/* Copyright (c) 2002,2003, Stefan Haustein, Oberhausen, Rhld., Germany
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or
 * sell copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The  above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
 * IN THE SOFTWARE. */

// Contributors: Paul Hackenberger (unterminated entity handling in relaxed mode)

package org.kxml2.io;

import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.Reader;
import java.util.HashMap;
import java.util.Map;
import org.xmlpull.v1.XmlPullParser;
import org.xmlpull.v1.XmlPullParserException;

/**
 * A pull based XML parser.
 */
public class KXmlParser implements XmlPullParser {

    private Object location;
    static final private String UNEXPECTED_EOF = "Unexpected EOF";
    static final private String ILLEGAL_TYPE = "Wrong event type";
    static final private int LEGACY = 999;
    static final private int XML_DECL = 998;

    // general

    private String version;
    private Boolean standalone;

    private boolean processNsp;
    private boolean relaxed;
    private boolean keepNamespaceAttributes;
    private Map<String, String> entityMap;
    private int depth;
    private String[] elementStack = new String[16];
    private String[] nspStack = new String[8];
    private int[] nspCounts = new int[4];

    // source

    private Reader reader;
    private String encoding;
    private char[] srcBuf;

    private int srcPos;
    private int srcCount;

    private int line;
    private int column;

    // txtbuffer

    /** Target buffer for storing incoming text (including aggregated resolved entities) */
    private char[] txtBuf = new char[128];
    /** Write position */
    private int txtPos;

    // Event-related

    private int type;
    private boolean isWhitespace;
    private String namespace;
    private String prefix;
    private String name;

    private boolean degenerated;
    private int attributeCount;

    /**
     * The current element's attributes arranged in groups of 4:
     * i + 0 = attribute namespace URI
     * i + 1 = attribute namespace prefix
     * i + 2 = attribute qualified name (may contain ":", as in "html:h1")
     * i + 3 = attribute value
     */
    private String[] attributes = new String[16];

    private String error;

    /**
     * A separate peek buffer seems simpler than managing wrap around in the first level read
     * buffer
     */
    private int[] peek = new int[2];
    private int peekCount;
    private boolean wasCR;

    private boolean unresolved;
    private boolean token;

    public KXmlParser() {
        srcBuf = new char[8192];
    }

    /**
     * Retains namespace attributes like {@code xmlns="http://foo"} or {@code xmlns:foo="http:foo"}
     * in pulled elements. Most applications will only be interested in the effective namespaces of
     * their elements, so these attributes aren't useful. But for structure preserving wrappers like
     * DOM, it is necessary to keep the namespace data around.
     */
    public void keepNamespaceAttributes() {
        this.keepNamespaceAttributes = true;
    }

    private boolean isProp(String n1, boolean prop, String n2) {
        if (!n1.startsWith("http://xmlpull.org/v1/doc/")) {
            return false;
        }
        if (prop) {
            return n1.substring(42).equals(n2);
        } else {
            return n1.substring(40).equals(n2);
        }
    }

    private boolean adjustNsp() throws XmlPullParserException {
        boolean any = false;

        for (int i = 0; i < attributeCount << 2; i += 4) {
            String attrName = attributes[i + 2];
            int cut = attrName.indexOf(':');
            String prefix;

            if (cut != -1) {
                prefix = attrName.substring(0, cut);
                attrName = attrName.substring(cut + 1);
            } else if (attrName.equals("xmlns")) {
                prefix = attrName;
                attrName = null;
            } else {
                continue;
            }

            if (!prefix.equals("xmlns")) {
                any = true;
            } else {
                int j = (nspCounts[depth]++) << 1;

                nspStack = ensureCapacity(nspStack, j + 2);
                nspStack[j] = attrName;
                nspStack[j + 1] = attributes[i + 3];

                if (attrName != null && attributes[i + 3].isEmpty()) {
                    error("illegal empty namespace");
                }

