/* radare - LGPL - Copyright 2015-2016 - pancake */

#include <r_util.h>
#include <r_cons.h>
#include <r_socket.h>

#define R2P_MAGIC 0x329193
#define R2P_PID(x) (((R2Pipe*)x->data)->pid)
#define R2P_INPUT(x) (((R2Pipe*)x->data)->input[0])
#define R2P_OUTPUT(x) (((R2Pipe*)x->data)->output[1])

#if !__WINDOWS__
static void env(const char *s, int f) {
        char *a = r_str_newf ("%d", f);
        r_sys_setenv (s, a);
        free (a);
}
#endif

R_API int r2p_close(R2Pipe *r2p) {
	if (!r2p) return 0;
#if __WINDOWS__ && !defined(__CYGWIN__)
	if (r2p->pipe) {
		CloseHandle (r2p->pipe);
		r2p->pipe = NULL;
	}
#else
	if (r2p->input[0] != -1) {
		close (r2p->input[0]);
		close (r2p->input[1]);
		r2p->input[0] = -1;
		r2p->input[1] = -1;
	}
	if (r2p->output[0] != -1) {
		close (r2p->output[0]);
		close (r2p->output[1]);
		r2p->output[0] = -1;
		r2p->output[1] = -1;
	}
	if (r2p->child != -1) {
		kill (r2p->child, SIGTERM);
		waitpid (r2p->child, NULL, 0);
		r2p->child = -1;
	}
#endif
	free (r2p);
	return 0;
}

#if __WINDOWS__ && !defined(__CYGWIN__)
static int w32_createChildProcess(const char * szCmdline) {
	PROCESS_INFORMATION piProcInfo;
	STARTUPINFO siStartInfo;
	BOOL bSuccess = FALSE;
	ZeroMemory (&piProcInfo, sizeof (PROCESS_INFORMATION));
	ZeroMemory (&siStartInfo, sizeof (STARTUPINFO));
	siStartInfo.cb = sizeof (STARTUPINFO);
	bSuccess = CreateProcess (NULL, (LPSTR)szCmdline, NULL, NULL,
		TRUE, 0, NULL, NULL, &siStartInfo, &piProcInfo);
	if (!bSuccess)
		return false;
	CloseHandle (piProcInfo.hProcess);
	CloseHandle (piProcInfo.hThread);
	return true;
}

static int w32_createPipe(R2Pipe *r2p, const char *cmd) {
	CHAR buf[1024];
	r2p->pipe = CreateNamedPipe ("\\\\.\\pipe\\R2PIPE_IN",
		PIPE_ACCESS_DUPLEX,PIPE_TYPE_MESSAGE | \
		PIPE_READMODE_MESSAGE | \
		PIPE_WAIT, PIPE_UNLIMITED_INSTANCES,
		sizeof (buf), sizeof (buf), 0, NULL);
	if (w32_createChildProcess (cmd)) {
		if (ConnectNamedPipe (r2p->pipe, NULL))
			return true;
	}
	return false;
}
#endif

static R2Pipe* r2p_open_spawn(R2Pipe* r2p, const char *cmd) {
#if __UNIX__ || defined(__CYGWIN__)
	char *out = r_sys_getenv ("R2PIPE_IN");
	char *in = r_sys_getenv ("R2PIPE_OUT");
	int done = false;
	if (in && out) {
		int i_in = atoi (in);
		int i_out = atoi (out);
		if (i_in >= 0 && i_out >= 0) {
			r2p->input[0] = r2p->input[1] = i_in;
			r2p->output[0] = r2p->output[1] = i_out;
			done = true;
		}
	}
	if (!done) {
		eprintf ("Cannot find R2PIPE_IN or R2PIPE_OUT environment\n");
		R_FREE (r2p);
	}
	free (in);
	free (out);
	return r2p;
#else
	eprintf ("r2p_open(NULL) not supported on windows\n");
	return NULL;
#endif
}

R_API R2Pipe *r2p_open(const char *cmd) {
	R2Pipe *r2p = R_NEW0 (R2Pipe);
	if (!r2p) {
		return NULL;
	}
	r2p->magic = R2P_MAGIC;
	if (!cmd) {
		r2p->child = -1;
		return r2p_open_spawn (r2p, cmd);
	}
#if __WINDOWS__ && !defined(__CYGWIN__)
	w32_createPipe (r2p, cmd);
	r2p->child = (int)(r2p->pipe);
#else
	pipe (r2p->input);
	pipe (r2p->output);
#if LIBC_HAVE_FORK
	r2p->child = fork ();
#else
	r2p->child = -1;
#endif
	if (r2p->child == -1) {
		r2p_close (r2p);
		return NULL;
	}
	env ("R2PIPE_IN", r2p->input[0]);
	env ("R2PIPE_OUT", r2p->output[1]);

