#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <sys/types.h>
#include <unistd.h> // for getopt
#include <getopt.h> // for getopt_long
#include <string.h> // for strcpy
#include "tricorn.h"

void save_bmp(const char *filename, unsigned char *img, size_t width, ssize_t height);

int main(int argc, char** argv)
{
    int opt_long; 
    // will be the returned optional character, 
    // example:  ./main -c     ->  opt_long here will be the optional 'c'

    const char* optstring = "V:B:s:d:n:r:o:Cht" ;
    // valid options that can be given to the programme. options with ":" after them expect an argument, which we'll later store in <char *optarg>
    // example:  B: <number>   ->  optional B expects an argument after it, and is valid    -> ./main -B 67 (optarg is now "67")
    // example:  h -> optional h doesn't expect an argument -> ./main -h

    // optind -> keeps track of the next index. initialised as 1 in the beginning. calling opt_long updates it every time

    // optarg -> is a charptr. stores the arguments given to the optionals

    static struct option long_options[] = {
        {"color",0,0,'C'},
        {"help",0,0,'h'},
        {"test",0,0,'t'},
        {0,0,0,0}
    };
    // these are the long optionals, which we can call with double "--".  "--help" or "--test". they are converted to the optionals "h" and "t" respectively
    // first argument is "name" -> name of the long. "--<name>"
    // second is "has_arg" -> 0 if no arg, 1 if arg, 2 if optional arg
    // third is "*flag" -> sets a flag so that "--help" simply returns "h" and does nothing else
    // fourth is "val" -> what to return when "--help" is given, returns "h"



    int version_to_use = 0;
    unsigned amount_function_called;
    unsigned n;
    float starting_point_real;
    float starting_point_imaginary;
    size_t width;
    ssize_t height;
    float step_amount;
    char* output_data;
    _Bool colored = 0;


    opt_long = getopt_long(argc,argv,optstring, long_options, NULL); 
    // first four arguments are self-explanatory, fifth argument is the index of which long_option we return in the struct "long_options", but it's irrelevant so we set it to NULL
    while (opt_long != -1)
    {   
        switch (opt_long)
        {
        case 'V': // done, function needed
            version_to_use = strtol(optarg,NULL,10);
            printf("version is %d\n", version_to_use);
            // Die Implementierung, die verwendet werden soll. Hierbei soll mit
            // -V 0 Ihre Hauptimplementierung verwendet werden. Wenn diese Option nicht
            // gesetzt wird, soll ebenfalls die Hauptimplementierung ausgeführt werden
            break;
        
        case 'B': // done, function needed
            // wird die Laufzeit der angegebenen Implementierung gemessen und ausgegeben (do this later)
            amount_function_called = strtoul(optarg,NULL,10);
            printf("amount function called is %d\n", amount_function_called);
            // Das Argument dieser Option gibt die Anzahl an Wiederholungen des Funktionsaufrufs an, z. B.-B 5 .
            break;

        case 's':
            char* imaginary_string;
            starting_point_real = strtof(optarg,&imaginary_string); // split into two
            starting_point_imaginary = strtof(imaginary_string + 1,NULL); // this is horrible
            printf("real %d, img %d\n", starting_point_real,starting_point_imaginary);
            // s <Realteil>,<Imaginärteil> — Startpunkt der Berechnung
            break;
            
        case 'd':
            char* height_string;
            width = strtol(optarg,&height_string,10);
            height = strtol(height_string + 1,NULL,10);
            printf("width %d, height %d\n", width,height);
            // -d <Zahl>,<Zahl> —Breite und Höhe des Bildausschnitts
            break;

        case 'n':
            n = strtol(optarg,NULL,10);
            printf("n:%d\n",n);
            // -n <Zahl> —MaximaleAnzahlanIterationen pro Bildpixel 
            break;

        case 'r':
            step_amount = strtof(optarg,NULL);
            printf("r:%d\n", step_amount);
            // r <Floating Point Zahl> —Schrittweite pro Bildpixel
            break;

        case 'o':
            output_data = malloc(strlen(optarg) + 1);
            strcpy(output_data,optarg);
            printf("%s\n", output_data); // test
            // -o <Dateiname> —Ausgabedatei
            break;

        case 'C':
            colored = 1;
            printf("colored:%d\n",colored);
            // C|--color —Farbausgabe
            break;

        case 'h':
            // print help message
            // Eine Beschreibung aller Optionen des Programms und Verwendungsbeispiele werden ausgegeben und das Programm danach beendet. 
            // Die Beschreibung soll mit "Help Message" anfangen.
            break;

        case 't':
            
