/*
 * Copyright (c) 1997, 2020 Oracle and/or its affiliates and others.
 * All rights reserved.
 * Copyright 2004 The Apache Software Foundation
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package jakarta.servlet.jsp.tagext;

/**
 * Information on the attributes of a Tag, available at translation time. This class is instantiated from the Tag
 * Library Descriptor file (TLD).
 * <p>
 * Only the information needed to generate code is included here. Other information like SCHEMA for validation belongs
 * elsewhere.
 * <p>
 * Note from the Expert Group:<br>
 * This should have been designed as an interface. Every time we change the TLD, we need to add a new constructor to
 * this class (not good). This class should only be instantiated by container implementations (not by JSP developers).
 */
public class TagAttributeInfo {

    /**
     * "id" is wired in to be ID. There is no real benefit in having it be something else IDREFs are not handled any
     * differently.
     */
    public static final String ID = "id";

    /**
     * Constructor for TagAttributeInfo. This class is to be instantiated only from the TagLibrary code under request
     * from some JSP code that is parsing a TLD (Tag Library Descriptor).
     *
     * @param name     The name of the attribute.
     * @param required If this attribute is required in tag instances.
     * @param type     The name of the type of the attribute.
     * @param reqTime  Whether this attribute holds a request-time Attribute.
     */
    public TagAttributeInfo(String name, boolean required, String type, boolean reqTime) {
        this.name = name;
        this.required = required;
        this.type = type;
        this.reqTime = reqTime;
    }

    /**
     * JSP 2.0 Constructor for TagAttributeInfo. This class is to be instantiated only from the TagLibrary code under
     * request from some JSP code that is parsing a TLD (Tag Library Descriptor).
     *
     * @param name     The name of the attribute.
     * @param required If this attribute is required in tag instances.
     * @param type     The name of the type of the attribute.
     * @param reqTime  Whether this attribute holds a request-time Attribute.
     * @param fragment Whether this attribute is of type JspFragment
     *
     * @since JSP 2.0
     */
    public TagAttributeInfo(String name, boolean required, String type, boolean reqTime, boolean fragment) {
        this(name, required, type, reqTime);
        this.fragment = fragment;
    }

    /**
     * JSP 2.1 Constructor for TagAttributeInfo. This class is to be instantiated only from the TagLibrary code under
     * request from some JSP code that is parsing a TLD (Tag Library Descriptor).
     *
     * @param name             The name of the attribute.
     * @param required         If this attribute is required in tag instances.
     * @param type             The name of the type of the attribute.
     * @param reqTime          Whether this attribute holds a request-time Attribute.
     * @param fragment         Whether this attribute is of type JspFragment
     * @param description      The description of the attribute.
     * @param deferredValue    Whether this attribute is a deferred value.
     * @param deferredMethod   Whether this attribute is a deferred method. rtexpr or deferred value.
     * @param expectedTypeName The name of the expected type of this deferred value (or <code>null</code> if this is not
     *                         a deferred value).
     * @param methodSignature  The expected method signature of this deferred method (or <code>null</code> if this is
     *                         not a deferred method).
     *
     * @since JSP 2.1
     */
    public TagAttributeInfo(String name, boolean required, String type, boolean reqTime, boolean fragment,
            String description, boolean deferredValue, boolean deferredMethod, String expectedTypeName,
            String methodSignature) {
        this(name, required, type, reqTime, fragment);
        this.description = description;
        this.deferredValue = deferredValue;
        this.deferredMethod = deferredMethod;
        this.expectedTypeName = expectedTypeName;
        this.methodSignature = methodSignature;
    }

    /**
     * The name of this attribute.
     *
     * @return the name of the attribute
     */
    public String getName() {
        return name;
    }

    /**
     * The type (as a String) of this attribute.
     *
     * <p>
     * This method must return <code>"jakarta.el.ValueExpression"</code> if <code>isDeferredValue()</code> returns
     * <code>true</code> and <code>canBeRequestTime()</code> returns <code>false</code>. It must return
     * <code>"jakarta.el.MethodExpression"</code> if <code>isDeferredMethod()</code> returns <code>true</code>. It must
     * return <code>"java.lang.Object"</code> if <code>isDeferredValue()</code> returns <code>true</code> and
     * <code>canBeRequestTime()</code> returns <code>true</code>.
     * </p>
     *
     * @return the type of the attribute
     */
    public String getTypeName() {
        return type;
    }

