Path.h

/*
 
MIT License
 
Copyright (c) 2017 FMI Open Development / Markus Peura, first.last@fmi.fi
 
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.
 
*/
/*
Part of Rack development has been done in the BALTRAD projects part-financed
by the European Union (European Regional Development Fund and European
Neighbourhood Partnership Instrument, Baltic Sea Region Programme 2007-2013)
*/
/*
 * Path.h
 *
 *  Created on: Jul 21, 2010
 *      Author: mpeura
 */
 
#ifndef DRAIN_PATH_H_
#define DRAIN_PATH_H_
 
#include <drain/UniTuple.h>
#include <stdexcept>
#include <iostream>
#include <string>
#include <list>
#include <iterator>
 
 
#include <drain/String.h> // ?
#include <drain/Sprinter.h>
 
 
 
namespace drain {
 
/*
 *
 *  In unix style, intermediate separators are accepted but not stored.
 *
 *  Note that technically, accepting leading, intermediate or trailing separators means also
 *  accepting \e empty path elements, respectively.
 *
 *  When using strings as path elements, the root is identified with an empty string -- not actually with the separator char like '/'.
 *
 */
struct PathSeparatorPolicy : UniTuple<bool,3> {
 
    // Separator character
    char character;
 
    bool & acceptLeading;
 
    bool & acceptRepeated;
 
    bool & acceptTrailing;
 
    PathSeparatorPolicy(char separator='/', bool lead=true, bool repeated=false, bool trail=true) :
            character(separator), acceptLeading(next()), acceptRepeated(next()), acceptTrailing(next()) {
        set(lead, repeated, trail);
        if (!separator)
            throw std::runtime_error("PathSeparatorPolict (char separator): separator=0, did you mean empty init (\"\")");
    }
    PathSeparatorPolicy(const PathSeparatorPolicy &policy) :  UniTuple<bool,3>(policy),
            character(policy.character), acceptLeading(next()), acceptRepeated(next()), acceptTrailing(next()) {
    };
 
 
};
 
inline
std::ostream & operator<<(std::ostream & ostr, const PathSeparatorPolicy & policy) {
    ostr << "Separator='" << policy.character << "', policy=" << policy.tuple();
    return ostr;
}
 
 
 
template <class T,char SEP='/', bool ALEAD=true, bool AREPEAT=false, bool ATRAIL=true>
class Path : public std::list<T> {
 
public:
 
    typedef T elem_t;
 
    typedef Path<T,SEP,ALEAD,AREPEAT,ATRAIL> path_t;
 
    typedef std::list< path_t > list_t;
 
    const PathSeparatorPolicy separator;
 
    inline
    Path() : separator(SEP, ALEAD, AREPEAT, ATRAIL){
    };
 
    inline
    Path(const path_t & p) : std::list<T>(p), separator(p.separator){
    };
 
    inline
    Path(typename path_t::const_iterator it, typename path_t::const_iterator it2) : separator(SEP, ALEAD, AREPEAT, ATRAIL) {
        while (it != it2){
            append(*it);
            ++it;
        }
    };
 
    // All the elements are treated as paths.
    template <typename ... TT>
    inline
    Path(const path_t & arg, const TT &... args) : separator(SEP, ALEAD, AREPEAT, ATRAIL){
        append(arg, args...);
    };
 
    // All the elements are treated as paths.
    template <typename ... TT>
    inline
    Path(const std::string & arg, const TT &... args) : separator(SEP, ALEAD, AREPEAT, ATRAIL){
        append(arg, args...);
    };
 
    // All the elements are treated as paths.
    template <typename ... TT>
    inline
    Path(const char * arg, const TT &... args) : separator(SEP, ALEAD, AREPEAT, ATRAIL){
        append(arg, args...);
    };
 
 
    //  Answer: to prevent elem and string
    /*
    template <typename ... TT>
    inline
    Path(const TT &... args) : separator(SEP, ALEAD, AREPEAT, ATRAIL){ //: separator(separator) {
        append(args...);
    };
    */
 
 
 
 
    virtual inline
    ~Path(){};
 
    // Design principle: handle all strings as paths!
    // This means that if path elements are strings, assigning elements goes through an "extra" path check.
    // If string arguments were accepted directly as elements, separator characters could be passed in the elements.
 
    template <typename ... TT>
    void set(const TT &... args) {
        this->clear();
        append(args...);
    }
 
