#include "utils.h"

#include <codecvt>
#include <cstring>
#include <iostream>
#include <locale>
#include <regex>
#include <string>

std::string to_utf8(std::wstring wide_string) {
    static std::wstring_convert<std::codecvt_utf8<wchar_t>> utf8_conv;
    return utf8_conv.to_bytes(wide_string);
}

std::wstring from_utf8(std::string string) {
    static std::wstring_convert<std::codecvt_utf8<wchar_t>> utf8_conv;
    return utf8_conv.from_bytes(string);
}

std::string get_path_relative_to_home(std::string path) {
    return std::string(std::getenv("HOME")) + "/" + path;
}

template <typename T>
bool vector_contains_element(const std::vector<T>& vector, const T& to_find) {
    for (const T& element : vector) {
        if (element == to_find) return true;
    }
    return false;
}

//ужас
template bool vector_contains_element<std::string>(const std::vector<std::string>& vector, const std::string& to_find);

std::vector<std::string> split(std::string s, std::string delimiter) {
    std::vector<std::string> result;
    size_t pos = 0;
    std::string token;
    while ((pos = s.find(delimiter)) != std::string::npos) {
        token = s.substr(0, pos);
        result.push_back(token);
        s.erase(0, pos + delimiter.length());
    }
    result.push_back(s);

    return result;
}

std::wstring substring_from_to(std::wstring& text, std::wstring from, std::wstring to) {
    unsigned int start_pos = 0;
    unsigned int end_pos = 0;

    std::wstring substring;

    std::wregex start_regex(from);
    std::wregex end_regex(to);

    for (std::wsregex_iterator it{text.begin(), text.end(), start_regex}, end{};
         it != end; it++) {
        start_pos = it->position() + it->str().size();
        break;
    }

    if(text == from_utf8("")) return text;
    substring = text.substr(start_pos, text.size());

    for (std::wsregex_iterator it{substring.begin(), substring.end(), end_regex}, end{};
         it != end; it++) {
        end_pos = it->position();
        break;
    }

    if (end_pos == 0) return substring;

    substring = substring.substr(0, end_pos);

    return substring;
}

std::wstring trim_html_response(std::wstring& check) {
    std::wstring begin_check_marker = from_utf8("<!-- Products -->");
    std::wstring end_check_marker = from_utf8("<!-- \\/Products -->");
    std::wstring trimmed = substring_from_to(check, begin_check_marker, end_check_marker);
    trimmed += from_utf8("\n</div>");
    return trimmed;
}

std::vector<std::wstring> find_in_html(std::string& html, std::string regex, std::string html_start, std::string html_end) {
    std::regex searching_regex(regex);

    std::vector<std::wstring> parsed;
    for (std::sregex_iterator it{html.begin(), html.end(), searching_regex}, end{};
         it != end; it++) {

        std::wstring found_entry = from_utf8(it->str());
        std::wstring extracted = substring_from_to(found_entry, from_utf8(html_start), from_utf8(html_end));

        parsed.push_back(extracted);
    }
    return parsed;
}

std::vector<std::wstring> find_products_in_html(std::string html) {
    return find_in_html(html, "<div class=\"ifw-col ifw-col-1 text-left\"><b>.*<\\/b><\\/div>", "<div class=\"ifw-col ifw-col-1 text-left\"><b>", "<\\/b><\\/div>");
}

std::vector<std::wstring> find_amounts_in_html(std::string html) {
    return find_in_html(html, "<span>\\d+<\\/span>", "<span>", "<\\/span>");
}

std::vector<std::wstring> find_prices_in_html(std::string html) {
    return find_in_html(html, "X <\\/span><span>\\d+\\.\\d{2}<\\/span>", "X <\\/span><span>", "<\\/span>");
}

Check parseOfdRuAnswer(std::string html) {
    std::wstring wstr_html = from_utf8(html);
    std::string trimmed = to_utf8(trim_html_response(wstr_html));

    std::vector<std::wstring> products = find_products_in_html(trimmed);
    std::vector<std::wstring> amounts = find_amounts_in_html(trimmed);
    std::vector<std::wstring> prices = find_prices_in_html(trimmed);

    if ((products.size() + amounts.size() + prices.size())/products.size() != 3) {
        std::cerr << "An error has occured during the parsing of html. Please, contact the developer." << std::endl;
        std::exit(-1);
    }

    Check c;

    for (int i = 0; i < products.size(); i ++) {
        Goods goods(to_utf8(products[i]), std::stod(prices[i]), std::stod(amounts[i]));
        c.add_goods(goods);
    }

    return c;
}