package org.leumasjaffe.observer;

import static org.junit.jupiter.api.Assertions.*;
import static org.mockito.Mockito.*;

import java.util.function.BiConsumer;
import java.util.function.BiFunction;
import java.util.function.Consumer;

import javax.swing.JFormattedTextField;
import javax.swing.JTextField;

import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.Test;
import org.junit.jupiter.api.extension.ExtendWith;
import org.mockito.Mock;
import org.mockito.Spy;
import org.mockito.junit.jupiter.MockitoExtension;

@ExtendWith(MockitoExtension.class)
class ObservableControllerTest extends SwingTestCase {
	private static class Value extends Observable.Instance {
		String str = "<INIT>";
		String get() { return str; }
		void set(String value) { this.str = value; }
	}
	
	@Spy MockObserverListener signal;
	@Mock Consumer<Value> onEmpty;
	
	@Spy Value value;
	
	@Spy JTextField component;
	@Spy JFormattedTextField formatted;
	
	@BeforeEach
	void setUp() {
		signal.setObserved(value);
		clearInvocations(signal);
	}

	@Test
	void testThrowsOnNullForAnythingButEmptyHandler() {
		assertThrows(NullPointerException.class,
				() -> ObservableController.from((JTextField) null, Value::get, Value::set));
		assertThrows(NullPointerException.class,
				() -> ObservableController.<JFormattedTextField, Value, String>from(null, Value::get, Value::set));
		assertThrows(NullPointerException.class,
				() -> ObservableController.from(component, null, Value::set));
		assertThrows(NullPointerException.class,
				() -> ObservableController.from(component, Value::get, null));

		assertThrows(NullPointerException.class,
				() -> ObservableController.from(null, (str, model) -> false, (comp, model) -> {}));
		assertThrows(NullPointerException.class,
				() -> ObservableController.from(component, (BiFunction<String, Value, Boolean>) null, (comp, model) -> {}));
		assertThrows(NullPointerException.class,
				() -> ObservableController.from(component, (str, model) -> false, null));

		assertThrows(NullPointerException.class,
				() -> ObservableController.from((JTextField) null, Value::get, Value::set, null));
		assertThrows(NullPointerException.class,
				() -> ObservableController.from(null, Value::get, Value::set, (String) null));
		assertThrows(NullPointerException.class,
				() -> ObservableController.from(component, null, Value::set, null));
		assertThrows(NullPointerException.class,
				() -> ObservableController.from(component, Value::get, null, null));

		assertThrows(NullPointerException.class,
				() -> ObservableController.from(null, (str, model) -> false, (comp, model) -> {}, null));
		assertThrows(NullPointerException.class,
				() -> ObservableController.from(component, (BiFunction<String, Value, Boolean>) null, (comp, model) -> {}, null));
		assertThrows(NullPointerException.class,
				() -> ObservableController.from(component, (str, model) -> false, null, null));
		
		assertDoesNotThrow(() -> ObservableController.from(component, Value::get, Value::set));
		assertDoesNotThrow(() -> ObservableController.from(component, Value::get, Value::set, null));
		assertDoesNotThrow(() -> ObservableController.from(component, (str, model) -> false, (comp, model) -> {}));
		assertDoesNotThrow(() -> ObservableController.from(component, (str, model) -> false, (comp, model) -> {}, null));

		assertDoesNotThrow(() -> ObservableController.<JFormattedTextField, Value, String>from(formatted, Value::get, Value::set));
		assertDoesNotThrow(() -> ObservableController.from(formatted, Value::get, Value::set, (String) null));
	}

	@Test
	void testCanLinkComponentToObjectBeanlike() {
		final ObservableListener<JTextField, Value> listener =
				ObservableController.from(component, Value::get, Value::set);
		
		listener.setObserved(value);
		
		verify(component).setText("<INIT>");
		
		component.setText("Hello");
		waitForSwing();
		
		verify(value).set(eq("Hello"));
		verify(signal).updateWasSignalled();
	}
	
	@Test
	void testWillNotSignalOnNonChangingOperation() {
		final ObservableListener<JTextField, Value> listener =
				ObservableController.from(component, Value::get, Value::set);
		
		listener.setObserved(value);
		
		component.setText("<INIT>");
		waitForSwing();
	
		verify(signal, never()).updateWasSignalled();
		verify(value, never()).set(eq("<INIT>"));
	}
	
	@Test
	void testWillNotFireUpdateIfModelHasNotChanged() {
		final ObservableListener<JTextField, Value> listener =
				ObservableController.from(component, Value::get, Value::set);
		
		listener.setObserved(value);
		