    //  needed?
    template <typename T2, typename ... TT>
    void append(const T2 & arg, const TT &... args) {
        _append(arg); // replace with appendElem(elem), remove _append?
        append(args...);
    }
 
    template <typename ... TT>
    void append(const path_t &p, const TT &... args) {
        this->insert(this->end(), p.begin(), p.end());
        append(args...);
    }
 
    template <typename ... TT>
    void append(const char * arg, const TT &... args) {
        _appendPath(arg, 0);
        append(args...);
    }
 
    template <typename ... TT>
    void append(const std::string &arg, const TT &... args) {
        _appendPath(arg, 0);
        append(args...);
    }
 
 
    inline
    void appendPath(const char *p){
        _appendPath(p, 0);
    }
 
    // Reverse convenience...
    inline
    void appendPath(const path_t &p){
        appendPath(p);
    }
 
 
    void appendElem(const elem_t & elem){
 
        if (!elem.empty()){
            // Always allow non-empty element
            // std::cerr << __FUNCTION__ << ":" << elem << '\n';
            if (!separator.acceptRepeated){
                //std::cerr << __FILE__ << ":" << __LINE__ << ":" << __FUNCTION__ << ":" << " validate " << *this << " + " << elem << '\n';
                //removeTrailing();
                trimTail();
            }
                //stripTail();
            this->push_back(elem);
        }
        // elem is EMPTY: -----------------------------------------------------------
        else if (this->empty()){
            if (separator.acceptLeading)
                this->push_back(elem); // empty
            // std::cerr << __FUNCTION__ << " leading=" << separator.acceptLeading << " "<< separator.character  << '\n';
        }
        else if (this->back().empty()){
            //std::cerr << __FUNCTION__<< " repeating=" << separator.acceptRepeated << " " << separator.character << '\n';
            if (separator.acceptRepeated){
                this->push_back(elem);
            }
        }
        else if (separator.acceptTrailing){
            // std::cerr << __FUNCTION__ << " trailing="  << separator.acceptTrailing << " " << separator.character << '\n';
            this->push_back(elem); // empty
        }
        else {
            std::cerr << __FUNCTION__ << "? failed in appending: " << sprinter(*this) << '\n';
        }
 
    };
 
    //
    inline
    bool isRoot() const {
        return ((this->size()==1) && this->front().empty());
        //return separator.acceptLeading && ((this->size()==1) && this->front().empty());
    }
 
 
    inline
    bool hasRoot() const {
        if (!this->empty()){
            return this->front().empty();
        }
        else {
            return false;
        }
    }
 
 
    inline
    path_t & ensureRoot(){
        if (!this->hasRoot()){
            this->push_front(elem_t());
        }
        return *this;
    }
 
 
 
    void trimHead(bool COMPLETE=false){
        const size_t minLength = COMPLETE ? 0 : 1;
        while (this->size() > minLength){
        //while (!this->empty()){
            if (!this->front().empty()){
                return;
            }
            this->pop_front();
            //this->trimHead();
        }
    }
 
 
    void trimTail(bool COMPLETE=false){ //
        const size_t minLength = COMPLETE ? 0 : 1;
        while (this->size() > minLength){
        //while (!this->empty()){
            if (!this->back().empty()){
                return;
            }
            this->pop_back();
            //this->trimTail();
        }
    }
 
 
 
    inline
    void simplify(){
        simplifyHead();
        simplifyTail();
    }
 
 
    void simplifyHead(){
 
        if (this->empty())
            return;
 
        if (this->front().empty()){
            typename path_t::const_iterator it0 = ++this->begin();
            typename path_t::const_iterator it = it0;
            while (it != this->end()) {
                if (!it->empty()){
                    break;
                }
                ++it;
            }
            if (it != it0)
                this->erase(it0,it);
        }
 
 
    }
 
 
    void simplifyTail(){
 
        if (this->empty())
            return;
 
        if (this->back().empty()){
            typename path_t::const_iterator it0 = --this->end();
            typename path_t::const_iterator it = it0;
 
            while (it != this->begin()) {
                --it;
                if (!it->empty()){
                    ++it;
                    break;
                }
            }
 
            if (it != it0)
                this->erase(it,it0);
        }
 
 
    }
 
 
 
 
    path_t & operator=(const path_t & p){
 
        if (&p != this){
            // Yes, important self-check.
            // Otherwise clear() also makes the"source" empty.
            set(p);
        }
        // std::list<T>::operator=(p);
        // return assignPa(*this);
        return *this;
    }
 
 
    template <class T2>
     path_t & operator=(const Path<T2> & p){
        set(p);
        return *this;
    }
 
 
    inline
     path_t & operator=(const std::string & p){
        set(p);
        return *this;
    }
 
    inline
     path_t & operator=(const char *p){
        set(p);
        return *this;
    }
 
