#define _CRT_SECURE_NO_WARNINGS
#include "pch.h"
#include <iostream>
#include <string>
#include <vector>
using namespace std;

//  to check: <имя_входного_файла> <имя_выходного_файла> 255 1 0 10 100 20 2.0

void to_black(vector<unsigned char> &pixel) {
    pixel.assign(pixel.size(), 0);
}

void draw_point(vector<unsigned char> &pixel, int &x, int &y, int &col, int &bright, int &h, int &w) {
    int now = (x * h + y) * col;
    pixel[now] = bright;
    if (col == 3) {
        pixel[now + 1] = bright;
        pixel[now + 2] = bright;
    }
}

void draw_line(vector<unsigned char> &pixel, int &x1, int &y1, int &x2, int &y2, int col, int &bright, int &h, int &w) {
    int dx = abs(x1 - x2),
        dy = abs(y1 - y2),
        e = 0,
        de = abs(y1 - y2) + 1,
        y = y1,
        diry = y2 - y1;
    if (diry > 0) {
        diry = 1;
    }
    else {
        diry = -1;
    }
    for (int x = x1; x <= x2; x++) {
        draw_point(pixel, x, y, col, bright);
        e += de;
        if (e >= dx + 1) {
            y += diry;
            e -= dx + 1;
        }
    }
}

int main(int argc, char *argv[]) {

    if (argc != 10) {
        cerr << "Invalid request";
        return 0;
    }
    string name_in = argv[1];
    string name_out = argv[2];
    int bright = atoi(argv[3]),
        thick = atoi(argv[4]),
        xs = atoi(argv[5]),
        ys = atoi(argv[6]),
        xf = atoi(argv[7]),
        yf = atoi(argv[8]);
    double gamma = atof(argv[9]);
    //kgig.exe <имя_входного_файла> <имя_выходного_файла> <яркость_линии> <толщина_линии> <x_начальный> <y_начальный> <x_конечный> <y_конечный> <гамма>

    FILE * fin = fopen(name_in.c_str(), "rb");
    if (!fin) {
        cerr << "Invalid input file";
        return 0;
    }

    if (!(thick == 1 && gamma == 2.0)) {
        cerr << "Invalid bright or gamma";
        return 0;
    }

    char p, number;
    int h, w, color;
    int count = fscanf(fin, "%c%c\n%d %d\n%d\n", &p, &number, &w, &h, &color);
    if (count != 5) {
        cerr << "Incorrect file content";
        return 0;
    }

    if (!(p == 'P' && (number == '5' || number == '6')) || h <= 0 || w <= 0 || color > 255 || color <= 0) {
        cerr << "Incorrect data in the file";
        return 0;
    }
    bool flag = 0;
    vector<unsigned char> pixel;
    if (number == '5') {
        pixel.resize(h * w, 0);
    }
    else if (number == '6') {
        pixel.resize(3 * h * w);
        flag = 1;
    }

    int cnt = fread(&pixel[0], sizeof(unsigned char), pixel.size(), fin);
    if (number == '5' && cnt != h * w || number == '6' && cnt != 3 * h * w) {
        cerr << "Incorrect data in the file";
        return 0;
    }

    fclose(fin);
    to_black(pixel);
    draw_line(pixel, xs, ys, xf, yf, (number == '5' ? 1 : 3), bright, h, w);


    FILE* fout = fopen(name_out.c_str(), "wb");

    if (!fout) {
        cerr << "Invalid output file";
        return 0;
    }

    fprintf(fout, "%c%c\n%d %d\n%d\n", p, number, w, h, color);
    fwrite(&pixel[0], sizeof(unsigned char), pixel.size(), fout);
    fclose(fout);
    return 0;
}