////////////////////////////////////////
// Programming project code
// UniBw M, 2022, 2023, 2024
// www.unibw.de/inf2
// (c) Mark Minas (mark.minas@unibw.de)
////////////////////////////////////////

package pp.dialog;

import com.jme3.scene.Spatial;
import com.simsilica.lemur.Button;
import com.simsilica.lemur.Container;
import com.simsilica.lemur.Label;
import com.simsilica.lemur.component.BorderLayout;
import com.simsilica.lemur.style.ElementId;

import java.util.ArrayList;
import java.util.List;
import java.util.function.Consumer;
import java.util.function.Function;

import static com.simsilica.lemur.component.BorderLayout.Position.East;
import static com.simsilica.lemur.component.BorderLayout.Position.West;

/**
 * A builder class for creating and customizing dialog boxes of type {@link SimpleDialog} or its subclasses.
 * This builder pattern facilitates the construction of dialog boxes with various configurations,
 * such as titles, text content, buttons, and additional custom behaviors.
 *
 * @param <D> the type of dialog to be built, typically extending {@link SimpleDialog}
 */
public class DialogBuilder<D extends SimpleDialog> {

    /**
     * Creates a {@link DialogBuilder} for a simple dialog with default settings.
     *
     * @param manager the dialog manager responsible for managing the dialog's lifecycle
     * @return a {@link DialogBuilder} instance for creating simple dialogs
     */
    public static DialogBuilder<SimpleDialog> simple(DialogManager manager) {
        return new DialogBuilder<>(manager, SimpleDialog::new);
    }

    protected final DialogManager manager;
    private final Function<DialogManager, D> dialogFactory;
    private final List<Consumer<D>> extensionList = new ArrayList<>();
    private String title;
    private String text;
    private String okLabel;
    private String noLabel;
    private Consumer<D> okAction = d -> {};
    private Consumer<D> noAction = d -> {};
    private boolean okClose = true;
    private boolean noClose = true;
    private Function<D, Spatial> focus;

    /**
     * Constructs a dialog builder with the specified dialog manager and dialog factory.
     *
     * @param manager       the dialog manager responsible for managing the dialog's lifecycle
     * @param dialogFactory a factory function to create instances of the dialog
     */
    public DialogBuilder(DialogManager manager, Function<DialogManager, D> dialogFactory) {
        this.manager = manager;
        this.dialogFactory = dialogFactory;
    }

    /**
     * Applies all registered extensions to the given dialog.
     * Extensions allow for additional customizations beyond the standard configurations.
     *
     * @param dialog the dialog object to which the extensions will be applied
     * @see #setExtension(java.util.function.Consumer)
     */
    protected void extendDialog(D dialog) {
        for (Consumer<D> extension : extensionList)
            extension.accept(dialog);
    }

    /**
     * Builds and returns the dialog with the specified configurations.
     * This method creates a new dialog object and applies all the configured settings.
     *
     * @return the fully configured dialog object
     */
    public D build() {
        return build(dialogFactory.apply(manager));
    }

    /**
     * Builds the dialog by configuring an existing dialog object with the specified settings.
     * This method allows for further customization of a pre-existing dialog object.
     *
     * @param dialog the dialog object to configure
     * @return the configured dialog object for chaining
     */
    public D build(D dialog) {
        configureTitle(dialog);
        configureText(dialog);
        extendDialog(dialog);
        configureButtons(dialog);
        configureFocus(dialog);

        return dialog;
    }

    /**
     * Configures the title of the dialog if a title has been set.
     *
     * @param dialog the dialog to which the title will be added
     */
    private void configureTitle(D dialog) {
        if (title != null)
            dialog.addChild(new Label(title, new ElementId("header"))); // NON-NLS
    }

    /**
     * Configures the main text content of the dialog if text has been set.
     *
     * @param dialog the dialog to which the text content will be added
     */
    private void configureText(D dialog) {
        if (text != null)
            dialog.addChild(new Label(text));
    }

    /**
     * Configures the OK and NO buttons for the dialog if labels for them have been set.
     *
     * @param dialog the dialog to which the buttons will be added
     */
    private void configureButtons(D dialog) {
        if (okLabel != null || noLabel != null) {
            final Container buttons = dialog.addChild(new Container(new BorderLayout()));
            if (okLabel != null) {
                final Button okButton = buttons.addChild(new Button(okLabel), West);
                dialog.setOkButton(okButton);
                configureButton(okButton, okAction, okClose, dialog);
            }
            if (noLabel != null) {
                final Button noButton = buttons.addChild(new Button(noLabel), East);
                configureButton(noButton, noAction, noClose, dialog);
            }
        }
    }

