/*
 * PLink - a Windows command-line (stdin/stdout) variant of PuTTY.
 */

#include <stdio.h>
#include <stdlib.h>
#include <assert.h>
#include <stdarg.h>

#define PUTTY_DO_GLOBALS	       /* actually _define_ globals */
#include "putty.h"
#include "storage.h"
#include "tree234.h"

#define WM_AGENT_CALLBACK (WM_XUSER + 4)

#define MAX_STDIN_BACKLOG 4096

struct agent_callback {
    void (*callback)(void *, void *, int);
    void *callback_ctx;
    void *data;
    int len;
};

void fatalbox(char *p, ...)
{
    va_list ap;
    fprintf(stderr, "FATAL ERROR: ");
    va_start(ap, p);
    vfprintf(stderr, p, ap);
    va_end(ap);
    fputc('\n', stderr);
    cleanup_exit(1);
}
void modalfatalbox(char *p, ...)
{
    va_list ap;
    fprintf(stderr, "FATAL ERROR: ");
    va_start(ap, p);
    vfprintf(stderr, p, ap);
    va_end(ap);
    fputc('\n', stderr);
    cleanup_exit(1);
}
void connection_fatal(void *frontend, char *p, ...)
{
    va_list ap;
    fprintf(stderr, "FATAL ERROR: ");
    va_start(ap, p);
    vfprintf(stderr, p, ap);
    va_end(ap);
    fputc('\n', stderr);
    cleanup_exit(1);
}
void cmdline_error(char *p, ...)
{
    va_list ap;
    fprintf(stderr, "plink: ");
    va_start(ap, p);
    vfprintf(stderr, p, ap);
    va_end(ap);
    fputc('\n', stderr);
    exit(1);
}

HANDLE inhandle, outhandle, errhandle;
DWORD orig_console_mode;

WSAEVENT netevent;

static Backend *back;
static void *backhandle;
static Config cfg;

int term_ldisc(Terminal *term, int mode)
{
    return FALSE;
}
void ldisc_update(void *frontend, int echo, int edit)
{
    /* Update stdin read mode to reflect changes in line discipline. */
    DWORD mode;

    mode = ENABLE_PROCESSED_INPUT;
    if (echo)
	mode = mode | ENABLE_ECHO_INPUT;
    else
	mode = mode & ~ENABLE_ECHO_INPUT;
    if (edit)
	mode = mode | ENABLE_LINE_INPUT;
    else
	mode = mode & ~ENABLE_LINE_INPUT;
    SetConsoleMode(inhandle, mode);
}

struct input_data {
    DWORD len;
    char buffer[4096];
    HANDLE event, eventback;
};

static DWORD WINAPI stdin_read_thread(void *param)
{
    struct input_data *idata = (struct input_data *) param;
    HANDLE inhandle;

    inhandle = GetStdHandle(STD_INPUT_HANDLE);

    while (ReadFile(inhandle, idata->buffer, sizeof(idata->buffer),
		    &idata->len, NULL) && idata->len > 0) {
	SetEvent(idata->event);
	WaitForSingleObject(idata->eventback, INFINITE);
    }

    idata->len = 0;
    SetEvent(idata->event);

    return 0;
}

struct output_data {
    DWORD len, lenwritten;
    int writeret;
    char *buffer;
    int is_stderr, done;
    HANDLE event, eventback;
    int busy;
};

static DWORD WINAPI stdout_write_thread(void *param)
{
    struct output_data *odata = (struct output_data *) param;
    HANDLE outhandle, errhandle;

    outhandle = GetStdHandle(STD_OUTPUT_HANDLE);
    errhandle = GetStdHandle(STD_ERROR_HANDLE);

    while (1) {
	WaitForSingleObject(odata->eventback, INFINITE);
	if (odata->done)
	    break;
	odata->writeret =
	    WriteFile(odata->is_stderr ? errhandle : outhandle,
		      odata->buffer, odata->len, &odata->lenwritten, NULL);
	SetEvent(odata->event);
    }

    return 0;
}

bufchain stdout_data, stderr_data;
struct output_data odata, edata;

void try_output(int is_stderr)
{
    struct output_data *data = (is_stderr ? &edata : &odata);
    void *senddata;
    int sendlen;

    if (!data->busy) {
	bufchain_prefix(is_stderr ? &stderr_data : &stdout_data,
			&senddata, &sendlen);
	data->buffer = senddata;
	data->len = sendlen;
	SetEvent(data->eventback);
	data->busy = 1;
    }
}

int from_backend(void *frontend_handle, int is_stderr,
		 const char *data, int len)
{
    int osize, esize;

    if (is_stderr) {
	bufchain_add(&stderr_data, data, len);
	try_output(1);
    } else {
	bufchain_add(&stdout_data, data, len);
	try_output(0);
    }

    osize = bufchain_size(&stdout_data);
    esize = bufchain_size(&stderr_data);

    return osize + esize;
}

static DWORD main_thread_id;

void agent_schedule_callback(void (*callback)(void *, void *, int),
			     void *callback_ctx, void *data, int len)
{
    struct agent_callback *c = snew(struct agent_callback);
    c->callback = callback;
    c->callback_ctx = callback_ctx;
    c->data = data;
    c->len = len;
    PostThreadMessage(main_thread_id, WM_AGENT_CALLBACK, 0, (LPARAM)c);
}

