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

#include "./num.h"
#include "./tga.h"
#include "./upc.h"

#define UPC_A_WIDTH 113
#define UPC_A_HEIGHT 79

typedef struct {
    int eflag;
    int nflag;
    char *ovalue;
} opts;

char *getInput( int index, char *argv[] );
opts parseOpts( int argc, char *argv[] );

void DrawBarcode( char *dst, const char *src );
void DrawNumbers( char *dst, const char *src );

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

    // Parse CLI options
    opts options = parseOpts( argc, argv );

    // Parse CLI input
    char *input = getInput( optind, argv );
    
    // Set final element of input array to the appropriate check digit
    input[11] = upc_a_calculate_check_digit( input );
    
    // Create array of chars to represent 1D barcode
    const char *barcode = create_upc_a( input );

    // Allocate memory to hold image data
    char *image = malloc( UPC_A_WIDTH * UPC_A_HEIGHT );
    
    // Draw barcode to image data
    DrawBarcode( image, barcode );
    
    // Draw human-readable interpretation if '-e' is used
    if( options.nflag ) {
        DrawNumbers( image, input );
    }

    free( input );
    
    // Create a .tga image file using image data
    CreateTGA( options.ovalue, UPC_A_WIDTH, UPC_A_HEIGHT, image );
    
    free( image );
    
    return 0;
}


char *getInput( int index, char *argv[] ) {

    char *result = malloc( 12 );

    int k = 0;

    for( int i = index; argv[i] != NULL; ++i ) {
        for( int j = 0; j < strlen(argv[i]); ++j ) {
            if( argv[i][j] < 58 && argv[i][j] > 47 ) {
                result[k] = argv[i][j];
                result[k] -= 48;
                ++k;
            }
        }
    }
    if( k != 11 ) {
        printf( "Inappropriate input detected!\nPlease provide an 11-digit number.\n" );
    }

    return result;
}

opts parseOpts( int argc, char *argv[] ) {

    opts options = { 0, 0, NULL };
    int c;
    while( ( c = getopt(argc, argv, "eno:")) != -1 ) {
        switch( c ) {
            case 'e':
                options.eflag = 1;
                break;
            case 'n':
                options.nflag = 1;
                break;
            case 'o':
                options.ovalue = optarg;
                break;
        }
    }
    return options;
}

void DrawBarcode( char *dst, const char *src ) {

    const char UPC_A_QUIET_ZONE[9] = {0};

    for(int i = 0; i < UPC_A_HEIGHT; ++i) {
        memcpy( dst + (i * UPC_A_WIDTH), &UPC_A_QUIET_ZONE, sizeof(UPC_A_QUIET_ZONE) );
        memcpy( dst + 9 + (i * UPC_A_WIDTH), src, 95 );
        memcpy( dst + 104 + (i * UPC_A_WIDTH), &UPC_A_QUIET_ZONE, sizeof(UPC_A_QUIET_ZONE) );
    }

}

void DrawNumbers( char *dst, const char *src ) {
    const int POSITION_0 = UPC_A_WIDTH * (UPC_A_HEIGHT - 16) + 1;
    const int POSITION_1 = UPC_A_WIDTH * (UPC_A_HEIGHT - 16) + 14;
    const int POSITION_2 = UPC_A_WIDTH * (UPC_A_HEIGHT - 16) + 59;
    const int POSITION_3 = UPC_A_WIDTH * (UPC_A_HEIGHT - 16) + 104;

    for(int i = 0; i < 16; ++i) {
        memcpy( dst + POSITION_0 + (i * UPC_A_WIDTH), NUMBER[src[0]][i], sizeof(NUMBER[0][i]) );
    }
    for( int i = 0; i < 5; ++i ) {
        for(int j = 0; j < 16; ++j) {
            memcpy( dst + POSITION_1 + (j * UPC_A_WIDTH) + (i * 8), NUMBER[src[i + 1]][j], sizeof(NUMBER[0][j]) );
        }
    }
    for( int i = 0; i < 5; ++i ) {
        for(int j = 0; j < 16; ++j) {
            memcpy( dst + POSITION_2 + (j * UPC_A_WIDTH) + (i * 8), NUMBER[src[i + 6]][j], sizeof(NUMBER[0][j]) );
        }
    }
    for(int i = 0; i < 16; ++i) {
        memcpy( dst + POSITION_3 + (i * UPC_A_WIDTH), NUMBER[src[11]][i], sizeof(NUMBER[0][i]) );
    }
}