		ObserverDispatch.notifySubscribers(value);
		
		verify(component, times(1)).setText("<INIT>");
	}
	
	@Test
	void testByDefaultWeIgnoreEmptyString() {
		final ObservableListener<JTextField, Value> listener =
				ObservableController.from(component, Value::get, Value::set);
		
		listener.setObserved(value);
		
		component.setText("");
		waitForSwing();

		verify(value, never()).set(eq(""));
		verify(signal, never()).updateWasSignalled();
	}
	
	@Test
	void testCanProvideEmptyStringHandler() {
		final ObservableListener<JTextField, Value> listener =
				ObservableController.from(component, Value::get, Value::set,
						onEmpty);
		
		listener.setObserved(value);
		
		component.setText("");
		waitForSwing();

		verify(onEmpty).accept(same(value));
		verify(signal, never()).updateWasSignalled();
	}
	
	@Test
	void testIfUpdateModelReturnsFalseThenWeDontSignal() {
		final ObservableListener<JTextField, Value> listener =
				ObservableController.from(component, (str, model) -> false,
						(comp, model) -> {});
		
		listener.setObserved(value);

		component.setText("Something");
		waitForSwing();
		
		verify(signal, never()).updateWasSignalled();
	}
	
	@Test
	void testIfUpdateModelReturnsTrueThenWeSignal() {
		final ObservableListener<JTextField, Value> listener =
				ObservableController.from(component, (str, model) -> true,
						(comp, model) -> {});
		
		listener.setObserved(value);
		
		component.setText("Something");
		waitForSwing();
		
		verify(signal).updateWasSignalled();
	}
	
	@Test
	void testIfSignalledThenConsumerIsInvoked() {
		@SuppressWarnings("unchecked")
		BiConsumer<JTextField, Value> updateComp = mock(BiConsumer.class);
		final ObservableListener<JTextField, Value> listener =
				ObservableController.from(component, (str, model) -> false,
						updateComp);
		
		listener.setObserved(value);
		ObserverDispatch.notifySubscribers(value);

		verify(updateComp, times(2)).accept(same(component), same(value));
	}

	@Test
	void testFormattedAffectValueOverText() {
		final ObservableListener<JFormattedTextField, Value> listener =
				ObservableController.<JFormattedTextField, Value, String>from(
						formatted, Value::get, Value::set);

		listener.setObserved(value);
		value.set("1");
		ObserverDispatch.notifySubscribers(value);

		verify(formatted).setValue(eq("1"));
	}

	@Test
	void testFormattedManipulatingTextDoesntPropogate() {
		final ObservableListener<JFormattedTextField, Value> listener =
				ObservableController.<JFormattedTextField, Value, String>from(
						formatted, Value::get, Value::set);

		listener.setObserved(value);
		formatted.setText("1");
		waitForSwing();

		verify(value, never()).set(eq("1"));
	}

	@Test
	void testFormattedManipulatingValuePropogates() {
		final ObservableListener<JFormattedTextField, Value> listener =
				ObservableController.<JFormattedTextField, Value, String>from(
						formatted, Value::get, Value::set);

		listener.setObserved(value);
		formatted.setValue("1");
		waitForSwing();

		verify(value).set(eq("1"));
	}

	@Test
	void testFormattedManipulatingValueDoesNothingWhenEqual() {
		final ObservableListener<JFormattedTextField, Value> listener =
				ObservableController.<JFormattedTextField, Value, String>from(
						formatted, Value::get, Value::set);

		listener.setObserved(value);
		formatted.setValue("<INIT>");
		waitForSwing();

		verify(value, never()).set(any());
	}

	@Test
	void testFormattedManipulatingModelDoesNothingWhenEqual() {
		final ObservableListener<JFormattedTextField, Value> listener =
				ObservableController.<JFormattedTextField, Value, String>from(
						formatted, Value::get, Value::set);

		listener.setObserved(value);
		clearInvocations(formatted);

		ObserverDispatch.notifySubscribers(value);

		verify(formatted, never()).setValue(any());
	}
	
	@Test
	void testFormattedCanProvideEmptyStringHandler() {
		final ObservableListener<JFormattedTextField, Value> listener =
				ObservableController.from(formatted, Value::get, Value::set,
						onEmpty);
		
		listener.setObserved(value);
		
		formatted.setValue("");
		waitForSwing();

		verify(onEmpty).accept(same(value));
		verify(signal, never()).updateWasSignalled();
	}
	
	@Test
	void testFormattedCanProvideDefaultValueOnEmpty() {
		final ObservableListener<JFormattedTextField, Value> listener =
				ObservableController.from(formatted, Value::get, Value::set,
						"<DEFAULT>");
		
		listener.setObserved(value);
		
		formatted.setValue("");
		waitForSwing();

		verify(signal, never()).updateWasSignalled();
		verify(value).set(eq("<DEFAULT>"));
		verify(value, never()).set(eq(""));
	}
}