                if (keepNamespaceAttributes) {
                    // explicitly set the namespace for unprefixed attributes
                    // such as xmlns="http://foo"
                    attributes[i] = "http://www.w3.org/2000/xmlns/";
                    any = true;
                } else {
                    System.arraycopy(
                            attributes,
                            i + 4,
                            attributes,
                            i,
                            ((--attributeCount) << 2) - i);

                    i -= 4;
                }
            }
        }

        if (any) {
            for (int i = (attributeCount << 2) - 4; i >= 0; i -= 4) {

                String attrName = attributes[i + 2];
                int cut = attrName.indexOf(':');

                if (cut == 0 && !relaxed) {
                    throw new RuntimeException(
                            "illegal attribute name: " + attrName + " at " + this);
                } else if (cut != -1) {
                    String attrPrefix = attrName.substring(0, cut);

                    attrName = attrName.substring(cut + 1);

                    String attrNs = getNamespace(attrPrefix);

                    if (attrNs == null && !relaxed) {
                        throw new RuntimeException(
                                "Undefined Prefix: " + attrPrefix + " in " + this);
                    }

                    attributes[i] = attrNs;
                    attributes[i + 1] = attrPrefix;
                    attributes[i + 2] = attrName;
                }
            }
        }

        int cut = name.indexOf(':');

        if (cut == 0) {
            error("illegal tag name: " + name);
        }

        if (cut != -1) {
            prefix = name.substring(0, cut);
            name = name.substring(cut + 1);
        }

        this.namespace = getNamespace(prefix);

        if (this.namespace == null) {
            if (prefix != null) {
                error("undefined prefix: " + prefix);
            }
            this.namespace = NO_NAMESPACE;
        }

        return any;
    }

    private String[] ensureCapacity(String[] arr, int required) {
        if (arr.length >= required) {
            return arr;
        }
        String[] bigger = new String[required + 16];
        System.arraycopy(arr, 0, bigger, 0, arr.length);
        return bigger;
    }

    private void error(String desc) throws XmlPullParserException {
        if (relaxed) {
            if (error == null) {
                error = "ERR: " + desc;
            }
        } else {
            exception(desc);
        }
    }

    private void exception(String desc) throws XmlPullParserException {
        throw new XmlPullParserException(
                desc.length() < 100 ? desc : desc.substring(0, 100) + "\n",
                this,
                null);
    }

    /**
     * Common base for next() and nextToken(). Clears the state, except from txtPos and whitespace.
     * Does not set the type variable.
     */
    private void nextImpl() throws IOException, XmlPullParserException {
        if (reader == null) {
            exception("No Input specified");
        }

        if (type == END_TAG) {
            depth--;
        }

        while (true) {
            attributeCount = -1;

            // degenerated needs to be handled before error because of possible
            // processor expectations(!)

            if (degenerated) {
                degenerated = false;
                type = END_TAG;
                return;
            }

            if (error != null) {
                for (int i = 0; i < error.length(); i++) {
                    push(error.charAt(i));
                }
                error = null;
                type = COMMENT;
                return;
            }

            prefix = null;
            name = null;
            namespace = null;

            type = peekType();

            switch (type) {

                case ENTITY_REF:
                    pushEntity();
                    return;

                case START_TAG:
                    parseStartTag(false);
                    return;

                case END_TAG:
                    parseEndTag();
                    return;

                case END_DOCUMENT:
                    return;

                case TEXT:
                    pushText('<', !token, false);
                    if (depth == 0) {
                        if (isWhitespace) {
                            type = IGNORABLE_WHITESPACE;
                        }
                    }
                    return;

                default:
                    type = parseLegacy(token);
                    if (type != XML_DECL) {
                        return;
                    }
            }
        }
    }

    private int parseLegacy(boolean push) throws IOException, XmlPullParserException {
        String req = "";
        int term;
        int result;
        int prev = 0;

        read(); // <
        int c = read();

        if (c == '?') {
            if ((peek(0) == 'x' || peek(0) == 'X')
                    && (peek(1) == 'm' || peek(1) == 'M')) {

