#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

unsigned int SIZE;

void print_file(const char* buffer);
void create_image(const unsigned char* data, const char* name);

int main(int argc, const char** argv) {
    
    FILE* fileptr;
    char* buffer;
    long filelen;
    
    fileptr = fopen(argv[1], "rb");
    if (fileptr == NULL) {
        printf("File not found\n");
        return 1;
    }
    (void)fseek(fileptr, 0, SEEK_END);
    SIZE = ftell(fileptr);
    rewind(fileptr);
    
    buffer = (char*)malloc(SIZE * sizeof(char) + 1);
    (void)fread(buffer, SIZE, 1, fileptr);
    buffer[SIZE] = 0;
    (void)fclose(fileptr);
    
    create_image((unsigned char*)buffer, argv[1]);
    
    free(buffer);
}

void create_image(const unsigned char* data, const char* name) {
    const float d_size = sqrt((float)SIZE / 3);
    const int dim = (int)ceil(d_size);
    const int remainder = (dim * dim) * 3 - SIZE;
    char str[20];
    (void)sprintf(str, "P3 %i %i 255 ", dim, dim);
    int header = strlen(str);
    
    unsigned char* outbuf = (unsigned char*)malloc(remainder * 3 + header + SIZE * 4);
    
    (void)printf("%s, Size:%i, dim: %i, remainder: %i, header: %i\n", str, SIZE, dim, remainder, header);
    (void)memcpy(outbuf, str, header);
    for (int i = 0; i < SIZE; i++) {
        outbuf[header + i * 4] = '0' + (data[i] / 100) % 10;
        outbuf[header + i * 4 + 1] = '0' + (data[i] / 10) % 10;
        outbuf[header + i * 4 + 2] = '0' + data[i] % 10;
        outbuf[header + i * 4 + 3] = ' ';
    }
    for (int i = 0; i < remainder; i++) {
        (void)memcpy(outbuf + header + SIZE * 4 + i * 2, "0 ", 2);
    }
    char* result_name = (char*)malloc(strlen(name) + 4);
    result_name[0] = '\0';
    (void)strcat(result_name, name);
    (void)strcat(result_name, ".ppm");
    (void)printf("%s", result_name);
    FILE* out;
    out = fopen(result_name, "wb");
    if (out == NULL) {
        (void)printf("Error creating file\n");
        return;
    }
    (void)fwrite(outbuf, sizeof(unsigned char), header + SIZE * 4 + remainder * 2, out);
    (void)fclose(out);
    free(outbuf);
    free(result_name);
}