TextQuery_ex32.h

#ifndef TEXTQUERY_H_
#define TEXTQUERY_H_

#include <string>
#include <vector>
#include <map>
#include <fstream>
#include <sstream>
#include <set>
#include <memory>
#include <iostream>
#include <algorithm>
#include <iterator>
#include "StrBlob_ex22.h"

class QueryResult;

class TextQuery
{
public:
	using line_no = std::vector<std::string>::size_type;
	TextQuery(std::ifstream&);
	QueryResult query(const std::string&) const;
private:
	StrBlob file;
	std::map<std::string, std::shared_ptr<std::set<line_no>>> wm;
};

class QueryResult
{
	friend std::ostream& print(std::ostream&, const QueryResult&);
public:
	QueryResult(std::string s, std::shared_ptr<std::set<TextQuery::line_no>> p, StrBlob f) : sought(s), lines(p), file(f) { }
private:
	std::string sought;
	std::shared_ptr<std::set<TextQuery::line_no>> lines;
	StrBlob file;
};

TextQuery::TextQuery(std::ifstream &ifs){
	std::string text;

	while(std::getline(ifs, text))
	{
		file.push_back(text);
		int n = file.size() - 1;
		std::istringstream line(text);
		std::string text;
		while(line >> text)
		{
			std::string word;
			std::copy_if(text.begin(), text.end(), std::back_inserter(word), isalpha);
			// std::cout << word << std::endl;
			auto &lines = wm[word];
			if(!lines)
				lines.reset(new std::set<line_no>);
			lines->insert(n);
		}
	}
}

QueryResult TextQuery::query(const std::string &sought) const
{
	static std::shared_ptr<std::set<TextQuery::line_no>> nodata(new std::set<TextQuery::line_no>);
	auto loc = wm.find(sought);
	if(loc == wm.end())
		return QueryResult(sought, nodata, file);
	else
		return QueryResult(sought, loc->second, file);
}

std::ostream &print(std::ostream &os, const QueryResult &qr)
{
	os << qr.sought << " occurs " << qr.lines->size() << " " /*<< make_plural(qr.lines->size(), "time", "s")*/ << std::endl;
	for(auto num : *qr.lines)
	{
		ConstStrBlobPtr p(qr.file, num);
		os << "\t(line " << num + 1 << ") " << p.deref() << std::endl;
	}
		
	return os;
}

#endif