                if (push) {
                    push(peek(0));
                    push(peek(1));
                }
                read();
                read();

                if ((peek(0) == 'l' || peek(0) == 'L') && peek(1) <= ' ') {

                    if (line != 1 || column > 4) {
                        error("PI must not start with xml");
                    }

                    parseStartTag(true);

                    if (attributeCount < 1 || !"version".equals(attributes[2])) {
                        error("version expected");
                    }

                    version = attributes[3];

                    int pos = 1;

                    if (pos < attributeCount
                            && "encoding".equals(attributes[2 + 4])) {
                        encoding = attributes[3 + 4];
                        pos++;
                    }

                    if (pos < attributeCount
                            && "standalone".equals(attributes[4 * pos + 2])) {
                        String st = attributes[3 + 4 * pos];
                        if ("yes".equals(st)) {
                            standalone = new Boolean(true);
                        } else if ("no".equals(st)) {
                            standalone = new Boolean(false);
                        } else {
                            error("illegal standalone value: " + st);
                        }
                        pos++;
                    }

                    if (pos != attributeCount) {
                        error("illegal xmldecl");
                    }

                    isWhitespace = true;
                    txtPos = 0;

                    return XML_DECL;
                }
            }

            term = '?';
            result = PROCESSING_INSTRUCTION;
        } else if (c == '!') {
            if (peek(0) == '-') {
                result = COMMENT;
                req = "--";
                term = '-';
            } else if (peek(0) == '[') {
                result = CDSECT;
                req = "[CDATA[";
                term = ']';
                push = true;
            } else {
                result = DOCDECL;
                req = "DOCTYPE";
                term = -1;
            }
        } else {
            error("illegal: <" + c);
            return COMMENT;
        }

        for (int i = 0; i < req.length(); i++) {
            read(req.charAt(i));
        }

        if (result == DOCDECL) {
            parseDoctype(push);
        } else {
            while (true) {
                c = read();
                if (c == -1) {
                    error(UNEXPECTED_EOF);
                    return COMMENT;
                }

                if (push) {
                    push(c);
                }

                if ((term == '?' || c == term)
                        && peek(0) == term
                        && peek(1) == '>') {
                    break;
                }

                prev = c;
            }

            if (term == '-' && prev == '-' && !relaxed) {
                error("illegal comment delimiter: --->");
            }

            read();
            read();

            if (push && term != '?') {
                txtPos--;
            }

        }
        return result;
    }

    /**
     * precondition: &lt! consumed
     */
    private void parseDoctype(boolean push) throws IOException, XmlPullParserException {
        int nesting = 1;
        boolean quoted = false;

        while (true) {
            int i = read();
            switch (i) {

                case -1:
                    error(UNEXPECTED_EOF);
                    return;

                case '\'':
                    quoted = !quoted;
                    break;

                case '<':
                    if (!quoted) {
                        nesting++;
                    }
                    break;

                case '>':
                    if (!quoted) {
                        if ((--nesting) == 0) {
                            return;
                        }
                    }
                    break;
            }
            if (push) {
                push(i);
            }
        }
    }

    /**
     * precondition: &lt;/ consumed
     */
    private void parseEndTag() throws IOException, XmlPullParserException {
        read(); // '<'
        read(); // '/'
        name = readName();
        skip();
        read('>');

        int sp = (depth - 1) << 2;

        if (depth == 0) {
            error("element stack empty");
            type = COMMENT;
            return;
        }

        if (!relaxed) {
            if (!name.equals(elementStack[sp + 3])) {
                error("expected: /" + elementStack[sp + 3] + " read: " + name);
            }

            namespace = elementStack[sp];
            prefix = elementStack[sp + 1];
            name = elementStack[sp + 2];
        }
    }

