/*

 * Copyright (c) 1998, 2013, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

package build.tools.dtdbuilder;

import javax.swing.text.html.parser.*;

import java.io.IOException;

import java.io.FileInputStream;

import java.io.InputStream;

import java.io.Reader;

import java.io.InputStreamReader;

import java.io.CharArrayReader;

import java.io.FilterReader;

import java.util.Stack;

import java.net.URL;

/**

 * A stream for reading HTML files. This stream takes care

 * of \r\n conversions and parameter entity expansion.

 *

 * @see DTD

 * @see DTDParser

 * @author Arthur van Hoff

 * @author Steven B. Byrne

 */

public final

class DTDInputStream extends FilterReader implements DTDConstants {

    public DTD dtd;

    public Stack<Object> stack = new Stack<>();

    public char str[] = new char[64];

    public int replace = 0;

    public int ln = 1;

    public int ch;

    /**

     * Create the stream.

     */

    public DTDInputStream(InputStream in, DTD dtd) throws IOException {

        super(new InputStreamReader(in));

        this.dtd = dtd;

        this.ch = in.read();

    }

    /**

     * Error

     */

    public void error(String msg) {

        System.out.println("line " + ln + ": dtd input error: " + msg);

    }

    /**

     * Push a single character

     */

    public void push(int ch) throws IOException {

        char data[] = {(char)ch};

        push(new CharArrayReader(data));

    }

    /**

     * Push an array of bytes.

     */

    public void push(char data[]) throws IOException {

        if (data.length > 0) {

            push(new CharArrayReader(data));

        }

    }

    /**

     * Push an entire input stream

     */

    void push(Reader in) throws IOException {

        stack.push(new Integer(ln));

        stack.push(new Integer(ch));

        stack.push(this.in);

        this.in = in;

        ch = in.read();

    }

    /**

     * Read a character from the input. Automatically pop

     * a stream of the stack if the EOF is reached. Also replaces

     * parameter entities.

     * [60] 350:22

     */

    @SuppressWarnings("fallthrough")

    public int read() throws IOException {

        switch (ch) {

          case '%': {

            ch = in.read();

            if (replace > 0) {

                return '%';

            }

            int pos = 0;

            while (((ch >= 'a') && (ch <= 'z')) || ((ch >= 'A') && (ch <= 'Z')) ||

                   ((ch >= '0') && (ch <= '9')) || (ch == '.') || (ch == '-')) {

                str[pos++] = (char)ch;

                ch = in.read();

            }

            if (pos == 0) {

                return '%';

            }

            String nm = new String(str, 0, pos);

            Entity ent = dtd.getEntity(nm);

            if (ent == null) {

                error("undefined entity reference: " + nm);

                return read();

            }

            // Skip ; or RE

            switch (ch) {

              case '\r':

                ln++;

                /* fall through */

              case ';':

                ch = in.read();

                break;

              case '\n':

                ln++;

                if ((ch = in.read()) == '\r') {

                    ch = in.read();

                }

                break;

            }

            // Push the entity.

            try {

                push(getEntityInputReader(ent));

            } catch (Exception e) {

                error("entity data not found: " + ent + ", " + ent.getString());

            }

            return read();

          }

          case '\n':

            ln++;

            if ((ch = in.read()) == '\r') {

                ch = in.read();

            }

            return '\n';

          case '\r':

            ln++;

            ch = in.read();

            return '\n';

          case -1:

            if (stack.size() > 0) {

                in = (Reader)stack.pop();

                ch = ((Integer)stack.pop()).intValue();

                ln = ((Integer)stack.pop()).intValue();

                return read();

            }

            return -1;

          default:

            int c = ch;

            ch = in.read();

            return c;

        }

    }

    /**

    * Return the data as a stream.

    */

    private Reader getEntityInputReader(Entity ent) throws IOException {

        if ((ent.type & Entity.PUBLIC) != 0) {

            // InputStream is = DTDBuilder.mapping.get(ent.getString()).openStream();

            // return new InputStreamReader(is);

            String path = DTDBuilder.mapping.get(ent.getString());

            return new InputStreamReader(new FileInputStream(path));

        }

        if ((ent.type & Entity.SYSTEM) != 0) {

            //InputStream is =  new URL(DTDBuilder.mapping.base, ent.getString()).openStream();

            String path = DTDBuilder.mapping.baseStr +  ent.getString();

            return new InputStreamReader(new FileInputStream(path));

        }

        return new CharArrayReader(ent.data);

    }

}