    /**
     * Whether this attribute has been specified in the TLD as rtexprvalue. If <code>true</code>, this means the
     * attribute can hold a request-time value.
     *
     * @return true if the attribute has been specified in the TLD as rtexprvalue
     */
    public boolean canBeRequestTime() {
        return reqTime;
    }

    /**
     * Whether this attribute is required.
     *
     * @return if the attribute is required.
     */
    public boolean isRequired() {
        return required;
    }

    /**
     * Convenience static method that goes through an array of TagAttributeInfo objects and looks for "id".
     *
     * @param a An array of TagAttributeInfo
     * @return The TagAttributeInfo reference with name "id"
     */
    public static TagAttributeInfo getIdAttribute(TagAttributeInfo a[]) {
        for (int i = 0; i < a.length; i++) {
            if (a[i].getName().equals(ID)) {
                return a[i];
            }
        }
        return null; // no such attribute
    }

    /**
     * Whether this attribute is of type JspFragment.
     *
     * @return if the attribute is of type JspFragment
     *
     * @since JSP 2.0
     */
    public boolean isFragment() {
        return fragment;
    }

    /**
     * Gets the description string of this tag attribute.
     *
     * @return the description string of this tag attribute
     */
    public String getDescription() {
        return description;
    }

    /**
     * Returns <code>true</code> if this attribute is to be passed a <code>ValueExpression</code> so that expression
     * evaluation can be deferred.
     *
     * <p>
     * If this method returns <code>true</code>, then <code>getTypeName()</code> must return
     * <code>"jakarta.el.ValueExpression"</code>.
     * </p>
     *
     * <p>
     * The <code>getExpectedType()</code> method can be used to retrieve the expected type this value expression will be
     * constructed with.
     * </p>
     *
     * @return <code>true</code> if this attribute accepts a deferred value; <code>false</code> otherwise.
     *
     * @since JSP 2.1
     */
    public boolean isDeferredValue() {
        return deferredValue;
    }

    /**
     * Returns <code>true</code> if this attribute is to be passed a <code>MethodExpression</code> so that expression
     * evaluation can be deferred.
     *
     * <p>
     * If this method returns <code>true</code>, then <code>getTypeName()</code> must return
     * <code>"jakarta.el.MethodExpression"</code>.
     * </p>
     *
     * <p>
     * The <code>getMethodSignature()</code> method can be used to retrieve the expected method signature this method
     * expression will be constructed with.
     * </p>
     *
     * @return <code>true</code> if this attribute accepts a deferred method; <code>false</code> otherwise.
     *
     * @since JSP 2.1
     */
    public boolean isDeferredMethod() {
        return deferredMethod;
    }

    /**
     * Returns the name of the expected type (as a String) of this deferred value attribute.
     *
     * <p>
     * This method returns <code>null</code> if <code>isDeferredValue()</code> returns <code>false</code>.
     * </p>
     *
     * @return the name of the expected type
     * @since JSP 2.1
     */
    public String getExpectedTypeName() {
        return expectedTypeName;
    }

    /**
     * Returns the expected method signature of this deferred method attribute.
     *
     * <p>
     * This method returns <code>null</code> if <code>isDeferredMethod()</code> returns <code>false</code>.
     * </p>
     *
     * @return the method signature
     * @since JSP 2.1
     */
    public String getMethodSignature() {
        return methodSignature;
    }

    /**
     * Returns a String representation of this TagAttributeInfo, suitable for debugging purposes.
     *
     * @return a String representation of this TagAttributeInfo
     */
    @Override
    public String toString() {
        StringBuffer b = new StringBuffer();
        b.append("name = " + name + " ");
        b.append("type = " + type + " ");
        b.append("reqTime = " + reqTime + " ");
        b.append("required = " + required + " ");
        b.append("fragment = " + fragment + " ");
        b.append("deferredValue = " + deferredValue + " ");
        b.append("deferredMethod = " + deferredMethod + " ");
        b.append("expectedTypeName = " + expectedTypeName + " ");
        b.append("methodSignature = " + methodSignature + " ");
        return b.toString();
    }

    /*
     * private fields
     */
    private String name;
    private String type;
    private boolean reqTime;
    private boolean required;

    /*
     * private fields for JSP 2.0
     */
    private boolean fragment;

    /*
     * private fields for JSP 2.1
     */
    private boolean deferredValue;
    private boolean deferredMethod;
    private String expectedTypeName;
    private String methodSignature;
    private String description;
}