    private int peekType() throws IOException {
        switch (peek(0)) {
            case -1:
                return END_DOCUMENT;
            case '&':
                return ENTITY_REF;
            case '<':
                switch (peek(1)) {
                    case '/':
                        return END_TAG;
                    case '?':
                    case '!':
                        return LEGACY;
                    default:
                        return START_TAG;
                }
            default:
                return TEXT;
        }
    }

    private String get(int pos) {
        return new String(txtBuf, pos, txtPos - pos);
    }

    private void push(int c) {
        isWhitespace &= c <= ' ';

        if (txtPos == txtBuf.length) {
            char[] bigger = new char[txtPos * 4 / 3 + 4];
            System.arraycopy(txtBuf, 0, bigger, 0, txtPos);
            txtBuf = bigger;
        }

        txtBuf[txtPos++] = (char) c;
    }

    /**
     * Sets name and attributes
     */
    private void parseStartTag(boolean xmldecl) throws IOException, XmlPullParserException {
        if (!xmldecl) {
            read();
        }
        name = readName();
        attributeCount = 0;

        while (true) {
            skip();

            int c = peek(0);

            if (xmldecl) {
                if (c == '?') {
                    read();
                    read('>');
                    return;
                }
            } else {
                if (c == '/') {
                    degenerated = true;
                    read();
                    skip();
                    read('>');
                    break;
                }

                if (c == '>' && !xmldecl) {
                    read();
                    break;
                }
            }

            if (c == -1) {
                error(UNEXPECTED_EOF);
                return;
            }

            String attrName = readName();

            if (attrName.length() == 0) {
                error("attr name expected");
                break;
            }

            int i = (attributeCount++) << 2;

            attributes = ensureCapacity(attributes, i + 4);

            attributes[i++] = "";
            attributes[i++] = null;
            attributes[i++] = attrName;

            skip();

            if (peek(0) != '=') {
                if (!relaxed) {
                    error("Attr.value missing f. " + attrName);
                }
                attributes[i] = attrName;
            } else {
                read('=');
                skip();
                int delimiter = peek(0);

                if (delimiter != '\'' && delimiter != '"') {
                    if (!relaxed) {
                        error("attr value delimiter missing!");
                    }
                    delimiter = ' ';
                } else {
                    read();
                }

                int p = txtPos;
                pushText(delimiter, true, true);

                attributes[i] = get(p);
                txtPos = p;

                if (delimiter != ' ') {
                    read(); // skip endquote
                }
            }
        }

        int sp = depth++ << 2;

        elementStack = ensureCapacity(elementStack, sp + 4);
        elementStack[sp + 3] = name;

        if (depth >= nspCounts.length) {
            int[] bigger = new int[depth + 4];
            System.arraycopy(nspCounts, 0, bigger, 0, nspCounts.length);
            nspCounts = bigger;
        }

        nspCounts[depth] = nspCounts[depth - 1];

        if (processNsp) {
            adjustNsp();
        } else {
            namespace = "";
        }

        elementStack[sp] = namespace;
        elementStack[sp + 1] = prefix;
        elementStack[sp + 2] = name;
    }

    /**
     * result: isWhitespace; if the setName parameter is set, the name of the entity is stored in
     * "name"
     */
    private void pushEntity() throws IOException, XmlPullParserException {
        push(read()); // &

        int pos = txtPos;

        while (true) {
            int c = peek(0);
            if (c == ';') {
                read();
                break;
            }
            if (c < 128 && (c < '0' || c > '9') && (c < 'a' || c > 'z') && (c < 'A' || c > 'Z')
                    && c != '_' && c != '-' && c != '#') {
                if (!relaxed) {
                    error("unterminated entity ref");
                }

                return;
            }

            push(read());
        }

        String code = get(pos);
        txtPos = pos - 1;
        if (token && type == ENTITY_REF) {
            name = code;
        }

        if (code.charAt(0) == '#') {
            int c = code.charAt(1) == 'x'
                    ? Integer.parseInt(code.substring(2), 16)
                    : Integer.parseInt(code.substring(1));
            push(c);
            return;
        }

