#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);

	splice(pipe.out, NULL, pipe.in, NULL, 1024, 0);
}

pipe_t spawn(wat_t what) {
	pipe_t pipe_result, pipe_process_in, pipe_process_out;
	pid_t pid;

	pipe((int *) &pipe_process_in);
	pipe((int *) &pipe_process_out);

	pipe_result.in = pipe_process_in.in;
	pipe_result.out = pipe_process_out.out;

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

	return pipe_result;
}

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

	fprintf(stderr, "starting\n");

	pipe_t compress_pipes = spawn(COMPRESS);

	fprintf(stderr, "compress pipes: %d, %d\n", compress_pipes.in, compress_pipes.out);
	pipe_t decompress_pipes = spawn(DECOMPRESS);
	fprintf(stderr, "decompress pipes: %d, %d\n", decompress_pipes.in, decompress_pipes.out);

	dup2(compress_pipes.out, STDOUT_FILENO);
	dup2(decompress_pipes.in, STDIN_FILENO);

	if (strstr(argv[0], "server") != NULL) {
		pipe_t server_pipe = {
			.in = decompress_pipes.out,
			.out = compress_pipes.in,
		};
		fprintf(stderr, "server pipe: %d, %d\n", server_pipe.in, server_pipe.out);
		server(server_pipe);
	} else {
		// TODO client
	}

}