package org.requirementsascode.extract.freemarker;

import static org.junit.Assert.assertEquals;

import java.io.StringWriter;
import java.io.Writer;
import java.util.function.Consumer;
import java.util.function.Function;

import org.junit.Before;
import org.junit.Test;
import org.requirementsascode.Actor;
import org.requirementsascode.Condition;
import org.requirementsascode.Model;
import org.requirementsascode.extract.freemarker.predicate.SomeConditionIsFulfilled;
import org.requirementsascode.extract.freemarker.predicate.ThereIsNoAlternative;
import org.requirementsascode.extract.freemarker.systemreaction.BlowsUp;
import org.requirementsascode.extract.freemarker.systemreaction.GreetsUser;
import org.requirementsascode.extract.freemarker.systemreaction.LogsException;
import org.requirementsascode.extract.freemarker.systemreaction.NameEntered;
import org.requirementsascode.extract.freemarker.systemreaction.PromptsUserToEnterName;
import org.requirementsascode.extract.freemarker.systemreaction.Quits;
import org.requirementsascode.extract.freemarker.usercommand.DecidesToQuit;
import org.requirementsascode.extract.freemarker.usercommand.EntersName;

public class FreemarkerEngineTest {
  private FreeMarkerEngine engine;

  @Before
  public void setUp() throws Exception {
    engine = new FreeMarkerEngine("org/requirementsascode/extract/freemarker");
  }

  @Test
  public void extractsEmptyStringFromEmptyModel() throws Exception {
    Model model = Model.builder().build();
    String templateFileName = "testextract.ftl";
    StringWriter outputWriter = new StringWriter();

    engine.extract(model, templateFileName, outputWriter);
    String output = outputWriter.toString();

    assertEquals("", output);
  }

  @Test
  public void extractsUseCaseModel() throws Exception {

    Actor firstActor = new Actor("First actor");
    Actor secondActor = new Actor("Second actor");

    Model model = Model.builder()
      .useCase("Get greeted")
      .basicFlow()
        .step("S1").system(promptsUserToEnterName())
        .step("S2").user(entersName()).system(greetsUser())
        .step("S3").as(firstActor).user(entersName()).system(greetsUser())
          .reactWhile(someConditionIsFulfilled())
        .step("S4").as(firstActor, secondActor).user(decidesToQuit())
        .step("S5").as(firstActor, secondActor).system(promptsUserToEnterName())
        .step("S6").system(quits())
      .flow("Alternative flow A").insteadOf("S4")
        .step("S4a_1").system(blowsUp())
        .step("S4a_2").continuesAt("S1")
      .flow("Alternative flow B").after("S3", "S4")
        .step("S4b_1").continuesAfter("S2")
      .flow("Alternative flow C").condition(thereIsNoAlternative())
        .step("S5a").continuesAt("S4")
      .flow("Alternative flow D").insteadOf("S4").condition(thereIsNoAlternative())
        .step("S4c_2").continuesAt("S1")
      .flow("EX").anytime()
        .step("EX1").on(Exception.class).system(logsException()).build();

    String templateFileName = "testextract.ftl";
    Writer outputWriter = new StringWriter();

    engine.extract(model, templateFileName, outputWriter);
    String output = outputWriter.toString();

    assertEquals("Use case: Get greeted. Flow: Basic flow After S4a_2,S4c_2:" 
      + " Step: S1. System prompts user to enter name."
      + " Step: S2. User enters name.System greets user."
      + " Step: S3. As long as some condition is fulfilled: As First actor: User enters name.System greets user."
      + " Step: S4. As First actor/Second actor: User decides to quit."
      + " Step: S5. As First actor/Second actor: System prompts user to enter name." + " Step: S6. System quits."
      + " Flow: Alternative flow A Instead of S4:" 
      + " Step: S4a_1. System blows up."
      + " Step: S4a_2. System continues at S1." 
      + " Flow: Alternative flow B After S3,S4:"
      + " Step: S4b_1. System continues after S2." 
      + " Flow: Alternative flow C When there is no alternative:"
      + " Step: S5a. System continues at S4."
      + " Flow: Alternative flow D Instead of S4, when there is no alternative:"
      + " Step: S4c_2. System continues at S1." 
      + " Flow: EX"
      + " Step: EX1. On Exception: System logs exception.", output);
  }

  @Test
  public void extractsFlowlessModel() throws Exception {
    Actor secondActor = new Actor("Second actor");

    Model model = Model.builder().on(entersName()).system(greetsUser()).on(entersName()).systemPublish(
      nameEntered()).condition(thereIsNoAlternative()).step("Three").on(entersName()).systemPublish(nameEntered()).to(
        secondActor).on(Exception.class).system(logsException()).build();

    String templateFileName = "testextract_flowless.ftl";
    Writer outputWriter = new StringWriter();

    engine.extract(model, templateFileName, outputWriter);
    String output = outputWriter.toString();

    assertEquals("Use case: Handles messages." + " Step: S1. On EntersName: System greets user."
      + " Step: S2. On EntersName: System publishes name entered."
      + " Step: Three. When there is no alternative: On EntersName: System publishes name entered to Second actor."
      + " Step: S4. On Exception: System logs exception.", output);
  }

  private Condition thereIsNoAlternative() {
    return new ThereIsNoAlternative();
  }

  private Runnable promptsUserToEnterName() {
    return new PromptsUserToEnterName();
  }

  private Class<EntersName> entersName() {
    return EntersName.class;
  }

  private Function<EntersName, String> nameEntered() {
    return new NameEntered();
  }

  private Consumer<EntersName> greetsUser() {
    return new GreetsUser();
  }

  private Condition someConditionIsFulfilled() {
    return new SomeConditionIsFulfilled();
  }

  private Class<DecidesToQuit> decidesToQuit() {
    return DecidesToQuit.class;
  }

  private Runnable quits() {
    return new Quits();
  }

  private Runnable blowsUp() {
    return new BlowsUp();
  }

  private Consumer<Exception> logsException() {
    return new LogsException();
  }
}

@@ -2387,16 +2387,47 @@
 p(%22S6%22).
+inCase(thereIsNoAlternative()).
 system(q
@@ -3662,16 +3662,23 @@
  name.%22 
+%0A      
 + %22 Step

Update FreemarkerEngineTest.java