#include "postgresHandler.h"
#include <cctype>
#include <cstddef>
#include <cstdlib>
#include <iostream>
#include <regex>
#include <stdexcept>

#define KEY_INDEX 1
#define INT_INDEX 3
#define STRING_INDEX 4
#define LIST_OF_INT_INDEX 5
#define NULL_INDEX 6
#define BOOL_INDEX 7

const pqxx::result execute_query(pqxx::work &t_transaction,
                                 std::string_view t_query) {
    return t_transaction.exec(t_query);
}

void display_query_result(const pqxx::result &t_r) {
    const int nb_columns = t_r.columns();
    for (const auto &row : t_r) {
        for (int i = 0; i < nb_columns; i++) {
            std::cout << row[i].c_str() << " | ";
        }
        std::cout << std::endl;
    }
}

static const unsigned int
get_type_of_regex_iterator(const std::sregex_iterator &t_sregex_it) {
    std::array<int, 5> types{INT_INDEX, STRING_INDEX, LIST_OF_INT_INDEX,
                             NULL_INDEX, BOOL_INDEX};
    for (const int &type : types) {
        if ((*t_sregex_it)[type] != "") {
            return type;
        }
    }
    throw std::invalid_argument("regex iterator input is invalid");
}

const std::string format_json_value_to_sql(const unsigned int &t_type_index,
                                           const std::string &t_json_value) {
    switch (t_type_index) {
    case BOOL_INDEX:
    case INT_INDEX:
        return t_json_value;
    case STRING_INDEX: {
        std::string json_copy = t_json_value;
        *json_copy.begin() = '\'';
        *std::prev(json_copy.end()) = '\'';
        return json_copy;
    }
    case NULL_INDEX:
        return "NULL";
    case LIST_OF_INT_INDEX: {
        std::string json_copy = t_json_value;
        json_copy.append("\'");
        json_copy.insert(json_copy.begin(), '\'');
        return json_copy;
    }
    default:
        throw std::invalid_argument("type index is invalid: ");
    }
}

std::string format_key(const std::string &key) {
    std::string key_copy(key);
    std::stack<size_t> uppercase_indexes;
    for (size_t i = 0; i < key.length(); i++) {
        if (std::isupper(key[i])) {
            uppercase_indexes.push(i);
        }
    }
    while (!uppercase_indexes.empty()) {
        size_t top_index = uppercase_indexes.top();
        uppercase_indexes.pop();
        key_copy[top_index] = std::tolower(key_copy[top_index]);
        key_copy.insert(std::next(key_copy.begin(), top_index), '_');
    }
    return key_copy;
}

static void
add_single_card_to_database(const std::string &t_cards, pqxx::work &t_tx,
                            const std::regex &key_regex,
                            const std::string::size_type &id_pos,
                            const std::string::size_type &closing_bracket_pos) {
    auto words_begin = std::sregex_iterator(
        std::next(t_cards.begin(), id_pos),
        std::next(t_cards.begin(), closing_bracket_pos), key_regex);
    auto words_end = std::sregex_iterator();
    if (words_begin != words_end) {
        std::string insert_columns("INSERT INTO cards (");
        std::string values(" VALUES (");
        for (auto it = words_begin; it != words_end; ++it) {
            insert_columns.append(format_key((*it)[KEY_INDEX].str()) +
                                  ","); // key
            const unsigned int type_index = get_type_of_regex_iterator(it);
            values.append(
                format_json_value_to_sql(type_index, (*it)[type_index].str()) +
                ",");
        }
        *std::prev(insert_columns.end()) = ')';
        *std::prev(values.end()) = ')';

        insert_columns.append(values);
        insert_columns.append(" ON CONFLICT (id) DO NOTHING;");
        std::cout << insert_columns.length() << std::endl;
        std::cout << insert_columns << std::endl;
        execute_query(t_tx, insert_columns);
    }
}

void add_cards_to_database(const std::string &t_cards, pqxx::work &t_tx) {
    std::regex key_regex("\"([^\"?]+)\":(([0-9]+)|(\"[^\"?]*\")|(\\[[0-9,]*\\])"
                         "|(null)|(true|false))");

    std::string::size_type id_pos = t_cards.find("{\"id");
    std::string::size_type closing_bracket_pos = t_cards.find("}");
    while (id_pos != std::string::npos &&
           closing_bracket_pos != std::string::npos) {
        add_single_card_to_database(t_cards, t_tx, key_regex, id_pos,
                                    closing_bracket_pos);
        id_pos = t_cards.find("{\"id", id_pos + 1);
        closing_bracket_pos = t_cards.find("}", closing_bracket_pos + 1);
    }
}