/*
 *  Short description of parameters.
 */
static void usage(void)
{
    printf("PuTTY Link: command-line connection utility\n");
    printf("%s\n", ver);
    printf("Usage: plink [options] [user@]host [command]\n");
    printf("       (\"host\" can also be a PuTTY saved session name)\n");
    printf("Options:\n");
    printf("  -V        print version information\n");
    printf("  -v        show verbose messages\n");
    printf("  -load sessname  Load settings from saved session\n");
    printf("  -ssh -telnet -rlogin -raw\n");
    printf("            force use of a particular protocol (default SSH)\n");
    printf("  -P port   connect to specified port\n");
    printf("  -l user   connect with specified username\n");
    printf("  -m file   read remote command(s) from file\n");
    printf("  -batch    disable all interactive prompts\n");
    printf("The following options only apply to SSH connections:\n");
    printf("  -pw passw login with specified password\n");
    printf("  -D [listen-IP:]listen-port\n");
    printf("            Dynamic SOCKS-based port forwarding\n");
    printf("  -L [listen-IP:]listen-port:host:port\n");
    printf("            Forward local port to remote address\n");
    printf("  -R [listen-IP:]listen-port:host:port\n");
    printf("            Forward remote port to local address\n");
    printf("  -X -x     enable / disable X11 forwarding\n");
    printf("  -A -a     enable / disable agent forwarding\n");
    printf("  -t -T     enable / disable pty allocation\n");
    printf("  -1 -2     force use of particular protocol version\n");
    printf("  -C        enable compression\n");
    printf("  -i key    private key file for authentication\n");
    printf("  -s        remote command is an SSH subsystem (SSH-2 only)\n");
    exit(1);
}

static void version(void)
{
    printf("plink: %s\n", ver);
    exit(1);
}

char *do_select(SOCKET skt, int startup)
{
    int events;
    if (startup) {
	events = (FD_CONNECT | FD_READ | FD_WRITE |
		  FD_OOB | FD_CLOSE | FD_ACCEPT);
    } else {
	events = 0;
    }
    if (p_WSAEventSelect(skt, netevent, events) == SOCKET_ERROR) {
	switch (p_WSAGetLastError()) {
	  case WSAENETDOWN:
	    return "Network is down";
	  default:
	    return "WSAEventSelect(): unknown error";
	}
    }
    return NULL;
}

int main(int argc, char **argv)
{
    WSAEVENT stdinevent, stdoutevent, stderrevent;
    HANDLE handles[4];
    DWORD in_threadid, out_threadid, err_threadid;
    struct input_data idata;
    int reading;
    int sending;
    int portnumber = -1;
    SOCKET *sklist;
    int skcount, sksize;
    int connopen;
    int exitcode;
    int errors;
    int use_subsystem = 0;

    ssh_get_line = console_get_line;

    sklist = NULL;
    skcount = sksize = 0;
    /*
     * Initialise port and protocol to sensible defaults. (These
     * will be overridden by more or less anything.)
     */
    default_protocol = PROT_SSH;
    default_port = 22;

    flags = FLAG_STDERR;
    /*
     * Process the command line.
     */
    do_defaults(NULL, &cfg);
    loaded_session = FALSE;
    default_protocol = cfg.protocol;
    default_port = cfg.port;
    errors = 0;
    {
	/*
	 * Override the default protocol if PLINK_PROTOCOL is set.
	 */
	char *p = getenv("PLINK_PROTOCOL");
	int i;
	if (p) {
	    for (i = 0; backends[i].backend != NULL; i++) {
		if (!strcmp(backends[i].name, p)) {
		    default_protocol = cfg.protocol = backends[i].protocol;
		    default_port = cfg.port =
			backends[i].backend->default_port;
		    break;
		}
	    }
	}
    }
    while (--argc) {
	char *p = *++argv;
	if (*p == '-') {
	    int ret = cmdline_process_param(p, (argc > 1 ? argv[1] : NULL),
					    1, &cfg);
	    if (ret == -2) {
		fprintf(stderr,
			"plink: option \"%s\" requires an argument\n", p);
		errors = 1;
	    } else if (ret == 2) {
		--argc, ++argv;
	    } else if (ret == 1) {
		continue;
	    } else if (!strcmp(p, "-batch")) {
		console_batch_mode = 1;
	    } else if (!strcmp(p, "-s")) {
		/* Save status to write to cfg later. */
		use_subsystem = 1;
	    } else if (!strcmp(p, "-V")) {
                version();
	    } else {
		fprintf(stderr, "plink: unknown option \"%s\"\n", p);
		errors = 1;
	    }
	} else if (*p) {
	    if (!*cfg.host) {
		char *q = p;
		/*
		 * If the hostname starts with "telnet:", set the
		 * protocol to Telnet and process the string as a
		 * Telnet URL.
		 */
		if (!strncmp(q, "telnet:", 7)) {
		    char c;

		    q += 7;
		    if (q[0] == '/' && q[1] == '/')
			q += 2;
		    cfg.protocol = PROT_TELNET;
		    p = q;
		    while (*p && *p != ':' && *p != '/')
			p++;
		    c = *p;
		    if (*p)
			*p++ = '\0';
		    if (c == ':')
			cfg.port = atoi(p);
		    else
			cfg.port = -1;
		    strncpy(cfg.host, q, sizeof(cfg.host) - 1);
		    cfg.host[sizeof(cfg.host) - 1] = '\0';
		} else {
		    char *r;
		    /*
		     * Before we process the [user@]host string, we
		     * first check for the presence of a protocol
		     * prefix (a protocol name followed by ",").
		     */
		    r = strchr(p, ',');
		    if (r) {
			int i, j;
			for (i = 0; backends[i].backend != NULL; i++) {
			    j = strlen(backends[i].name);
			    if (j == r - p &&
				!memcmp(backends[i].name, p, j)) {
				default_protocol = cfg.protocol =
				    backends[i].protocol;
				portnumber =
				    backends[i].backend->default_port;
				p = r + 1;
				break;
			    }
			}
		    }