//=-------------------------------------------------------------------------=//
//  XML management tools                                                     //
//                                                                           //
//  Copyright © 2021 The Gem-graph Project                                   //
//                                                                           //
//  This file is part of gem-graph.                                          //
//                                                                           //
//  This program is free software: you can redistribute it and/or modify     //
//  it under the terms of the GNU Affero General Public License as           //
//  published by the Free Software Foundation, either version 3 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 Affero General Public License for more details.                      //
//                                                                           //
//  You should have received a copy of the GNU Affero General Public License //
//  along with this program.  If not, see <https://www.gnu.org/licenses/>.   //
//=-------------------------------------------------------------------------=//

#ifndef BASE_H
    #include "../include/base.h"
#endif

#include <string.h>
#include <stdlib.h>
#include <libxml2/libxml/xmlmemory.h>
#include <libxml2/libxml/parser.h>

static xmlDocPtr currentDocument = NULL;
static xmlNodePtr currentDocumentRoot = NULL;

void openCurrentDocument(const char *filename)
{
    currentDocument = xmlParseFile(filename);

    if (currentDocument == NULL ) {
        printLog("%s not parsed successfully.\n", filename);
        xmlFreeDoc(currentDocument);
        currentDocument = NULL;
        return;
    }

    currentDocumentRoot = xmlDocGetRootElement(currentDocument);

    if (currentDocumentRoot == NULL ) {
        printLog("%s is invalid (no root)\n", filename);
        xmlFreeDoc(currentDocument);
        currentDocument = NULL;
        currentDocumentRoot = NULL;
        return;
    }
}

void closeCurrentDocument(void)
{
    xmlFreeDoc(currentDocument);
    currentDocumentRoot = NULL;
    currentDocument = NULL;
}

static void resetDocumentRoot(void)
{
    currentDocumentRoot = xmlDocGetRootElement(currentDocument);
}

int parseTag(const char* tagName, char *destination, char destSize)
{
    char *curString;
    char res = 0;

    xmlNodePtr cur = currentDocumentRoot;

    //printLog("Asked for %s\n", tagName);

    while (cur != NULL) {
        if ((!xmlStrcmp(cur->name, (const xmlChar *)tagName))) {
            curString = (char*)xmlNodeListGetString(currentDocument,
                                        cur->xmlChildrenNode, 1);

            if (curString[0] != '\n' && destination) {
                snprintf(destination, destSize, "%s\n", curString);
                res++;
            }
            free(curString);
        }
            cur = cur->next;
    }
    return res;
}

xmlNodePtr findRoot(const char *tagName, xmlNodePtr curRoot)
{
    xmlNodePtr cur = curRoot;
    xmlNodePtr recur;

    //printLog("Asked for %s\n", tagName);

    while (cur != NULL) {
        if ((!xmlStrcmp(cur->name, (const xmlChar *)tagName))){
            currentDocumentRoot = cur;
            return cur;
        }

        if (cur->xmlChildrenNode) {
            if ((recur = findRoot(tagName, cur->xmlChildrenNode) != NULL))
                return recur;
        }

        cur = cur->next;
    }

    return NULL;
}

int parseTree(ModelField_t *tree)
{
    ModelField_t *curTree;
    char tempString[50];

    curTree = tree;

    while (curTree) {
        //printLog("Asked for %s\n", curTree->id);
        if ((findRoot(curTree->id, currentDocumentRoot)) == NULL)
            return EBADF;

        bzero(tempString, sizeof(tempString));
        if ((parseTag(curTree->id, tempString, sizeof(tempString)) == 0
             && curTree->value))
            return EBADF;

        if (!(tempString[0] == '\0')) {
            printLog("Field %s: %s", curTree->id, tempString);
        }

        if (curTree->son)
            parseTree(curTree->son);

        curTree = curTree->next;
    }
    return 0;
}