        String result = entityMap.get(code);

        unresolved = result == null;

        if (unresolved) {
            if (!token) {
                error("unresolved: &" + code + ";");
            }
        } else {
            for (int i = 0; i < result.length(); i++) {
                push(result.charAt(i));
            }
        }
    }

    /**
     * types: '<': parse to any token (for nextToken ()) '"': parse to quote ' ': parse to
     * whitespace or '>'
     */
    private void pushText(int delimiter, boolean resolveEntities, boolean inAttributeValue)
            throws IOException, XmlPullParserException {

        int next = peek(0);
        int cbrCount = 0;

        while (next != -1 && next != delimiter) { // covers eof, '<', '"'

            if (delimiter == ' ' && (next <= ' ' || next == '>')) {
                break;
            }

            if (next == '&') {
                if (!resolveEntities) {
                    break;
                }

                pushEntity();
            } else if (next == '<' && inAttributeValue) {
                error("Illegal: \"<\" inside attribute value");
            } else if (next == '\n' && type == START_TAG) {
                read();
                push(' ');
            } else {
                push(read());
            }

            /*
             * "]]>" is allowed in attribute values, but is not allowed in
             * regular text between markup.
             */
            final boolean allowCloseCdata = inAttributeValue;
            if (!allowCloseCdata && (next == '>' && cbrCount >= 2 && delimiter != ']')) {
                error("Illegal: \"]]>\" outside CDATA section");
            }

            if (next == ']') {
                cbrCount++;
            } else {
                cbrCount = 0;
            }

            next = peek(0);
        }
    }

    private void read(char c) throws IOException, XmlPullParserException {
        int a = read();
        if (a != c) {
            error("expected: '" + c + "' actual: '" + ((char) a) + "'");
        }
    }

    private int read() throws IOException {
        int result;

        if (peekCount == 0) {
            result = peek(0);
        } else {
            result = peek[0];
            peek[0] = peek[1];
        }
        peekCount--;

        column++;

        if (result == '\n') {

            line++;
            column = 1;
        }

        return result;
    }

    /**
     * Does never read more than needed
     */
    private int peek(int pos) throws IOException {
        while (pos >= peekCount) {
            int nw;
            if (srcBuf.length <= 1) {
                nw = reader.read();
            } else if (srcPos < srcCount) {
                nw = srcBuf[srcPos++];
            } else {
                srcCount = reader.read(srcBuf, 0, srcBuf.length);
                if (srcCount <= 0) {
                    nw = -1;
                } else {
                    nw = srcBuf[0];
                }

                srcPos = 1;
            }

            if (nw == '\r') {
                wasCR = true;
                peek[peekCount++] = '\n';
            } else {
                if (nw == '\n') {
                    if (!wasCR) {
                        peek[peekCount++] = '\n';
                    }
                } else {
                    peek[peekCount++] = nw;
                }

                wasCR = false;
            }
        }

        return peek[pos];
    }

    private String readName() throws IOException, XmlPullParserException {
        int pos = txtPos;
        int c = peek(0);
        if ((c < 'a' || c > 'z')
                && (c < 'A' || c > 'Z')
                && c != '_'
                && c != ':'
                && c < 0x0c0
                && !relaxed) {
            error("name expected");
        }

        do {
            push(read());
            c = peek(0);
        }
        while ((c >= 'a' && c <= 'z')
                || (c >= 'A' && c <= 'Z')
                || (c >= '0' && c <= '9')
                || c == '_'
                || c == '-'
                || c == ':'
                || c == '.'
                || c >= 0x0b7);

        String result = get(pos);
        txtPos = pos;
        return result;
    }

    private void skip() throws IOException {
        while (true) {
            int c = peek(0);
            if (c > ' ' || c == -1) {
                break;
            }
            read();
        }
    }

    //  public part starts here...

