cpp
@@ -413,8 +413,8 @@ QUIZ_CASE(poincare_expression_additional_results) {
   assert_additional_results_compute_to("-4×_°F", array17, 2);
 
   // Energy
-  const char * array8[2] = {"1×_kW×_h", "2.246943ᴇ13×_TeV"};
-  assert_additional_results_compute_to("3.6×_MN_m", array8, 2);
+  const char * array8[3] = {"3.6×_MJ", "1×_kW×_h", "2.246943ᴇ13×_TeV"};
+  assert_additional_results_compute_to("3.6×_MN_m", array8, 3);
 
   // Volume
   const char * array9[2] = {"264×_gal+1×_pt+0.7528377×_cup", "1000×_L"};