    /**
     * Configures a button with its action and whether the dialog should close after the action is performed.
     *
     * @param button the button to configure
     * @param action the action to perform when the button is clicked
     * @param close  whether the dialog should close after the action is performed
     * @param dialog the dialog that contains the button
     */
    private void configureButton(Button button, Consumer<D> action, boolean close, D dialog) {
        button.addClickCommands(s -> {
            if (dialog.isTopDialog()) {
                action.accept(dialog);
                if (close) {
                    dialog.close();
                }
            }
        });
    }

    /**
     * Configures the initial focus for the dialog when it is displayed.
     * The focus will be set to either a specified component or the OK button if available.
     *
     * @param dialog the dialog to configure focus for
     */
    private void configureFocus(D dialog) {
        final Spatial focusComponent = focus == null ? null : focus.apply(dialog);
        if (focusComponent != null || dialog.getOkButton() != null)
            manager.setFocus(focusComponent != null ? focusComponent : dialog.getOkButton());
    }

    /**
     * Sets the title of the dialog.
     *
     * @param title the title text to be displayed at the top of the dialog
     * @return this builder instance for chaining
     */
    public DialogBuilder<D> setTitle(String title) {
        this.title = title;
        return this;
    }

    /**
     * Sets the main text content of the dialog.
     *
     * @param text the main content text to be displayed in the dialog
     * @return this builder instance for chaining
     */
    public DialogBuilder<D> setText(String text) {
        this.text = text;
        return this;
    }

    /**
     * Sets the label for the OK button.
     *
     * @param okLabel the text label to display on the OK button
     * @return this builder instance for chaining
     */
    public DialogBuilder<D> setOkButton(String okLabel) {
        this.okLabel = okLabel;
        return this;
    }

    /**
     * Sets the label and action for the OK button.
     * When the OK button is clicked, the specified action will be executed.
     *
     * @param okLabel  the text label to display on the OK button
     * @param okAction the action to perform when the OK button is clicked
     * @return this builder instance for chaining
     */
    public DialogBuilder<D> setOkButton(String okLabel, Consumer<D> okAction) {
        this.okAction = okAction;
        return setOkButton(okLabel);
    }

    /**
     * Sets the label and action for the OK button.
     * When the OK button is clicked, the specified runnable action will be executed.
     *
     * @param okLabel  the text label to display on the OK button
     * @param okAction the runnable action to perform when the OK button is clicked
     * @return this builder instance for chaining
     */
    public DialogBuilder<D> setOkButton(String okLabel, Runnable okAction) {
        this.okAction = d -> okAction.run();
        return setOkButton(okLabel);
    }

    /**
     * Sets the label for the NO button.
     *
     * @param noLabel the text label to display on the NO button
     * @return this builder instance for chaining
     */
    public DialogBuilder<D> setNoButton(String noLabel) {
        this.noLabel = noLabel;
        return this;
    }

    /**
     * Sets the label and action for the NO button.
     * When the NO button is clicked, the specified action will be executed.
     *
     * @param noLabel  the text label to display on the NO button
     * @param noAction the action to perform when the NO button is clicked
     * @return this builder instance for chaining
     */
    public DialogBuilder<D> setNoButton(String noLabel, Consumer<D> noAction) {
        this.noAction = noAction;
        return setNoButton(noLabel);
    }

    /**
     * Sets the label and action for the NO button.
     * When the NO button is clicked, the specified runnable action will be executed.
     *
     * @param noLabel  the text label to display on the NO button
     * @param noAction the runnable action to perform when the NO button is clicked
     * @return this builder instance for chaining
     */
    public DialogBuilder<D> setNoButton(String noLabel, Runnable noAction) {
        this.noAction = d -> noAction.run();
        return setNoButton(noLabel);
    }

    /**
     * Sets whether the dialog should automatically close when the OK button is clicked.
     *
     * @param okClose true to close the dialog when the OK button is clicked, false otherwise
     * @return this builder instance for chaining
     */
    public DialogBuilder<D> setOkClose(boolean okClose) {
        this.okClose = okClose;
        return this;
    }

    /**
     * Sets whether the dialog should automatically close when the NO button is clicked.
     *
     * @param noClose true to close the dialog when the NO button is clicked, false otherwise
     * @return this builder instance for chaining
     */
    public DialogBuilder<D> setNoClose(boolean noClose) {
        this.noClose = noClose;
        return this;
    }

    /**
     * Sets the component that should initially receive focus when the dialog is displayed.
     * If a focus function is not provided, the focus defaults to the OK button.
     *
     * @param focus a function specifying which component of the dialog should receive focus
     * @return this builder instance for chaining
     */
    public DialogBuilder<D> setFocus(Function<D, Spatial> focus) {
        this.focus = focus;
        return this;
    }

    /**
     * Adds an extension to the dialog.
     * Extensions allow for additional customizations and behaviors beyond the basic configuration.
     *
     * @param extender a consumer that applies the extension to the dialog
     * @return this builder instance for chaining
     */
    public DialogBuilder<D> setExtension(Consumer<D> extender) {
        extensionList.add(extender);
        return this;
    }
}