    public void setInput(Reader reader) throws XmlPullParserException {
        this.reader = reader;

        line = 1;
        column = 0;
        type = START_DOCUMENT;
        name = null;
        namespace = null;
        degenerated = false;
        attributeCount = -1;
        encoding = null;
        version = null;
        standalone = null;

        if (reader == null) {
            return;
        }

        srcPos = 0;
        srcCount = 0;
        peekCount = 0;
        depth = 0;

        entityMap = new HashMap<String, String>();
        entityMap.put("amp", "&");
        entityMap.put("apos", "'");
        entityMap.put("gt", ">");
        entityMap.put("lt", "<");
        entityMap.put("quot", "\"");
    }

    public void setInput(InputStream is, String _enc) throws XmlPullParserException {
        srcPos = 0;
        srcCount = 0;
        String enc = _enc;

        if (is == null) {
            throw new IllegalArgumentException();
        }

        try {
            if (enc == null) {
                // read four bytes

                int chk = 0;

                while (srcCount < 4) {
                    int i = is.read();
                    if (i == -1) {
                        break;
                    }
                    chk = (chk << 8) | i;
                    srcBuf[srcCount++] = (char) i;
                }

                if (srcCount == 4) {
                    switch (chk) {
                        case 0x00000FEFF:
                            enc = "UTF-32BE";
                            srcCount = 0;
                            break;

                        case 0x0FFFE0000:
                            enc = "UTF-32LE";
                            srcCount = 0;
                            break;

                        case 0x03c:
                            enc = "UTF-32BE";
                            srcBuf[0] = '<';
                            srcCount = 1;
                            break;

                        case 0x03c000000:
                            enc = "UTF-32LE";
                            srcBuf[0] = '<';
                            srcCount = 1;
                            break;

                        case 0x0003c003f:
                            enc = "UTF-16BE";
                            srcBuf[0] = '<';
                            srcBuf[1] = '?';
                            srcCount = 2;
                            break;

                        case 0x03c003f00:
                            enc = "UTF-16LE";
                            srcBuf[0] = '<';
                            srcBuf[1] = '?';
                            srcCount = 2;
                            break;

                        case 0x03c3f786d:
                            while (true) {
                                int i = is.read();
                                if (i == -1) {
                                    break;
                                }
                                srcBuf[srcCount++] = (char) i;
                                if (i == '>') {
                                    String s = new String(srcBuf, 0, srcCount);
                                    int i0 = s.indexOf("encoding");
                                    if (i0 != -1) {
                                        while (s.charAt(i0) != '"'
                                                && s.charAt(i0) != '\'') {
                                            i0++;
                                        }
                                        char deli = s.charAt(i0++);
                                        int i1 = s.indexOf(deli, i0);
                                        enc = s.substring(i0, i1);
                                    }
                                    break;
                                }
                            }

                        default:
                            if ((chk & 0x0ffff0000) == 0x0FEFF0000) {
                                enc = "UTF-16BE";
                                srcBuf[0] =
                                        (char) ((srcBuf[2] << 8) | srcBuf[3]);
                                srcCount = 1;
                            } else if ((chk & 0x0ffff0000) == 0x0fffe0000) {
                                enc = "UTF-16LE";
                                srcBuf[0] =
                                        (char) ((srcBuf[3] << 8) | srcBuf[2]);
                                srcCount = 1;
                            } else if ((chk & 0x0ffffff00) == 0x0EFBBBF00) {
                                enc = "UTF-8";
                                srcBuf[0] = srcBuf[3];
                                srcCount = 1;
                            }
                    }
                }
            }

            if (enc == null) {
                enc = "UTF-8";
            }

            int sc = srcCount;
            setInput(new InputStreamReader(is, enc));
            encoding = _enc;
            srcCount = sc;
        } catch (Exception e) {
            throw new XmlPullParserException(
                    "Invalid stream or encoding: " + e.toString(),
                    this,
                    e);
        }
    }

    public boolean getFeature(String feature) {
        if (XmlPullParser.FEATURE_PROCESS_NAMESPACES.equals(feature)) {
            return processNsp;
        } else if (isProp(feature, false, "relaxed")) {
            return relaxed;
        } else {
            return false;
        }
    }

