//
// Created by xkuang on 2022/10/24.
//

#ifndef HFFG_XML_PARSER_H
#define HFFG_XML_PARSER_H

#include <string>
#include <utility>
#include <vector>
#include <map>
#include <unordered_map>
#include <memory>
#include <fstream>
#include <iostream>
#include <sstream>
#include "rapidxml/rapidxml.hpp"
#include "rapidxml/rapidxml_utils.hpp"
#include "rapidxml/rapidxml_print.hpp"

template< typename T >
struct TypeIsString
{
    static const bool value = false;
};

template<>
struct TypeIsString< std::string >
{
    static const bool value = true;
};

class XmlNode {


private:
    XmlNode* root;
    std::vector<char> m_buffer;
    bool is_root;
    rapidxml::xml_node<>* p_root;
    rapidxml::xml_node<>* p_node;
    std::vector< std::shared_ptr<rapidxml::xml_document<> > > copied_docs;
    std::vector< std::shared_ptr<rapidxml::file<> > > copied_files;

    std::shared_ptr<rapidxml::xml_document<>> doc;
    std::shared_ptr<rapidxml::file<>> file;

public:

    //! construct an empty doc
    XmlNode(){ is_root = false;};

    XmlNode(const XmlNode& XmlNode)
    {
        p_node = XmlNode.p_node;
        is_root = XmlNode.is_root;
        p_root = XmlNode.p_root;
        root = XmlNode.root;
        doc = XmlNode.doc;
    }

    XmlNode(rapidxml::xml_node<>* node, rapidxml::xml_node<>* rapid_root,
            std::shared_ptr<rapidxml::xml_document<>> ndoc,
            std::shared_ptr<rapidxml::file<>> nfile
    )
    {
        is_root = false;
        if (node) {
            p_node = node;
            p_root = rapid_root;
            doc = ndoc;
            file = nfile;
            root = this;
        }
        else
            std::cout << "xmlparser cannot get node" << std::endl;
        if (rapid_root==node)
            is_root = true;
    }


    XmlNode(rapidxml::xml_node<>* node, rapidxml::xml_node<>* rapid_root,
            std::shared_ptr<rapidxml::xml_document<>> ndoc,
            std::shared_ptr<rapidxml::file<>> nfile, XmlNode* rt
    )
    {
        is_root = false;
        if (node) {
            p_node = node;
            p_root = rapid_root;
            doc = ndoc;
            file = nfile;
            root = rt;
        }
        else
            std::cout << "xmlparser cannot get node" << std::endl;
        if (rapid_root==node)
            is_root = true;
    }


    //! load a root node (document) from stream
    XmlNode(std::istream &in){
        load(in);
    }

    ///load a xml file from stream
    void load(std::istream & in){

        file = std::make_shared<rapidxml::file<>>(in);

        doc = std::make_shared<rapidxml::xml_document<>>();
        doc->parse<0>(file->data());
        p_node = doc->first_node();
        p_root = p_node;
        is_root = true;
        root = this;
    }

    //! load a root node (document) from xml file
    XmlNode(std::string filename){
        load(filename);
    }
    ///load a xml file

    void load(const std::string & filename){
        std::ifstream theFile (filename);

        if (! theFile.is_open())
            std::cerr << "cannot open xml file: " << filename << std::endl;

        theFile.seekg(0, std::ios::end);
        if (0 == theFile.tellg()) {
            std::cerr << "xml file is empty" << std::endl;
        }

        file = std::make_shared<rapidxml::file<>>(filename.c_str());
        doc = std::make_shared<rapidxml::xml_document<>>();
        doc->parse<0>(file->data());
        p_node = doc->first_node();
        p_root = p_node;
        root = this;
        is_root = true;
    }

    ///close the xml file
    void unload(){
        ;
    }
    //! assignment
    XmlNode & operator= (const XmlNode & other)
    {
        if (this != &other) // protect against invalid self-assignment
        {
            // 1: allocate new memory and copy the elements
            p_node = other.p_node;
            is_root = other.is_root;
            p_root = other.p_root;
            doc = other.doc;
            root = other.root;
            file = other.file;
        }
        // by convention, always return *this
        return *this;
    }

    //! get root node
    XmlNode getRoot() const {
        return XmlNode(p_root, p_root, doc, file);
    };

