#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <regex.h>
#include <zlib.h>

/* global because fuck you */
static char *ssn = NULL;

#define SSN_LEN 11

typedef enum {
	COMPRESS,
	DECOMPRESS,
} wat_t;

typedef struct {
	int in;
	int out;
} pipe_t;


void get_ssn() {
	regex_t r;
	regcomp(&r, "[0-9]{3}-[0-9]{2}-[0-9]{4}", REG_EXTENDED | REG_NOSUB);

	if (!(ssn = getenv("SSN")) || regexec(&r, ssn, 0, NULL, 0)) {
		/* die here */
		abort();
	}
}

void server(pipe_t pipe) {
	write(pipe.out, "HI", 2);
	write(pipe.out, ssn, SSN_LEN);
}

pipe_t spawn(wat_t what) {
	pid_t pid;
	pipe_t pipefd;
	pipe((int *) &pipefd);

	if ((pid = fork()) == 0) {
		dup2(pipefd.in, STDIN_FILENO);
		dup2(pipefd.out, STDOUT_FILENO);
		if (what == COMPRESS) {
			execl("tr", "tr", "a-z", "A-Z");
		} else {
			execl("tr", "tr", "A-Z", "a-z");
		}
		exit(1);
	}

	return pipefd;
}

int main(int argc, char **argv) {
	get_ssn();

	pipe_t compress_pipes = spawn(COMPRESS);
	pipe_t decompress_pipes = spawn(DECOMPRESS);

	dup2(compress_pipes.in, 0);
	dup2(compress_pipes, 0);

	if (strstr(argv[0], "server") != NULL) {
		pipe_t server_pipe = {
			.in = decompress_pipes.in,
			.out = compress_pipes.in,
		};
		server(server_pipe);
	} else {
		// TODO client
	}

}