    // Note: this would be ambiguous!
    // If (elem_t == std::string), elem cannot be assigned directly, because string suggest full path assignment, at least
    //  path_t & operator=(const elem_t & e)
 
    /*
    inline
     path_t & operator<<(const char *elem){
        *this <<
    }
    */
 
 
    // TODO: replace these with single
    /*
    template <class T2>
    path_t & operator<<(const T2 & arg){
        append(args);
        return *this;
    }
    */
 
 
     path_t & operator<<(const elem_t & elem){
        appendElem(elem);
        return *this;
    }
 
    inline
     path_t & operator<<(const  path_t & path){
        this->insert(this->end(), path.begin(), path.end());
        return *this;
    }
 
 
    // Experimental
    template <class T2>
     path_t & operator<<(const T2 & strlike){
        appendPath((const std::string &) strlike);
        return *this;
    }
 
 
     path_t & operator>>(elem_t & e){
        e = this->back();
        this->pop_back();
        return *this;
    }
 
 
    virtual
    std::ostream & toStream(std::ostream & ostr) const { //, char dirSeparator = 0) const {
 
        if (isRoot())
            ostr << separator.character;
        else {
            static const SprinterLayout layout("/", "", "", "");
            layout.arrayChars.separator = separator.character;
            // SprinterLayout layout;
            // layout.arrayChars.set(0, separator.character,0);
            // layout.stringChars.fill(0);
            Sprinter::sequenceToStream(ostr, *this, layout);
        }
 
        //Sprinter::toStream(ostr, *this, layout);
        return ostr;
    }
 
    virtual
    std::string  str() const {
        std::stringstream sstr;
        toStream(sstr);
        return sstr.str();
    }
 
    virtual
    operator std::string() const {
        return str();
    }
 
    std::ostream & debug(std::ostream & ostr = std::cout) const {
        //ostr << "Path<" << typeid(T).name() << "> " << separator << "\n";
        ostr << "Path elems:" << this->size() << " sep:" << separator << " typeid: " << typeid(T).name() << "\n";
        ostr << *this << '\n';
        int i=0;
        for (typename  path_t::const_iterator it = this->begin(); it != this->end(); ++it) {
            //if (it->empty())
            //  ostr << "  " << i << '\t' << "{empty}" << '\n';     //else
            ostr << "    " << i << '\t' << *it << '\n';
            ++i;
        }
        return ostr;
    }
 
protected:
 
    void _append(const elem_t &elem){
        appendElem(elem);
    }
 
 
    //  Handler for all the rest (non elem_t) arguments.
    template <typename T2>
    void _append(const T2 & p){
        appendElem(p);
        //_appendPath(p);
    }
 
    void _appendPath(const std::string & p, size_t start=0){
 
        if (start == p.length()){
            // Last char in the string has been passed by one, meaning that: previous elem was empty
            // That is: the previous char was a separator.
            //appendElems(elem_t()); // Try to append empty.
            appendElem(elem_t()); // Try to append empty.
            return;
        }
 
        // Append next segment, ie. up to next separator char.
        size_t nextSep = p.find(separator.character, start);
 
        // Remaining string...
        if (nextSep==std::string::npos){
            // ... is a single element
            appendElem(p.substr(start));
            return;
        }
        else {
            // ... contains separator, hence contains several elements
            appendElem(p.substr(start, nextSep - start)); // maybe empty, nextSep==start
            _appendPath(p, nextSep + 1);
        }
 
    }
 
 
protected:
 
    void append(){
    }
 
    //void appendElems(){
    //}
 
    //void setElems(){
    // };
 
};
 
 
 
template <class T, char SEP='/', bool ALEAD=true, bool AREPEAT=false, bool ATRAIL=true>
inline
std::ostream & operator<<(std::ostream & ostr, const Path<T,SEP,ALEAD,AREPEAT,ATRAIL> & p) {
    return p.toStream(ostr);
}
 
 
template <class T, char SEP='/', bool ALEAD=true, bool AREPEAT=false, bool ATRAIL=true>
inline
std::istream & operator>>(std::istream &istr, Path<T,SEP,ALEAD,AREPEAT,ATRAIL> & p) {
    std::string s;
    istr >> s;
    p = s;
    return istr;
}
 
/*
template <class T>
inline
Path<T> & operator<<(Path<T> & path, const Path<T> & path2){
    path.insert(path.end(), path2.begin(), path2.end());
    return path;
}
*/
 
 
}
 
#endif /* Path_H_ */
 
// Drain