/******************************************************************************
 * This program that searches a dictionary file to find palindromes.
 * 
 * Copyright © 2021 Richard Lesh.  All rights reserved.
 *****************************************************************************/

#include "Utils.hpp"
#include <clocale>
#include <codecvt>
#include <fstream>
#include <iostream>
#include <regex>
#include <string>

std::locale utf8loc(std::locale(), new std::codecvt_utf8<wchar_t>);
using namespace std;

bool isPalindrome(wstring s) noexcept {
    wstring s0 = std::regex_replace(s, wregex(L"\\W+"), L"");
    s0 = Utils::tolower(s0);
    int const sLen = s0.length();
    if (sLen < 4) {
        return false;
    }
    for (int x = 0; x <= (sLen - 1) / 2; ++x) {
        if ((int)(s0[x]) != (int)(s0[sLen - 1 - x])) {
            return false;
        }
    }
    return true;
}

void searchTextFile(wstring filespec) {
    wifstream ifh(filesystem::path(filespec).c_str());
    if (!ifh.good()) {
        throw ios_base::failure(Utils::wchar_to_UTF8(L"Problem opening input file!"));
    }
    ifh.imbue(utf8loc);
    wstring line;
    while (getline(ifh, line)) {
        if (isPalindrome(line)) {
            wcout << line << endl;
        }
    }
    ifh.close();
}

int main(int argc, char **argv) {
    setlocale(LC_ALL, "en_US.UTF-8");
    wcout.imbue(utf8loc);
    wcin.imbue(utf8loc);

    if (argc != 2) {
        wcout << L"Syntax: " << Utils::UTF8_to_wstring(argv[0]) << L" {filename}" << endl;
        exit(1);
    }
    wstring filespec = Utils::UTF8_to_wstring(argv[1]);
    try {
        searchTextFile(filespec);
    } catch (ios_base::failure ex) {
        wcout << L"Error: " << Utils::exceptionMessage<wchar_t>(ex) << endl;
    }
    return 0;
}