/*
 * XML Parser/Generator
 *
 * Copyright (C) 2001 Barnaby Gray <barnaby@beedesign.co.uk>.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or (at
 * your option) any later version.
 *
 * This program 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 for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 */

#include "xml.h"

using namespace std;

// ---------- XmlNode ---------------------------

XmlNode::XmlNode(const string& t) : tag(t) { }

XmlNode::~XmlNode() { }

bool XmlNode::isLeaf() { return !isBranch(); }

string XmlNode::getTag() { return tag; }

string XmlNode::replace_all(const string& s, const string& r1, const string& r2) {
    string t(s.c_str());
    int curr = 0, next;
    while ( (next = t.find( r1, curr )) != -1) {
        t.replace( next, r1.size(), r2 );
        curr = next + r2.size();
    }
    return t;
}

string XmlNode::quote(const string& a) {
    return
        replace_all(
            replace_all(
                replace_all(a,
                            "&", "&amp;"),
                "<", "&lt;"),
            ">", "&gt;");
}

string XmlNode::unquote(const string& a) {
    return
        replace_all(
            replace_all(
                replace_all(a,
                            "&lt;", "<"),
                "&gt;", ">"),
            "&amp;", "&");
}

XmlNode *XmlNode::parse(string::iterator& curr, string::iterator end) {

    skipWS(curr,end);
    if (curr == end || *curr != '<') return NULL;

    string tag = parseTag(curr,end);
    if (tag.empty() || tag[0] == '/') return NULL;

    skipWS(curr,end);
    if (curr == end) return NULL;

    if (*curr == '<') {

        XmlNode *p = NULL;
        while (curr != end) {
            string::iterator mark = curr;
            string nexttag = parseTag(curr,end);
            if (nexttag.empty()) { if (p != NULL) delete p; return NULL; }
            if (nexttag[0] == '/') {
                // should be the closing </tag>
                if (nexttag.size() == tag.size()+1 && nexttag.find(tag,1) == 1) {
                    // is closing tag
                    if (p == NULL) p = new XmlLeaf(unquote(tag),"");
                    return p;
                } else {
                    if (p != NULL) delete p;
                    return NULL;
                }
            } else {
                if (p == NULL) p = new XmlBranch(unquote(tag));
                // an opening tag
                curr = mark;
                XmlNode *c = parse(curr,end);
                if (c != NULL) ((XmlBranch*)p)->pushnode(c);
            }
            skipWS(curr,end);
            if(curr == end || *curr != '<') {
                if (p != NULL) delete p;

            }
        }
        return NULL;

    }
    // XmlLeaf
    string value;
    while (curr != end && *curr != '<') {
        value += *curr;
        curr++;
    }
    if(curr == end) return NULL;
    string nexttag = parseTag(curr,end);
    if (nexttag.empty() || nexttag[0] != '/') return NULL;
    if (nexttag.size() == tag.size()+1 && nexttag.find(tag,1) == 1) {
        return new XmlLeaf(unquote(tag),unquote(value));
    }
    // error
    return NULL;
}

string XmlNode::parseTag(string::iterator& curr, string::iterator end) {
    string tag;
    if(curr == end || *curr != '<') return string();
    curr++;
    while(curr != end && *curr != '>') {
        tag += *curr;
        curr++;
    }
    if (curr == end) return string();
    curr++;
    return tag;
}

void XmlNode::skipWS(string::iterator& curr, string::iterator end) {
    while(curr != end && isspace(*curr)) curr++;
}

// ----------- XmlBranch ------------------------

XmlBranch::XmlBranch(const string& t) : XmlNode(t) { }

XmlBranch::~XmlBranch() {
    list<XmlNode*>::iterator curr = children.begin();
    while (curr != children.end()) {
        delete (*curr);
        curr++;
    }
    children.clear();
}

bool XmlBranch::isBranch() { return true; }

bool XmlBranch::exists(const string& tag) {
    list<XmlNode*>::iterator curr = children.begin();
    while (curr != children.end()) {
        if ((*curr)->getTag() == tag) return true;
        curr++;
    }
    return false;
}

XmlNode *XmlBranch::getNode(const string& tag) {
    list<XmlNode*>::iterator curr = children.begin();
    while (curr != children.end()) {
        if ((*curr)->getTag() == tag) return (*curr);
        curr++;
    }
    return NULL;
}

XmlBranch *XmlBranch::getBranch(const string& tag) {
    XmlNode *t = getNode(tag);
    if (t == NULL || !t->isBranch()) return NULL;
    return static_cast<XmlBranch*>(t);
}

XmlLeaf *XmlBranch::getLeaf(const string& tag) {
    XmlNode *t = getNode(tag);
    if (t == NULL || !t->isLeaf()) return NULL;
    return static_cast<XmlLeaf*>(t);
}

void XmlBranch::pushnode(XmlNode *c) {
    children.push_back(c);
}

string XmlBranch::toString(int n) {
    string ret(n,'\t');
    ret += '<' + quote(tag) + ">\n";
    list<XmlNode*>::iterator curr = children.begin();
    while (curr != children.end()) {
        ret += (*curr)->toString(n+1);
        curr++;
    }
    ret += string(n,'\t') + "</" + quote(tag) + ">\n";

    return ret;
}

// ----------- XmlLeaf --------------------------

XmlLeaf::XmlLeaf(const string& t, const string& v)
        : XmlNode(t), value(v) { }

XmlLeaf::~XmlLeaf() { }

bool XmlLeaf::isBranch() { return false; }

string XmlLeaf::getValue() { return value; }

string XmlLeaf::toString(int n) {
    return string(n,'\t') + '<' + quote(tag) + '>' + quote(value) + "</" + quote(tag) + ">\n";
}