    public String getInputEncoding() {
        return encoding;
    }

    public void defineEntityReplacementText(String entity, String value)
            throws XmlPullParserException {
        if (entityMap == null) {
            throw new RuntimeException("entity replacement text must be defined after setInput!");
        }
        entityMap.put(entity, value);
    }

    public Object getProperty(String property) {
        if (isProp(property, true, "xmldecl-version")) {
            return version;
        }
        if (isProp(property, true, "xmldecl-standalone")) {
            return standalone;
        }
        if (isProp(property, true, "location")) {
            return location != null ? location : reader.toString();
        }
        return null;
    }

    public int getNamespaceCount(int depth) {
        if (depth > this.depth) {
            throw new IndexOutOfBoundsException();
        }
        return nspCounts[depth];
    }

    public String getNamespacePrefix(int pos) {
        return nspStack[pos << 1];
    }

    public String getNamespaceUri(int pos) {
        return nspStack[(pos << 1) + 1];
    }

    public String getNamespace(String prefix) {

        if ("xml".equals(prefix)) {
            return "http://www.w3.org/XML/1998/namespace";
        }
        if ("xmlns".equals(prefix)) {
            return "http://www.w3.org/2000/xmlns/";
        }

        for (int i = (getNamespaceCount(depth) << 1) - 2; i >= 0; i -= 2) {
            if (prefix == null) {
                if (nspStack[i] == null) {
                    return nspStack[i + 1];
                }
            } else if (prefix.equals(nspStack[i])) {
                return nspStack[i + 1];
            }
        }
        return null;
    }

    public int getDepth() {
        return depth;
    }

    public String getPositionDescription() {
        StringBuilder buf = new StringBuilder(type < TYPES.length ? TYPES[type] : "unknown");
        buf.append(' ');

        if (type == START_TAG || type == END_TAG) {
            if (degenerated) {
                buf.append("(empty) ");
            }
            buf.append('<');
            if (type == END_TAG) {
                buf.append('/');
            }

            if (prefix != null) {
                buf.append("{" + namespace + "}" + prefix + ":");
            }
            buf.append(name);

            int cnt = attributeCount << 2;
            for (int i = 0; i < cnt; i += 4) {
                buf.append(' ');
                if (attributes[i + 1] != null) {
                    buf.append(
                            "{" + attributes[i] + "}" + attributes[i + 1] + ":");
                }
                buf.append(attributes[i + 2] + "='" + attributes[i + 3] + "'");
            }

            buf.append('>');
        } else if (type == IGNORABLE_WHITESPACE) {
            ;
        } else if (type != TEXT) {
            buf.append(getText());
        } else if (isWhitespace) {
            buf.append("(whitespace)");
        } else {
            String text = getText();
            if (text.length() > 16) {
                text = text.substring(0, 16) + "...";
            }
            buf.append(text);
        }

        buf.append("@" + line + ":" + column);
        if (location != null) {
            buf.append(" in ");
            buf.append(location);
        } else if (reader != null) {
            buf.append(" in ");
            buf.append(reader.toString());
        }
        return buf.toString();
    }

    public int getLineNumber() {
        return line;
    }

    public int getColumnNumber() {
        return column;
    }

    public boolean isWhitespace() throws XmlPullParserException {
        if (type != TEXT && type != IGNORABLE_WHITESPACE && type != CDSECT) {
            exception(ILLEGAL_TYPE);
        }
        return isWhitespace;
    }

    public String getText() {
        return type < TEXT
                || (type == ENTITY_REF && unresolved) ? null : get(0);
    }

    public char[] getTextCharacters(int[] poslen) {
        if (type >= TEXT) {
            if (type == ENTITY_REF) {
                poslen[0] = 0;
                poslen[1] = name.length();
                return name.toCharArray();
            }
            poslen[0] = 0;
            poslen[1] = txtPos;
            return txtBuf;
        }

