package de.aikiit.game.kaiser;
   
   import org.junit.jupiter.api.BeforeEach;
   import org.junit.jupiter.api.Test;
   
   import java.math.BigDecimal;
   import java.math.RoundingMode;
   
   import static org.assertj.core.api.Assertions.assertThat;
  import static org.junit.jupiter.api.Assertions.assertThrows;
  
  public class KaiserEngineCultivateTest {
      private KaiserEngine engine;
  
      @BeforeEach
      void createNewEngineUnderTest() {
          this.engine = new KaiserEngine();
      }
  
      @Test
      void cultivateZeroChangesCostForNextRound() {
          BigDecimal costB4 = engine.getCost();
  
          engine.cultivate(0L);
  
          assertThat(engine.getCost()).isNotEqualTo(costB4);
      }
  
      @Test
      void cultivateNegativeInputDoesNotChangeCost() {
          BigDecimal costB4 = engine.getCost();
  
          engine.cultivate(-1234L);
  
          assertThat(engine.getCost()).isEqualTo(costB4);
      }
  
      @Test
      void youCanNotCultivateMoreThanYourArea() {
          BigDecimal areaB4 = engine.getArea();
  
          Exception exception = assertThrows(IllegalArgumentException.class, () -> engine.cultivate(Long.MAX_VALUE));
  
          String expectedMessage = "You cannot cultivate more area than you have.";
          assertThat(exception.getMessage()).contains(expectedMessage);
          assertThat(engine.getArea()).isEqualTo(areaB4);
      }
  
      @Test
      void youNeedToHaveEnoughSupplies() {
          engine.setArea(BigDecimal.valueOf(Long.MAX_VALUE));
          engine.setSupplies(BigDecimal.valueOf(Long.MAX_VALUE).divide(BigDecimal.valueOf(3), RoundingMode.HALF_UP));
          BigDecimal suppliesB4 = engine.getSupplies();
          BigDecimal areaB4 = engine.getArea();
  
          Exception exception = assertThrows(IllegalArgumentException.class, () -> engine.cultivate(Long.MAX_VALUE));
  
          String expectedMessage = "You cannot cultivate more than you have.";
          assertThat(exception.getMessage()).contains(expectedMessage);
          assertThat(engine.getSupplies()).isEqualTo(suppliesB4);
          assertThat(engine.getArea()).isEqualTo(areaB4);
      }
  
      @Test
      void youNeedWorkersForCultivation() {
          engine.setArea(BigDecimal.valueOf(Long.MAX_VALUE));
          engine.setSupplies(BigDecimal.valueOf(Long.MAX_VALUE).divide(BigDecimal.valueOf(3), RoundingMode.HALF_UP));
          BigDecimal suppliesB4 = engine.getSupplies();
          BigDecimal areaB4 = engine.getArea();
  
          assertThat(engine.getPopulation()).isEqualTo(BigDecimal.valueOf(95L)); // is default value
          Exception exception = assertThrows(IllegalArgumentException.class, () -> {
              engine.cultivate(BigDecimal.valueOf(1000L).longValue()); // is 10 times more than population
          });
  
          String expectedMessage = "Not enough workers available.";
          assertThat(exception.getMessage()).contains(expectedMessage);
          assertThat(engine.getSupplies()).isEqualTo(suppliesB4);
          assertThat(engine.getArea()).isEqualTo(areaB4);
      }
  
      @Test
      void cultivateRegularUseCaseAndSetPriceToOneAfterwards() {
          BigDecimal supplyB4 = engine.getSupplies();
          BigDecimal costB4 = engine.getCost();
          engine.cultivate(4L);
  
          assertThat(engine.getSupplies()).isNotEqualTo(supplyB4);
          assertThat(engine.getCost()).isNotEqualTo(costB4);
      }
  }