package flintstones.helper.extensionpoint;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.HashSet;
import java.util.Set;

import org.eclipse.core.runtime.CoreException;
import org.eclipse.core.runtime.IConfigurationElement;
import org.eclipse.core.runtime.IExtensionRegistry;
import org.eclipse.core.runtime.Platform;
import org.eclipse.e4.core.contexts.ContextInjectionFactory;
import org.eclipse.e4.core.contexts.IEclipseContext;

import flintstones.entity.extensionenum.ExtensionEnum;

/**
 * The Class BaseRegistry.
 */
public class BaseRegistry {

	/** The registers. */
	private final ArrayList<ExtensionRegistry> registers;

	/** The extension point. */
	private final String extensionPoint;

	/** The label id. */
	private String label_id = "uid"; //$NON-NLS-1$

	/** The label implementation. */
	private String label_implementation = "implementation"; //$NON-NLS-1$

	/**
	 * Instantiates a new domain service provider.
	 * @param extensionPoint The extensionPoint
	 */
	public BaseRegistry(String extensionPoint) {
		this.extensionPoint = extensionPoint;
		this.registers = new ArrayList<>();
		this.loadRegisters();
	}
	

	/**
	 * Gets the registry id.
	 *
	 * @return the registry id
	 */
	public String getRegistryId() {
		return this.extensionPoint;
	}


	/**
	 * Load registers.
	 */
	private void loadRegisters() {
		IExtensionRegistry extensionRegistry = Platform.getExtensionRegistry();
		IConfigurationElement[] extensionElements = extensionRegistry.getConfigurationElementsFor(this.extensionPoint); // Domain.EXTENSION_POINT
		Arrays.stream(extensionElements)
				.forEach(this::loadRegistry);
	}

	/**
	 * Load registry.
	 *
	 * @param extensionElement the extension element
	 */
	private void loadRegistry(IConfigurationElement extensionElement) {
		ExtensionRegistry registry = new ExtensionRegistry(extensionElement);
		this.registers.add(registry);
	}

	/**
	 * Gets the first registry where.
	 *
	 * @param key The key of the item you are looking for
	 * @param value The value of the key.
	 * @return The first ExtensionRegistry with the given key,value, null if the value does not exists for the given key. If the ke
	 */
	public ExtensionRegistry getFirstRegistryWhere(ExtensionEnum key, String value) {
		return this.getFirstRegistryWhere(key.toString(), value);
	}

	/**
	 * Gets the first registry where.
	 *
	 * @param key The key of the item you are looking for
	 * @param value The value of the key.
	 * @return The first ExtensionRegistry with the given key,value, null if the value does not exists for the given key. If the ke
	 */
	public ExtensionRegistry getFirstRegistryWhere(String key, String value) {
		for (ExtensionRegistry er : this.registers) {
			if (er.getAttribute(key) == null)
				throw new InvalidKeyIdentifier(key,value);
			if (er.getAttribute(key)
					.equals(value))
				return er;
		}
		return null;
	}

	/**
	 * Gets the all registries where.
	 *
	 * @param key The key of the item you are looking for
	 * @param value The value of the key.
	 * @return all the ExtensionRegistry with the given key
	 */
	public ExtensionRegistry[] getAllRegistriesWhere(ExtensionEnum key, String value) {
		return this.getAllRegistriesWhere(key.toString(), value);
	}

	/**
	 * Gets the all registries where.
	 *
	 * @param key The key of the item you are looking for
	 * @param value The value of the key.
	 * @return all the ExtensionRegistry with the given key
	 */
	public ExtensionRegistry[] getAllRegistriesWhere(String key, String value) {
		ArrayList<ExtensionRegistry> erl = new ArrayList<>();
		for (ExtensionRegistry er : this.registers)
			if (er.getAttribute(key)
					.equals(value))
				erl.add(er);
		return erl.toArray(new ExtensionRegistry[erl.size()]);
	}

