#include <iostream>
#include <fstream>
#include <string>
#include <vector>
#include <regex>
#include <algorithm>

static const std::regex number_regex_full(R"(\d+)");
static const std::regex number_regex_1to3(R"(\b\d{1,3}\b)");

// Helper: find first number in 's', put into out, return true if found
bool find_first_number_in_line(const std::string &s, int &out, const std::regex &rx) {
    std::smatch m;
    if (std::regex_search(s, m, rx)) {
        out = std::stoi(m.str());
        return true;
    }
    return false;
}

int main(int argc, char* argv[]) {
    if (argc < 3) {
        std::cerr << "Usage: " << argv[0] << " <inputfile> <outputfile>\n";
        return 1;
    }

    std::ifstream infile(argv[1]);
    if (!infile) {
        std::cerr << "Error opening input file.\n";
        return 1;
    }

    std::ofstream outfile(argv[2]);
    if (!outfile) {
        std::cerr << "Error opening output file.\n";
        return 1;
    }

    // Read entire file into memory
    std::vector<std::string> lines;
    std::string line;
    while (std::getline(infile, line)) {
        lines.push_back(line);
    }

    const std::string marker = "F.L.C.M. %";

    // === 1) Find marker index (for truncation) ===
    bool marker_found = false;
    size_t marker_index = 0;
    for (size_t i = 0; i < lines.size(); ++i) {
        if (lines[i].find(marker) != std::string::npos) {
            marker_found = true;
            marker_index = i;
            break;
        }
    }

    if (!marker_found) {
        for (const auto &l : lines) outfile << l << '\n';
        return 0;
    }

    // === 2) Extract gyros (first number on SAME line as "BBGYRO") ===
    int gyros = 0;
    bool gyros_found = false;
    size_t bbgyro_index = std::string::npos;
    const std::string bbgyro_token = "BBGYRO";

    for (size_t i = 0; i < lines.size(); ++i) {
        size_t pos = lines[i].find(bbgyro_token);
        if (pos != std::string::npos) {
            bbgyro_index = i;
            std::string tail = lines[i].substr(pos + bbgyro_token.size());
            if (find_first_number_in_line(tail, gyros, number_regex_full)) {
                gyros_found = true;
            }
            break; // only first occurrence matters
        }
    }

    // === 3) Extract total_subs (1–3 digit number after 'Ä' line) ===
    int total_subs = 0;
    bool total_found = false;

    auto find_total_after_start_index = [&](size_t start_index)->bool {
        for (size_t j = start_index; j < lines.size(); ++j) {
            size_t countA = 0;
            for (u_char c : lines[j]) if (c == u'Ä') ++countA;
            if (countA >= 10) {
                // look in the next line and up to 3 lines after if needed
                for (size_t k = j + 1; k < lines.size(); ++k) {
                    if (find_first_number_in_line(lines[k], total_subs, number_regex_1to3)) {
                        return true;
                    }
                }
                return false;
            }
        }
        return false;
    };

    if (gyros_found) {
        total_found = find_total_after_start_index(bbgyro_index + 1);
    } else {
        // BBGYRO not found -> find 2nd occurrence of "SUBS" then start from there
        int subs_count = 0;
        size_t subs_index = std::string::npos;
        for (size_t i = 0; i < lines.size(); ++i) {
            if (lines[i].find("SUBS") != std::string::npos) {
                subs_count++;
                if (subs_count == 2) {
                    subs_index = i;
                    break;
                }
            }
        }
        if (subs_index != std::string::npos) {
            total_found = find_total_after_start_index(subs_index + 1);
        }
    }

    // === 4) Truncate to include up to and including the marker line ===
    std::vector<std::string> truncated(lines.begin(), lines.begin() + marker_index + 1);

    // === 5) Insert "TOTAL SUBS  ---  <diff>" immediately before first form feed ===
    int diff = total_subs - gyros;
    const std::string insert_line = "\n\n        TOTAL SUBS  ---  " + std::to_string(diff);

    bool inserted = false;
    for (const auto &l : truncated) {
        size_t ff_pos = l.find('\f');
        if (!inserted && ff_pos != std::string::npos) {
            // insert directly before first form feed
            std::string modified = l.substr(0, ff_pos) + insert_line + l.substr(ff_pos);
            outfile << modified << '\n';
            inserted = true;
        } else {
            outfile << l << '\n';
        }
    }
    if (!inserted) {
        outfile << insert_line << '\n';
    }

    return 0;
}