	if (r2p->child) {
		eprintf ("[+] r2pipe child is %d\n", r2p->child);
		char ch;
		if (read (r2p->output[0], &ch, 1) != 1) {
			eprintf ("Failed to read 1 byte\n");
			r2p_close (r2p);
			return NULL;
		}
		if (ch != 0x00) {
			eprintf ("[+] r2pipe-io link failed. Expected two null bytes.\n");
			r2p_close (r2p);
			return NULL;
		} else {
			if (read (r2p->output[0], &ch, 1) != 1) {
				eprintf ("Failed to read 1 byte\n");
				r2p_close (r2p);
				return NULL;
			}
			if (ch == 0x00) {
				eprintf ("[+] r2pipe-io link stablished\n");
			}
		}
	} else {
		int rc = 0;
		if (cmd && *cmd) {
			close (0);
			close (1);
			dup2 (r2p->input[0], 0);
			dup2 (r2p->output[1], 1);
			rc = r_sandbox_system (cmd, 0);
		}
		r2p_close (r2p);
		exit (rc);
		return NULL;
	}
#endif
	return r2p;
}

R_API char *r2p_cmd(R2Pipe *r2p, const char *str) {
	if (!r2p_write (r2p, str)) {
		perror ("r2p_write");
		return NULL;
	}
	return r2p_read (r2p);
}

R_API char *r2p_cmdf(R2Pipe *r2p, const char *fmt, ...) {
	int ret, ret2;
	char *p, string[1024];
	va_list ap, ap2;
	va_start (ap, fmt);
	va_start (ap2, fmt);
	ret = vsnprintf (string, sizeof (string) - 1, fmt, ap);
	if (ret < 1 || ret >= sizeof (string)) {
		p = malloc (ret + 2);
		if (!p) {
			va_end (ap2);
			va_end (ap);
			return NULL;
		}
		ret2 = vsnprintf (p, ret+1, fmt, ap2);
		if (ret2 < 1 || ret2 > ret + 1) {
			free (p);
			va_end (ap2);
			va_end (ap);
			return NULL;
		}
		fmt = r2p_cmd (r2p, p);
		free (p);
	} else {
		fmt = r2p_cmd (r2p, string);
	}
	va_end (ap2);
	va_end (ap);
	return (char*)fmt;
}

R_API int r2p_write(R2Pipe *r2p, const char *str) {
	char *cmd;
	int ret, len;
	if (!r2p || !str) {
		return -1;
	}
	len = strlen (str) + 2; /* include \n\x00 */
	cmd = malloc (len + 2);
	if (!cmd) {
		return 0;
	}
	memcpy (cmd, str, len - 1);
	strcpy (cmd + len - 2, "\n");
#if __WINDOWS__ && !defined(__CYGWIN__)
	DWORD dwWritten = -1;
	WriteFile (r2p->pipe, cmd, len, &dwWritten, NULL);
	ret = (dwWritten == len);
#else
	ret = (write (r2p->input[1], cmd, len) == len);
#endif
	free (cmd);
	return ret;
}

/* TODO: add timeout here ? */
R_API char *r2p_read(R2Pipe *r2p) {
	int bufsz = 0;
	char *newbuf, *buf = NULL;
	if (!r2p) return NULL;
	bufsz = 4096;
	buf = calloc (1, bufsz);
	if (!buf) return NULL;
#if __WINDOWS__ && !defined(__CYGWIN__)
	BOOL bSuccess = FALSE;
	DWORD dwRead = 0;
	// TODO: handle > 4096 buffers here
	bSuccess = ReadFile (r2p->pipe, buf, bufsz, &dwRead, NULL);
	if (!bSuccess || !buf[0]) {
		return NULL;
	}
	if (dwRead > 0) {
		buf[dwRead] = 0;
	}
	buf[bufsz - 1] = 0;
#else
	int i, rv;
	for (i = 0; i < bufsz; i++) {
		rv = read (r2p->output[0], buf + i, 1);
		if (i + 2 >= bufsz) {
			bufsz += 4096;
			newbuf = realloc (buf, bufsz);
			if (!newbuf) {
				free (buf);
				buf = NULL;
				break;
			}
			buf = newbuf;
		}
		if (rv != 1 || !buf[i]) {
			break;
		}
	}
	if (buf) {
		int zpos = (i < bufsz)? i: i - 1;
		buf[zpos] = 0;
	}
#endif
	return buf;
}

R_API void r2p_free (R2Pipe *r2p) {
	r2p->magic = 0;
	r2p_close (r2p);
}