	/**
	 * Gets the all attributes where.
	 *
	 * @param key The key of the item you are looking for
	 * @param value The value of the key.
	 * @param attribute The attribute to get from the obtained registers
	 * @return An array with the wanted attribute from the registers where key=value.
	 */
	public String[] getAllAttributesWhere(ExtensionEnum key, String value, ExtensionEnum attribute) {
		return this.getAllAttributesWhere(key.toString(), value, attribute.toString());
	}

	/**
	 * Gets the all attributes where.
	 *
	 * @param key The key of the item you are looking for
	 * @param value The value of the key.
	 * @param attribute The attribute to get from the obtained registers
	 * @return An array with the wanted attribute from the registers where key=value.
	 */
	public String[] getAllAttributesWhere(String key, String value, String attribute) {
		ExtensionRegistry[] arr = this.getAllRegistriesWhere(key, value);
		return Arrays.asList(arr)
				.stream()
				.map(k -> k.getAttribute(attribute))
				.toArray(String[]::new);
	}

	/**
	 * Gets the all registries.
	 *
	 * @return Every ExtensionRegistry available.
	 */
	public ExtensionRegistry[] getAllRegistries() {
		return this.registers.toArray(new ExtensionRegistry[this.registers.size()]);
	}

	/**
	 * Gets the all attributes.
	 *
	 * @param attr The attribute of the ExtensionRegistry you are looking for
	 * @return The value for the given attribute of every ExtensionRegistry.
	 */
	public String[] getAllAttributes(ExtensionEnum attr) {
		return this.getAllAttributes(attr.toString());
	}

	/**
	 * Gets the all attributes.
	 *
	 * @param attr The attribute of the ExtensionRegistry you are looking for
	 * @return The value for the given attribute of every ExtensionRegistry.
	 */
	public String[] getAllAttributes(String attr) {
		ArrayList<String> attrs = new ArrayList<>();
		for (ExtensionRegistry er : this.registers) {
			String val = er.getAttribute(attr);
			if (val != null)
				attrs.add(val);
		}
		return attrs.toArray(new String[attrs.size()]);
	}

	/**
	 * Gets the all attributes unique.
	 *
	 * @param attr The attribute of the ExtensionRegistry you are looking for
	 * @return The value for the given attribute of every ExtensionRegistry, deleting the duplicated ones.
	 */
	public String[] getAllAttributesUnique(ExtensionEnum attr) {
		return this.getAllAttributesUnique(attr.toString());
	}

	/**
	 * Gets the all attributes unique.
	 *
	 * @param attr The attribute of the ExtensionRegistry you are looking for
	 * @return The value for the given attribute of every ExtensionRegistry, deleting the duplicated ones.
	 */
	public String[] getAllAttributesUnique(String attr) {
		return this.unique(this.getAllAttributes(attr));
	}
	
	/**
	 * Gets the attribute from an ExtensionRegistry id
	 * @param attrId The ExtensionRegistry id
	 * @param attr The attribute you are looking for
	 * @return
	 */
	public String getAttributeFromId(String attrId, ExtensionEnum attr) {
		ExtensionRegistry extensionRegistry = this.getFirstRegistryWhere(this.getLabel_id(), attrId);
		return extensionRegistry.getAttribute(attr);
	}

	/**
	 * Unique.
	 *
	 * @param arr An array of items
	 * @return The same items without repeats
	 */
	private String[] unique(String[] arr) {
		int end = arr.length;

		Set<String> set = new HashSet<>();
		for (int i = 0; i < end; i++)
			set.add(arr[i]);
		return set.toArray(new String[set.size()]);
	}

	/**
	 * Instantiate.
	 *
	 * @param id The ID of the extension registry to instantiate
	 * @return The instantiated item
	 */
	public Object instantiate(String id) {
		return this.instantiate(id, null);
	}

	/**
	 * Instantiate using the extension Registry directy. Pretty usefull for creating child items.
	 * @param extensionRegistry The extension registry to instantiate
	 * @return The instantiated item
	 */
	public Object instantiate(ExtensionRegistry extensionRegistry) {
		return this.instantiate(extensionRegistry, null);
	}