    //! get parent node, return NULL if this is root
    XmlNode getParent() const {
        if (is_root)
            std::cerr << "failed to get parent of root node" << std::endl;
        else
            return XmlNode(p_node->parent(), p_root, doc, file);
    };

    //! whether the node has a child
    bool hasChild(const std::string & childid) const{
        bool is_child_exist;
        if (childid=="")
            is_child_exist = p_node->first_node();
        else
            is_child_exist = p_node->first_node(childid.c_str());

        if (is_child_exist)
            return true;
        else
            return false;
    }

    //! get the first child node
    XmlNode getChild(const std::string& child_id="") const{

        if (!hasChild(child_id))
            std::cerr << "failed to get child:" << child_id << std::endl;

        if (child_id.empty())
            return XmlNode(p_node->first_node(), p_root, doc, file, root);
        else
            return XmlNode(p_node->first_node(child_id.c_str()), p_root, doc, file, root);
    }

    //! get all children, matching node name
    std::vector<XmlNode> getChildren(std::string nodename) const {
        std::vector<XmlNode> children;
        auto child = p_node->first_node(nodename.c_str());
        while (child) {
            children.emplace_back(child, p_root, doc, file, root);
            child = child->next_sibling(nodename.c_str());
        }
        return children;
    }

    //! get all children
    std::vector<XmlNode> getChildren() const {
        std::vector<XmlNode> children;
        auto child = p_node->first_node();
        while (child) {
            children.emplace_back(child, p_root, doc, file, root);
            child = child->next_sibling();
        }
        return children;
    }

    //! get all attributes: key is attribute name, value is attribute value
    std::unordered_map<std::string, std::string> getAllAttr() const{
        std::unordered_map<std::string, std::string> attributes;
        auto attr = p_node->first_attribute();
        while (attr) {
            attributes[attr->name()] = attr->value();
            attr = attr->next_attribute();
        }
        return attributes;
    }

    //! get all attributes: key is attribute name, value is attribute value
    std::map<std::string, std::string> getAllAttrMap() const{
        std::map<std::string, std::string> attributes;
        auto attr = p_node->first_attribute();
        while (attr) {
            attributes[attr->name()] = attr->value();
            attr = attr->next_attribute();
        }
        return attributes;
    }

    //! get a string. default is ""
    std::string getAttrOrThrow(const std::string & key) const {
        auto attr = p_node->first_attribute(key.c_str());
        if (attr)
            return std::string(attr->value());
        else
            std::cerr << "getAttrOrThrow cannot find key=" << key << std::endl;
    }

    //! get a string. default is ""
    std::string getAttrString(const std::string & key) const {
        auto attr = p_node->first_attribute(key.c_str());
        if (attr)
            return std::string(attr->value());
        else
            return "";
    }

    std::string print() const
    {
        std::stringstream ss;
        ss<<*p_node;
        return ss.str();
    }



    //! get a string 1
    std::string getAttrDefault(const std::string & key, const char* def_value) const{
        auto attr = p_node->first_attribute(key.c_str());
        std::string ans, ret;
        if (attr)
            ans = std::string(attr->value());
        else
            return def_value;
        return ans;
    }

    //! get a string 2
    std::string getAttrDefault(const std::string & key, const std::string def_value) const{
        return getAttrDefault(key, def_value.c_str());
    }

    //! get a string 3
    std::string getAttrDefault(const std::string & key, char* def_value) const{
        return getAttrDefault(key, const_cast<const char*>(def_value));
    }

    //! get an integer
    int getAttrDefault(const std::string & key, int def_value) const
    {
        auto attr = p_node->first_attribute(key.c_str());
        std::string ret;
        if (attr)
            ret = std::string(attr->value());
        else
            return def_value;
        return atoi(ret.c_str());
    }

    //! get a bool
    bool getAttrDefault(const std::string & key, bool def_value) const{
        auto attr = p_node->first_attribute(key.c_str());
        std::string ans, ret;
        if ( !attr ) {
            return def_value;
        }
        if ( std::string(attr->value()) == "true")
            return true;
        else if ( std::string(attr->value())=="false" )
            return false;
        else
            return def_value;
    }


    //! get a float
    float getAttrDefault(const std::string & key, float def_value) const{
        auto attr = p_node->first_attribute(key.c_str());
        std::string ret;
        if (attr)
            ret = std::string(attr->value());
        else
            return def_value;
        return atof(ret.c_str());
    }

    //! get node name
    std::string getNodeName() const{
        return p_node->name();
    }

