/* Movie Studio / Vegas Pro version spoofer 
 * by Paper
*/

#include <stdio.h>
#include <unistd.h>
#include <getopt.h>
#include <inttypes.h>
#include <string.h>
#include <stdlib.h>
#if __STDC_VERSION__ >= 199901L
#include <stdbool.h>
#else
typedef enum { false, true } bool;  /* less than C99 */
#endif
#ifdef _MSC_VER
#define strdup(p) _strdup(p)
#endif

static struct option options_long[] = {
	{"input", required_argument, NULL, 'i'},
	{"output", required_argument, NULL, 'o'},
	{"version", required_argument, NULL, 'v'},
	{"type", required_argument, NULL, 't'},
	{"help", 0, NULL, 'h'}
};

char* strremove(char* str, const char* sub) {
    size_t len = strlen(sub);
    if (len > 0) {
        char *p = str;
        while ((p = strstr(p, sub)) != NULL) {
            memmove(p, p + len, strlen(p + len) + 1);
        }
    }
    return str;
}

void set_data(unsigned char magic[], uint16_t version, FILE* target) {
	int i;
	fseek(target, 0x46, SEEK_SET);
	fputc(version, target);
	for (i=0; i<=sizeof(*magic); ++i) {
		fseek(target, 0x18+i, SEEK_SET);
		fputc(magic[i], target);
	}
}

int copy_file(char* source_file, char* target_file) {
	FILE *source, *target;

	source = fopen(source_file, "rb");
	if (source == NULL) {
		return 1;
	}
	target = fopen(target_file, "wb");
	if (target == NULL) {
		return 1;
	}

	size_t n, m;
	unsigned char buff[8192];
	do {
		n = fread(buff, 1, sizeof(buff), source);
		if (n) m = fwrite(buff, 1, n, target);
		else m = 0;
	} while ((n > 0) && (n == m));

	fclose(target);
	fclose(source);
	return 0;
}

int main(int argc, char *argv[]) {
	int c, option_index = 0;
	unsigned char magic[16];
	FILE* outfile;
	struct arguments {
		char input[128];
		char output[128];
		int version;
		char type[128];
	} args;
	strcpy(args.input, " ");
	strcpy(args.output, " ");
	args.version = -1;
	strcpy(args.type, " ");

	while ((c = getopt_long(argc, argv, "i:o:v:t:h", options_long, &option_index)) != -1)
		switch(c) {
			case 'i':
				strncpy(args.input, optarg, sizeof(args.input)-1);  /* subtract 1 to make sure it's "null-safe" */
				break;
			case 'o':
				strncpy(args.output, optarg, sizeof(args.input)-1);
				break;
			case 'v':
				args.version = abs(atoi(strdup(optarg)));  /* abs() for possible negative inputs */
				break;
			case 't':
				strncpy(args.type, optarg, sizeof(args.input)-1);
				break;
			case 'h':
			default:
				printf("msvpvf by Paper\nusage: %s (-i/--input) infile [(-o/--output) outfile] (-v/--version) version (-t/--type) [vf, veg]", argv[0]);
				return 0;
		}
	int* ptr = &args.version;
	if (argc <= 5) {
		if (strcmp(args.input, " ") == 0) {
			printf("Input file name?\n");
			fflush(stdout);
			fgets(args.input, sizeof(args.input)-1, stdin);
			args.input[strcspn(args.input, "\r\n")] = 0;
		}
		if (strcmp(args.output, " ") == 0) {
			char* temp;
			temp = strncat(strncat("PRO_V", (char*)(intptr_t)args.version, 7), args.input, 127);
			char* file_extension = strrchr(args.input, ('.'));  /* this won't work if your path is /path.to/file but why would you do that in the first place */
			strncpy(args.output, strncat(strncat(strremove(temp, file_extension), ".", 127), args.type, 127), 127);
		}
		if (args.version == -1) {
			printf("What version would you like to convert to?\n");
			fflush(stdout);
			scanf("%d", ptr);
		}
		if (strcmp(args.type, " ") == 0) {
			printf("Which type of project file would you like to use?[veg/vf]:\n");
			fflush(stdout);
			fgets(args.type, sizeof(args.input)-1, stdin);
			args.type[strcspn(args.type, "\r\n")] = 0;
		}
		if (argc == 1) {
			printf("msvpvf by Paper\nusage: %s -i infile [-o outfile] -v version -t [vf, veg]", argv[0]);
			return 0;
		}
	}
	if (access(args.input, F_OK) != 0) {  /* input file doesn't exist */
		fprintf(stderr, "Input file %s doesn't exist! Exiting.", args.input);
		return 1;
	}
	if (fgetc(fopen(args.input, "r")) == EOF) {  /* input file is empty */
		fprintf(stderr, "Input file %s is empty.", args.input);
		return 1;
	}
	if (strcmp(args.type, "veg") == 0) {
		unsigned char T[] = {0xEF, 0x29, 0xC4, 0x46, 0x4A, 0x90, 0xD2, 0x11, 0x87, 0x22, 0x00, 0xC0, 0x4F, 0x8E, 0xDB, 0x8A};
		for (option_index = 0; option_index <= 15; option_index++) {
			magic[option_index] = T[option_index];
		}
	} else if (strcmp(args.type, "vf") == 0) {
		unsigned char T[] = {0xF6, 0x1B, 0x3C, 0x53, 0x35, 0xD6, 0xF3, 0x43, 0x8A, 0x90, 0x64, 0xB8, 0x87, 0x23, 0x1F, 0x7F};
		for (option_index = 0; option_index <= 15; option_index++) {
			magic[option_index] = T[option_index];
		}
	} else {
		fprintf(stderr, "Type %s is invalid!", args.type);
		return 1;
	}
	copy_file(args.input, args.output);
	outfile = fopen(args.output, "r+b");
	set_data(magic, args.version, outfile);
	fclose(outfile);
	return 0;
}