        poslen[0] = -1;
        poslen[1] = -1;
        return null;
    }

    public String getNamespace() {
        return namespace;
    }

    public String getName() {
        return name;
    }

    public String getPrefix() {
        return prefix;
    }

    public boolean isEmptyElementTag() throws XmlPullParserException {
        if (type != START_TAG) {
            exception(ILLEGAL_TYPE);
        }
        return degenerated;
    }

    public int getAttributeCount() {
        return attributeCount;
    }

    public String getAttributeType(int index) {
        return "CDATA";
    }

    public boolean isAttributeDefault(int index) {
        return false;
    }

    public String getAttributeNamespace(int index) {
        if (index >= attributeCount) {
            throw new IndexOutOfBoundsException();
        }
        return attributes[index << 2];
    }

    public String getAttributeName(int index) {
        if (index >= attributeCount) {
            throw new IndexOutOfBoundsException();
        }
        return attributes[(index << 2) + 2];
    }

    public String getAttributePrefix(int index) {
        if (index >= attributeCount) {
            throw new IndexOutOfBoundsException();
        }
        return attributes[(index << 2) + 1];
    }

    public String getAttributeValue(int index) {
        if (index >= attributeCount) {
            throw new IndexOutOfBoundsException();
        }
        return attributes[(index << 2) + 3];
    }

    public String getAttributeValue(String namespace, String name) {

        for (int i = (attributeCount << 2) - 4; i >= 0; i -= 4) {
            if (attributes[i + 2].equals(name)
                    && (namespace == null || attributes[i].equals(namespace))) {
                return attributes[i + 3];
            }
        }

        return null;
    }

    public int getEventType() throws XmlPullParserException {
        return type;
    }

    public int next() throws XmlPullParserException, IOException {

        txtPos = 0;
        isWhitespace = true;
        int minType = 9999;
        token = false;

        do {
            nextImpl();
            if (type < minType) {
                minType = type;
            }
            //    if (curr <= TEXT) type = curr;
        }
        while (minType > ENTITY_REF // ignorable
                || (minType >= TEXT && peekType() >= TEXT));

        type = minType;
        if (type > TEXT) {
            type = TEXT;
        }

        return type;
    }

    public int nextToken() throws XmlPullParserException, IOException {
        isWhitespace = true;
        txtPos = 0;

        token = true;
        nextImpl();
        return type;
    }

    // utility methods to make XML parsing easier ...

    public int nextTag() throws XmlPullParserException, IOException {
        next();
        if (type == TEXT && isWhitespace) {
            next();
        }

        if (type != END_TAG && type != START_TAG) {
            exception("unexpected type");
        }

        return type;
    }

    public void require(int type, String namespace, String name)
            throws XmlPullParserException, IOException {

        if (type != this.type
                || (namespace != null && !namespace.equals(getNamespace()))
                || (name != null && !name.equals(getName()))) {
            exception(
                    "expected: " + TYPES[type] + " {" + namespace + "}" + name);
        }
    }

    public String nextText() throws XmlPullParserException, IOException {
        if (type != START_TAG) {
            exception("precondition: START_TAG");
        }

        next();

        String result;
        if (type == TEXT) {
            result = getText();
            next();
        } else {
            result = "";
        }

        if (type != END_TAG) {
            exception("END_TAG expected");
        }

        return result;
    }

    public void setFeature(String feature, boolean value) throws XmlPullParserException {
        if (XmlPullParser.FEATURE_PROCESS_NAMESPACES.equals(feature)) {
            processNsp = value;
        } else if (isProp(feature, false, "relaxed")) {
            relaxed = value;
        } else {
            exception("unsupported feature: " + feature);
        }
    }

    public void setProperty(String property, Object value) throws XmlPullParserException {
        if (isProp(property, true, "location")) {
            location = value;
        } else {
            throw new XmlPullParserException("unsupported property: " + property);
        }
    }
}