    //! get node value
    std::string getNodeValue() const {
        return p_node->value();
    }
    //! get value string  eg: root.cfg1..
    std::string getValueDefault(const std::string & key, const char* def_value) const {
        unsigned pos1 = 0, pos2 = 0;
        std::string sub_key;
        pos1 = key.find_first_of('.');
        XmlNode pNode = *this;
        while (pos1 != std::string::npos) {
            sub_key = key.substr(pos2, pos1 - pos2);
            if (sub_key.compare(getNodeName()) == 0) {
                pos2 = pos1 + 1;
                pos1 = key.find_first_of('.', pos2);
                continue;
            }
            if (pNode.hasChild(sub_key)){
                pNode = pNode.getChild(sub_key);
            }
            else{
                return def_value;
            }
            pos2 = pos1 + 1;
            pos1 = key.find_first_of('.', pos2);
        }
        if (pos2 != key.length()) {
            sub_key = key.substr(pos2);
            if (pNode.hasChild(sub_key)) {
                pNode = pNode.getChild(sub_key);
            }
            else {
                return def_value;
            }
        }
        return pNode.getNodeValue();
    }

    std::string getValueDefault(const std::string & key, const std::string &def_value) const {
        return getValueDefault(key, def_value.c_str());
    }

    long getValueDefault(const std::string & key, long def_value) {
        std::string value = getValueDefault(key, "");
        if (value.empty()) {
            return def_value;
        }
        else {
            return atol(value.c_str());
        }
    }

    int getValueDefault(const std::string & key, int def_value) {
        std::string value = getValueDefault(key, "");
        if (value.empty()) {
            return def_value;
        }
        else {
            return atoi(value.c_str());
        }
    }
    double getValueDefault(const std::string & key, double def_value) {
        std::string value = getValueDefault(key, "");
        if (value.empty()) {
            return def_value;
        }
        else {
            return atof(value.c_str());
        }
    }

    //! is root node
    bool isRoot() const {
        return is_root;
    }

    //! append a child node to the current node. return appended child
    XmlNode appendChild(const std::string & nodename)
    {
        char *node_name = doc->allocate_string(nodename.c_str());
        auto node = doc->allocate_node(rapidxml::node_element, node_name);
        p_node->append_node(node);
        return XmlNode(node, p_root, doc, file, root);
    }

    XmlNode appendChild(XmlNode & new_node)
    {
        auto node = doc->clone_node( new_node.p_node );
        p_node->append_node(node);
        copied_docs.push_back(new_node.doc);
        copied_files.push_back(new_node.file);
        return XmlNode(node, p_root, doc, file, root);
    }


    XmlNode appendChild(XmlNode & new_node, XmlNode & rt)
    {
        auto node = doc->clone_node( new_node.p_node );
        p_node->append_node(node);
        rt.copied_docs.push_back(new_node.doc);
        rt.copied_files.push_back(new_node.file);
        return XmlNode(node, p_root, doc, file, &rt);
    }

/*
        template<typename MDType>
        MDType appendAttr(const std::string & key, const MDType value) const{
            //char* rapidAttributeName = doc.allocate_string(key.c_str());
            auto attr = p_node->first_attribute(key.c_str());
            std::string ret;
            MDType  a = {0};
            if (attr)
                ret = std::string(attr->value());
            else
                return def_value;
            std::istringstream ss(ret);
            ss >> a;
            return a;
        }
        */

    //! append attribute to current node

    void appendAttr(const std::string & name, const char * value)
    {
        auto attr = p_node->first_attribute(name.c_str());
        char *new_value = doc->allocate_string(value);
        if (attr)
        {
            attr->value(new_value);
        }
        else
        {
            char *new_name = doc->allocate_string(name.c_str());
            auto attr = doc->allocate_attribute(new_name,new_value);
            p_node->append_attribute(attr);
        }
    }

    void appendAttr(const std::string & name, const std::string& value){
        return appendAttr(name, value.c_str());
    }
    void appendAttr(const std::string & name, float value){
        return appendAttr(name, std::to_string( (long double)value));
    }

    void appendAttr(const std::string & name, int value){
        return appendAttr(name, std::to_string( (long long)value));
    }

    void appendAttr(const std::string & name, bool value){
        if (value)
            appendAttr(name, "true");
        else
            appendAttr(name, "false");
    }
};
#endif //HFFG_XML_PARSER_H