	/**
	 * Instantiate.
	 *
	 * @param id The ID of the extension registry to instantiate
	 * @param context The context to register the object in. If it is null, it won't be registered.
	 * @return The instantiated item
	 */
	public Object instantiate(String id, IEclipseContext context) {

		// Grab
		ExtensionRegistry extensionRegistry = this.getFirstRegistryWhere(this.getLabel_id(), id);
		if (extensionRegistry == null) {
			System.err.println("Extensión no encontrada: ID: " + id); //$NON-NLS-1$
			System.err.println("Extensiones disponibles para el punto de extension " + this.extensionPoint); //$NON-NLS-1$
			System.err.println(this.toString());
			throw new InvalidExtensionIdentifier(id);
		}

		return this.instantiate(extensionRegistry, context);
	}

	/**
	 * Instantiate using the extension Registry directy. Pretty usefull for creating child items.
	 * @param extensionRegistry The extension registry to instantiate
	 * @param context The context to register the object in. If it is null, it won't be registered.
	 * @return The instantiated item
	 */
	public Object instantiate(ExtensionRegistry extensionRegistry, IEclipseContext context) {

		// Grab
		IConfigurationElement conf = extensionRegistry.getConfiguration();
		try {

			Object item = conf.createExecutableExtension(this.getLabel_implementation());
			if (context != null)
				ContextInjectionFactory.inject(item, context);

			return item;
		} catch (CoreException e) {
			e.printStackTrace();
			return null;
		}
	}

	/* (non-Javadoc)
	 * @see java.lang.Object#toString()
	 */
	@Override
	public String toString() {
		StringBuilder sb = new StringBuilder();

		for (ExtensionRegistry de : this.getAllRegistries()) {
			sb.append(de.toString());
			sb.append("\n"); //$NON-NLS-1$
		}

		return sb.toString();
	}

	/**
	 * Gets the label id.
	 *
	 * @return The label for the extension point ID. The default value is "id".
	 */
	public String getLabel_id() {
		return this.label_id;
	}

	/**
	 * Sets the label id.
	 *
	 * @param label_id The new label for the extension point ID. The default value is "id".
	 */
	public void setLabel_id(String label_id) {
		this.label_id = label_id;
	}

	/**
	 * Gets the label implementation.
	 *
	 * @return The label for the extension point implementation. The default value is "implementation".
	 */
	public String getLabel_implementation() {
		return this.label_implementation;
	}

	/**
	 * Sets the label implementation.
	 *
	 * @param label_implementation The new label for the extension point implementation. The default value is "implementation".
	 */
	public void setLabel_implementation(ExtensionEnum label_implementation) {
		this.setLabel_implementation(label_implementation.toString());
	}

	/**
	 * Sets the label implementation.
	 *
	 * @param label_implementation The new label for the extension point implementation. The default value is "implementation".
	 */
	public void setLabel_implementation(String label_implementation) {
		this.label_implementation = label_implementation;
	}

	/**
	 * The Class InvalidExtensionIdentifier.
	 */
	public class InvalidExtensionIdentifier extends RuntimeException {

		/** The Constant serialVersionUID. */
		private static final long serialVersionUID = -517005676614953393L;

		/**
		 * Instantiates a new invalid extension identifier.
		 *
		 * @param text the text
		 */
		private InvalidExtensionIdentifier(String text) {
			super("Identificador de extensión no encontrado: " + text); //$NON-NLS-1$
		}
	}

	/**
	 * The Class InvalidKeyIdentifier.
	 */
	private class InvalidKeyIdentifier extends RuntimeException {

		/** The Constant serialVersionUID. */
		private static final long serialVersionUID = 924357389433409796L;

		/**
		 * Instantiates a new invalid key identifier.
		 *
		 * @param text the text
		 */
		private InvalidKeyIdentifier(String text) {
			super("Clave no encontrada en el punto de extensión: " + text); //$NON-NLS-1$
		}

		private InvalidKeyIdentifier(String text, String t2) {
			super("Clave no encontrada en el punto de extensión: " + text + "// " + t2); //$NON-NLS-1$
		}

	}


}