            // do testing
            // Führt eine vordefinierte Testsuite aus, welche sämtliche von Ihnen
            // verwendete Benchmarking-Szenarien gesammelt durchläuft. Das Programm gibt
            // die jeweiligen Parameter, eine kurze Beschreibungen sowie die Ergebnisse in einer
            // übersichtlichen und gut lesbaren Form aus und terminiert anschließend.
            break;

        default: // case '?' -> when the argument is not valid
            // print error msg
            break;
        }

        opt_long = getopt_long(argc,argv,optstring, long_options, NULL); 
    }

    float complex complexA = (starting_point_real + starting_point_imaginary*I);
    char tempArr[width*height*3];
    printf("yashar\n");
    tricorn(complexA,width,height,step_amount,n,colored,tempArr);
    printf("yashar\n");
    save_bmp(output_data,tempArr,width,height);
    
    free(optarg); // 
    return 0;
}


void save_bmp(const char *filename, unsigned char *img, size_t width, ssize_t height) {
    FILE *fptr = fopen(filename,"wb");
    if(fptr == NULL) {
        fprintf(stderr,"ERROR: Could not open output file at %s\n.",filename);
        exit(EXIT_FAILURE);
    }
    int actual_height = (height < 0) ? -height : height;
    size_t row_padding = (4 - (width) * 3 % 4) % 4;
    size_t row_width = width * 3 + row_padding;

    size_t image_size = actual_height * row_width;
    size_t file_size = image_size + 54;

    unsigned char file_header[14] = {
        'B', 'M',           
        0, 0, 0, 0,         
        0, 0, 0, 0,         
        54, 0, 0, 0         
    };

    file_header[2] = (unsigned char)(file_size);
    file_header[3] = (unsigned char)(file_size >> 8);
    file_header[4] = (unsigned char)(file_size >> 16);
    file_header[5] = (unsigned char)(file_size >> 24);

    unsigned char info_header[40] = {
        40, 0, 0, 0,        
        0, 0, 0, 0,         
        0, 0, 0, 0,         
        1, 0,               
        24, 0,              
        0, 0, 0, 0,         
        0, 0, 0, 0,         
        0x13, 0x0B, 0, 0,   
        0x13, 0x0B, 0, 0,   
        0, 0, 0, 0,         
        0, 0, 0, 0          
    };

    info_header[4] = (unsigned char)(width);
    info_header[5] = (unsigned char)(width >> 8);
    info_header[6] = (unsigned char)(width >> 16);
    info_header[7] = (unsigned char)(width >> 24);

    uint32_t h = (uint32_t)height; 
    info_header[8] = (unsigned char)(h);
    info_header[9] = (unsigned char)(h >> 8);
    info_header[10] = (unsigned char)(h >> 16);
    info_header[11] = (unsigned char)(h >> 24);

    info_header[20] = (unsigned char)(image_size);
    info_header[21] = (unsigned char)(image_size >> 8);
    info_header[22] = (unsigned char)(image_size >> 16);
    info_header[23] = (unsigned char)(image_size >> 24);

    fwrite(file_header,1,14,fptr);
    fwrite(info_header,1,40,fptr);

    unsigned char padding_bytes[3] = {0, 0, 0};

    for(int i = 0; i < actual_height; i++) {
        fwrite(img + (i * width * 3), 3, width, fptr);
        if(row_padding > 0) {
            fwrite(padding_bytes,1,row_padding,fptr);
        }
    }
    
    fclose(fptr);
}